The invention relates generally to surgical instruments for creating a liquid jet and methods for using the instruments in surgical procedures.
Traditionally, many surgical procedures have been performed on patients using open surgical methods that utilize relatively large incisions to expose a surgical field. Many traditional methods have also typically utilized surgical tools such as scalpels, scrapers, blunt dissectors, lasers, electrosurgical devices, etc., which have poor tissue differentiating capability and which can easily cause inadvertent damage to tissue surrounding a surgical treatment site unless carefully utilized. Open surgery with such prior art surgical instruments often involves extensive trauma to the patient, with associated problems of long recovery periods and potential complications.
There has been a trend in recent years to perform many surgical procedures using less invasive techniques by accessing surgical sites via small holes through the skin or through body orifices. These techniques are known as “minimally invasive surgery.” Minimally invasive surgical techniques commonly employed include endoscopic, laparoscopic, and arthroscopic surgical procedures. Minimally invasive surgical procedures are commonly preferred to open surgical procedures for many applications because the minimally invasive procedures induce less trauma to the patient during surgery and involve, in many cases, fewer potential complications and reduced recovery time.
A variety of instruments have been developed and utilized for minimally invasive surgical procedures. Frequently used instruments include blades and scalpel-type instruments, motorized rotary blade instruments, laser instruments, and electrosurgical or electrocautery instruments. Typically, these prior art instruments suffer from a variety of disadvantages. For example, the instruments can be slow and laborious to use, typically they lack the ability to selectively differentiate tissue to be excised from non-target tissue, they tend to have sizes and/or shapes which make access of many surgical sites difficult, and they tend to cause unintended damage to tissue surrounding the intended target tissue. Most prior art instruments also require the operator to manually remove excised tissue, for example with forceps, or require an external source of vacuum to be applied to the surgical site, for example, via an aspiration tube that is separate from the surgical instrument, in order to remove excised tissue. For many minimally invasive surgical applications such as arthroscopy, certain spinal procedures etc., where visualization of the surgical site is typically effected using an imaging system having a probe such as a fiber optic probe inserted into the surgical site, the above mentioned prior art surgical instruments also typically make it difficult to clearly visualize the site of tissue excision within the surgical field by not effectively evacuating tissue and debris from the surgical site.
Instruments that employ liquid jets have also been utilized in surgical procedures for cutting and ablating tissue. Such instruments have many advantages over the above mentioned surgical instruments for performing both open and minimally invasive surgical procedures. For example, liquid jet instruments can avoid the thermal damage to surrounding tissues that is often caused by instruments such as lasers and electrosurgical devices. In recent years, liquid jet instruments have been utilized for a variety of surgical procedures including open surgical procedures such as liver resection, endoscopic procedures such as kidney stone disruption and removal, and arthrectomy procedures for removal of thrombotic tissue from the vascular system.
A variety of liquid jet instruments for surgery have been developed, including instruments described in commonly-owned U.S. Pat. No. 5,944,688, U.S. Pat. No. 6,375,635, U.S. Pat. No. 6,511,493, U.S. Pat. No. 6,451,017, U.S. Application Publication No. US2002-0177802, U.S. Application Publication No. US2002-0111579, U.S. Application Publication No. US2003-0125660, U.S. Application Publication No. US2002-0176788, U.S. Application Publication No. US2004-0228736, U.S. Application Publication No. US2004-0243157, and International Application Publication No. 2004/069064, which are incorporated by reference in their entirety. These surgical liquid jet cutting systems typically have a pump for pressurizing a liquid, such as isotonic saline or other physiologically-compatible liquid. The pressurized liquid is conveyed, for example by flexible tubing, to a handpiece which has a handle region, and a distal end configured to perform a surgical or medical procedure on a patient. The distal end of the instrument typically has a pressurizable pressure tube providing a lumen for conveying the pressurized liquid, and a nozzle, through which the pressurized liquid exits to form a liquid jet. These instruments may include an evacuation tube providing an evacuation lumen, which receives some or all of the liquid from the jet, as well as excised tissue, and removes such materials for disposal. The evacuation tube may have a diameter considerably larger than the diameter of the pressure tube. In some of these instruments, the jet is emitted “proximally”, i.e., in a direction back towards the handle. In other configurations, the jet may be emitted “laterally”, i.e. in a direction substantially perpendicular to the longitudinal axis of the pressure tube in regions proximal to the distal end of the instrument, “distally”, or at some intermediate angle.
