Patent Grant
8192435
The present invention relates to methods and apparatus for selective surgical removal of tissue, such as for the treatment of spinal neural and neurovascular impingement, through selective resection, ablation, and remodeling of tissue in the lateral recess, neural foramina and central spinal canal, more particularly, for safely performing lateral recess and neuroforaminal enlargement of the spine.
More particularly, the present invention relates to treating neural and neurovascular impingement in the spine through the creation of a safe working space adjacent to neural and neurovascular structures, followed by selective surgical removal of tissue. Both percutaneous and open surgical variations of the invention are disclosed.
Pathological compression of spinal neural and neurovascular structures most commonly results from a degenerative, age-related process, increasing in prevalence and severity in elderly populations, with potential congenital anatomic components, that result in back, radicular extremity pain and both neurological (e.g., sensory) and mechanical (e.g., motor) dysfunction. Prevalence is also influenced by congenital spinal anatomy. Disease progression leads to increased neural irritation, neural and neurovascular impingement, and ischemia, and is frequently accompanied by progressively increased pain, often in conjunction with reflex, sensory and motor neurological deficits.
In the United States, Spinal Stenosis occurs with an incidence of between 4 percent and 6 percent of adults 50 years of age or older, and is the most frequent reason cited for back surgery in patients 60 years of age and older.
Spinal Stenosis often includes neural and/or neurovascular impingement, which may occur in the central spinal canal, the lateral recesses of the spinal canal, or in the spinal neural foramina. The most common causes of neural compression within the spine are spinal disc disease (collapse, bulging, herniation); ligamentum flavum buckling, thickening and/or hypertrophy; zygapophysial (facet) joint hypertrophy; osteophyte formation; and spondylolisthesis.
Disease progression increases neural irritation, impingement, and ischemia, and is frequently accompanied by progressively increased pain, often in conjunction with reflex, sensory and motor neurological changes (e.g., deficits).
Current surgical treatments for Spinal Stenosis include laminectomy (usually partial, but sometimes complete), laminotomy and/or facetectomy (usually partial, but sometimes complete), with or without fusion. While standard surgical procedures (e.g., spinal decompressions) lead to improvements in symptoms for 6 months or more in approximately 60% of cases, there is an unacceptable incidence of long-term complications and morbidity: approximately 40% of patients do not obtain sustained improvement with current surgical decompressions.
Several companies offer tools that facilitate surgical access to the areas of the spine where neural impingement is likely to occur, in order to allow the surgeon to decompress the impinged neural structures through the removal of vertebral lamina, ligamentum flavum, facet complex, bone spurs, and/or intervertebral disc material. These surgical resections are frequently (i.e., occurs in 15% to 20% of cases) accompanied by fusion (arthrodesis). Spinal arthrodesis is performed to fuse adjacent vertebrae and prevent movement of these structures in relation to each other. The fusion is commonly a treatment for pain of presumed disc or facet joint origin; for severe spondylolisthesis; for presumed spinal instability; and for spines that have been rendered “unstable” by the surgical decompression procedures, as described above. The definition of “spinal instability” remains controversial in current literature.
Spinal arthrodesis may be achieved through various surgical techniques. Biocompatible metallic hardware and/or autograft or allograft bone is commonly placed (e.g., secured) anteriorly and/or posteriorly in the vertebral column in order to achieve surgical fusion. These materials are secured along and between the vertebral bodies (to restore vertebral height and replace disk material) and/or within the posterior elements, typically with pedicle screw fixation. Autograft bone is often harvested from the patient's iliac crest. Cadaveric allograft is frequently cut in disc shaped sections of long bones for replacement of the intervertebral discs in the fusion procedure.
Critics have frequently stated that, while discectomy and fusion procedures frequently improve symptoms of neural impingement in the short term, both are highly destructive procedures that diminish spinal function, drastically disrupt normal anatomy, and increase long-term morbidity above levels seen in untreated patients.
The high morbidity associated with discectomy may be due to several factors. First, discectomy reduces disc height, causing increased pressure on facet joints. This stress leads to facet arthritis and facet joint hypertrophy, which then causes further neural compression. The surgically-imposed reduction in disc height also may lead to neuroforaminal stenosis, as the vertebral pedicles, which form the superior and inferior borders of the neural foramina, become closer to one another. The loss of disc height also creates ligament laxity, which may lead to spondylolisthesis, spinal instability or osteophyte or “bone spur” formation, as it has been hypothesized that ligaments may calcify in their attempt to become more “bone-like”. In addition, discectomy frequently leads to an incised and further compromised disc annulus. This frequently leads to recurrent herniation of nuclear material through the surgically created or expanded annular opening. It may also cause further buckling of the ligamentum flavum. The high morbidity associated with fusion is related to several factors. First, extensive hardware implantation may lead to complications due to breakage, loosening, nerve injury, infection, rejection, or scar tissue formation. In addition, autograft bone donor sites (typically the patient's iliac crest) are a frequent source of complaints, such as infection, deformity, and protracted pain. Perhaps the most important reason for the long-term morbidity caused by spinal fusion is the loss of mobility in the fused segment of the spine. Not only do immobile vertebral segments lead to functional limitations, but they also cause increased stress on adjacent vertebral structures, thereby frequently accelerating the degeneration of other discs, joints, bone and other soft tissue structures within the spine.
Recently, less invasive, percutaneous approaches to spinal discectomy and fusion have been tried with some success. While these less invasive techniques offer advantages, such as a quicker recovery and less tissue destruction during the procedure, the new procedures do not diminish the fact that even less invasive spinal discectomy or fusion techniques are inherently destructive procedures that accelerate the onset of acquired spinal stenosis and result in severe long-term consequences.
Additional less invasive treatments of neural impingement within the spine include percutaneous removal of nuclear disc material and procedures that decrease the size and volume of the disc through the creation of thermal disc injury. While these percutaneous procedures may produce less tissue injury, their efficacy remains unproven.
Even more recently, attempts have been made to replace pathological discs with prosthetic materials. While prosthetic disc replacement is a restorative procedure, it is a highly invasive and complex surgery. Any synthetic lumbar disc will be required to withstand tremendous mechanical stresses and will require several years of development. Current synthetic disc designs can not achieve the longevity desired. Further, synthetic discs may not be an appropriate therapeutic approach to a severely degenerative spine, where profound facet arthropathy and other changes are likely to increase the complexity of disc replacement. Like most prosthetic joints, it is likely that synthetic discs will have a limited lifespan and that there will be continued need for minimally invasive techniques that delay the need for disc replacement.
Even if prosthetic discs become a viable solution, the prosthetic discs will be very difficult to revise for patients. The prosthesis will, therefore, be best avoided in many cases. A simpler, less invasive approach to restoration of functional spinal anatomy would play an important role in the treatment of neural impingent in the spine. The artificial discs in U.S. clinical trials, as with any first generation prosthesis, are bound to fail in many cases, and will be very difficult to revise for patients. The prostheses will, therefore, be best avoided, in many cases. Lumbar prosthetic discs are available in several countries worldwide.
In view of the aforementioned limitations of prior art techniques for treating neural and neurovascular impingement in the spine, it would be desirable to provide methods and apparatus for selective surgical removal of tissue that reduce or overcome these limitations.
In view of the foregoing, the present invention provides apparatus and methods for selective removal of tissue, e.g., soft tissue and bone, preferably in a minimally invasive fashion. The present invention provides apparatus and methods for safe and selective delivery of surgical tools into to the epidural space; and for apparatus and methods that enable safe and selective surgical removal, ablation, and remodeling of soft tissue and bone, preferably in a minimally invasive fashion, with the apparatus delivered into the epidural space. An important preferred variation of the methods and apparatus are used to treat neural and neurovascular impingement in the spine, through a novel approach to safe and selective enlargement of the pathologically narrow spinal neural foramen, the impinged lateral recess, and central canal.
The present invention eliminates much or all of the need to resect non-impinging tissues in order to gain surgical access. In a preferred embodiment, the methods and apparatus are used for the treatment of neural and neurovascular impingement in the spine through a novel approach to safe enlargement of the pathologically narrow spinal neural foramen and the impinged lateral recess. Tissue removal may be performed in a partially or completely open surgical fashion, or in a less invasive or minimally invasive percutaneous fashion. In some embodiments, the invention provides neural stimulation, localization, and/or protection in order to provide a protected working space and to facilitate safe tissue remodeling or removal.
The apparatus and methods have been designed to avoid removal of non-target tissue and to minimize and/or completely prevent trauma to adjacent neural and vascular structures. The methods and apparatus can be used for the treatment of neural and neurovascular impingement in the spine, for example, safe enlargement of the pathologically impinged lateral recess and narrowed spinal neural foramen. Perineural tissue can be removed safely and selectively in a partially or completely open surgical fashion, or in a less invasive or minimally invasive percutaneous fashion. The apparatus and methods described herein can be utilized for lateral recess and neuroforaminal enlargement to provide adequate bone and soft tissue resection. The apparatus and methods described herein can reduce unnecessary destruction of functional bone, ligament or muscle in order to gain access to tissues to be resected.
The present invention encompasses both open and percutaneous approaches to spinal neurovascular decompression, for example, through passage of an atraumatic, thin tissue removal device from the epidural space laterally through the neural foramen. Variations of the present invention preferably provide for access, neural protection and/or decompression.
Methods and apparatus for spinal lateral recess, neuroforaminal, and/or central canal enlargement, through selective and safe alteration of the tissues that pathologically impinge neural and neurovascular structures in the spine are disclosed. Impinging tissues to be removed from, or remodeled in, the spine's central canal, lateral recess, and neural foramen, with the herein described methods and apparatus, can include ligamentum flavum; bone spurs or ligamentous calcifications; localized disc extrusions; enlarged facet joint complex; bone; scar tissue or adhesions; and osteophytes.
In an open variation, access may be achieved via an access element comprising a cannulated probe, which optionally may be similar in shape to currently used neuroforaminal instruments, such as the Ball-tipped, Woodson Elevator, or “Hockey Stick” Probes. The probe may be placed through the surgical incision into the epidural space. A curved atraumatic needle then may be advanced through the cannula of the probe and driven laterally to cannulate the neural foramen. A preferably straight, flexible guide wire or needle then may be advanced through the curved needle and driven posteriorly through the skin of the patient's back. Alternatively, surgical incisions may be made on either side of the foramen, and the guide wire may be pulled through the second incision.
Another preferred open surgical approach utilizes a cannulated probe, as described above, the tip of which is placed into the lateral recess, adjacent to or into the neural foramina. Next, a curved and atraumatic guide wire is advanced out of the distal lumen of the cannulated probe, through the neural foramina laterally, and around the lateral then posterior aspect of the facet capsule, until the distal tip of the wire is driven back into the surgical opening. At that point, the surgeon has access to both ends of the guide wire, and the tissue removal device may be pulled or advanced into position via the guide wire. The guide wire may be attached to the tissue removal device by any of several possible means. One simple method for using a guide wire to pull a tissue removal device would be to have an eyelet present in the proximal guide wire, through which the tissue removal device may be thread. Open access optionally may be aided by the use of image guidance, an epidural endoscope, an endoscopic channel added to the cannulated probes described above, or any other visualization technique.
In a percutaneous variation, access may be achieved via an access element comprising an epidural needle or probe, or via an epidural endoscope having a working channel. The access element may be positioned in the epidural space, and a curved atraumatic needle then may be advanced through the needle, probe or working channel and driven laterally to cannulate the neural foramen. As with the open variation, a preferably straight, flexible guide wire or needle may be advanced through the curved needle and driven posteriorly through the skin of the patient's back. Percutaneous access optionally may be aided by the use of image guidance, an epidural endoscope or any other visualization technique.
In a preferred embodiment, the methods and apparatus include the placement of a working backstop or barrier into the epidural space or neural foramina, to a location between the tool positioned for tissue alteration, and adjacent vulnerable neural or vascular structures, to help prevent neural or vascular injury during surgery. In a further preferred embodiment, the methods and apparatus utilize neural stimulation techniques, to enable neural localization, as a means of improving the safety of the procedure.
In one variation of the present invention, an epidural needle may be converted to a working tool in order to resect or remodel spinal tissue, which is enabled by the use of methods and apparatuses described herein.
After placement of an epidural needle into the epidural space, a special epidural catheter is threaded through the needle into the epidural space. This catheter apparatus contains a needle tip cover in its distal end, which, after it is converted to an open position in the epidural space, is pulled back over the needle tip, by pulling on the proximal portion of the catheter. The catheter based cover blunts and thereby protects the vulnerable structures of the spine, such as the dura, from the sharp epidural needle tip. With the epidural needle tip covered, the needle may be more safely advanced into the epidural space, in a direction somewhat parallel to the dura, towards the contralateral or ipsilateral lateral recess and neural foramen. The needle may be advanced blindly; with image guidance; or with endoscopic guidance.
The epidural catheter, with the cap or cover for the epidural needle, may or may not contain a rigid or flexible fiberoptic cable. With a fiberoptic element and a clear tip to the catheter, the epidural needle may be converted to an epidural endoscope or “needlescope”.
One preferred embodiment of the epidural needle apparatus contains two adjacent lumens (“double barreled”), with a working channel adjacent to the epidural needle. The working channel may be fixed and permanent, or removable, as in with a rail and track connection. A removable working channel, in one embodiment, may be inserted or removed while the tip of the epidural needle remains in the epidural space. The distal beveled opening of the working channel, in a preferred variation, is located proximal to and on the same side of the needle as the epidural needle tip beveled opening faces, facilitating visualization of the working channel tools when a fiberoptic element has been placed in through the epidural needle lumen.
The epidural needle or the working channel of the epidural needle may be a vehicle for insertion of a working backstop or barrier, another apparatus that facilitates safe tissue resection and remodeling in the epidural space. The barrier is a thin flat device that may be delivered into or adjacent to the epidural space or neural foramina, through the needle or working channel, or through an endoscope or open incision. Such a backstop may consist of a flexible, curved, thin and flat piece of material. This barrier will serve to protect neural and neurovascular structures from being damaged during tissue manipulation and resection, because it will be placed between the tissue to be ablated, resected, irritated, manipulated or remodeled, and the vulnerable neural and vascular structures or dura. The tools for tissue resection and ablation will be used on the side of the barrier opposite from the vulnerable neural and vascular structures, which will be safely protected from inadvertent injury.
With access, as well as optional neural protection and/or neural localization, established, decompression or selective tissue removal or remodeling may proceed. A tissue removal device with a tissue removal surface is advanced into position, for example, through, along, over or with the neural protection element, e.g. via rail(s) or channel(s) of the neural protection element, or along the guide wire(s); or is pulled into position via the guide wire or the neural protection element, etc. When properly positioned, the tissue removal surface contacts the impinging tissue slated for removal.
