Patent Application
20080103504
The present invention relates generally to medical/surgical devices and methods. More specifically, the present invention relates to devices and methods for spinal stenosis treatment.
In recent years, less invasive (or “minimally invasive”) surgical techniques have become increasingly more popular, as physicians, patients and medical device innovators have sought to reduce the trauma, recovery time and side effects typically associated with conventional surgery. Developing less invasive surgical methods and devices, however, poses many challenges. For example, less invasive techniques typically involve working in a smaller operating field, working with smaller devices, and trying to operate with reduced or even no direct visualization of the structures being treated. These challenges are often compounded when target tissues of a given procedure reside very close to one or more vital, non-target tissues.
One area of surgery which would likely benefit from the development of less invasive techniques is the treatment of spinal stenosis. Spinal stenosis occurs when nerve tissue and/or the blood vessels supplying nerve tissue in the spine become impinged by one or more structures the lower (or lumbar) spine and can cause severe pain, numbness and/or loss of function in the lower back and/or one or both lower limb.
In the United States, spinal stenosis occurs with an incidence of between 4% and 6% of adults aged 50 and older and is the most frequent reason cited for back surgery in patients aged 60 and older. Patients suffering from spinal stenosis are typically first treated with conservative approaches such as exercise therapy, analgesics, anti-inflammatory medications, and epidural steroid injections. When these conservative treatment options fail and symptoms are severe, as is frequently the case, surgery may be required to remove impinging tissue and decompress the impinged nerve tissue.
Lumbar spinal stenosis surgery involves first making an incision in the back and stripping muscles and supporting structures away from the spine to expose the posterior aspect of the vertebral column. Thickened ligamentum flavum is then exposed by complete or partial removal of the bony arch (lamina) covering the back of the spinal canal (laminectomy or laminotomy). In addition, the surgery often includes partial or complete facetectomy (removal of all or part of one or more facet joints), to remove impinging ligamentum flavum or bone tissue. Spinal stenosis surgery is performed under general anesthesia, and patients are usually admitted to the hospital for five to seven days after surgery, with full recovery from surgery requiring between six weeks and three months. Many patients need extended therapy at a rehabilitation facility to regain enough mobility to live independently.
Removal of vertebral bone, as occurs in laminectomy and facetectomy, often leaves the effected area of the spine very unstable, leading to a need for an additional highly invasive fusion procedure that puts extra demands on the patient's vertebrae and limits the patient's ability to move. Unfortunately, a surgical spine fusion results in a loss of ability to move the fused section of the back, diminishing the patient's range of motion and causing stress on the discs and facet joints of adjacent vertebral segments. Such stress on adjacent vertebrae often leads to further dysfunction of the spine, back pain, lower leg weakness or pain, and/or other symptoms. Furthermore, using current surgical techniques, gaining sufficient access to the spine to perform a laminectomy, facetectomy and spinal fusion requires dissecting through a wide incision on the back and typically causes extensive muscle damage, leading to significant post-operative pain and lengthy rehabilitation. Thus, while laminectomy, facetectomy, and spinal fusion frequently improve symptoms of neural and neurovascular impingement in the short term, these procedures are highly invasive, diminish spinal function, drastically disrupt normal anatomy, and increase long-term morbidity above levels seen in untreated patients.
Therefore, it would be desirable to provide less invasive surgical methods and devices for treating spinal stenosis. For example, it would be desirable to method and device for removing impinging tissue from a spine percutaneously, or at least with a minimally invasive incision, while maintaining safety and preventing damage to non-target tissues. At least some of these objectives will be met by the present invention.
In one aspect of the present invention, a method for percutaneously removing ligamentum flavum tissue in a spine to treat spinal stenosis may involve: percutaneously advancing a distal portion of a tissue removal cannula into the ligamentum flavum tissue; uncovering a side-opening aperture disposed on the distal portion of the cannula to expose a tissue cutter disposed in the cannula; and cutting ligamentum flavum tissue using the tissue cutter while the aperture is uncovered. In some embodiments, uncovering the aperture may involve retracting an inner cannula through the tissue removal cannula. Cutting ligamentum flavum tissue may involve cutting tissue using a tissue cutter selected from the group consisting of blades, abrasive surfaces, files, rasps, saws, planes, electrosurgical devices, bipolar electrodes, monopolar electrodes, thermal electrodes, cold ablation devices, rotary powered mechanical shavers, reciprocating powered mechanical shavers, powered mechanical burrs, lasers, ultrasound devices, cryogenic devices, and water jet devices.
In some embodiments, the ligamentum flavum tissue may be cut using a radiofrequency device, and the method further involves, before the uncovering step, activating the radiofrequency device. In some embodiments, the method may include, before the uncovering step: articulating the distal portion of the cannula relative to the proximal portion; and advancing the articulated distal portion at least partway into an intervertebral foramen of the spine. In some embodiment, the method may further involve extending the cutter out of the aperture before the cutting step.
Optionally, the method may include removing the cut ligamentum flavum tissue through the cannula. In some embodiments, removing the cut tissue comprises applying suction to the cannula. In some embodiments, removing the cut tissue includes: engaging the cut tissue with the tissue cutter or a separate tissue engaging member; and retracting the tissue cutter or tissue engaging member through the cannula. Some embodiments may further involve introducing a substance through the side-facing aperture of the cannula, the substance selected from the group consisting of a hemostatic agent, an analgesic, an anesthetic and a steroid.