While currently available surgical liquid jet instruments represent, in some instances, significant improvements over many prior art surgical instruments for performing open and minimally invasive surgical procedures, there remains a need in the art to provide liquid jet surgical instruments which have certain improved capabilities, and which have the ability to be utilized in a wide variety of open and minimally invasive surgical procedures. The present invention provides, in many embodiments, such improved surgical liquid jet instruments, and further provides methods for their use in a variety of surgical procedures.
There further remains a need in the art for a liquid jet surgical instrument which minimizes the trauma to the tissue surrounding the excised tissue. Although certain conventional surgical liquid jet instruments may be capable of cutting or ablating and/or removing tissue in a desired surgical area, they may not be designed to restrict tissue damage or removal from the adjacent healthy tissue regions for specific surgical procedures. Consequently, many of the prior surgical liquid jet instruments may have a tendency to inadvertently cut, ablate, and/or damage tissue regions surrounding a target tissue. This may lead to further scarring, additional pain, and further recovery time.
For example, the walls of the pressure and/or evacuation tubes of certain conventional liquid jet surgical instruments may be thin to enable them to be sufficiently small to fit into tight surgical spaces. Such a thin tube wall, e.g. one having a thickness of about 0.005 inch (0.125 mm), may be sharp. Thus, the action of moving an instrument with such thin tubing within a confined space may result in the inadvertent cutting of or damage to tissue other than the intended target, through the cutting action of a thin-walled component on the surgical instrument. In some procedures, providing a cutting edge as well as a liquid jet component may be desirable, as described in our copending U.S. Application Publication No. US2004-0243157. In other circumstances, however, this may be undesirable. In particular, there is a need for an improved surgical liquid jet instrument which minimizes trauma to tissue adjacent to tissue being ablated by the liquid jet. It is difficult to achieve the purposes of many surgical procedures if tissue removal cannot be confined to a desired area, or if functional surfaces adjacent to the operating site are damaged.
Disclosed herein are a series of devices related to surgical procedures utilizing liquid jets for cutting, ablating, sculpting, trimming, etc., tissues and/or materials from the body of a patient. The invention includes, in one aspect, a series of devices comprising surgical liquid jet instruments for forming a liquid jet, in another aspect, methods for using the surgical liquid jet instruments, and, in yet another aspect, methods for forming certain components of the surgical liquid jet instruments. In certain surgical method embodiments of the invention using certain embodiments of the inventive liquid jet instrument, the cutting or ablating power of the liquid jet may be adjusted or controlled by an operator of the instrument, for example by varying the pressure of the liquid supplied to form the jet, to allow for improved tissue differentiation and to reduce inadvertent damage to surrounding tissues when cutting or ablating the target tissue. Liquid jet instruments of the invention may also be operated in certain inventive surgical procedures to avoid thermal damage to surrounding tissues that is often caused by instruments such as lasers and electrosurgical devices.