The abrasion device may, for example, include a thin belt or ribbon, with an abrasive, shaving, and/or cutting surface, that is placed through the neural foramina and is held firmly against the tissue to be removed. The belt optionally may be placed, at least partially, within a protective sheath or covering, with the area exposed to the abrasive surface of the device somewhat limited to the area where tissue abrasion and removal is desired. The abrasive element may be provided in one or more of a variety of potentially interchangeable shapes, ranging from flat to curved; narrow to wide; or solid to perforated. The abrasive surface may also have various enabling designs, or surface patterns, or coarseness of abrasive material. The apparatus is placed with both free ends of the abrasive element, as well as the ends of the optional protective sleeve or covering, external to the patient for manipulation by a medical practitioner.
When the optional protective sleeve or sheath is provided, both ends of the sleeve may be held under tension, external to the patient, such that the abrasive belt or ribbon may be pulled back and forth through the sleeve without causing significant friction against and/or trauma to adjacent tissues. Initially, both ends of the abrasive ribbon are pulled simultaneously, pulling the device in a posterior and/or lateral direction, thereby bringing impinging spinal tissue in contact with the abrasive and/or cutting surface of the ribbon. When one end of the ribbon is pulled with more force than the other, the ribbon moves in the direction of the stronger pull, while the lesser pull on the opposite end maintains force and creates friction with movement between the abrasive surface and the tissue to be resected.
In an open surgical variation, the ribbon or belt and/or the protective covering or sleeve may be placed through the surgical incision. In a percutaneous variation, the device may be inserted through a needle over a wire. As with the percutaneous approaches, placement may be aided by the use of image guidance and/or the use of an epidural endoscope.
Once the surgical apparatus has been placed, the medical practitioner may enlarge the lateral recess and neural foramina via frictional abrasion, i.e., by sliding the abrasive surface across the tissue to be resected. Impinging tissue to be targeted for abrasion may include, but is not limited to, lateral ligamentum flavum, anterior and medial facet, and osteophytes. The medical practitioner controls the force and speed of the abrasive surface against the tissue to be removed, while optional covers define the tissue exposed to the abrasive element.
One variation of the abrasive element cover envelopes the abrasive surface and the backside of the belt or ribbon in areas where tissue abrasion is not intended. A nerve stimulator may be incorporated into the abrasive surface and/or the protective cover or sleeve in order to verify correct placement and enhance safety by allowing the medical practitioner to ensure that neural tissue is not subject to inadvertent abrasion.
In one variation, the methods and apparatus include placement of a compression dressing following the surgical procedure. Following neuroforaminal and lateral recess enlargement, it may be advantageous to leave, as a surgical dressing, a belt or ribbon pulled tightly against the abraded tissue surface. It is expected that a compression dressing will enhance hemostasis, promote healing and promote subsequent tissue remodeling with the neural foramen more widely open. Furthermore, the surgical dressing would provide a barrier to trap tissue debris away from neural or neurovascular structures, while providing an optional technique for delivering medication, possibly as a depot, to the operative site. Finally, the dressing would also present a smooth surface towards the nerve root during the immediate post-operative period.
The present invention also describes methods and apparatus that may be used as a compression dressing, after tissue resection or ablation. One variation of the compression dressing is placed in a position where it is firmly wrapped around the facet and ligamentum flavum through the neural foramina, as illustrated in
This neuroforaminal compression dressing may, for example, comprise the optional protective sheath, percutaneously held tightly in place against the abraded surface. Alternatively or additionally, a separate percutaneously removable compression dressing may be placed following tissue abrasion, with or without a biodegradable component. In a further alternative embodiment, an entirely biodegradable compression dressing may be placed tightly against the abraded surface, with the compression dressing remaining completely implanted following the procedure.
In order to reduce a risk of neurological damage during selective tissue removal, variations of the present invention optionally may provide neural protection during tissue removal. In one variation, a neural protection element, e.g., a sheath, shield or backstop, is positioned (e.g., advanced over, or is pulled into place via the guide wire) such that the neural protection element separates impinging tissue in the neural foramen from the underlying dura, adjacent nerve root, dorsal root ganglion, and/or neural vasculature. Tissue removal then may proceed by advancing a tissue removal device into position between impinging tissue and the neural protection element. The neural protection element preferably comprises an atraumatic profile, to reduce tissue injury. For example, the element may comprise rounded edges. Further, low friction materials, coatings, or hydrophilic coatings on the tissue removal element or on the shield may be helpful in atraumatic introduction of these devices through the epidural space and neural foramen.
The neural protection element may comprise a window or local opening that limits exposure of the tissue removal device to the patient's tissue only to the localized area of the opening. The opening may be positioned such that it directly underlies the area of desired tissue removal, e.g., such that it directly underlies the neural foramen and impinging tissue. Irrigation and/or aspiration optionally may be performed through the window, e.g., for debris removal. Suction also may be drawn through the window to engage the impinging tissue and/or to provide a seal against the target tissue. Optionally, the sheath window may comprise a cutting element that coacts with the tissue removal device. Furthermore, the tissue removal device may present its cutting elements at the window. The window optionally may be opened, closed or resized by a medical practitioner as desired. For example, the window may be closed during delivery, opened during tissue removal, then closed during retrieval of the sheath. When the neural protection element comprises a backside shield, the tissue removal device may be delivered through rails within the edges of the shield, or in conjunction with the shield.
Neural protection can be provided during tissue removal, for example, to reduce the risk of neurological damage during selective tissue removal. The neural protection element can be positioned after the needle tip has been placed adjacent to, or within the neural foramina. The neural protection element can be a sheath, shield, backstop, or combinations thereof.
As an added safety precaution, variations of the present invention optionally may comprise neural localization elements to ensure proper positioning of the neural protection element and/or the tissue removal device. The neural localization elements may comprise separate elements or may be integrated with the neural protection element and/or the tissue removal device. In one variation, the neural protection element may comprise a sheath with integrated neural localization elements. In another variation, the neural protection element may comprise a shield with integrated neural localization elements. In yet another variation, the neural protection element may comprise a portion of the tissue removal apparatus that is intended to remain stationary during tissue removal, located adjacent to the moving tissue removal elements. The conductive neural localization elements may be used to ensure that the neural structures and their adjacent vascular structures are on the non-working or backside of the neural protection element.
Neural localization elements on the backside of the neural protection element (i.e., the side of the neural protection element that contacts or is in proximity to the nerve root when properly positioned) may be activated with a stimulation waveform to stimulate the nerve root, thereby providing a positive control that confirms placement of the backside in proximity to the nerve root. Appropriate low intensity electrical stimulation on the backside surface should result in the stimulation of sensory and/or motor nerves in the patient's extremity. Likewise, neural localization elements on the working side of the neural protection element, or on the tissue removal element, (i.e., the side of the neural protection element or tissue removal element that faces impinging tissue slated for removal) may be activated with a stimulation waveform in anticipation of a negative response or no neural stimulation that confirms that the working side is not in contact with the nerve root and that tissue removal may safely proceed. Neural localization elements may be provided on any side or surface of the neural protection element and/or tissue removal element.
Safe tissue removal, ablation and remodeling with these methods and devices is further enabled by complementary methods and apparatuses that assist with accurate neural localization. Neural localization will be performed by neural stimulation through electrically conductive materials located within the capped epidural needle tip; within the epidural tools that will be in contact with tissue to be modified; or one or both sides of the working barrier. Neural stimulation will be performed in conjunction with monitoring of the patient for sensory and/or motor response to the electrical impulses.
Said backstop may also contain neural localization capabilities, including a conductive element on the working side and/or the non-working side. The conductive element may be used to ensure that the neural and their adjacent vascular structures are on the non-working side of the barrier. In the instance that the barrier is placed through the lateral recess or neural foramina, appropriate low intensity electrical stimulation on the non-working surface should result in the stimulation of sensory or motor nerves in the patient's extremity, while appropriate electrical conduction on the working surface should result in no neural stimulation.
Neural stimulation may be monitored by monitoring somatosensory-evoked potentials (SSEPs), motor-evoked potentials (MEPs), and/or by looking for visual signs of muscular contraction within the extremities. (Somatosensory evoked potentials (SSEPs) are non-invasive studies performed by repetitive, sub-maximal, electrical stimulation of a sensory or mixed sensory and motor nerve. In response to the nerve stimulation the brain generates cerebral action potentials (electrical waves), that can be measured and recorded over the scalp and spine with surface electrodes. Typically, needle electrodes are used for intraoperative SSEP monitoring, as they require less current, and reduce artifact. The recorded response is a series of waves that reflect activation of neural structures.) SSEP, SEP, MEP or EMG feedback may be monitored and/or recorded visually, or may be monitored audibly, potentially conveying quantitative feedback related to the volume or frequency of the auditory signal (e.g., a Geiger counter type of quantitative auditory feedback). Intensity of signal or stimulation may be monitored and used to localize the nerve during placement, as well.
For example, the surgeon may use the neural stimulator to ensure that there is not stimulation of vulnerable neurons on the working side of the barrier, prior to initiating tissue manipulation with the working tools. For example, with the barrier in position in the lateral recess or neural foramina, the surgeon may send electrical current first along the working side of the barrier, then along the backside of the barrier. Low level stimulation of the working side would be expected to result in no neural stimulation, while the same stimulation on the backside of the barrier would be expected to stimulate dorsal roots, nerve roots, or ganglia.
Neural localization may be further enabled by the addition of surgical instruments (e.g. cautery devices, graspers, shavers, burrs, probes, etc.). The surgical instruments can be used that selectively deliver electrical current while the patient is monitored for nerve stimulation, for example to further enable neural localization, that selectively deliver electrical current (e.g., stimulate electrically) while the patient is monitored for nerve stimulation in similar fashions, for example to further neural localization. Quantification of stimulation can enable neural localization. For example, the user can use a calibrated sensor input that recognizes stronger stimulation as the device is moved closer to neural structures, or is able to differentiate between stimulators that are closer to or further from neural structures. For added safety, a surgical device can be designed to automatically stimulate before or during tissue removal (e.g., resection), and can be designed to automatically stop tissue removal (e.g., resection) when nerve stimulation has been sensed.
The tissue removal device (e.g., a tissue abrasion device) can be placed, either percutaneously or through an open surgical approach, through the neural foramina of the spine, and at least partially around the anterior border of the facet joint, anterior to the ligamentum flavum. The removal device (e.g., the abrasion device) alternatively or additionally can be placed through the neural foramen anterior to the facet joint, but into and through the body of, or posterior to the ligamentum flavum. After spinal neuroforaminal placement, the device can be used to remove or selectively remove tissues that impinge on the neurovascular structures within the lateral recess and neural foramen, anterior to the facet joint, thereby enlarging the lateral recess and neural foramina via selective tissue removal. Impinging tissue to be targeted for removal can include, but is not limited to, lateral ligamentum flavum, anterior and medial facet capsule, facet bone, and/or osteophytes. In another variation the tissue removal device can be positioned for removal of central stenosis.
The tissue removal surface of the tissue removal device may comprise various tissue removal elements for selectively removing all or a portion of the impinging tissue. In one variation, the tissue removal surface comprises one or more non-powered mechanical tissue removal elements that are drawn or pulled, e.g., under tension, across the impinging tissue to remove the tissue by cutting, shaving, etc.
During tissue removal, the tissue removal device may be drawn across impinging tissue in a single direction or may be reciprocated. The mechanical elements may comprise cutting elements, such as blades, band saws, or wire saws. The blades may comprise various shapes (e.g. serrated), sizes, and configurations, as desired. Alternatively, the mechanical elements may comprise abrasives, such as a diamond or oxide coating. Furthermore, coacting blades may be provided to achieve a guillotine-type or scissor-type cutting action. Blades may be attached to the tissue removal device or may be formed by punching, grinding, or stamping through the device with optional subsequent grinding of the punched edge. Alternatively, the blades may be formed by a chemical etching process. The blades may comprise a 3-dimensional profile to facilitate cutting, for example, a bow or a corrugation or a ‘cheese grater’ profile. Furthermore, the blades may be placed at one or more angles relative to the direction of tissue removal. Cutting surfaces of the blades may be oriented in a single direction or may be oriented in multiple directions. Additionally, the blades may be serrated. As another alternative, the mechanical elements may comprise cutting wires or wire saws, for example, one or more Gigli saws. A plurality or cutting wires or Gigli saws may be joined or woven together or flattened to form a substantially planar cutting surface. Further, a wire saw(s) or Gigli saw(s) may be attached to a ribbon backing, said ribbon thereby limiting the depth of penetration of the tissue removal device (“depth-stop ribbon”).
In another variation, the tissue removal surface comprises one or more powered mechanical tissue removal elements. The powered mechanical tissue removal elements may comprise, for example, band saws, belt shavers, rotary burrs or blades, reciprocating burrs or blades, etc.
The tissue removal surface can have an energy delivery system that ablates, vaporizes, breaks up, or changes the modulus of the tissue, for example, aiding tissue removal. The tissue removal system can deliver one or more of various energies to facilitate removal of tissue. The energies can be electrical, ultrasound, thermal, microwave, laser, cryo, or combinations thereof. In another variation, the tissue removal surface comprises one or more electrosurgery elements for tissue removal/ablation. The electrosurgery elements additionally or alternatively can be utilized to achieve hemostasis and/or to facilitate neural localization. Monopolar or bipolar RF elements can, for example, be utilized and activated with a thermal or substantially non-thermal waveform.
Any other known tissue removal elements may be utilized with the tissue removal device including, for example, lasers, high-pressure fluid, thermal elements, radioactive elements, etc. It should be understood that various tissue removal elements may be used in any combination, as desired.
In order to reduce friction during placement, diagnosis, treatment and/or removal, the access elements, the neural protection element and/or the tissue removal device can have or comprise a lubricious coating, for example, a hydrophilic coating, a poly(tetrafluoroethylene) coating, etc. The coating can reduce friction during placement, diagnosis, treatment and/or removal. Furthermore, the tissue removal device, the access elements and/or the neural protection element may by biocompatible and/or non-friable. Debris removal elements also may be provided.
The method can be performed through an epidural needle that has been inserted into the epidural space. The epidural needle may be inserted percutaneously, or via an open incision, via a standard posterior paramedian (interlaminar) or midline (interspinous) approach, for example, using a loss of resistance technique known to those having an ordinary level of skill in the art.
A catheter can then be threaded through the needle and into the epidural space. The catheter distal tip can have a protective hood, cover, or needle cap, for example, which can be designed to be placed over the needle tip. When the catheter distal tip has been placed in the epidural space, the user can open the protective hood covering. After the protective covering is opened, the catheter can be slidably retracted through the needle until the protective hood cover firmly encloses the sharp edges or points in the area of the epidural needle tip. When the protective hood cover firmly protects the needle tip, the catheter can be fixed to the needle. The needle with the protective hood covering on the needle tip can be configured as a blunt instrument.