Optionally, some embodiments of the method may include, before the cutting step: activating a nerve stimulator coupled with the distal portion of the cannula; and monitoring for response to the activation. Some embodiments of the method may also include deploying a shield between the cannula and non-target tissue before the cutting step. In one embodiment, the method may also include, before the cutting step: activating a nerve stimulator coupled with the shield; and monitoring for response to the activation.
In another aspect of the present invention, a method for percutaneously removing ligamentum flavum tissue in a spine to treat spinal stenosis may involve: percutaneously advancing a distal portion of a tissue removal cannula into the ligamentum flavum tissue; activating at least a first nerve stimulator coupled with the distal portion of the cannula; monitoring for response to the activation; uncovering a side-opening aperture disposed on the distal portion of the cannula to expose a tissue engaging member disposed in the cannula; engaging ligamentum flavum tissue with the tissue engaging member; and cutting ligamentum flavum tissue with a tissue cutter disposed in or on the cannula.
In some embodiments, the method may include, before the uncovering step: activating at least a second nerve stimulator coupled with the distal portion of the cannula apart from the first nerve stimulator; monitoring for response to activation; and comparing an amount of activation required to illicit a response using the first nerve stimulator with an amount of activation required to illicit a response using the second nerve stimulator. In some embodiments, cutting the ligamentum flavum tissue may involve advancing an inner cannula having a sharp distal end and disposed around the tissue engaging member and within the tissue removal cannula.
In another aspect of the present invention, a method for percutaneously removing ligamentum flavum tissue in a spine to treat spinal stenosis may involve: coupling a flexible distal portion of a tissue removal cannula with one end of a guidewire; pulling the flexible distal portion into the ligamentum flavum tissue by pulling the guidewire; uncovering a side-opening aperture disposed on the distal portion of the cannula to expose a tissue cutter disposed in the cannula; and cutting ligamentum flavum tissue using the tissue cutter.
In some embodiments, the method may further include applying tensioning force to the tissue removal cannula and the guidewire, before the cutting step, to urge the aperture against the ligamentum flavum tissue. The method may optionally further involve, before the cutting step: activating a nerve stimulator coupled with the distal portion of the cannula; and monitoring for response to the activation. In some embodiments, the method may also include deploying a shield between the cannula and non-target tissue before the cutting step. Optionally, the method may include, before the cutting step: activating a nerve stimulator coupled with the shield; and monitoring for response to the activation.
In another aspect of the present invention, a method for percutaneously removing ligamentum flavum tissue in a spine to treat spinal stenosis may involve: percutaneously advancing a distal portion of a tissue removal device into at least one of an epidural space or a ligamentum flavum of the spine; activating an energy delivery member disposed on or in the distal portion of the tissue removal device; and cutting ligamentum flavum tissue with the activated energy delivery member.
In some embodiments, advancing the distal portion may involve pulling the distal portion behind a guidewire. In some embodiments, the distal portion may be advanced at least partway into an intervertebral foramen of the spine. In some embodiments, the distal portion of the tissue removal device may be flexible. In some embodiments, a proximal portion extending proximally from the distal portion of the tissue removal device may be flexible. In some embodiments, activating the energy delivery member may involve activating a member selected from the group consisting of electrosurgical devices, bipolar electrodes, monopolar electrodes, thermal electrodes, cold ablation devices, lasers, ultrasound devices and cryogenic devices. In some embodiments, cutting the tissue involves retracting the energy delivery member through tissue. In some embodiments, cutting the tissue may involve advancing the energy delivery member through tissue. Some embodiments may further involve extending the energy delivery member out of the tissue removal device before the cutting step. Some embodiments may further involve removing the cut ligamentum flavum tissue through a lumen in the tissue removal device. In some embodiments, removing the cut tissue may involve applying suction to the tissue removal device. In some embodiments, removing the cut tissue may involve: engaging the cut tissue with the energy delivery member or a separate tissue engaging member; and retracting the energy delivery member or tissue engaging member through the tissue removal device.
Some embodiments may further involve introducing a substance through an aperture in the tissue removal device, the substance selected from the group consisting of a hemostatic agent, an analgesic, an anesthetic and a steroid. Some embodiments may involve, before the cutting step: activating at least a first nerve stimulator coupled with the distal portion of the tissue removal device; and monitoring for response to the activation. Some embodiments may involve, before the cutting step: activating at least a second nerve stimulator coupled with the distal portion of the tissue removal device apart from the first nerve stimulator; monitoring for response to activation; and comparing an amount of activation required to illicit a response using the first nerve stimulator with an amount of activation required to illicit a response using the second nerve stimulator. Optionally, the method may also involve automatically deactivating the energy delivery member if the response to activation by the nerve stimulator(s) indicates that the energy delivery member is in contact with or near nerve tissue. The method may also include repeating the activating and monitoring steps during the cutting step; and repeating the automatic deactivating step whenever the response to activation indicates that the energy delivery member is in contact with or near nerve tissue. In one embodiment, the method may include deploying a shield between the cannula and non-target tissue before the cutting step. Such a method may also include, before the cutting step: activating at least a first nerve stimulator coupled with the shield; and monitoring for response to the activation. Such a method may also include, before the cutting step: activating at least a second nerve stimulator coupled with the shield apart from the first nerve stimulator; monitoring for response to activation; and comparing an amount of activation required to illicit a response using the first nerve stimulator with an amount of activation required to illicit a response using the second nerve stimulator. In some embodiments, the method also may include automatically deactivating the energy delivery member if the response to activation by the nerve stimulator(s) indicates that the energy delivery member is in contact with or near nerve tissue. In one embodiment, the method may also include: repeating the activating and monitoring steps during the cutting step; and repeating the automatic deactivating step whenever the response to activation indicates that the energy delivery member is in contact with or near nerve tissue.