In one aspect, the invention provides a surgical liquid jet device that minimizes the trauma to the tissue surrounding the excised tissue. According to one embodiment of the present invention, the edges of the terminal tip of an evacuation tube, as well as, in certain embodiments, the edges of the terminal tip of the pressure tube at the distal end of the instrument, are “blunted,” i.e. smoothed, rounded, and/or repositioned/deflected with respect to a center axis of the lumen, at the terminal tip, formed by the tube, etc., to a sufficient extent so as to be substantially non-traumatic to tissue against which the terminal tip(s) of the tube(s) may be brought into contact in normal usage for procedures for which the instrument is indicated. Moreover, in some embodiments, the method of blunting the edges provides a desired narrowed opening of the evacuation lumen, which may be helpful in maintaining evacuation of liquid and debris from the tissue site. The term “terminal tip” as used herein in the context above, refers to either the region at the inlet end of the evacuation tube that circumscribes the jet-receiving opening of the evacuation tube or the region at the outlet end of the pressure tube that forms, defines, or circumscribes the nozzle, depending on whether this term is modifying the evacuation tube or the pressure tube, respectively. The “terminal tip” of both of the evacuation tube and the pressure tube are typically located at the “distal end” of the surgical liquid jet instrument, as that term is defined below.
In one aspect, the invention provides a surgical instrument having a distal end adapted to perform a surgical procedure on a patient and a proximal end adapted to be controllable by an operator. The instrument includes a pressure tube having a pressure lumen defined by a wall of the pressure tube, the pressure tube having sufficient burst strength to conduct a high pressure liquid towards the distal end of the instrument, and the pressure tube includes at least one nozzle providing a jet opening. The instrument also includes an evacuation tube having an evacuation lumen defined by a wall of the evacuation tube, where the evacuation lumen includes a jet-receiving opening locatable opposite the jet opening to receive a liquid jet when the instrument is in operation. The nozzle is shaped to form the liquid jet as a liquid at high pressure flows therethrough, and the evacuation tube wall has a blunted terminal tip.
In another aspect, the invention provides a surgical instrument having a distal end adapted to perform a surgical procedure on a patient and a proximal end adapted to be controllable by an operator. The instrument includes a pressure tube having a pressure lumen defined by a wall of the pressure tube, the pressure tube having sufficient burst strength to conduct a high pressure liquid towards the distal end of the instrument, and the pressure tube includes at least one nozzle providing a jet opening. The instrument also includes an evacuation tube having an evacuation lumen defined by a wall of the evacuation tube, where the evacuation tube includes a jet-receiving opening locatable opposite the jet opening to receive a liquid jet when the instrument is in operation. The nozzle is shaped to form a liquid jet as a liquid at high pressure flows therethrough. The instrument also includes a terminal tip of the evacuation tube having a center axis and a perimeter, where the terminal tip of the evacuation tube wall is curved and/or is angled inwardly towards the center axis around a majority of the perimeter of the evacuation tube.
In another aspect, the invention provides a method comprising inserting a surgical liquid-jet instrument into a surgical site in the body of a patient, creating a liquid jet with the surgical liquid-jet instrument, directing the liquid jet towards a jet-receiving opening of an evacuation tube of the surgical liquid-jet instrument, where the evacuation tube wall has a blunted terminal tip, and cutting or ablating a selected tissue within the surgical site with the liquid jet.
In yet another aspect, the invention provides a method comprising inserting a surgical liquid jet instrument into the spine of a patient, e.g. into an intervertebral disc of the patient, and cutting, ablating, and/or removing with a liquid jet of the instrument a first tissue within the spine while not cutting, ablating, and/or removing with the liquid jet of the instrument a second tissue within the spine.
In another aspect, the invention provides a method of manufacturing a surgical liquid jet instrument, the method comprising forming a blunted terminal tip on an evacuation tube wall of the surgical liquid jet instrument. The pressure tube of the instrument comprises a pressure lumen defined by a wall of the pressure tube, and the pressure tube has sufficient burst strength to conduct a high pressure liquid towards a distal end of the instrument. The pressure tube includes at least one nozzle providing a jet opening, where the nozzle is shaped to form a liquid jet as a liquid at high pressure flows therethrough. The evacuation tube comprises an evacuation lumen defined by a wall of the evacuation tube, and the evacuation tube includes a jet-receiving opening having a cross-sectional area and locatable opposite the jet opening.