The needle can then be advanced until the needle distal end is in a lateral recess, adjacent to the neural foramina. The user can use tactile feedback from the needle, image guidance (e.g., fluoroscopy), or combinations thereof, to position the needle distal end to the lateral recess.
A tissue removal device can be positioned between the impinging tissue to be removed and the neural protection element. A curved flexible stylet can be inserted into the catheter. The catheter can then be advanced through the needle. The tip of the catheter can be driven, for example, along the inferior border of the facet, cephalad to the neural and neurovascular structures, and through the neural foramina laterally.
An atraumatic curved needle can be advanced through the epidural catheter and driven through the neural foramina, also between the tissue to be removed and the neural structures to be protected.
A curved thin shield can be advanced through the epidural needle and driven through the neural foramina, also positioned between the tissues to be removed and tissues to be protected.
The catheter, curved needle, or shield can serve as a barrier, for example, between the tissue to be removed and the neural and neurovascular structures. The catheter, curved needle, or shield can serve can assist in the delivery of a barrier, for example, between the tissue to be removed and the neural and neurovascular structures. The catheter, curved needle, or shield can be expanded within the neural foramina to serve as a barrier, for example, between the tissue to be removed and the neural and neurovascular structures. The neural protection element can have an atraumatic profile, for example, to reduce tissue injury. The neural protection element can have rounded edges.
The user can visualize the epidural space, for example, via a fiber optic element that can be covered by a distal clear tip. The fiber optic element can be delivered within the epidural catheter. The fiber optic element can be delivered via a working channel within or adjacent to the epidural needle.
In an open surgery variation, access can be achieved via an access element comprising a cannulated probe, such as a cannulated ball-tipped probe, Woodson elevator, or Hockey Stick hybrid. The probe can be placed through the surgical incision into the epidural space. A curved element, such as an atraumatic needle, then can be advanced through the cannula of the probe and driven laterally to cannulate the neural foramen. In addition to direct visualization and tactile feedback, open access can be aided by the use of image guidance, an epidural endoscope or any other visualization technique.
When the neural protection element comprises a sheath, the tissue removal device can be delivered through or along the sheath, or in conjunction with the sheath. The sheath can have a window or local opening that limits exposure of the tissue removal device to the patient's tissue only to the localized area of the opening. The opening can be positioned directly underlying the area of desired tissue removal, e.g., directly underlying the neural foramen and impinging tissue in the central canal, the lateral recess, and/or within the neural foramen.
Irrigation and/or aspiration can be performed through the window, e.g., for debris removal. Suction also can be drawn through the window to engage the impinging tissue and/or to provide a seal against the target tissue and/or to remove tissue debris and/or to remove fluid. The sheath window can have a cutting or ablation element that coacts with the tissue removal device. The tissue removal device can present the tissue removal elements at the window. The window optionally can be opened, closed or resized by a medical practitioner as desired. For example, the window can be closed during delivery, opened during tissue removal, then closed during retrieval of the sheath.
Neural localization elements can be used to improve positioning of the neural protection element and/or the tissue removal device. The neural localization elements can have separate elements or can be integrated with the neural protection element and/or the tissue removal device. In one variation, the neural protection element can have a sheath or other element with integrated neural localization elements. Electrically conductive neural localization elements can be used to ensure that the neural structures are on the non-working or backside of the barrier. Neural localization elements on the back side of the neural protection element (i.e., the side of the neural protection element that contacts the nerve root when properly positioned) can be activated with a back side electrical current (e.g., delivered as a waveform). The back side electrical current can stimulate the nerve root or other neural structures, for example, providing a signal to the user that the back side has been placed adjacent to the nerve root. Low intensity electrical current on the back side surface can result in the stimulation of sensory or motor nerves in the patient's extremity. Neural localization elements on the working side of the neural protection element (i.e., the side of the neural protection element that faces impinging tissue slated for removal) can be activated with a front side electrical current (e.g., delivered as a waveform, for example with distinct characteristics than the waveform of the back side electrical current). The electrical current can stimulate a negative response or no neural stimulation, for example, providing a signal to the user that the working side is not in contact with the nerve root and that tissue removal may safely proceed. Neural localization elements can be provided on any or all sides of the neural protection element.
After access is established, optionally including neural protection and/or neural localization, and the tissue removal device can be positioned such that the tissue removal surface contacts the impinging tissue slated for removal, then the user can selectively remove tissue. Tissue removal can result in neural and/or neurovascular decompression. The elastic modulus of impinging tissue can be altered, for example, to facilitate removal of the tissue. For example, the modulus of soft tissue can be increased to gain purchase on the soft tissue with the tissue removal elements. Such modulus alteration can be achieved, for example, through compression, denaturation, electrosurgical exposure, thermal remodeling (hot or cold), chemical alteration, epoxy or glues or hydrogels, or any combination thereof. Remodeling of the tissue during or after modulus alteration can alleviate impingement and obviate or reduce a need for tissue removal.
In combination with the energy delivery system, or as a stand alone tissue removal option, one or more non-powered mechanical tissue removal elements (e.g. abrasives or cutting elements such as blades or saws) can be drawn across the impinging tissue to remove the tissue by cutting, shaving, slicing, scissoring, guillotining, scraping, tearing, abrading, or combinations thereof. The blade can be drawn across impinging tissue in a single direction and/or can be reciprocated. The mechanical tissue removal elements can have abrasives, such as a diamond or oxide coating.
The blades can have various shapes, sizes and configurations. The blades can coact, for example, in a guillotine-type or scissor-type cutting action. The blades can be attached to or integral with the tissue removal device. The blades can be formed by grinding, punching or stamping through the tissue removal device. The blades can be formed by grinding of a punched or stamped edge of the tissue removal device. The blades can be formed by a chemical etching process. The blades can have a 3-dimensional profile to facilitate cutting, for example, a bow or a corrugation or a ‘cheese grater’ profile. The blades can be placed at one or more angles relative to the direction of tissue removal. The blades can be configured with the blade cutting across the tissue (i.e., similar to a band saw). The blades can have cutting surfaces. The cutting surfaces can be oriented in a single or multiple directions. The blades can be serrated.
The saw can be a wire saw or saws. The wire saw can be a Gigli saw. Multiple wire saws or Gigli saws can be joined or woven together or flattened to form a substantially planar cutting surface. The wire saw can be mounted on a flat ribbon. The ribbon can be a depth stop, for example, limiting for saw penetration.
The tissue removal surface can have one or more powered mechanical tissue removal elements. The powered mechanical tissue removal elements can have, for example, band saws, belt shavers, rotary burrs or blades, reciprocating burrs or blades, or combinations thereof
The apparatus and methods can facilitate selective elimination of pathological spinal tissue, thereby enabling symptomatic relief in patients suffering from spinal stenosis.
A method for modifying spinal anatomy is disclosed. The method includes delivering a surgical apparatus to an epidural space and surgically altering tissues that impinge neural or vascular structures in the lateral recess, neural foramina or central canal of the spine with the apparatus. Surgically altering tissues can include ablating tissue, resecting tissue, removing tissue, abrading tissue, retracting tissue, stenting tissue, retaining tissue, or thermally shrinking tissue. Surgically altering tissues can additionally include enlarging the lateral recess, neural foramina or central canal of the spine.
Delivering the surgical apparatus to an epidural space can include delivering an epidural needle to the epidural space, and enlarging the lateral recess, neural foramina or central canal of the spine can include focally altering tissue with tools delivered through the epidural needle. Delivering the surgical apparatus to an epidural space also can include delivering an epidural needle to the epidural space, and enlarging the lateral recess, neural foramina or central canal of the spine also can include focally altering tissue with tools delivered through a working channel disposed adjacent to the epidural needle.
Delivering the surgical apparatus can include converting the epidural needle to an endoscope within the epidural space. Delivering the surgical apparatus to an epidural space also can include delivering a working endoscope to the epidural space, and enlarging the lateral recess, neural foramina or central canal of the spine can also include focally altering tissue with tools delivered through the working endoscope. Delivering the surgical apparatus can also include converting the epidural needle into a blunt tipped instrument after placement of the needle's tip within the epidural space. Converting the epidural needle can also include threading an epidural catheter through the epidural needle into the epidural space, and covering the needle's tip with an epidural needle cover delivered via the catheter.
Delivering the surgical apparatus can also include converting the epidural needle into an endoscope via a visualization element disposed within the epidural catheter. Delivering the surgical apparatus can include infusing fluid into the epidural space to improve visualization. Delivering the surgical apparatus can include inserting a removable working channel alongside the surgical apparatus. Delivering the surgical apparatus can include inserting a distal tip of a dual lumened epidural needle into the epidural space and using at least one of the dual lumens as a working channel for the delivery of instruments into the epidural space. Delivering the surgical apparatus can include inserting an instrument chosen from the group consisting of a tissue cauterization tool, a tissue laser device, a radiofrequency delivery device, a ronguer, a tissue grasper, a tissue rasp, a probe, a bone drill, a tissue shaver, a burr, a tissue sander and combinations thereof through the surgical apparatus.
Delivering the epidural needle can include inserting the epidural needle to a position with a tip of the needle in proximity to where treatment will be directed. Delivering the epidural needle can include inserting the epidural needle at an interspace below the level of the spine where the treatment will be directed.
Delivering surgical apparatus can include delivering the apparatus via an open surgical route. Delivering the epidural needle can include delivering the needle via a posterior, interlaminar percutaneous route. Delivering the epidural needle can include delivering the needle via a posterior, translaminar, percutaneous route. Delivering the epidural needle can include delivering the needle via a posterior, midline, interspinous, percutaneous route. Delivering the epidural needle can include delivering the needle via a percutaneous route through the neural foramen from its lateral aspect. Enlarging can include placing a mechanical barrier or backstop between tissue to be resected and adjacent neural or vascular structures. The barrier can be steerable.
The method of modifying the spinal anatomy can include confirming proper placement of the surgical apparatus. Confirming proper placement can include confirming proper placement with a nerve stimulator. Confirming proper placement with a nerve stimulator further comprises confirming proper placement with stimulation leads placed on a tissue remodeling side of the surgical apparatus. The method of modifying the spinal anatomy can include confirming proper placement of the surgical apparatus or barrier with a nerve stimulator having stimulation leads placed on a tissue remodeling side of the barrier or on a back side of the barrier.
The method of modifying the spinal anatomy can include monitoring nerve stimulation with the nerve stimulator via somatosensory evoked potentials (SSEPs). The method of modifying the spinal anatomy can include monitoring nerve stimulation with the nerve stimulator via motor evoked potentials (MEPs). The method of modifying the spinal anatomy can include monitoring nerve stimulation with the nerve stimulator via motor evoked patient movement. The method of modifying the spinal anatomy can include monitoring nerve stimulation via verbal patient sensory response to the nerve stimulator.
The method of modifying the spinal anatomy can include monitoring enlargement via imaging. The method of modifying the spinal anatomy can include surgically altering the tissues under fluoroscopic imaging, MRI imaging, CT imaging., ultrasound imaging, radiological imaging, surgical triangulation, infrared or RF surgical triangulation.
The method of modifying the spinal anatomy can include placing an element that provides tissue compression of surgically remodeled tissue or bone surface in order to enlarge the neural pathway or foramina post-surgical enlargement. The method of modifying the spinal anatomy can include placing an element that provides tissue compression and retention in order to remodel tissue or bone surface in order to enlarge the neural pathway or foramina de novo. Placing the element can include placing the element using a percutaneous technique via the epidural space, through a neural foramen at a level to be treated for spinal stenosis, and around a facet complex or a lamina adjacent to the facet complex. The method of modifying the spinal anatomy can include tightening the element to a determined tension. Placing the element can include placing an element having a posterior anchor that is a cord or tie looped through a hole that has been drilled in the cephalad lamina of the immediately adjacent vertebrae. The method of modifying the spinal anatomy can include tensioning the element to a determined level via a tension gauge or other measurement device element holding tension against the tissue to be remodeled.
The method of modifying the spinal anatomy can include releasing a biologically active material for the purposes of decreasing inflammation, or promoting remodeling of soft tissue or bone growth from the element.
Apparatus for focal tissue alteration are disclosed herein. The apparatus have an element configured for placement into an epidural space, and surgical tools configured for delivery through the element into the epidural space to remodel spinal anatomy that impinges upon neural, neurovascular or tendon structures. The element can include an epidural needle, and wherein the surgical tools further comprise a tissue remodeling device configured for placement via the epidural needle.
The epidural needle can be configured for placement into the epidural space via an approach chosen from the group consisting of a posterior interspinal midline approach, a posterior paramedian interlaminar approach, a posterior translaminar paramedian approach through a hole in the lamina, a neural foramina approach around an anterior border of a facet joint, and combinations thereof. The epidural needle can include two adjacent lumens, the second lumen configured to act as a working channel for the delivery of the surgical tools into the epidural space.
The apparatus can have an epidural catheter configured to convert the epidural needle into a blunt tipped instrument via an epidural needle tip cover that may be opened and then pulled back to cover the needle's tip. The epidural catheter can have a fiberoptic cable for visualization. The apparatus can have an insertable and removable working channel for tool access configured for placement alongside the needle.
The tissue remodeling device can be chosen from the group consisting of a tissue cauterization tool, a tissue laser device, a radiofrequency delivery device, a ronguer, a tissue grasper, a tissue rasp, a probe, a bone drill, a tissue shaver, a burr, a tissue sander, and combinations thereof.
The surgical tools can produce nerve stimulation. The apparatus can have a device for monitoring neural stimulation to identify when a working surface of the surgical tools is in close proximity to vulnerable neural tissue during tissue remodeling.
An apparatus for protecting adjacent structures during remodeling of spinal anatomy that impinges upon neural, neurovascular or tendon structures is disclosed. The apparatus has a mechanical barrier configured for placement between tissue to be resected and the adjacent structures. The mechanical barrier can be configured for insertion through an open incision. The mechanical barrier can be configured for insertion through a working channel of an endoscope.
The apparatus can be configured for use with a visualization element. The visualization element can be chosen from the group consisting of an epidural endoscope, a fluoroscope, ultrasound, XRay, MRI and combinations thereof. The apparatus can have a nerve stimulator to facilitate proper placement of the barrier. A conductive element can be included on a tissue modification side of the barrier or on a backside of the barrier to facilitate nerve localization. A working surface of the tissue remodeling device can have neurostimulation capabilities, thereby allowing for a positive and negative control in localizing neural tissue prior to tissue removal.
The apparatus can include a monitoring technique for monitoring electrical nerve stimulation. The monitoring technique can be chosen from the group consisting of SSEPs (somatosensory evoked potentials); MEPs (motor evoked potentials); EMG; verbal inquiries of the patient's sensory experience to the electrical stimulation; visual techniques, mechanical techniques, tactile techniques monitoring neuro muscular stimulation and movement, and combinations thereof.