In another aspect of the present invention, a device for percutaneously removing ligamentum flavum tissue in a spine to treat spinal stenosis may include: a cannula having a proximal end, a tissue-penetrating distal end, and a side-facing aperture closer to the distal end than the proximal end; an aperture cover slidably coupled with the cannula and configured to advance and retract to cover and uncover the aperture; and a tissue cutter slidably disposed within the cannula and configured to extend through the aperture to cut ligamentum flavum tissue. In some embodiments, the aperture cover may comprise an inner cannula slidably disposed in the tissue removal cannula. In some embodiments, a distal portion of the cannula may be articulatable relative to a proximal portion of the cannula.
In various embodiments, the tissue cutter may be selected from the group consisting of blades, abrasive surfaces, files, rasps, saws, planes, electrosurgical devices, bipolar electrodes, monopolar electrodes, thermal electrodes, cold ablation devices, rotary powered mechanical shavers, reciprocating powered mechanical shavers, powered mechanical burrs, lasers, ultrasound devices, cryogenic devices, and water jet devices. In some embodiments, the tissue cutter may be configured to extend out of the aperture. In some embodiments, the tissue cutter may be configured to engage cut ligamentum flavum tissue and to be retracted through the cannula to remove the engaged tissue.
Optionally, the device may also include a suction connector for coupling the proximal end of the cannula with a suction device for removing cut tissue through the cannula. Also optionally, the device may include at least a first nerve stimulator coupled with the cannula at or near the aperture. Such a device may also include at least a second nerve stimulator coupled with the cannula, where the first nerve stimulator is disposed generally on the same side of the cannula as the aperture and the second nerve stimulator is disposed between about 90 degrees and about 180 degrees away from the first stimulator along a circumference of the cannula. Some embodiments may also include a shield coupled with the cannula for preventing the cutter from contacting non-target tissue.
In another aspect of the present invention, a device for percutaneously removing ligamentum flavum tissue in a spine to treat spinal stenosis may include: a cannula having a proximal end, a tissue-penetrating distal end, and a side-facing aperture closer to the distal end than the proximal end; a tissue-engaging member disposed within the cannula and adapted to engage tissue via the aperture; an aperture cover slidably coupled with the cannula and configured to advance and retract to cover and uncover the aperture, the cover having a sharp, tissue cutting edge to cut tissue engaged by the tissue-engaging member; and a nerve stimulation member coupled with the cannula adjacent or near the aperture. In some embodiments, a distal portion of the cannula may be articulatable relative to a proximal portion of the cannula. In various embodiments, the tissue-engaging member is selected from the group consisting of needles, hooks, blades, teeth and barbs. The tissue-engaging member may be slidably disposed within the cannula such that it can be retracted through the cannula to remove cut tissue from the cannula.
The aperture cover may comprise an inner cannula slidably disposed in the outer cannula. Optionally, the device may include a suction connector for coupling the proximal end of the cannula with a suction device for removing cut tissue through the cannula. Some embodiments may also include at least a second nerve stimulator coupled with the cannula apart from the first nerve stimulator. The device may further include a shield coupled with the cannula for preventing the cutter from contacting non-target tissue. The device may optionally further include a nerve stimulator coupled with the shield.
In another aspect of the present invention, a device for percutaneously removing ligamentum flavum tissue in a spine to treat spinal stenosis may include: an elongate body having a proximal portion, a flexible distal portion, and a side-facing aperture disposed on the distal portion, wherein the distal portion is configured to be passed percutaneously into at least one of an epidural space or a ligamentum flavum of the spine; and an energy delivery member disposed within the elongate body and configured to extend through the aperture to cut ligamentum flavum tissue. In some embodiments, the proximal portion of the body may be at least partially flexible. Alternatively, the proximal portion of the body may be rigid. In some embodiments, the distal portion of the body may be configured to be passed at least partway into an intervertebral foramen of the spine.
The device may further include a guidewire coupling member disposed on the distal portion of the elongate body for pulling the distal portion into the spine. In some embodiments, the energy delivery member may be selected from the group consisting of electrosurgical devices, bipolar electrodes, monopolar electrodes, thermal electrodes, cold ablation devices, lasers, ultrasound devices and cryogenic devices. In some embodiments, the energy delivery member may be slidably disposed within the elongate body and is configured to be advanced through the aperture. In one embodiment, the energy delivery member may comprise a wire loop electrode. In some embodiments, the elongate body may further include a lumen through which cut ligamentum flavum tissue may be removed.