The accompanying drawings are schematic and are not intended to be drawn to scale. In the figures, each identical, or substantially similar component that is illustrated in various figures is typically represented by a single numeral or notation. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention. In the drawings:
a is a partially-cutaway schematic illustration of a portion of the distal end of a surgical liquid jet instrument for use in a surrounding liquid environment;
b is a partially-cutaway schematic illustration of a portion of the distal end of a surgical liquid jet instrument for use in a surrounding liquid environment, where the evacuation lumen includes a constriction;
c is a schematic illustration of a portion of the distal end of a surgical liquid jet instrument, illustrating various geometric relationships;
d is a partially-cutaway schematic illustration of a portion of the distal end of a surgical liquid jet instrument for use in a surrounding gaseous environment;
e is a partially-cutaway schematic illustration of a portion of the distal end of a surgical liquid jet instrument for use in a surrounding gaseous environment, where the evacuation lumen includes a constriction;
a is a partially-cutaway schematic illustration of a portion of a surgical liquid jet instrument, the portion including the distal end of the surgical liquid jet instrument;
b is a partially-cutaway schematic illustration of a portion of a surgical liquid jet instrument, the portion including the distal end of the surgical liquid jet instrument;
c is a partially-cutaway schematic illustration of a portion of a surgical liquid jet instrument, the portion including the distal end of the surgical liquid jet instrument;
a is a schematic cross-sectional illustration of a portion of one embodiment of a liquid jet surgical instrument;
b is a schematic perspective illustration of the portion of one embodiment of a liquid jet surgical instrument illustrated in
a is a schematic cross-sectional illustration of the distal end of an evacuation tube and a cupping device for forming a blunted terminal tip of the evacuation tube in a configuration prior to blunting;
b is a schematic cross-sectional illustration of the distal end of an the evacuation tube and cupping device for forming a blunted terminal tip of the evacuation tube of
a is a schematic cross-sectional illustration of a distal end of an evacuation tube;
b-8e are schematic cross-sectional illustrations of various embodiments of a blunted terminal tip of an evacuation tube according to certain embodiments of the invention;
a-9d are schematic cross-sectional illustrations of additional embodiments of a blunted terminal tip of an evacuation tube according to certain embodiments of the invention; and
e-9f are schematic cross-sectional illustrations showing the formation of a blunted terminal tip of an evacuation tube by the addition of an attachment, such as an external collar.
The present invention provides a variety of liquid jet instruments useful in a variety of applications, many of which are especially well suited for a variety of surgical procedures. The liquid jet instruments provided by the invention can be configured in a variety of different ways for use in various surgical operating fields. Certain surgical instruments, according to the invention, are configured as surgical handpieces having a proximal end with a grasping region, or handle, shaped and configured to be comfortably held in the hand of an operator. The instruments also have a distal end that includes at least one nozzle for forming a liquid jet. The distal end of the inventive surgical instruments is used to perform a surgical procedure on a patient. Although the liquid jet instruments described herein are shown as having a handpiece configuration, it should be understood that the invention is not strictly limited to surgical handpieces, and that the invention may also be practiced utilizing liquid jet instruments having a variety of configurations and purposes. The liquid jet instruments provided by the invention can be used in a wide variety of surgical applications to utilize a high pressure liquid stream to cut, drill, bore, perforate, strip, delaminate, liquefy, ablate, shape, or form various tissues, organs, etc. of the body of a patient.