The apparatus can include an element configured to provide tissue compression against surgically remodeled tissue or bone surface in a neural pathway or foramina post-enlargement. The element is configured for percutaneous placement via the epidural space, through the neuroforamen at the level to be treated for spinal stenosis, and around the facet complex or the lamina adjacent to the facet complex. The element is configured to release a biologically active material for the purposes of decreasing inflammation, or promoting remodeling of soft tissue or bone growth.
The apparatus can be configured for tightening to a determined tension for purposes of relieving spinal stenosis. The element can include a posterior anchor having a cord or tie looped through a hole that has been drilled in the cephalad lamina of the immediately adjacent vertebrae. Tension of the element is configured to be set at a determined level by a tension gauge, or other measurement device element holding tension against tissue to be remodeled.
The apparatus can have a neuro foraminal compression element configured to retract and hold pressure on spinal tissue when placed under tension, in order to relieve pressure on impinged neural and vascular structures and promote tissue remodeling. The apparatus can have a tensioning device for the neuro foraminal compression element configured to secure two ends of the element together at a posterior aspect of the vertebral lamina at a desired tension by pulling the element to the desired level of tension prior to locking the opposite ends of the element together at said tension.
The apparatus can have a tensioning device configured to tighten a loop formed by the neuro foraminal compression element around the facet joint complex, within the lateral aspect of the lamina, and configured to tighten the compression element across a locking or crimping element to a specified tension, pulling the ligamentum flavum posteriorly in the spinal canal, in the lateral recess and in the neural foramen.
The apparatus can have a tensioning device configured to tighten a loop formed by the neural foraminal compression element around the lamina, close to a facet joint complex, within a lateral aspect of the lamina, and configured to tighten the compression element across a locking or crimping element to a specified tension, pulling the ligamentum flavum posteriorly in the spinal canal, in the lateral recess and in the neural foramen.
At least one free end of the neural foraminal compression element can be configured for subcutaneous placement to facilitate future removal of the element. The compression element can be biodegradable.
The compression element can contain a therapeutic agent chosen from the group consisting of medications, bioactive compounds, steroids, depot steroids, anti-inflammatories, and combinations thereof The agent can be configured for immediate release. The agent can be configured for sustained local delivery.
A method of altering bone or soft tissue in a patient is disclosed. The method includes placing a tissue abrasion device through tissue to be altered, holding the tissue abrasion device under tension to bring an abrasive surface of the device firmly against the tissue to be altered, and sliding the abrasive surface of the abrasive element against the tissue to be altered, thereby altering bone or soft tissue immediately adjacent to the abrasive surface. Altering can include abrading, removing, or remodeling.
Placing the tissue abrasion device through tissue to be altered can include placing the device through spinal tissue that impinges on neural, neurovascular or ligamentous structures in the patient's spine. Placing the tissue abrasion device can include placing the tissue abrasion device through a neural, neurovascular, or ligamentous pathway within the patient's spine, holding the tissue abrasion device under tension to bring the abrasive surface against tissue within the pathway, and where sliding includes enlarging the pathway via frictional abrasion of the tissue. Placing a tissue abrasion device through the pathway can include placing the tissue abrasion device through neural foramina of the patient's spine and around the anterior border of a facet joint. Placing the tissue abrasion device through neural foramina of the patient's spine and around the anterior border of a facet joint can include placing the device via a route chosen from the group consisting of an open surgical approach, a percutaneous approach, a posterior percutaneous approach, an interlaminar percutaneous approach, a translaminar percutaneous approach, an interspinous percutaneous approach, through the neural foramen from a lateral direction, and combinations thereof. Placing the tissue abrasion device can include placing the device within a protective sheath or cover.
The method can include altering spinal tissues that impinge on neural, neurovascular, or ligamentous structures in the patient's spine.
Enlarging the pathway can include enlarging a diseased pathway within the patient's spine.
Holding the tissue abrasion device under tension against tissue within the pathway can include placing an abrasive surface of the tissue abrasion device against tissue chosen from the group consisting of an anterior surface of facet joint capsule, a medial surface of facet joint capsule, a superior articular process of the facet joint, ligamentum flavum, tissues attached to ligamentum flavum, extruded spinal disc material, scar tissue, and combinations thereof.
Sliding the tissue abrasion device against the tissue can include sliding the abrasive surface of the tissue abrasion device against the tissue. Sliding the abrasive surface can include enlarging the lateral recess, neural foramina or central spinal canal via frictional abrasion. Sliding the abrasive surface can include preferentially abrading tissue chosen from the group consisting of ligamentum flavum, bone spurs, facet capsule, superior articular process, extruded spinal disc material, scar tissue and combinations thereof that impinge on neural or vascular structures.
The method can include confirming proper placement of the tissue abrasion device. Confirming proper placement of the device can include confirming proper placement with a nerve stimulator. Confirming proper placement with a nerve stimulator can include confirming proper placement with a nerve stimulator having stimulation leads placed at a location chosen from the group consisting of a non-abrasive side of the tissue abrasion device, a back side of a protective sleeve or cover placed over the tissue abrasion device, an abrasive side of the tissue abrasion device, a working side of the tissue abrasion device, and combinations thereof. Confirming proper placement can include confirming placement via a modality chosen from the group consisting of fluoroscopic, MRI, CT, infrared, ultrasound imaging, surgical triangulation, and combinations thereof.
The method can include monitoring nerve stimulation via somatosensory-evoked potentials (SSEPs) with the nerve stimulator. The method can include monitoring nerve stimulation via motor-evoked potentials (MEPs) with the nerve stimulator. The method can include monitoring nerve stimulation via verbal patient sensory response to the nerve stimulator.
The method can include replacing the tissue abrasion device with a compression element that is held against altered tissue or bone.
Apparatus for the removal of impinging soft tissue or bone within a patient are disclosed. The apparatus can have a tissue abrasion device configured for placement through impinged tissue pathways. The tissue abrasion device can have an abrasive surface configured for placement adjacent to the impinging tissue. The impinged tissue pathways can have pathways chosen from the group consisting of neural pathways, neurovascular pathways, ligamentous pathways, and combinations thereof. The tissue abrasion device can be configured for the removal of spinal structures that impinge neural or neurovascular tissues within the patient, and wherein the tissue abrasion device is configured for placement through neural foramina of the patient's spine and around the anterior border of a facet joint.
The apparatus can have a protective cover disposed about the tissue abrasion device, where the protective cover is configured to limit exposure of an abrasive surface of the device to areas where tissue removal is desired. The apparatus can have a nerve stimulator in communication with the tissue abrasion device to facilitate proper placement of the device.
The apparatus can have a conductive element disposed on an abrasive surface of the device to enable nerve localization by sending a small electrical current through the conductive element.
The apparatus can have an epidural needle, where the tissue abrasion device is configured for placement through the epidural needle.
The apparatus can have a visualization element for direct visualization of the neural foramina. The apparatus can have a neural foramina compression element.
The compression element can be configured to promote hemostasis and desired tissue remodeling during healing. The element can be configured to be left in place after being secured with adequate tension against tissue abraded with the tissue abrasion device. The compression element can be configuredto protect a tissue surface abraded with the device. The compression element can be configured to prevent adhesions during healing. The compression element can be configured to protect vulnerable structures adjacent to tissue abraded with the tissue abrasion device from an inflammatory response triggered by tissue abrasion.
The tissue abrasion device can be configured for placement in front of, across, and then behind tissue to be abraded, such as through a naturally occurring or artificially created anatomical foramen or tissue pathway. The abrasive surface can be disposed on all or part of one side of the tissue abrasion device. The abrasive surface can be disposed on an element chosen from the group consisting of a length of ribbon, strap, cable, belt, cord, string, suture, wire and combinations thereof. The ends of the device can be configured for manual grasping. The apparatus can have a handle to which ends of the device are attached for manual grasping. The device can be configured for attachment to an electromechanical power-driven device.
The device can be configured to be placed under tension in order to bring the abrasive surface into contact with tissue to be removed. The abrasive surface can be configured to be pulled against tissue to be removed. The abrasive device can have multiple abrasive elements with different abrasive surfaces, configured for interchangeable use. The multiple abrasive elements can have varying grades of abrasive material. The multiple abrasive elements can have different grooves, patterns of grooves, or material patterns on the abrasive surface to facilitate preferential abrasion of tissue at desired locations. The patterns of grooves can have diagonal parallel grooves that preferentially move the abrasive element towards one direction on the surface being abraded as the abrasive element is pulled in one direction, and towards an opposing direction as the abrasive element is pulled in a second direction. The multiple abrasive elements can have different shapes that guide the extent and location of tissue removal.
The apparatus can be configured to carry debris away from the site of tissue removal.
The tissue abrasion device can vary in profile along its length. The tissue abrasion device can have openings that facilitate passage of debris behind the device for storage or removal.
The apparatus can have a monitor for monitoring. electrical nerve stimulation with the nerve stimulator. The monitor can be configured to monitor a feedback chosen from the group consisting of SSEPs, MEPs, EMG, verbal communication of patient sensation, visual monitoring, mechanical monitoring, tactile means, monitoring of neuromuscular stimulation and movement, and combinations thereof.
The compression element can be biodegradable. The compression element can contain a therapeutic agent configured for delivery to abraded tissue or adjacent neural and neurovascular structures. The therapeutic agent can be a medication, bioactive compound, steroid, depot steroid, anti-inflammatory, adhesion barrier, procoagulant compound, or combination thereof.
The protective cover can be attached, external to the patient, to a suspension system that includes elements to firmly and individually grasp each end of the cover and hold it in position under tension against the tissue surface to be abraded, with an open portion of the cover exposing the abrasive element directly over tissue to be abraded. The protective cover can be configured to protect a non-abrasive side of the tissue abrasion device. The protective cover can have channels along its lateral aspects for the insertion and sliding of the tissue abrasion device. The protective cover can include channels along its lateral aspects for the insertion and sliding of a second protective cover configured for placement between an abrasive surface of the tissue abrasion device, and tissue adjacent to tissue to be abraded with the abrasive surface.
Apparatus for selective surgical removal of tissue is disclosed. The apparatus can have an access element, a neural protection element, and a tissue removal device. The apparatus can have a neural localization element. The neural localization element can be integrated into the neural protection element. The apparatus can have debris removal elements. The apparatus can have hemostasis elements.
The access element can be a cannulated probe, ball-tip probe, elevator, epidural needle, epidural probe, epidural endoscope, curved tube, curved cannula, guide wire, straight guide wire, curved guide wire, or combination thereof.
The neural protection element can be an element configured for delivery via the access element. The neural protection element can be configured for transforaminal placement between impinging tissue and a nerve root. The access element can be configured for transforaminal placement. The neural protection element can have a sheath having a window. The tissue removal device can be configured for placement within the sheath such that tissue removal elements disposed on a tissue removal surface of the device are locally exposed within the window. The window can be configured for transforaminal placement.
The tissue removal device can be configured for transforaminal placement between the neural protection element and the impinging tissue. The tissue removal device can be a tissue removal surface having tissue removal element configured to remove the impinging tissue. The tissue removal elements can be powered tissue removal elements, non-powered tissue removal elements, mechanical tissue removal elements, cutting tissue removal elements, abrasive tissue removal elements, electrosurgical tissue removal elements, blades, punched features, stamped features, etched features, ground features, sharpened features, electrodes, monopolar electrodes, bipolar electrodes, or combinations thereof.
A method for selective surgical removal of tissue is disclosed. The method can include accessing a spinal neural foramen having impinging tissue, placing a neural protection element transforaminally between the impinging tissue and an underlying nerve root, placing a tissue removal device transforaminally between the impinging tissue and the neural protection element; and selectively removing the impinging tissue with the tissue removal device.
Accessing the spinal neural foramen can include accessing the neural foramen via an open surgical approach. Accessing the spinal neural foramen can include accessing the neural foramen via a percutaneous approach. Accessing the spinal neural foramen can include placing a guide wire transforaminally.
Placing the neural protection element transforaminally can include placing the neural protection element via the guide wire. Placing the tissue removal device transforaminally can include placing the tissue removal device via the neural protection element.
Selectively removing the impinging tissue can include mechanically cutting the tissue. Selectively removing the impinging tissue can include mechanically abrading the tissue. Selectively removing the impinging tissue can include electrosurgically removing the tissue.
The method can include, prior to selective removal of the impinging tissue, confirming proper placement of the neural protection element and the tissue removal device. Confirming proper placement can include localizing the nerve root with a stimulation waveform.
The method can include removing debris generated during selective tissue removal. The method can include stanching bleeding from the site of selective tissue removal. The method can include removing the neural protection element and the tissue removal device from the neural foramen.
A method for selective surgical removal of tissue is disclosed. The method can include accessing impinging tissue, placing a neural protection element transforaminally between the impinging tissue and an underlying nerve root, placing a tissue removal device between the impinging tissue and the neural protection element, and selectively removing the impinging tissue with the tissue removal device.
An apparatus for selectively removing a first tissue adjacent to a second tissue is disclosed. The apparatus can have a tissue removal device and a tissue protection device, where the tissue protection device can have a first side and a second side, where the first side is configured to deliver a first electrical stimulation, and the second side is configured to deliver a second electrical stimulation. The apparatus can have an atraumatic access device.
The tissue protection device can be configured to prevent the removal of the second tissue. The tissue removal device can have an RF device. The tissue removal device can have an electrical textile conductor. The tissue removal device can have an ablation needle. The tissue removal device can have a conductive wire loop. The tissue removal device can have a mechanical tissue removal device. The tissue removal device can be slidably attached to the tissue protection device. The tissue removal device can be attached by a rail to the tissue protection device. The mechanical tissue removal device can be configured to reciprocate to remove tissue.
An apparatus for selectively removing a first tissue adjacent to a second tissue is disclosed. The apparatus can have a tissue removal device comprising a first tissue removal element and a second tissue removal element, where the first tissue removal element is configured to remove tissue in a first direction, the second tissue removal element is configured to remove tissue in a second direction, and the first direction is substantially opposite the second direction. The first tissue removal element can have a first leading edge and a first scoop, the first leading edge can be adjacent or integral with the first scoop, and the first leading edge can be configured to deliver energy. The energy can have RF. The first leading edge can have a beveled configuration.
An apparatus for selectively removing a first tissue adjacent to a second tissue is disclosed. The apparatus can have a tissue removal device comprising a first tissue removal element, the first tissue removal element ca have a first leading edge and a first scoop, the first leading edge can be adjacent or integral with the first scoop, and the first leading edge can be configured to emit energy. The first leading edge can have a dull edge.
The energy can have RF. The energy can have mechanical vibrations. The energy can have acoustic energy. The energy can have ultrasound energy. The first tissue and the second tissue can be spinal tissue.