Some embodiments may further include a suction device couplable with the elongate body for removing the cut ligamentum flavum tissue through the lumen. Some embodiments may further include an irrigation device couplable with the elongate body for passing fluid through the lumen. Some embodiments may further include a substance disposed in the lumen for delivery through the aperture, where the substance may be selected from the group consisting of a hemostatic agent, an analgesic, an anesthetic and a steroid.
The device may optionally include at least a first nerve stimulator coupled with the distal portion of the elongate body. In some embodiments, the device may also include at least a second nerve stimulator coupled with the distal portion of the elongate body apart from the first nerve stimulator. The device may also include means for detecting stimulation of a nerve. The device may also include means for automatically deactivating the energy delivery member if the means for detecting stimulation indicates that the energy delivery member is in contact with or near nerve tissue.
In some embodiments, the device may include a shield coupled with the elongate body for preventing the energy delivery member from contacting non-target tissue. In some embodiments, the device may include at least a first nerve stimulator coupled with the shield. The device may also include at least a second nerve stimulator coupled with the shield apart from the first nerve stimulator. Optionally, the device may include means for detecting stimulation of a nerve. The device may also include means for automatically deactivating the energy delivery member if the means for detecting indicates that the energy delivery member is in contact with or near nerve tissue.
In another aspect of the present invention, a system for percutaneously removing ligamentum flavum tissue in a spine to treat spinal stenosis may include: a tissue removal device, comprising: an elongate body having a proximal portion, a flexible distal portion, and a side-facing aperture disposed on the distal portion, wherein the distal portion is configured to be passed percutaneously into at least one of an epidural space or a ligamentum flavum of the spine; and an energy delivery member disposed within the elongate body and configured to extend through the aperture to cut ligamentum flavum tissue; and an energy source removably couplable with the tissue removal device for supplying energy to the energy delivery member. The tissue removal device may include any of the features and configurations described above.
Optionally, the system may also include a guidewire configured to couple with the guidewire coupling member. The system may further include a handle removably couplable with the guidewire for pulling the guidewire from outside a patient. In some embodiments, the energy delivery member may be selected, for example, from the group consisting of electrosurgical devices, bipolar electrodes, monopolar electrodes, thermal electrodes, cold ablation devices, lasers, ultrasound devices and cryogenic devices. In some embodiments, the energy source may be selected from the group consisting of a radiofrequency device, a heating device, a cooling device, a cryogenic device, a laser and an ultrasound generator.
The system may optionally further include a suction device for removing the cut ligamentum flavum tissue through the lumen. The system may optionally include an irrigation device for passing fluid through the lumen. The system may further include a substance disposed in the lumen of the tissue removal device for delivery through the aperture, wherein the substance is selected from the group consisting of a hemostatic agent, an analgesic, an anesthetic and a steroid.
The system may further include one or more nerve stimulation members, such as those described above. Optionally, the system may include means for detecting stimulation of a nerve. In some embodiments, the system may automatically deactivate the tissue removal device when nerve stimulation is detected. In some embodiments, nerve stimulators may be powered by the energy source, and means for detecting stimulation and the means for automatically deactivating the energy delivery member are coupled with the energy source.
These and other aspects and embodiments are described more fully below in the Detailed Description, with reference to the attached Drawings.
Referring to
In one embodiment, referring to
With distal tip 13 located in ligamentum flavum tissue, and referring now to
To confirm placement of distal tip 13 in ligamentum flavum (LF), any suitable technique may be used. For example, in some embodiments all or part of shaft 12 and distal tip 13 may be radiopaque, and a physician may view the location of shaft 12 and distal tip 13 via fluoroscopy. In some embodiments, cutting member 22 may also serve as a nerve stimulation member. In such embodiments, when cutting member 22 is extended into tissue, it may be activated, such as by transmitting RF energy, and the patient may be monitored for a response to the stimulation. For example, if cutting member 22 were accidentally placed into a nerve or nerve root, rather than ligamentum flavum (LF), activating cutting member 22 with a stimulating current would typically cause a response in the nerve, seen as a muscle twitch and/or detectable using a monitoring technique, such as electromyography (EMG). If cutting member 22 were in contact with a nerve, the physician might withdraw cutting member 22 and device 10 and reposition distal tip 13.
Once cutting member 22 is extended into ligamentum flavum (LF) tissue, energy, such as RF energy, may be transmitted to cutting member 22 via power source 18, and cutting member 22 may be moved through the tissue (hollow-tipped arrow), such as by sliding second actuator 16 along shaft 12. In some embodiments, as shown, cutting member 22 may be retracted, while in others it may be advanced, rotated, reciprocated or moved in any of a number of suitable ways to cut tissue.