Certain embodiments of the liquid jet surgical instruments provided by the invention include a pressure tube, having a terminal end defining, forming, or circumscribing in at least one nozzle providing a liquid jet opening, and having a proximal end that is connectable to a source of liquid under high pressure, supplied, for example, by a high pressure pump or liquid dispenser. The liquid jet nozzle is shaped to form a liquid jet as a liquid under high pressure flows through the nozzle, as described below. The liquid jet, in certain embodiments, can be used to cut, ablate, sculpt, trim, form, debride, etc., various tissues of a patient in surgical procedures. In certain embodiments, the liquid pressure supplied to the instrument by the pump or dispenser is variably controllable by an operator of the instrument so that the cutting or ablating power of the liquid jet is adjustable by the operator. This adjustability of the pressure can allow an operator to create a liquid jet with the instrument that can differentiate between different types of tissue within a surgical operating field. For example, a lower pressure can be utilized for cutting or ablating a soft tissue such as fat or the nucleus pulposus of an intervertebral disc from a surface of a harder tissue, such as muscle, bone, cartilage, or the annulus fibrosus of an intervertebral disc, where the liquid jet has sufficient strength to cut or ablate the soft tissue without damaging the underlying, surrounding, adjacent, and/or interdigitated harder tissue. A higher pressure can then be selected that is sufficient to form a liquid jet capable of cutting or ablating hard tissue, such as muscle or bone. In this way, a liquid jet surgical instrument provided by certain embodiments of the invention can provide highly selective and controllable tissue cutting in various surgical procedures, such as, for example, surgical procedures on the spine.
In some embodiments, an external source of suction, for example a vacuum pump or aspirator, can be provided in fluid communication with a proximal end of an evacuation lumen of an evacuation tube of the instrument in order to provide the suction driving force required for evacuating material from the surgical field via a jet-receiving opening of the evacuation tube. In certain embodiments, however, the invention provides surgical instruments having an evacuation tube that is shaped and positionable relative to the jet nozzle to enable evacuation of essentially all of the liquid comprising the liquid jet as well as ablated tissue and debris from the surgical site without requiring an external source of suction. In certain embodiments, the evacuating force created by the liquid jet being directed into the evacuation lumen is sufficient to evacuate material from the operating site to a drainage reservoir located at the proximal end of the evacuation tube or an evacuation conduit connected to the proximal end of the evacuation tube. In such embodiments, the liquid jet and the evacuation tube together can act as an eductor pump, which utilizes the momentum and kinetic energy of the moving fluid of the liquid jet to create an evacuating force capable of driving the liquid, ablated material, and debris through the evacuation lumen and away from the surgical site.
The inventive surgical liquid jet instruments, in certain embodiments, can be configured to effectively remove material from a surgical site and transport the material through an evacuation lumen without the need for an external source of suction, for a wide variety of angular orientations between the central region of the liquid jet and the longitudinal axis of the evacuation lumen. The term “central region of the liquid jet” as used herein refers to a region defining the geometric center of the liquid jet. This region is typically an essentially cylindrical region of the liquid jet confined within a cylinder whose outer surface has a shape and perimeter defined by the inner circumference of the liquid jet opening, which circumference is projected from the liquid jet opening to the jet-receiving opening along an axis that is co-linear with the longitudinal axis of the jet nozzle. The “longitudinal axis” of the jet nozzle, as will be described in more detail below, is defined by the axial center line of the nozzle region of the pressure tube, which is typically at the terminal tip of the pressure tube. The “longitudinal axis” of the evacuation lumen refers to an axis defining the geometric center of the evacuation lumen in a region that is proximal to the jet-receiving opening. In typical embodiments, this region of the evacuation lumen will have a longitudinal axis that is essentially parallel to the longitudinal axis of the elongated body of the instrument, which is held and controlled by the hand of the operator. As used herein in the context of describing geometric relationships between longitudinal axes of various components, the term “co-linear” refers to components whose longitudinal axes are superimposed on essentially the same line in space. The term “parallel” when used in the same context herein refers to longitudinal axes that are not co-linear, but that are oriented in an essentially identical direction in space. Accordingly, the surgical instruments provided by the invention, in certain embodiments, can enable effective evacuation of material and debris from the surgical site, without the need for an external source of vacuum, for a wide variety of liquid jet angular configurations, including instruments providing liquid jets that are directed axially, transversely, or at any angle between 0 and 180° with respect to a longitudinal axis defining the proximal end, or body, of the surgical instrument.