The apparatus can have a tissue protection device comprising a first side and a second side, the first side can be configured to deliver a first electrical stimulation, and the second side can be configured to deliver a second electrical stimulation.
The tissue removal device can be slidably attached to the tissue protection device.
An apparatus for damaging a first spinal tissue and preserving a second spinal tissue adjacent to the first spinal tissue is disclosed. The apparatus can have a tissue removal device comprising a first tip and a body, the tip can be configured to transmit an energy to the first spinal tissue, and the body can be configured to not transmit energy. The energy can have RF.
A method for damaging a first spinal tissue and preserving a second spinal tissue adjacent to the first spinal tissue is disclosed. The method can include inserting a needle through the first spinal tissue where the needle can have a body and a tip, placing the tip into the second spinal tissue where the body is in the second spinal tissue, and emitting an energy through the tip.
The method can include suctioning through the tip. The body can emit no energy. The second tissue can have a tissue surface. The energy can have an electrical energy. The energy can have RF energy. The energy can have acoustic energy. The energy can have ultrasound energy.
A method for damaging a target spinal tissue is disclosed. The method can include deploying a tissue protection barrier adjacent to the target spinal tissue, where the tissue protection barrier can have a first side and a second side. The method can include monitoring electrical signals against the first side, delivering an electrical signal through the back side, and reciprocating a tissue removal device against the spinal tissue.
The tissue protection barrier can have a window, and the method can include positioning the window adjacent to the target spinal tissue. The window can be on the first side. The tissue protection barrier can have a lubricious coating.
The tissue removal device can be in the tissue protection barrier. The tissue removal device can be slidably attached to the tissue protection barrier. The tissue removal device comprises a lubricious coating. The tissue removal device can emit an energy. The energy can have RF. The tissue removal device can have a scoop. The tissue removal device can have a spring. The method can include deploying energy to the target tissue through the spring.
Finally, the present invention also describes methods and apparatus that promote tissue remodeling, separate from the tissue resection or ablation. These devices tightly wrap, retract, or hold in position, under tension, impinging tissues within the spinous posterior elements.
It is expected that the apparatus and methods of the present invention will facilitate a minimally invasive approach to the selective elimination of pathological spinal tissue, thereby enabling symptomatic relief in patients suffering from spinal stenosis.
The above and other objects and advantages of the present invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:
a, b, c are sagittal views through a patient's spine, illustrating a prior art method for epidural needle insertion, a loss of resistance method;
a illustrates a needle inserted to an interspinal ligament.
b illustrates constant pressure applied on the syringe plunger.
c illustrates saline injected into the epidural space.
a, b, c are schematic side views of variations of the apparatus of
d, e are schematic side views of an epidural portal over needle apparatus, as shown in
a is a schematic side view, partially in section, of variations of the apparatus, illustrating methods of safely utilizing the apparatus for safe placement and use of surgical tools in or around the epidural space;
b is a side view, partially in section, illustrating a method and apparatuses for safe placement of a tool or working channel into the epidural space;
b is a frontal view from above;
c is a front view;
d is a frontal view of the working backstop or barrier apparatus folded for compact delivery;
a-40d are cross-sectional views through a patient's spine, illustrating another variation of the method and apparatus of
40E are a detailed view and a close up of the cross section of the apparatus used in
a-c illustrate various embodiments of a clear tipped cannula with a clear shaft;
d-f illustrate various embodiments of a clear tipped cannula with an opaque shaft;
a illustrates an embodiment of a clear tipped cannula with a working channel for a tool;
b illustrates an embodiment of a clear tipped cannula with a nerve stimulator at a working channel exit;
The present invention relates to methods and apparatus for the selective surgical alteration (e.g., removal and remodeling) of tissue that impinges upon spinal neural or vascular structures, with particular attention towards avoiding injury and/or trauma to the affected or adjacent neural, vascular and neurovascular structures. More particularly, the present invention relates to methods and apparatus for spinal lateral recess 108 and neural foraminal 110 enlargement, and central canal enlargement of the spine, in cases of neurovascular impingement, through a novel approach to selective and safe enlargement of the pathologically narrow spinal neural foramen, impinged lateral recess 108 and/or compromised central spinal canal. The approach includes alteration of the tissues that pathologically impinge neural and neurovascular structures in the spine. Impinging tissues to be removed from or remodeled in the spine's central canal, lateral recess 108, and neural foramen 110 may include, but are not limited to, ligamentum flavum 10; bone spurs or ligamentous calcifications; localized disc extrusions; enlarged facet joint complex 12, facet capsule, superior articular processes; osteophytes, and scar tissue or adhesions.
The variations of the invention designed to treat spinal stenosis are summarized in this paragraph, and described in greater detail in the paragraphs that follow. The methods begin with insertion of an epidural needle apparatus 2, which is converted, after placement in the epidural space, from a sharp tipped instrument, into a blunt tipped tool. The blunt tool is manipulated within the epidural space 42, either under image guidance; under direct vision with an accompanying epidural endoscope; or under direct vision when the instrument itself is given endoscopic function. The same blunt tipped epidural instrument may have an attached fixed or removable working channel. An additional apparatus of the current invention, a working backstop or barrier 134 that serves to protect adjacent vulnerable structures during the procedure, may subsequently be inserted into the epidural space 42, as well as through the neural foramina 110, through the needle or endoscope or an adjacent working channel. Safe resection, ablation, and remodeling may be further ensured through the integration into the invention of electrical neural stimulation and monitoring for localization, optionally available through nerve stimulation functionality in the epidural instrument; the working tools used through the needle or working channel; and/or the working backstop. Finally, further variations of the device and method enable the surgeon to remodel stenotic spinal anatomy, either after tissue resection or as a stand-alone procedure, through the placement of devices for holding, retracting or retaining anatomic structures away from vulnerable neural and neurovascular structures within the posterior elements of the spine.
For posterior approaches to the lateral recess 108 and neural foramen 110, the needle 2 is inserted at or one level below the spinal interspace where tissue abrasion and removal is desired. The epidural needle 2 may be inserted into the epidural space 42, midline, ipsilateral, or contralateral to the area where the spinal canal, lateral recess 108 and/or neuroforaminal stenosis or impingement is to be treated. Referring now to
With any percutaneous epidural approach, after a sterile prep and drape, the epidural needle's 2 sharp tip is inserted through the skin to perform a loss-of-resistance technique.
The epidural needle's 2 sharp tip is inserted through the skin until it begins to engage the interspinous ligaments 78. Subsequently, a fluid or air filled (loss of resistance) syringe 60 is depressed and will meet resistance to injection, until the needle tip is advanced, through the ligamentum flavum 10, entering the epidural space 42, which actually has a slight negative pressure. There is a clear “loss of resistance” to the pressurized contents of the syringe 60, which occurs upon entering the epidural space 42, signifying correct needle tip placement.
When interlaminar access is not possible (e.g. unusual cases when laminae are too tightly approximated, even with flexion of the back), the epidural space 42 may be entered via a translarninar burr hole, using a drill designed for safe epidural entry. Each of these approaches allows placement of the epidural needle 2 tip in the posterior epidural space 42, poised for access to the lateral recess 108 and neural foramen 110.
As seen in
This prior art surgical procedure is imprecise and may not provide for an adequate decompression due to an inability to access all of the foramen 110. Furthermore, a risk of injuring nerve root 62 exists due to a lack of neural protection. Furtherstill, instability caused by the procedure often necessitates spinal fusion.
After the epidural needle's 2 distal tip has been placed in the posterior epidural space 42, a specially designed epidural catheter 24 is threaded through the needle 2. Once threaded into the epidural space 42, the epidural catheter's unique epidural needle tip cover 36, located in the distal end of the epidural catheter 24 (with needle tip covering capabilities), is opened and pulled back to cover the sharp epidural needle 2 tip, locked in place, and thereby converts the needle to a non-sharp instrument. The needle, thus converted, may be manipulated and advanced more safely in the epidural space. The blunted needle is subsequently advanced in a direction parallel to the dura 46, in a gentle manner, taking care to avoid inadvertent dural, neural or vascular trauma. With reference to
Once the tip of the epidural needle 2 has been blunted or capped, and is no longer sharp, the needle may be move safely advanced within the epidural space, preferably in a direction parallel to the dura 46. In one variation, the epidural needle tip is covered by the catheter based device, then is advanced through the epidural space under image guidance (e.g. fluoroscopy, CT, x-ray, MRI, Ultrasound, etc.), towards the area where tissue resection, ablation or remodeling is to be performed.
In an alternative variation of the method and device, as in
In this apparatus and method for enabling safe manipulation of the apparatus in the epidural space, an epidural needle 2 is first placed in the posterior epidural space 42 in a similar manner to what was described above. With the needle tip in the epidural space 42, an epidural catheter 24 apparatus is used to deliver a cover 36 to the sharp epidural needle tip, converting the needle to a blunt instrument, as shown in
Once the cover 36 in the distal catheter 24 is opened, the catheter 24 is gently pulled back until the needle tip is covered and thereby blunted. The capped needle is next carefully advanced within the epidural space 42, between the ligamentum flavum 10 and the dura 46, somewhat parallel to both, towards one of the neural foramen 110, with much less risk of inadvertent dural puncture. In order to further facilitate safe advancement of the capped needle in the epidural space 42, image guidance may be used. Additionally or alternatively, the epidural needle 2 may be converted to an epidural endoscope. Conversion to an endoscope may be performed by either converting the epidural needle 2 to an endoscope directly (“needlescope”), or by utilizing the epidural needle 2 to enable placement of an endoscope cannula or portal 56, which will replace the needle 2. The needle 2 may be converted to an endoscope directly through use of the catheter 24 that is used to cover, blunt, or “safe” the epidural needle tip. The epidural catheter optionally may contain a rigid or flexible fiberoptic element 38, through which the surgeon may view the epidural space 42, thereby converting the epidural needle 2 into an epidural endoscope. The tip of the fiberoptic catheter 38 would, in such a case, be clear.
In a further variation of the apparatus and method, an epidural portal 56 would allow interchangeable epidural endoscopes to be used to view or work within the epidural space. An epidural needle 2 may be used to place an endoscope portal 56, using one of the three following general approaches: (a) In one variation, a portal is an expandable catheter that is delivered as a catheter through the epidural needle 2; (b) In another preferred embodiment, an epidural needle 2 may be inserted into the epidural space, with a thin walled epidural cannula or portal 56 already in place over it, similar to the method and apparatus of standard intravenous cannulation with IV catheters used today. This technique would ideally be used in conjunction with the epidural needle method and apparatus, so that the needle may be advanced far enough to safely also place the neck of the cannula 56 or portal 56, which is a short distance proximal to the distal tip of the epidural needle 2, into the epidural space. In order be able to safely advance the portal 56 into the epidural space, the needle may be covered or blunted, as described above, using a catheter that does not contain a fiberoptic element, as in
With reference to
In
In order to further facilitate working in the epidural space 42, the epidural portal or cannula may have, preferably close to its distal tip, an anchor system 40 to prevent said apparatus from inadvertently slipping out of the epidural space, as illustrated in
Referring now to
Referring now to
In yet an additional embodiment of the invention (“portal over epidural needle” variation), an epidural portal 56 may be inserted into the epidural space as a catheter over the epidural needle 2 (as in
In one variation, the epidural needle 2, needle based endoscope, flexible or rigid endoscope, or portal 56 (for placement over an epidural needle) may have, preferably close to its distal tip, an (e.g., distal) anchor mechanism 40 that may be inflated or otherwise opened (e.g., in the epidural space), to help prevent inadvertent removal of the device from the epidural space 42. It is expected that utilization of an anchor anterior to, or within, the ligamentum flavum 10, will prevent the portal from being pulled inadvertently through the ligamentum flavum 10, and will enhance the reliability and safety of epidural access for minimally invasive endoscopic surgery.
In one variation, the epidural needle is curved towards its distal end, e.g., into a hockey stick shape. In a curved configuration, the lumen exits the bevel, distal to, and on the concave side of the bend in the needle's distal shaft. With such a configuration, a “safe zone” 44 is created by inserting the needle so that the side opposite the bevel (convex side of the bend) is in direct contact with the dura 46, and the lumen, on the concave side of the bend, faces the ligamentum flavum 10. This configuration provides a “safe zone” 44, where tools, or a working channel 51, may be reliably placed on the needle side opposite the dura 46.
In
Referring now to
In addition to the insertion of tools through the epidural needle, or through an adjacent working channel 50, the same channels may be utilized to insert a barrier 134, or “working backstop” 134 (
The barrier or backstop 134 may be placed percutaneously via a needle 2, endoscope 38, or double barreled needle 84. In addition to epidural endoscopy, image guidance may be combined with the use of straight, curved, or steerable guidewires for the proper placement of the barrier or backstop 134. In an open surgical variation, the barrier or backstop device 134 may be placed through the surgical incision.
The barrier 134 may be synthesized from one of several possible materials, for example, it may be partially fabricated from a spring steel, Nitinol, polymers, or other memory material that will allow a thin, flat barrier to be reconfigured into a more condensed configuration for passage through a straight needle (
As is illustrated in
The patient may be kept awake and responsive throughout this procedure, with no neuraxial anesthetics and no systemic analgesia. In this manner, the medical practitioner may, through verbal questioning, elicit responses from the patient in order to ensure that any severe pain that would accompany undue pressure on the nerve root during placement of the tissue modification device and/or during tissue removal or remodeling is immediately recognized prior to nerve injury. Alternatively, for a deeply sedated patient, or one under general anesthesia, nerve stimulation may be monitored via SSEPs or SEPs; visually (motor movement of extremities); via MEPs; and/or via EMG (motor stimulation). In one embodiment of the device, one might use a calibrated sensor, combined with computer analysis, to accurately quantify neural stimulation at different locations, in order to more accurately localize neural structures.
As is illustrated in
In a preferred variation, impinging spinal tissue is removed using tissue abrasion apparatus and method. Variations of the apparatus and method may be utilized during an open surgical procedure(s); during an endoscopic surgical procedure(s); or via a percutaneous (needle delivered) surgical approach. Use of a needle-based posterior interlaminar or interspinous approach, a posterior-lateral neuroforaminal approach or a minimally-invasive surgical approach for placement of the neuroforaminal abrasive tissue removal device avoids unnecessary tissue resection and minimizes tissue injury. In addition, further embodiments of the device include nerve stimulation and monitoring capabilities, which, when added to a spinal tissue alteration device, may enable the surgeon to more safely perform the procedure.