As seen in
After ligamentum flavum (LF) tissue on one side of the vertebra is removed, device 10 may be repositioned to remove similar tissue on the opposite side. As shown in
Referring now to
As best seen in
Cutting member 31 may comprise a wire loop RF electrode of a shape-memory or super-elastic material, such that when cover 38 is retracted to open window 36, the looped portion of cutting member 31 automatically extends out of window 36. Cutting member 31 may then be retracted, using second actuator 35, to cut tissue. Cutting member 31 may extend through shaft 32 (dotted lines) and exit proximally, for connection to an external power source (not shown), which may comprise any suitable RF source or other power source in alternative embodiments. In some embodiments, cutting member 31 and return electrode 31′ may form a bipolar electrosurgical cutting device, such that RF energy transmitted from a power source through cutting member 31 and thus through tissue is returned through device 30 via return electrode 31′. In an alternative embodiment, cutting member 31 may comprise a monopolar electrosurgical device, in which case a return electrode may be placed separately on a patient. Due to the proximity of nervous tissues, it may be advantageous to use bipolar electrosurgical devices in spinal procedures, although it may also be possible to use monopolar devices.
In an alternative embodiment, window 36 may be replaced with one or more small apertures, and first actuator 33 may be configured to extend cutting member 31 out of shaft 32 through such apertures and retract cutting member 31 back into shaft 32 after use. In such an embodiment, second actuator 35 may be used to move cutting member 31 back and forth longitudinally, relative to shaft 32, to cause cutting member 31 to cut tissue. In another alternative embodiment, cutting member 31 may be advanced out of one or more apertures on shaft 32, and shaft 32 may be retracted and/or advanced to move cutting member 31 through tissue and thus cut the tissue.
Cutting member 31 may comprise any suitable RF electrode, such as those commonly used and known in the electrosurgical arts. Any of a number of different ranges of radio frequency may be applied to cutting member 31, according to various embodiments. For example, some embodiments may use RF energy in a range of between about 70 hertz and about 5 megahertz. In some embodiments, the power range for RF energy may be between about 0.5 Watts and about 200 Watts. Additionally, in various embodiments, RF current may be delivered directly into conductive tissue or may be delivered to a conductive medium, such as saline or Lactate Ringers solution, which may in some embodiments be heated or vaporized or converted to plasma that in turn modifies target tissue. Similarly, cutting member 31 may be powered by an internal or external RF generator. Any suitable generators may be used, such as those commonly available at the present time and any generators invented hereafter. Examples of external generators that may be used include, but are not limited to, those provided by ValleyLabs (a division of Tyco Healthcare Group, LP (Pembroke, Bermuda and Princeton, N.J.)), Gyrus Medical, Inc. (Maple Grove, Minn.), and the high-frequency generators provided by Ellman International, Inc. (Oceanside, N.Y.).
In various embodiments, many of which are described in further detail below, cutting member 31 may comprise one or more devices and may have any of a number of configurations, sizes, shapes and the like. In other words, although energy such as RF energy may be applied to a bipolar loop electrode cutting member 31, as shown in
Referring now to
Once the distal portion of device 30 is positioned in ligamentum flavum tissue 33, which may be confirmed, for example, by fluoroscopy, cover 38 may be retracted to open window 36, as in
Cutting member 31 may then be activated, with current returning proximally through return electrode 31′. (In an alternative embodiment, cutting member 31 may be activated while window 36 is closed by cover 38, so that cutting member 31 is activated before it contacts tissue 33.) As in
In some embodiments, with one or more pieces of cut tissue 33′ in lumen 39, cover 38 may be advanced to close window 36, as in
As shown in
Referring now to
As shown in
As shown in
Referring to
In alternative embodiments, a blade may be advanced rather than retracted, two blades may be moved toward one another, or other configurations of blades may be used. In some embodiments, energy (such as RF energy) may be transmitted to blade 49, to enhance tissue cutting. A number of different embodiments of bladed tissue cutting devices, any of which may be used percutaneously in various embodiments of the present invention, are described in U.S. patent application Ser. No. 11/405,848 (Original Attorney Docket No. 78117-200101), entitled “Mechanical Tissue Modificatino Devices and Methods,” and filed on Apr. 17, 2006, the full disclosure of which is hereby incorporated by reference.
Referring now to
During percutaneous insertion of device 52 into ligamentum flavum tissue 66, inner shaft 60 may be in an advanced position to close window 58. In some embodiments, window 58 may be visible under external imaging guidance, such as fluoroscopy, to facilitate orienting window 58 away from the epidural space of the spine and thus protect non-target structures from injury during the surgical procedure. In other embodiments, an endoscopic visualization device may be coupled with device 52 to facilitate internal imaging. Examples of such visualization devices include, but are not limited to, flexible fiber optic scopes, CCD (charge-coupled device) or CMOS (complementary metal-oxide semiconductor) chips at the distal end of flexible probes, LED illumination, fibers or transmission of an external light source for illumination, and the like.
Once a distal portion of device 52 is positioned in the ligamentum flavum or other tissue removal site, nerve stimulating energy may be transmitted through first electrode 68 or second electrode 69, and the patient may be monitored for a nerve response. If a nerve response is detected, it may be determined that device 52 is too close to nervous tissue to safely perform a procedure, and device 52 may be repositioned in tissue 66. Optionally, the other electrode, which was not already activated, may be activated to see if it stimulates nervous tissue. Alternative embodiments may include only one electrode or more than two electrodes. In any case, based on the stimulation or lack of stimulation of nerve tissue by one or both electrodes 68, 69, it may be determined that device 52 is in a safe location for performing a tissue removal procedure. Various methods and apparatus for stimulating electrodes and monitoring for response are described in U.S. patent application Ser. No. 11/429,377 (Attorney Docket No. 026445-000724US), entitled “Spinal Access and Neural Localization,” and filed Jul. 13, 2006, the full disclosure of which is hereby incorporated by reference.