Such flexibility allows certain embodiments of the inventive surgical instruments to be designed having a distal end that has a variety of predetermined contours, shapes, and sizes specifically selected for particular surgical procedures. Such customization of the instruments can allow certain embodiments of the liquid jet instruments to be designed and configured to facilitate and reduce the difficulty of insertion of the distal end of the device into confined regions of the body defining a surgical operating space. For example, as will be discussed in greater detail below, the invention provides surgical liquid jet instruments and a surgical method for performing surgical procedures on the spine of a patient.
Certain embodiments of the inventive liquid jet surgical instruments may include distal ends that are designed and configured to prevent or reduce plugging of the evacuation lumen, blow-by of the liquid jet, or back spray or misting of the liquid jet when the instrument is in operation. “Blow-by” of the liquid jet, as used herein, refers to a portion of the liquid jet, or a high velocity fluid entrained by the liquid jet (comprising the “entrainment region” as discussed below), having a cross-sectional area, at the plane of the jet-receiving opening, that is larger than the cross-sectional area of the jet-receiving opening so that at least a portion of the liquid jet or high velocity fluid misses or “blows by” the jet-receiving opening. Blow-by is generally undesirable because it can lead to unintended tissue damage and poor evacuation efficiency. “Back spray” as used herein refers to a liquid jet, or high velocity fluid entrained by the liquid jet, entering the jet-receiving opening in the evacuation tube and subsequently reflecting or flowing back into the surgical field from the jet-receiving opening. Such back spray is undesirable in operation due to the potential of contamination of the surgical operating field and/or aerosolization of infective material, in addition, back spray typically indicates a poor efficiency level of the evacuation of material by the instrument via eductor pump action. As described in more detail below, the surgical instruments provided by the invention, in certain embodiments, substantially reduce, and in certain embodiments essentially eliminate, performance problems associated with blow-by and back spray when the instruments are in operation.
Plugging of the evacuation lumen can be prevented, for certain embodiments involving surgical instruments designed for operation in a liquid environment, by constructing the evacuation tube to have a region that is within and/or downstream of the jet-receiving opening that is designed to be able to macerate at least a portion of the tissue entrained by the liquid jet into a plurality of particles when the instrument is in operation. The term “macerate” as used herein refers to a disaggregation of entrained material, for example an entrained tissue, by a liquid within the evacuation lumen undergoing intensely turbulent flow that creates a region of extremely high fluid shear and impacting forces capable of partitioning the material into particles having a size small enough to pass through the evacuation lumen without plugging the lumen. In certain embodiments, the evacuation tube is able to macerate a substantial fraction of the tissue entrained into a plurality of essentially microscopic particles. “Microscopic” as used herein refers to particles having a dimension too small to be visualized unaided by the human eye.
Prevention of blow-by and back spray can be accomplished by providing a surgical liquid jet instrument having a distal end configured so that when in operation, the liquid jet and the high velocity fluid entrained by the liquid jet occupies a substantial fraction of the cross-sectional area of the jet-receiving opening, but does not occupy a region larger than the cross-sectional area of the jet-receiving opening. As discussed in more detail below, this “substantial fraction” refers to at least 50%, but less than 100% of the cross-sectional area of the jet-receiving opening being occupied by an entrainment region created by the liquid jet.
The inventive surgical liquid jet instruments will now be described in more complete detail in the context of several specific embodiments illustrated in the appended figures. It is to be understood that the embodiments described are for illustrative purposes only and that the novel features of the invention, as described in the appended claims, can be practiced in other ways or utilized for instruments having other configurations, as apparent to those of ordinary skill in the art.