As discussed previously, variations of the present invention preferably provide for access, neural protection and/or decompression for treatment of spinal stenosis. With reference to
In the second variation (
In
As seen in
With reference to
Access also may be achieved in a percutaneous fashion. For example, access may be achieved via an access element comprising an epidural needle or probe, or via an epidural endoscope having a working channel, that is positioned within the epidural space. In one variation, a curved atraumatic needle or cannula may be advanced through the percutaneous access element and driven laterally to cannulate the neural foramen. A preferably straight, flexible guide wire or needle then may be advanced through the curved needle and driven posteriorly through the skin of the patient's back. In an alternative variation, a curved guide wire may be advanced through the percutaneous access element and passed transforaminally. Percutaneous access optionally may be aided by the use of image guidance, an epidural endoscope or any other visualization technique.
Once the curved element is in position through the neural foramen, the surgeon subsequently passes a smaller gauge straight and sharp flexible guidewire 4 (or needle), as in
As an alternative to deploying cannula 16 through access element 2, the cannula 16 may be delivered over the access element. As yet another alternative, upon placement of the access element in the epidural space, a stiff rod may be advanced through the lumen of the access element, and the access element may be removed. Cannula 16 then may be deployed over the stiff rod, which then may be removed from the lumen of the cannula and replaced with guide wire 4.
As seen in
Studies and tests may be performed to ensure that the transforaminally placed apparatus has been properly positioned between the nerve root 62 or ganglia and the facet joint complex 12. For example, imaging of the abrasion element and spinal anatomy (fluoroscopic or other imaging modalities); monitored neural stimulation through the apparatus; or direct (endoscopic or open) visualization may be utilized.
After proper placement has been confirmed, the curved element 16 that was used to initially cannulate the neural foramen is removed, by pulling it back out of the hub of the epidural needle 2, leaving the transforaminal wire 4 in place, as illustrated in
With the wire in position through the neural foramina, there are multiple possible methods for replacing the wire with the abrasion apparatus. One method is illustrated in
In an alternative preferred embodiment, the abrasive element 14 is positioned within the protective sleeve cover 6, before or after placement of the abrasive element in position through the neural foramina. Please note that the terms “protective sleeve” and “protective cover” are used interchangeably in these descriptions of several examples of the apparatus and methods for protecting vulnerable tissue from the abrasion apparatus. Embodiments of the protective methods and apparatus are illustrated in
Once the abrasion apparatus has been properly positioned through the neural foramina 110, with its protective cover in place 6, it is ready to be tested to ensure it has been properly located. The apparatus may subsequently be utilized for tissue abrasion, tissue removal, and tissue remodeling, as will be described in detail below. Before describing tissue modification in further detail, however, we will describe alternative approaches for placement of the abrasion device into position through the neural foramina. Referring now to
Neural protection element 6 illustratively comprises a sheath having opening or window that is placed across the foramen at the position of desired selective tissue removal. The end regions of neural protection element 6 disposed outside the patient optionally may be attached or clipped together to stabilize the element and free up the medical practitioner's hands.
As illustrated in
In
As an added safety precaution, variations of the present invention optionally may comprise neural localization elements to ensure proper positioning of the access element or guide wire, the neural protection element, and/or the tissue removal device. The neural localization elements may comprise separate elements or may be integrated with the access element, the neural protection element and/or the tissue removal device.
As seen
Neural localization element may be used to ensure that neural structures and adjacent vascular structures are on the non-working or backside of neural protection element 6. Neural localization element on the backside of the sheath (i.e., the side of the sheath that contacts the nerve root when properly positioned) may be activated with a stimulation waveform to stimulate the nerve root, thereby providing a positive control that confirms placement of the backside in proximity to the nerve root. Appropriate low intensity electrical stimulation on the backside surface should result in the stimulation of sensory or motor nerves in the patient's extremity. Likewise, optional neural localization elements on the working side of the sheath (i.e., the side of the sheath that faces impinging tissue slated for removal) may be activated with a stimulation waveform in anticipation of a negative response or no neural stimulation that confirms that the working side is not in contact with the nerve root and that tissue removal may safely proceed. Neural localization elements also may be provided on sides of the sheath 6.
Neural stimulation may be monitored by monitoring somatosensory-evoked potentials (SSEPs), motor-evoked potentials (MEPs), and/or by looking for visual signs of muscular contraction within the extremities. SSEP, SEP, MEP or EMG feedback may be monitored and/or recorded visually, or may be monitored audibly, potentially conveying quantitative feedback related to the volume or frequency of the auditory signal (e.g. a Geiger counter-type of quantitative auditory feedback). Intensity of signal or stimulation may be monitored and used to localize the nerve during placement of neural protection element, as well.
Neural localization may be enabled further by the addition of surgical instruments (e.g. cautery devices, graspers, shavers, burrs, probes, etc.) that are able to selectively stimulate electrically while monitoring nerve stimulation in similar fashions. Quantification of stimulation may enable neural localization. For instance, one might use a calibrated sensor input that recognizes stronger stimulation as the device is moved closer to neural structures. For added safety, tissue removal device 114 may be designed to automatically stimulate before or during tissue removal, and may even be designed to automatically stop tissue removal when nerve stimulation has been sensed.
With reference to
This variation of the apparatus and method, as seen in
With reference to
Irrigation optionally may be provided through element 20 via irrigation lumen 324 of member 20. Suction optionally may be provided through element 20 via suction lumen 326 of member 20. Suction and/or irrigation may be provided intermittently or continuously, as desired by the medical practitioner.
Referring now to
In
In an open surgical variation, the abrasive element 14 and its cover 6 may be placed through the surgical incision, from a interlaminar, translaminar, or neuroforaminal approach. Visualization and placement may be aided via partial or complete laminectomy, facetectomy, or ligamentectomy. Methods for threading the neural foramina include, but are not limited to the use of a wire, blunt needle, probe, endoscope, or suture. After spinal neuroforaminal placement, the abrasion device 14 is used to selectively remove tissues that impinge on the neurovascular structures within the lateral recess 108 and neural foramen 110, on the anterior side of the facet joint 12. In an open approach, as with a percutaneous approach, the device may be inserted through a needle, optionally under image guidance or with the aid of an epidural endoscope. Once placed through the neural foramina 110 of the spine, around the anterior border of the facet joint 12, and anterior to the ligamentum flavum 10, the medical practitioner may enlarge the lateral recess and neural foramina via frictional abrasion, i.e., by sliding the abrasive surface across the tissue to be resected (e.g., far lateral ligamentum flavum, anterior and medial facet, osteophytes). The abrasion device alternatively or additionally may be placed through the neural foramen 110 anterior to the facet joint 12, but through or posterior to the ligamentum flavum 10. The medical practitioner controls the force and speed of the abrasive surface against the tissue to be removed, while optional protective covers, tubes or sleeves 6 help limit the area exposed to the abrasive element for treatment.
Referring now to
In order to reduce a risk of neurological damage during selective tissue removal, variations of the present invention optionally may provide neural protection during tissue removal. In one variation, a neural protection element, such as a sheath, shield or backstop, is positioned such that the neural protection element separates impinging tissue in the neural foramen from the underlying nerve root. Tissue removal then may proceed by advancing a tissue removal device into position between the foramen and the neural protection element. When access to the stenosed region is via an open surgical procedure, it may be possible for the medical practitioner to manually place the neural protection element. Alternatively, when using either an open or a percutaneous access, the neural protection element may by advanced over, or pulled into place by, an access guide wire placed as described previously.
Alternatively, the two wires 4a and 4b may be opposite ends of the same continuous wire, with the cover 6 for the abrasive element 14 already placed over the mid-portion of the wire 4. Alternatively, the abrasive element 14 may already have been placed inside said cover 6, and attached at each end to the wires 4a and 4b.
A nerve stimulator may be incorporated into the abrasive surface of the abrasive element, and/or incorporated into the protective cover or sheath for the abrasive element, in order to verify correct placement and enhance safety by allowing the medical practitioner to ensure that neural tissue is not subject to inadvertent abrasion.
The stimulation apparatus 114 delivers a small electrical current through the working surface and/or the non-working surface (backside) of either the tools used in the epidural space, the abrasive element 14, and/or the protective cover 6 of the abrasive element. Preferably, one electrode 120 would be connected to each side (abrasive and non-abrasive) of the entire device and sheath complex, along the full distance where tissue abrasion is planned to occur, in the lateral recess, central canal, or neural foramen. Neural stimulation may be monitored via verbal response to stimulation in an awake or lightly sedated patient, or SSEP, MEP, EMG, or motor evoked muscular movement in an asleep or sedated patient. One possible mechanism for avoiding inadvertent neural damage may be to ensure that there is no neural stimulation when stimulating the working surface of the device. A positive control should be obtainable in the lateral recess and neural foramen, when stimulating the non working surface (back side) of the device or, preferably, the backside of the device cover or sheath 6 (e.g., first portion of locking mechanism).
After the abrasion element, and possibly its protective sheath or cover 6, have been placed through the neural foramina 110 the abrasive surface is brought into firm contact with the tissue to be abraded by pulling tension simultaneously on each end of the abrasion element. When both ends of the abrasive element 14 are pulled simultaneously, the abrasive surface of the device is brought under tension and into firm contact with the impinging spinal tissue on the anterior and medial sides of the facet joint complex. Subsequently, one end of the abrasive element is pulled more forcefully than the other, sliding the abrasive surface is across the target tissue. When one end of the abrasive element is pulled with more force than the other, the ribbon moves in the direction of the stronger pull, while the lesser pull on the opposite end maintains force and creates friction with movement between the abrasive surface and the tissue to be resected. When the optional protective cover 6 or sheath is provided, both of its ends of the are, in one variation, pulled under traction and anchored in place, such that the abrasive element 14 may be pulled in either or both directions through the cover 6 or sheath without significant friction against and/or without causing trauma to adjacent tissues.
Alternatively, the abrasive element 14 may be pulled in a single direction across the tissue. The abrasive belt, strap or ribbon may be a single length, pulled alternately in each direction, or it may be dispensed from a spool, as in
In one variation of the invention, a tissue retention or compression dressing (
As in
An additional embodiment of the method and apparatus may combine both the working backstop 134 and the compression element 150, as illustrated in
Most of the safety issues related to the methods and apparatus described herein are similar to those associated with any surgical procedure, e.g., infection and/or bleeding. Some safety issues are more specific to surgery in and around the spine or spinal cord, and are therefore given special consideration below. These generally relate to spinal nerve injury. Morbidity could result from instruments inadvertently passed through the dura mater, and creating a cerebrospinal fluid leak and/or damaging the cauda equina (caudal to T12-L1) or spinal cord (cephalad to T12-L1) when entering the epidural space. Potentially traumatized structures further include nerve roots, adjacent vasculature, or dorsal root ganglia.
Referring now to
As shown, the abrasion element may, for example, be structured as a thin belt or ribbon 14, with an abrasive and/or cutting surface on one of its sides. The abrasive element 14 may exist in a variety of shapes, ranging from flat to curved; from narrow to wide; and from a solid to perforated. The abrasive surface of the abrasive element 14 may, in one variation, contain deep grooves 118 or perforations for the transport of debris away from the operative site. Alternatively, the pattern of abrasive may be designed to control the direction and speed of movement of the surface across the tissue to be abraded (e.g. deep grooves, at a diagonal to the edge of the straps, may be used to facilitate lateral movement of the abrasive element). The width and shape of the abrasive elements may also be varied, in further effort to control the area of tissue to be resected. Finally, in one preferred variation, the surgeon would begin with a coarser grade of abrasive material, in order to gain more aggressive tissue removal. Sequential use of less and less aggressive surfaces would serve to smooth the abraded tissue surface, with the aim of creating an atraumatic surface for contact with neurovascular structures.
Placement of a tissue abrasion device 14 through protective sleeve(s) 6 and into position for selective tissue removal, brings the abrasive surface 14 into contact with the tissue to be removed. A medical practitioner may remove tissue in contact with abrasive surface (
a-90c illustrate additional mechanical variations of tissue removal elements.
With reference to
Window 204 limits exposure of tissue removal surface of tissue removal device 14 only to the localized region of the patient's tissue where selective tissue removal is desired. As seen in the cross-sectional view of
Neural protection element 6 preferably comprises an atraumatic profile to reduce tissue injury during placement and retrieval. For example, the element may comprise rounded edges 82, as seen in
As seen in
As seen in
With reference again to
In another variation of tissue removal device, tissue removal elements 304 comprises one or more electrosurgery elements for tissue removal/ablation. The electrosurgery elements additionally or alternatively may be utilized to achieve hemostasis and/or to facilitate neural localization. Monopolar or bipolar RF elements may, for example, be utilized and may be activated with a thermal or substantially non-thermal waveform.
Referring now to
The medical practitioner may move support 400 laterally while drawing or reciprocating the wire saw across tissue in order to enlarge a width of the region in which tissue is removed. Support 400 may limit a depth of cutting during such lateral expansion of the cut area. When the lateral expansion exceeds the width of support 400, cutting to greater depth may be performed as desired. The width of the area of tissue removal alternatively or additionally may be enlarged or expanded by utilizing multiple wire saws 410, as seen in
With reference to
Referring to
Any other tissue removal elements 304 may be utilized with any of the variations of tissue removal device 300, including, but not limited to, lasers, which may comprise one or more optical fibers for delivering a laser beam, high-pressure fluids, thermal elements, radioactive elements, etc. It should be understood that various tissue removal elements may be used in any combination, as desired.
In one variation, device 300 may be reciprocated, either manually or under power, to cut, abrade or otherwise remove tissue.
In another variation, device 300 may be pulled in a single direction, either manually or under power, to remove tissue.
Tissue removal device 300 may be tapered, such that the width of the device increases as it is wound between the reels to provide for a gradual decompression. The device optionally may comprise measuring elements 316, such as sensors or progressively larger sounds, for determining the effectiveness of decompression, thereby providing the medical practitioner with an indicator for when the reels may be advanced. Tissue removal surface 302 optionally may comprise section 316 that contacts the tissue surface after selective tissue removal for delivery of bone wax, hemostatic agents such as thrombin, antiproliferative agents, steroids, non-steroidal anti-inflammatory drugs, or any other therapeutic agent.
In one variation, the device includes a compression dressing as illustrated in the percutaneous embodiment described above in
The neuroforaminal compression dressing may, in one preferred embodiment, comprise the optional protective sheath, percutaneously held tightly in place against the abraded surface, after the abrasive apparatus has been removed from its lumen, for a period of time. Alternatively or additionally, a separate percutaneously removable compression dressing may be placed following tissue abrasion. The abrasive material may be followed by a length of compression dressing material on the same reel or spool, or a subsequent reel or spool. Alternatively, a compression dressing may be delivered through the neural foramen as a separate element. The compression element may also be used to deliver medications or other bioactive components (e.g. steroid, biodegradable adhesion barriers, etc.), to the surgical site. The compression dressing material may be, in one variation, partially or completely biodegradable. An entirely biodegradable compression dressing may be placed tightly against the abraded surface, and left completely implanted following the procedure.