With the distal portion of device 52 positioned in a desired location in ligamentum flavum tissue 66, inner shaft 60 may be retracted/slid proximally so that it no longer closes window 58, as shown in
Referring to
Referring to
In various embodiments, device 52 may have one or more additional features, some of which are described in greater detail below. For example, in some embodiments, the distal portion of device 52 may be articulatable relative to a proximal portion of device 52, to facilitate passage of the distal portion into or through curved passages or channels, such as an intervertebral foramen. In another embodiment, the distal portion of device 52 may be flexible and/or curved, again to facilitate passage at least partway into an intervertebral foramen. In either an articulatable or a flexible embodiment, device 52 may optionally also include a guidewire coupling member for attaching device 52 with a guidewire. Such a guidewire may be used to pull device 52 into place and apply force to device 52 to urge barbs 62 into tissue 66. Examples of various guidewire mechanisms are described in greater detail in U.S. patent application Ser. Nos. 11/468,247 and 11/468,252 (Attorney Docket Nos. 026445-001000US and 026445-001100US, respectively), both of which are entitled “Tissue Access Guidewire System and Method, and both of which were filed on Aug. 29, 2006, the full disclosures of which are hereby incorporated by reference. In an alternative embodiment, device 52 may include a guidewire lumen or track over so that device 52 may be passed into the spine over a guidewire. Some of these optional features are described in greater detail below.
Referring now to
Referring to
Referring now to
Any of a number of suitable powered tissue removal devices may be used percutaneously to remove ligamentum flavum tissue and/or bone in the spine to treat neural impingement, neurovascular impingement and/or spinal stenosis. Examples of various alternative powered tissue removal devices are provided in U.S. patent application Ser. No. 11/406,486 (Original Attorney Docket No. 78117-200501), entitled “Powered Tissue Modification Devices and Methods,” and filed Apr. 17, 2006, the full disclosure of which is hereby incorporated by reference. Other powered devices which may be used percutaneously are described in U.S. patent application Ser. Nos. 11/468,247 and 11/468,252, both of which were previously incorporated by reference.
Referring now to
In various alternative embodiments, device 70 may be percutaneously advanced into a patient to advance distal portion 73 in ligamentum flavum tissue, between ligamentum flavum tissue and bone, and between ligamentum flavum tissue and nervous tissue. Flexible distal portion 73 may allow or facilitate passage of at least part of distal portion 73 into an intervertebral foramen (IF) of the spine. Cutting member 82 and the various other features of device 70 may be similar to any of those described in reference to alternative embodiments above.
Referring now to
Referring now to
As seen in
In some embodiments, cutting member 122 may be caused to extend out of window 115, expand, retract, translate and/or the like. Some embodiments may optionally include a second actuator (not shown), such as a foot switch for activating an RF generator to delivery RF current to an electrode.
Insulators 126 may be disposed around a portion of wire loop cutting member 122 so that only a desired portion of cutting member 122 may transfer RF current into target tissue. Cutting member 122, covered with insulators 126 may extend proximally into support tubes 124. In various alternative embodiments, cutting member 122 may be bipolar or monopolar. For example, as shown in
In one embodiment, cutting member 122 may be housed within distal portion 113 during delivery of distal portion 113 into a patient, and then caused to extend up out of window 115, relative to the rest of distal portion 113, to remove tissue. Cutting member 122 may also be flexible so that it may pop or bow up out of window 115 and may deflect when it encounters hard tissue surfaces. Cutting member 122 may have any of a number of shapes, such as curved, flat, spiral or ridged. Cutting member 122 may have a diameter similar to the width of distal portion 113, while in alternative embodiments it may expand when extended out of window 115 to have a smaller or larger diameter than that of distal portion 113. Pull wires (not shown) may be retracted proximally, in a manner similar to that described above, in order to collapse cutting member 122, decrease the diameter and lower the profile of the cutting member 122, and/or pull cutting member 122 proximally to remove tissue or be housed within distal portion 113. The low profile of the collapsed cutting member 122 facilitates insertion and removal of distal portion 113 into and out of a patient prior to and after tissue modification. As the cutting member 122 diameter is reduced, support tubes 124 deflect toward the center of distal portion 113.
In an alternative embodiment (not shown), tissue modification device 110 may include multiple RF wire loops or other RF members. In another embodiment, device 110 may include one or more blades as well as an RF wire loop. In such an embodiment, the wire loop may be used to remove or otherwise modify soft tissues, such as ligamentum flavum, or to provide hemostasis, and blades may be used to modify hard tissues, such as bone. In other embodiments, as described further below, two separate tissue modification devices 110 (or more than two devices) may be used in one procedure to modify different types of tissue, enhance modification of one type of tissue or the like.