Whether placing the apparatus with an epidural needle 2; through the working channel of an epidural needle 50; with an epidural endoscope; or during an open surgical procedure; image guidance may be used to facilitate safe and accurate placement. If the epidural needle 2 has been replaced by, or converted to, an endoscope, direct visualization of the epidural space 42 may be accomplished. In this case, as illustrated in
Referring now to
The needle 464 can have multiple barrels or lumen, for example a first lumen and a second lumen (not shown). The first lumen can extend distally of the second lumen. The first lumen and/or the second lumen can terminate in open or closed configurations at the needle tip 466.
The user can visualize the epidural space 42, for example, via a fiber optic element (not shown). The fiber optic element can be covered by a clear distal tip. The fiber optic element can be deployed to the epidural space 42 integral with, or separate from but within, the catheter 24. The fiber optic element can be deployed to the epidural space 42 integral with, or separate from but within, the needle 464. The fiber optic element can be deployed to the epidural space 42 via a working space adjacent the needle 464. The user can deploy an epidural endoscope, for example, to visualize the epidural space 42 including the lateral recess 108 and neural foramen 110.
An access element (not shown) that can have a cannulated probe such as a cannulated ball-tipped probe, Woodson elevator, or Hockey Stick hybrid, can be placed into the epidural space 42. A curved element, such as an atraumatic needle, can then be advanced through the cannula of the probe and into the neural foramen 110. The curved element can cannulate the neural foramen 110.
The tissue protection barrier can be deployed into the lateral recess 108 and/or the neural foramen 110. The tissue protection barrier 528 can be deployed between the tissue to be removed, for example the impinging tissue 424, and the tissue to be protected, for example, the dura mater 46 and associated neural (e.g., spinal cord, nerve roots, dorsal root ganglion) and neurovascular structures. The tissue protection barrier 528 can have contracted and expanded configurations. During deployment, the tissue protection barrier 528 can be in the contracted or expanded configurations. The tissue protection barrier 528 can be separate from, or integral with, the catheter 24 and/or needle 464. The tissue protection barrier 528 in a contracted configuration can be slidably attached to the catheter 24 and/or the needle 464.
The tissue protection barrier 528 can have an atraumatic profile. The tissue protection barrier 528 can have rounded edges. The tissue protection barrier 528 can be a catheter, curved or straight needle, curved or straight shield, sheath, backstop, stent, net, screen, mesh or weave, panel, fan, coil, plate, balloon, accordioning panels, or combinations thereof. The tissue protection barrier 528 can have a tapered configuration.
The tissue protection barrier 528 can have a front side (i.e., working side) and a back side (i.e., neural protection side). The front side 456 can be electrically isolated from the back side 428. The front side 456 can have an electrically conductive surface. The back side 428 can have an electrically conductive surface. The neural stimulation and localization device 114 can be in electrical communication with the front side 456 and/or the back side 428.
Neural stimulation can be monitored via spinal somatosensory-evoked potentials (SSEPs), motor-evoked potentials (MEPs), and/or by looking for visual signs of muscular contraction within the extremities. SSEP, SEP, MEP or electromyogram (EMG) feedback can be monitored and/or recorded visually, and/or can be monitored audibly, potentially conveying quantitative feedback related to the volume or frequency of the auditory signal (e.g. a quantitative auditory feedback). Intensity of signal or stimulation can be monitored and used to localize the nerve during placement.
The neural stimulation and localization device 114 can deliver electrical current to the front side 462. If there is a nervous system response, the tissue protection barrier 528 can be retracted and redeployed with the front side and the back side switched. The neural stimulation and localization device 114 can then deliver electrical current to the front side 456 again and the tissue protection barrier 528 can be readjusted and redeployed until there is no nervous system response from delivering electrical current to the front side 456.
The neural stimulation and localization device 114 can deliver electrical current to the back side 428. If there is no nervous system response, the tissue protection barrier 528 can be retracted and redeployed with the front side and the back side switched. The neural stimulation and localization device 114 can then deliver electrical current to the back side 428 again and the tissue protection barrier 528 can be redeployed and readjusted until there is a nervous system response from delivering electrical current to the back side 428.
The neural stimulation and localization device 114 can deliver electrical current to the back side 428 and the front side 456 and the tissue protection barrier 528 can be readjusted and redeployed until there is a nervous system response from delivering electrical current to the back side 428 and no nervous system response from the front side 456.
The user can deploy to the neural foramen 110 and/or the lateral recess 108 one or more surgical stimulating and monitoring instruments (e.g., cautery devices, graspers, shavers, burrs, probes, combinations thereof) that can selectively stimulate electrically while monitoring nerve stimulation. The surgical can quantify the stimulation to localize the neural tissue (e.g., dura mater, spinal cord, spinal root, dorsal root ganglion). For instance, the user can use a calibrated sensor input that recognizes stronger stimulation as the device is moved closer to neural structures.
A spring can be inside the tissue protection barrier 528. The tissue protection barrier can be the spring, for example when the tissue protection barrier 528 is or has a self-expandable stent or mesh. The spring can be releasably fixed in a compressed state when the tissue protection barrier 528 is in the contracted configuration. When released, the spring can expand the tissue protection barrier 528. The spring can be released by a trigger mechanism.
The expansion of the tissue protection barrier 528 can apply a non-damaging pressure to the nerve branches 62. The tissue protection barrier 528 can have a window 536. The window 536 can be open in the contracted and/or expanded configuration of the tissue protection barrier 528.
The tissue removal device 300 can have an energy delivery system (not shown). The energy delivery system can be configured to deliver one or more energies to tissue adjacent to the energy delivery system. The energies can be configured to ablate, vaporize, break up, combinations thereof, or otherwise change the modulus of the tissue. The tissue removal device 300 can be configured to deliver electrical, ultrasound, thermal, microwave, laser, cryo (i.e., removing thermal energy), or combinations thereof.
The tissue removal device 300 can have one or more electrosurgery elements (not shown). The electrosurgery elements can be configured to remove and/or ablate tissue. The electrosurgery elements can achieve hemostasis and/or neural localization in tissue adjacent to the electrosurgery elements. The electrosurgery elements can have monopolar or bipolar RF elements. The RF elements can be activated with a thermal or substantially non-thermal waveform.
The tissue removal device 300 can have or be lasers, high-pressure fluid, thermal elements, radioactive elements, textile electric conductors, conductive wire loops and/or needles configured to be used in tissue contact (e.g., needle ablation), springs, open and/or spring wire weaves, conductive polymers that can have conductive metals chemically deposited thereon, or combinations thereof.
The tissue removal device 300 can be designed to automatically stimulate the site of tissue removal, or have the neural stimulation and localization device 114 stimulate the site of tissue removal, before or during tissue removal. The tissue removal device 300 can be configured to automatically stop tissue removal when nerve stimulation is sensed by the front side 456, and/or no nerve stimulation is sensed by the back side 428.
An external activating force, for example as shown by arrow 530 (activating tissue removal) on a handle, can activate the tissue removal device 300, as shown by arrow 530 (tissue removal device operating). The mechanical tissue removal elements can be used in combination or not in combination with the energy delivery device. The mechanical tissue removal elements can be pushed into and/or drawn across the impinging tissue 424 to remove the tissue by cutting, shaving, slicing, scissoring, guillotining, scraping, tearing, abrading, debriding, poking, mutilating, or combinations thereof. The mechanical tissue removal elements (e.g., blades) can be drawn across the impinging tissue 424 in a single direction and/or can be reciprocated. The mechanical tissue removal elements can be manually controlled and/or electronically, pneumatically or hydraulically powered. The mechanical tissue removal elements can be embedded with abrasives and/or have abrasive coatings, such as a diamond or oxide coating.
The blades can have various shapes, sizes and configurations. The blades can coact, for example, in a guillotine-type or scissor-type cutting action. The blades can be attached to or integral with the tissue removal device. The blades can be formed by grinding, punching or stamping through the tissue removal device. The blades can be formed by grinding of a punched or stamped edge of the tissue removal device. The blades can be formed by a chemical etching process. The blades can have a 3-dimensional profile to facilitate cutting, for example, a bow or a corrugation or a ‘cheese grater’ profile. The blades can be placed at one or more angles relative to the direction of tissue removal. The blades can be configured with the blade cutting across the tissue (i.e., similar to a band saw). The blades can have cutting surfaces. The cutting surfaces can be oriented in a single or multiple directions. The blades can be serrated.
The saw can be a wire saw or saws. The wire saw can be a Gigli saw: Multiple wire saws or Gigli saws can be joined or woven together or flattened to form a substantially planar cutting surface. The wire saw can be mounted on a flat ribbon. The ribbon can be a depth stop, for example, limiting for saw penetration.
The tissue removal device 300 can have one or more powered mechanical tissue removal elements. The powered mechanical tissue removal elements can have, for example, band saws, belt shavers, rotary burrs or blades, reciprocating burrs or blades, or combinations thereof.
Devices and elements known to those having ordinary skill in the art can be used to remove debris from, and/or irrigate, and/or provide suction to, the epidural space 42 including the lateral recess 108 and neural foramen 110 and/or to the tissue removal device itself. The devices and elements for removing debris can be integral with the needle 464 and/or the catheter 24. Debris removal, and/or suction and/or irrigation may be provided intermittently or continuously, as desired by the medical practitioner. Debris removal can include suction and/or irrigation. The tissue removal device 300 can capture debris. Irrigation and/or suction in the tissue removal device 300 can remove the debris from the tissue removal device 300, for example by the debris exiting along the needle 464 and/or catheter 24.
The tissue removal device 300 can have an energy delivery system, such as including the neural stimulation and localization device 114 and the needlette tips. The energy delivery system can be configured to deliver one or more energies to tissue adjacent to the energy delivery system. The energies can be configured to ablate, vaporize, break up, combinations thereof, or otherwise change the modulus of the tissue. The tissue removal device 300, for example via the needlette tips 474, can be configured to deliver electrical, ultrasound, thermal, microwave, laser, cryo (i.e., removing thermal energy), or combinations thereof, energy 44.
The tissue removal device 300 can have one or more electrosurgery elements, for example the needlette tips 474. The electrosurgery elements can be configured to remove and/or ablate tissue. The electrosurgery elements can achieve hemostasis and/or neural localization in tissue adjacent to the electrosurgery elements. The electrosurgery elements can have monopolar or bipolar RF elements. The RF elements can be activated with a thermal or substantially non-thermal waveform.
The tissue removal device 300, for example at the needlette tips 474, can have or be lasers, high-pressure fluid, thermal elements, radioactive elements, textile electric conductors, conductive wire loops and/or needles configured to be used in tissue contact (e.g., needle ablation), springs, open and/or spring wire weaves, conductive polymers that can have conductive metals chemically deposited thereon, or combinations thereof.
The tissue protection barrier 528 (and/or tissue removal device 300) can have needlette conduits 470. The needlettes can be slidably attached to needlette conduits 470. The needlette 468 can be solid. The needlette 468 can be hollow. The needlette 468 can have a conducting wire (not shown) extending therethrough. The needlette tips 474 can be sharp or dull.
The second needlette tips 474 can be configured to deploy in a second deployment direction. The first deployment direction can form a deployment angle with respect to the second deployment direction. The first deployment direction and the second deployment direction can configured to fixedly attach the first and second needlette tips to the impinging tissue 424. The deployment angle can be from about 90 degrees to about 270 degrees, more narrowly from about 90 degrees to about 180 degrees, for example about 120 degrees (as shown in
The tissue removal device 300, for example the energy delivery system, can transmit an energy 44 to the tissue to be removed, for example, the impinging tissue 424. The energy 44 can alter the compression, denaturation, electrosurgical exposure, thermal remodeling (hot or cold), chemical alteration, epoxy or glues or hydrogels, modulus of elasticity, or any combination thereof of the impinging tissue 424. For example, the modulus of elasticity of soft impinging tissue 424 can be increased. An increased modulus of elasticity can improve purchase on the soft impinging tissue 424 with the tissue removal device 300. Remodeling of the tissue during modulus alteration can alleviate impingement and obviate or reduce a need for tissue removal.
The tissue removal device 300 can be designed to automatically stimulate the site of tissue removal, or have the neural stimulation and localization device 114 stimulate the site of tissue removal, before or during tissue removal. The tissue removal device 300 can be configured to automatically stop tissue removal when nerve stimulation is sensed by the front side 456, and/or no nerve stimulation is sensed by the back side 428.
The working surface 538 can have one or more non-powered mechanical tissue removal elements. The non-powered mechanical tissue removal elements can be abrasives such as abrasive belts or ribbons, cutting elements such as blades, knives, scissors or saws, rongeurs, grinders, files, debriders, scrapers, graters, forks, picks, burrs, rasps, shavers, or combinations thereof.
The mechanical tissue removal elements can be used in combination or not in combination with the energy delivery device. The mechanical tissue removal elements can be pushed into and/or drawn across the impinging tissue 424 to remove the tissue by cutting, shaving, slicing, scissoring, guillotining, scraping, tearing, abrading, debriding, poking, mutilating, or combinations thereof. The mechanical tissue removal elements (e.g., blades) can be drawn across the impinging tissue 424 in a single direction and/or can be reciprocated. The mechanical tissue removal elements can be manually controlled and/or electronically, pneumatically or hydraulically powered. The mechanical tissue removal elements can be embedded with abrasives and/or have abrasive coatings, such as a diamond or oxide coating.
The blades can have various shapes, sizes and configurations. The blades can coact, for example, in a guillotine-type or scissor-type cutting action. The blades can be attached to or integral with the tissue removal device. The blades can be formed by grinding, punching or stamping through the tissue removal device. The blades can be formed by grinding of a punched or stamped edge of the tissue removal device. The blades can be formed by a chemical etching process. The blades can have a 3-dimensional profile to facilitate cutting, for example, a bow or a corrugation or a ‘cheese grater’ profile. The blades can be placed at one or more angles relative to the direction of tissue removal. The blades can be configured with the blade cutting across the tissue (i.e., similar to a band saw). The blades can have cutting surfaces. The cutting surfaces can be oriented in a single or multiple directions. The blades can be serrated.
The saw can be a wire saw or saws. The wire saw can be a Gigli saw. Multiple wire saws or Gigli saws can be joined or woven together or flattened to form a substantially planar cutting surface. The wire saw can be mounted on a flat ribbon. The ribbon can be a depth stop, for example, limiting for saw penetration.
The tissue removal device 300 can have one or more powered mechanical tissue removal elements. The powered mechanical tissue removal elements can have, for example, band saws, belt shavers, rotary burrs or blades, reciprocating burrs or blades, or combinations thereof.