In other alternative embodiments, tissue modification devices 110 may include tissue modifying members such as a rongeur, a curette, a scalpel, a scissors, a forceps, a probe, a rasp, a file, an abrasive element, one or more small planes, a rotary powered mechanical shaver, a reciprocating powered mechanical shaver, a powered mechanical burr, a laser, an ultrasound crystal a cryogenic probe, a pressurized water jet, a drug dispensing element, a needle, a needle electrode, or some combination thereof. In some embodiments, for example, it may be advantageous to have one or more tissue modifying members that stabilize target tissue, such as by grasping the tissue or using tissue restraints such as barbs, hooks, compressive members or the like. In one embodiment, soft tissue may be stabilized by applying a contained, low-temperature substance (for example, in the cryo-range of temperatures) that hardens the tissue, thus facilitating resection of the tissue by a blade, rasp or other device. In another embodiment, one or more stiffening substances or members may be applied to tissue, such as bioabsorbable rods. In various embodiments, energy such as RF energy may be transmitted to any or all such tissue modification members, such as an RF transmitting blade or the like.
Referring now to
In some embodiments, tissue cutter device 210 may be advanced percutaneously into a patient's back by coupling guidewire connector 230 with guidewire 232 that has been advanced between target and non-target tissues, and then pulling guidewire 232 to pull device 210 between the tissues. In alternative embodiments, device 210 may be advanced over guidewire 232, such as via a guidewire lumen or track. The flexibility of distal shaft portion 213 may facilitate passage of device 210 between tissues in hard-to-reach or tortuous areas of the body, such as between a nerve root (NR) and facet joint and through an intervertebral foramen (IF). Generally, device 210 may be advanced to a position such that blades 226 face tissue to be cut in a tissue removal procedure (“target tissue”) and one or more non-cutting surfaces of device 210 face non-target tissue, such as nerve and/or neurovascular tissue. In the embodiment shown in
Before or after tissue cutter device 210 is pulled into the patient to pull blades 226 to a desired position, guidewire 232 may be removably coupled with distal handle 234, such as by passing guidewire 232 through a central bore in handle 234 and tightening handle 234 around guidewire 232 via a tightening lever 236. Proximal handle 216 and distal handle 234 may then be pulled (hollow-tipped arrows) to apply tensioning force to device 210 and thus to urge the cutting portion of device 210 (e.g., blades 226) against ligamentum flavum (LF), superior articular process (SAP), and/or other tissue to be cut. Proximal handle 216 may then be actuated, such as by squeezing in the embodiment shown, which advances the flexible wires and proximal blade 226, to cut tissue between blades 226. Proximal handle 216 may be released and squeezed as many times as desired to remove a desired amount of tissue. When a desired amount of tissue has been cut, guidewire 232 may be released from distal handle 234, and cutter device 210 and guidewire 232 may be removed from the patient's back.
In various alternative embodiments of the method just described, device 210 may be positioned with at least part of distal shaft portion 213 located in ligamentum flavum tissue or above ligamentum flavum in contact with bone. In the latter example, device 210 may be use to cut bone while leaving the ligamentum flavum largely or entirely intact. Again, for further description of various mechanical tissue modification devices, any of which may be used percutaneously, reference may be made to U.S. patent application Ser. No. 11/535,000, which was previously incorporated by reference.
Referring now to
Tissue access device 306 may include, for example, a proximal handle 307 having a hollow bore 308 and an actuator 309, a hollow shaft 310 extending from proximal handle 307 and having a distal curved portion and a distal window 312, and a guidewire coupling member 314 coupled with a tapered distal end of shaft 310. Any of a number of different tissue modification devices 316, 317, 320 may be inserted and removed from access device 306 to perform a tissue modification procedure, such as a rongeur 316, an ultrasound device 317 (including a wire 318 and generator 319), and an abrasive device 320. Handle 307 and actuator 309 may be used to activate one or more tissue modifying members of various tissue modification devices. For example, rongeur 316 may be advanced into hollow bore 308 and shaft 310, to position blades 321 of rongeur 316 so as to be exposed through window 312, and to lock a locking member 315 of rongeur 316 within handle 307. Actuator 309 may then be moved back and forth (by squeezing and releasing, in the embodiment shown) to move one or both blades 321 back and forth to cut target tissue. Optionally, rongeur 316 may then be removed from access device 306 and a different modification device 317, 320 inserted to further modify target tissue. Actuator 309 may be used with some modification devices and not others. Again, in some embodiments, access device 306, guidewire system 240 and one or more modification devices 316, 317, 320 may be provided as a system or kit.
Referring now to
In various embodiments, barrier 500 may be configured as one piece of super-elastic or shape-memory material, as a scaffold with material draped between the scaffolding, as a series of expandable wires or tubes, as a semicircular stent-like device, as one or more expandable balloons or bladders, as a fan or spring-loaded device, or as any of a number of different devices configured to expand upon release from delivery device 514 to protect tissue. As shown in
In an alternative embodiment, as shown in
Introducer device 514 may comprise any suitable catheter, introducer, sheath or other device for delivering one or more barrier devices into a patient. In various alternative embodiments, barrier devices may be delivered into a patient either through a delivery device, over one or more guide members, behind one or more guidewires, or some combination thereof. In various embodiments, introducer device 514 may have any suitable dimensions, profile or configuration. For example, in various embodiments, introducer device 514 may have a circular cross-sectional shape, an oval cross-sectional shape, or a shape that varies between circular and oval along the length of device 514. In some embodiments, an outer diameter of introducer device 514 or delivery device 601 may range from about 0.025″ to about 1.0″, with a wall thickness range of about 0.001″ to about 0.125″. Optionally, introducer device 514 may taper along its length. Introducer device 514 may be rigid, partially flexible or flexible along its entire length and may be made from any suitable material, such as but not limited to: a metal, such as stainless steel (303, 304, 316, 316L), nickel-titanium alloy, cobalt-chromium, or nickel-cobalt; a polymer, such as nylon, silicone, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polytetrafluoroethylene (PTFE), polyurethane (Tecothane), Pebax (co, USA), polycarbonate, Delrin (co, USA), high-density polyethylene (HDPE), low-density polyethylene (LDPE), HMWPE, and UHMWPE; or a combination of metals and polymers. Introducer device 514 may be manufactured by methods known in the art, such as CNC machining, extruding, casting, injection molding, welding, RF shaping, electrochemical fabrication (EFAB), LIGA (lithographic, galvanoforming and abforming), electrical discharge machining (EDM) laser machining, silicon micromachining, weaving, braiding or non-woven fabrication techniques (e.g., spunbound, meltblown, and the like). In some embodiments, introducer device 514 may be woven from polymer or metal into a tube-like structure for flexibility and conformability. Such embodiments may optionally be fiber-reinforced for added strength to allow for a thinner wall thickness.
Turning to
Referring to
In another embodiment, as in
Referring now to
In various embodiments, needle 864 may have multiple barrels or lumens. In one embodiment, for example, a first lumen may extend farther than a second lumen. In one embodiment, a first lumen and/or a second lumen may terminate in open or closed configurations at needle tip 866.
As shown in
Referring to
In some embodiments, as shown in
Referring now to
In some embodiments, tissue protection barrier 828 may include a front side 856 (i.e., working side) and a back side 928 (i.e., neural protection side). Front side 856 may be electrically isolated from back side 928. Either or both of front side 856 and back side 928 may have an electrically conductive surface, and neural stimulation device 914 may be in electrical communication with either or both. In various embodiments, neural stimulation may 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 may be monitored and/or recorded visually, and/or may 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 may be monitored and used to localize the nerve during placement. Further explanation and details of various embodiments of nerve stimulation and localization methods and devices for use in spinal access are provided in U.S. patent application Ser. No. 11/429,377 (Attorney Docket No. 026445-000724US), titled “Spinal Access and Neural Localization,” and filed Jul. 13, 2006, the full disclosure of which is hereby incorporated by reference.
Referring now to
Tissue removal device 800 may include an energy delivery system 1114 configured to deliver RF or other energy to target tissue. Such energy may be used to ablate, vaporize, break up, combinations thereof, or otherwise change the modulus of the tissue. In various alternative embodiments, tissue removal device 800 may be configured to deliver electrical, ultrasound, thermal, microwave, laser, cryo (i.e., removing thermal energy), or combinations thereof. In one embodiment, for example, tissue removal device 800 may include one or more electrosurgery elements. The electrosurgery elements may be configured to remove and/or ablate tissue, achieve hemostasis, and/or provide neural localization in tissue adjacent to the electrosurgery elements. The electrosurgery elements may be either monopolar or bipolar RF in some embodiments. In various embodiments, the RF elements may be activated with a thermal or substantially non-thermal waveform. In other embodiments, tissue removal device 800 may include one or more lasers, high-pressure fluid devices, 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.
In
An external activating force, for example as shown by arrow 830 (activating tissue removal) on a handle, can activate tissue removal device 800. The mechanical tissue removal elements may be used in combination or not in combination with the energy delivery device. The mechanical tissue removal elements may be pushed into and/or drawn across the impinging tissue 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) may be drawn across the impinging tissue in a single direction and/or can be reciprocated. The mechanical tissue removal elements may be manually controlled and/or electronically, pneumatically or hydraulically powered. The mechanical tissue removal elements may be embedded with abrasives and/or have abrasive coatings, such as a diamond or oxide coating. Further details of various mechanical tissue modification devices are set forth above and in the patent applications incorporated by reference herein.
Referring now to
In one embodiment, tissue protection barrier 528 may include multiple needlette conduits 970. Needlettes 968 may be slidably attached to needlette conduits 970. In alternative embodiments, needlettes 468 may be either solid or hollow, and in the latter case needlettes 968 may optionally be used to deliver one or more drugs or other substances to target tissue.
Referring now to
In an alternative embodiment, shown in
Although various illustrative embodiments are described above, any of a number of changes may be made to various embodiments without departing from the scope of the invention as described by the claims. For example, the order in which various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments one or more method steps may be skipped altogether. Optional features of various device and system embodiments may be included in some embodiments and not in others. These and many other modifications may be made to many of the described embodiments. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims.
This application claims priority to U.S. Provisional Patent Application Ser. No. 60/863,544 (Attorney Docket No. 10376-710.101), entitled “Percutaneous Spinal Stenosis Treatment,” and filed Oct. 30, 2006, the full disclosure of which is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60863544 | Oct 2006 | US |