Devices and elements known to those having ordinary skill in the art can be used to remove debris from, and/or irrigate, and/or provide suction to, the epidural space 42 including the lateral recess 108 and neural foramen 110 and/or to the tissue removal device itself. The devices and elements for removing debris can be integral with the needle 464 and/or the catheter 24. Debris removal, and/or suction and/or irrigation may be provided intermittently or continuously, as desired by the medical practitioner. Debris removal can include suction and/or irrigation. The tissue removal device 300 can capture debris. Irrigation and/or suction in the tissue removal device 300 can remove the debris from the tissue removal device 300, for example by the debris exiting along the needle 464 and/or catheter 24.
The tissue protection barrier 528 can have a tissue protection barrier test strength. The tissue protection barrier test strength can be equal to or less than about 890 N (200 lbs.), more narrowly equal to or less than about 710 (160 lbs.), yet more narrowly equal to or less than about 350 N (80 lbs.), for example about 180 N (40 lbs.).
The tissue protection barrier 528 can have a taper 516 at a first end. The taper 516 can be configured to dissect tissue, for example, during deployment. The taper 516 can be configured to bluntly dissect tissue, for example, during deployment. The taper 516 can be configured to be atraumatic, for example, not being able to substantially dissect tissue during deployment. The taper 516 can be configured to interference fit the tissue removal device 300.
During use, the distal wire 440 and/or the taper 516 can be deployed posteriorly exiting the skin. During use, the distal wire 440 and/or the taper 516 can be deployed posteriorly around or through the spine, exiting the spine and deploying substantially to the site at which the needle and/or tissue protection barrier entered. The distal wire 440 and/or the taper 516 can be secured to a substantially fixed location (e.g., the skin, the spine, the user's hand). Additional force can be applied, for example, posteriorly on the tissue protection barrier (e.g., on the first end, and/or a second end). The tissue protection barrier 528 can be forced into the impinging tissue 424.
The distal anchor lock 438 can be integral with, or fixedly attached to, the taper 516. The distal anchor lock 438 can extend from the taper 516. The distal anchor lock 438 can have a test strength. The test strength can be equal to or less than about 890 N (200 lbs.), more narrowly equal to or less than about 710 (160 lbs.), yet more narrowly equal to or less than about 350 N (80 lbs.), for example about 180 N (40 lbs.).
The distal wire 440 can be integral with, or fixedly attached to, the tissue removal device 300 (not shown in
The tissue protection barrier 528 can have one or more wires and no tapers 540. The wires can extend from be integral with, or fixedly attached to, and/or extend from non-tapered ends.
The springs 512 can be in electrical communication with a circuit, for example the neural stimulation and localization device. The circuit can have a ground 116, a power source 480, and a switch 514. The power source 480 can have a frequency range from about 100 kHz to about 10 MHz. The springs 512 can be grounded at one or more points. The circuit can create a monopolar spring 512. The base 430 can electrically insulate the spring 512 and the remainder of the tissue removal device 300 (e.g., a ribbon). The circuit can be closed during use.
The spring 512 can have various configurations to alter the cutting performance. For example, the spring can have a circular configuration.
The springs 512 can emit low level voltage prior to tissue removal, for example, to check for nerve stimulation.
The impedance between the first spring 512 and the second spring 512 can be monitored. For example, if the impedance exceeds threshold values (e.g., the impedance of burning tissue), the circuit can be configured to open.
The tissue protection barrier, and/or the access elements, and/or the neural protection element and/or the tissue removal device can have a lubricious coating, for example, a hydrophilic coating, a poly(tetrafluoroethylene) coating. The coating can reduce friction during placement, diagnosis, treatment and/or removal. The tissue removal device, the access elements and/or the neural protection element can by biocompatible and/or non-friable.
Any of the elements and/or entire apparatuses described herein can be made from, for example, a single or multiple stainless steel alloys, nickel titanium alloys (e.g., Nitinol), cobalt-chrome alloys (e.g., ELGILOY® from Elgin Specialty Metals, Elgin, Ill.; CONICHROME® from Carpenter Metals Corp., Wyomissing, Pa.), molybdenum alloys (e.g., molybdenum TZM alloy, for example as disclosed in International Pub. No. WO 03/082363 A2, published Oct. 9, 2003, which is herein incorporated by reference in its entirety), tungsten-rhenium alloys, for example, as disclosed in International Pub. No. WO 03/082363, polymers such as polyester (e.g., DACRON® from E. I. Du Pont de Nemours and Company, Wilmington, Del.), carbon fiber composites (e.g., carbon fiber nylon composite, such as carbon fiber reinforced nylon 66), polypropylene, polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), polyether ether ketone (PEEK), nylon, polyether-block co-polyamide polymers (e.g., PEBAX® from ATOFINA, Paris, France), aliphatic polyether polyurethanes (e.g., TECOFLEX® from Thermedics Polymer Products, Wilmington, Mass.), polyvinyl chloride (PVC), polyurethane, thermoplastic, fluorinated ethylene propylene (FEP), absorbable or resorbable polymers such as polyglycolic acid (PGA), polylactic acid (PLA), polydioxanone, and pseudo-polyamino tyrosine-based acids, extruded collagen, silicone, zinc, echogenic, radioactive, radiopaque materials or combinations thereof. Examples of radiopaque materials are barium sulfate, zinc oxide, titanium, stainless steel, nickel-titanium alloys, tantalum and gold.
Any of the elements and/or entire apparatuses described herein can be or have a matrix for cell ingrowth or used with a fabric, for example a covering (not shown) that acts as a matrix for cell ingrowth. The matrix and/or fabric can be, for example, polyester (e.g., DACRON® from E. I. du Pont de Nemours and Company, Wilmington, Del.), polypropylene, PTFE, ePTFE, nylon, extruded collagen, silicone or combinations thereof.
Any of the elements and/or entire apparatuses described herein can be filled and/or coated with an agent delivery matrix known to one having ordinary skill in the art and/or a therapeutic and/or diagnostic agent. The agents within these matrices can include radioactive materials; radiopaque materials; cytogenic agents; cytotoxic agents; cytostatic agents; thrombogenic agents, for example polyurethane, cellulose acetate polymer mixed with bismuth trioxide, and ethylene vinyl alcohol; lubricious, hydrophilic materials; phosphor cholene; anti-inflammatory agents, for example non-steroidal anti-inflammatories (NSAIDs) such as cyclooxygenase-1 (COX-1) inhibitors (e.g., acetylsalicylic acid, for example ASPIRINS® from Bayer AG, Leverkusen, Germany; ibuprofen, for example ADVIL® from Wyeth, Collegeville, Pa.; indomethacin; mefenamic acid), COX-2 inhibitors (e.g., VIOXX® from Merck & Co., Inc., Whitehouse Station, N.J.; CELEBREX® from Pharmacia Corp., Peapack, N.J.; COX-1 inhibitors); immunosuppressive agents, for example Sirolimus (RAPAMUNE®, from Wyeth, Collegeville, Pa.), or matrix metalloproteinase (MMP) inhibitors (e.g., tetracycline and tetracycline derivatives) that act early within the pathways of an inflammatory response. Examples of other agents are provided in Walton et al, Inhibition of Prostoglandin E2 Synthesis in Abdominal Aortic Aneurysms, Circulation, Jul. 6, 1999, 48-54; Tambiah et al, Provocation of Experimental Aortic Inflammation Mediators and Chlamydia Pneumoniae, Brit. J. Surgery 88 (7), 935-940; Franklin et al, Uptake of Tetracycline by Aortic Aneurysm Wall and Its Effect on Inflammation and Proteolysis, Brit. J. Surgery 86 (6), 771-775; Xu et al, SpI Increases Expression of Cyclooxygenase-2 in Hypoxic Vascular Endothelium, J. Biological Chemistry 275 (32) 24583-24589; and Pyo et al, Targeted Gene Disruption of Matrix Metalloproteinase-9 (Gelatinase B) Suppresses Development of Experimental Abdominal Aortic Aneurysms, J. Clinical Investigation 105 (11), 1641-1649 which are all incorporated by reference in their entireties.
Many of the safety issues related to the methods and apparatus described herein are similar to those associated with any surgical procedure, e.g., infection and/or bleeding. Some safety issues are more specific to surgery in and around the spine or spinal cord, and are therefore given special consideration below. These generally relate to spinal neural and neurovascular injury. Central Nervous System injury could result from instruments inadvertently traumatizing the dura mater when entering the epidural space, injuring the nerve root (s), the adjacent vasculature, or the dorsal root ganglion as the apparatus is advanced and utilized towards and through the neural foramen.
Several techniques may be used to reduce a risk of dural, neural or neurovascular injury, including potentially traumatizing structures including nerve roots, adjacent vasculature, or dorsal root ganglia. For example, the tissue alteration (e.g., abrasion) devices may be placed under direct visualization when utilizing an open surgical approach or technique. Likewise, image guidance may be provided during placement or to confirm correct placement. Candidate image guidance techniques include fluoroscopy, fluoroscopy alone, fluoroscopy with additional technology for triangulation and tracking of instruments (e.g. infrared, RF, etc.), NRI, CT, OCT, ultrasound, etc. Catheters or guidewires may include their own image guidance capabilities such as catheter or guidewire-based image guidance, e.g., fiberoptic visualization, catheter-based ultrasound, catheter-based MRI, optical tomography, etc. Alternatively or additionally, endoscopic visualization may be utilized (e.g. flexible fiberoptic endoscope as in Epiduroscope, or via rigid surgical endoscopes), during placement and/or post-placement confirmation of correct placement.
In addition to epidural endoscopy, image guidance may be combined with the use of straight, curved, or steerable guidewires for the proper placement of the neuroforaminal abrasive element. Placement may be achieved percutaneously or through a surgical incision. Such a device may be implanted as an adjunct to an open surgical procedure(s); as an adjunct to an endoscopic surgical procedure(s); or as a separate open, image-guided percutaneous or endoscopic surgical procedure. Percutaneous approaches will enable the surgeon to perform the procedure under local anesthetic in awake or sedated patients, if desired. As discussed, nerve stimulation and localization capabilities may be added to the device in order to enable the surgeon to more safely perform the procedure in an anesthetized, but un-paralyzed patient.
It is expected that the apparatus and methods of the present invention will facilitate a minimally invasive approach to the selective elimination (e.g., alteration, ablation, removal) of pathological spinal tissue, thereby enabling symptomatic relief in patients suffering from spinal stenosis. Spinal neural and neurovascular impingement cause tremendous pain and disability, with symptoms that include back and leg pain, weakness, and decreased sensation. Neural ischemia and injury caused by compression and inflammation may result in a wide range of symptoms or degrees of nerve damage. Symptoms range in severity from mild to severe, and from intermittent to permanent. For example, neurogenic claudication, which is exacerbated by back extension (as occurs when one stands erect and places the spine in extension), may be mild or severe. Symptoms of neurogenic claudication are usually improved by changes in posture that lead to back flexion, such as sitting. The most severe cases of spinal stenosis may lead to permanent neurological damage, including the possibility of the development of cauda equina syndrome.
Spine surgeons lack safe and effective techniques or tools to minimally invasively or percutaneously reduce neural and neurovascular impingement in the spine, while minimizing collateral tissue damage. It is expected that the apparatus and methods of the present invention may be utilized for lateral recess and neuroforaminal enlargement to provide adequate bone and soft tissue resection, while reducing unnecessary destruction of functional bone, ligament or muscle in order to gain access to the tissues to be resected.
Spine surgeons lack safe and effective techniques or tools to minimally invasively or percutaneously reduce neural and neurovascular impingement in the spine, while minimizing collateral tissue damage. It is expected that the apparatus and methods of the present invention may be utilized to provide adequate bone and soft tissue resection to achieve lateral recess, neuroforaminal, and spinal canal enlargement, while reducing unnecessary destruction of flnctional bone, ligament or muscle in gaining access to the tissues to be modified.
Because critical neural and neurovascular structures are in close proximity to the areas where surgical manipulation, dissection, resection, ablation and remodeling would be therapeutically valuable in the spine, safety at each step in the procedure is of critical importance in order to avoid disabling neurological damage to the patient. For this reason, safety measures, such as working barriers and nerve localization via an integrated nerve stimulator, are described.
It may be desirable to alter an elastic modulus of impinging tissue to facilitate removal of the tissue. For example, it may be desirable to increase the modulus of soft tissue to gain purchase on the soft tissue with the tissue removal elements. Such modulus alteration may be achieved, for example, through compression, denaturation, electrosurgical exposure, thermal remodeling (hot or cold), chemical alteration, epoxy or glues or hydrogels, or any combination thereof, etc. Remodeling of the tissue during modulus alteration may alleviate impingement and obviate or reduce a need for tissue removal.
In order to reduce friction during placement, diagnosis, treatment and/or removal, the open or percutaneous access elements, neural protection element 200 and/or tissue removal device 300 may comprise a lubricious coating, for example, a hydrophilic coating, a poly(tetrafluoroethylene) coating, etc. Furthermore, the tissue removal device, the access elements and/or the neural protection element may by biocompatible and/or non-friable. Integrated or separate debris removal elements also may be provided.
It is expected that the apparatus and methods of the present invention will facilitate selective elimination of pathological spinal tissue, thereby enabling symptomatic relief in patients suffering from spinal stenosis.
Spine surgeons presently lack safe and effective techniques or tools to minimally invasively or percutaneously reduce neural and neurovascular impingement in the spine, while minimizing collateral tissue damage. It is expected that the apparatus and methods of the present invention may be utilized for lateral recess and neuroforaminal enlargement to provide adequate bone and soft tissue resection, while reducing unnecessary destruction of functional bone, ligament or muscle in order to gain access to the tissues to be resected.
Because critical neural and neurovascular structures are in close proximity to the areas where surgical manipulation, dissection and remodeling would be therapeutically valuable in the spine, safety at each step in the procedure is of critical importance in order to avoid disabling neurological damage to the patient. For this reason, safety measures, such as neural protection element 200 and neural localization element 210, may be provided.
It will be apparent to those skilled in the art that various changes and modifications can be made thereto. For example, elements of any of the described variations may be used in any combination, as desired. Furthermore, the apparatus described herein may be used for a variety of selective tissue removal procedures in addition to neural foraminal tissue impingement. For example, the apparatus may be used for treatment of central spinal stenosis. Further, the methods and apparatus described hereinafter are equally applicable to both open and percutaneous approaches. For the purpose of clarity, they have been disclosed utilizing only a percutaneous or open access, but this shall not be construed as limiting.
Although preferred illustrative embodiments of the present invention are described hereinabove, it will be apparent to those skilled in the art that various changes and modifications may be made thereto without departing from the invention. It is intended in the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the invention.
This application claims the benefit of U.S. Provisional Application No. 60/619,306, filed Oct. 15, 2004, U.S. application Ser. No. 60/622,865, filed Oct. 28, 2004, U.S. application Ser. No. 60/681,719, filed May 16, 2005, U.S. application Ser. No. 60/681,864, filed May 16, 2005, and U.S. application Ser. No. 60/685,190, filed May 27, 2005, each of which is incorporated by reference herein in its entirety.
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