At the outset, it should be noted that a detailed treatment and discussion of a wide variety of design parameters, configurations, materials of construction, and other aspects of the design, fabrication, and construction of liquid jet surgical instruments are provided in commonly owned U.S. Pat. Nos. 5,944,686; 6,375,635; and 6,511,493; in U.S. Patent Application Publication Nos. 2003/0125660 A1, 2004/0243157 A1, and in International Application No. 2004/069064 A2, each of which is incorporated herein by reference. The reader is referred to these issued patents and patent publications for detailed description of and guidance as to the construction and design of certain embodiments of the liquid jet components of the instruments described herein. For example, U.S. Pat. No. 6,375,635 describes in detail design considerations related to the configuration and sizing of the nozzle, evacuation lumen, liquid jet length and dispersion, materials of construction, liquid pressures for operation, etc. for liquid jets configured to directly contact, cut and/or fragment and/or disaggregate tissue and facilitate removal of tissue through an evacuation lumen. Accordingly, while certain specific design parameters are called out and discussed in more detail below, others that may not specifically mentioned or discussed are discussed in detail in one or more of the above-referenced U.S. Patents or Patent Publications. Such parameters, configurations and design considerations disclosed in these references can be, in many cases, applicable to and useful for practicing many aspects of the current invention.
Pressure tube 110 and evacuation tube 112 are preferably constructed from a surgical grade stainless steel, however, in alternative embodiments, either or both of the tubes may be constructed from other suitable materials, for example certain polymeric materials, as apparent to those of ordinary skill in the art. Regardless of the specific material from which the pressure tube is constructed, the pressure tube must have sufficient burst strength to enable it to conduct a high pressure liquid to nozzle 116 to form liquid jet 120. The burst strength of the pressure tube should be selected to meet or exceed the highest contemplated pressure of the liquid supplied for use in the specific surgical procedure to be performed. Typically, surgical instrument 102 will operate at liquid pressure between about 500 psig and about 50,000 psig, depending on the intended material to be cut and/or ablated. Those of ordinary skill in the art will readily be able to select appropriate materials for forming pressure tube 110 and evacuation tube 112 for particular surgical requirements.
In certain embodiments, pressure tube 110 and evacuation tube 112 are constructed and supported so that the distal ends of the walls of the tubes are sufficiently stiff to prevent deflection of the tubes by, for example, contact of the walls with surfaces within the surgical operating space, which deflection could potentially lead to misdirection of liquid jet 120 so that it is no longer incident upon jet-receiving opening 118, thus potentially causing unintended tissue damage to the patient.
Pressure tube 110 is in fluid communication with high pressure pump 124 via high pressure liquid supply conduit 126. High pressure liquid supply conduit 126 also has a burst strength capable of withstanding the highest liquid pressures contemplated for using the instrument 102 for a particular surgical application. In some embodiments, high pressure liquid supply conduit 126 comprises a burst-resistant stainless steel hypotube constructed to withstand at least 50,000 psig. In some embodiments, the hypotube may be helically coiled to improve the flexibility and maneuverability of the surgical instrument 102. In certain embodiments, high pressure liquid supply conduit 126 comprises a Kevlar reinforced nylon tube that is connectable to the pressure tube 110.
In fluid communication with high pressure liquid supply conduit 126 is a high pressure pump 124, which can be any suitable pump capable of supplying the liquid pressures required for performing the desired surgical procedure. Those of ordinary skill in the art will readily appreciate that many types of high pressure pumps may be utilized for the present purpose, including, but not limited to, piston pumps and diaphragm pumps. In certain embodiments, high pressure pump 124 comprises a disposable piston or diaphragm pump, which is coupled to a reusable pump drive console 128. High pressure pump 124 has an inlet that is in fluid communication with a low pressure liquid supply line 130, which receives liquid from liquid supply reservoir 132. Pump drive console 128 may include an electric motor that can be utilized to provide a driving force to high pressure pump 124 for supplying a high pressure liquid in liquid supply conduit 126.
While a variety of known pump consoles may be utilized in the context of the present invention, certain pump drive consoles include a constant speed electric motor that can be turned on and off by means of an operator-controlled switch 134. In certain embodiments, operator-controlled switch 134 comprises a foot pedal or a button or trigger located on grasping region 106 of the surgical instrument 102 that may be easily accessed by the operator of the instrument. In some embodiments, pump drive console 128 can have a delivery pressure/flow rate that is factory preset and not adjustable in use. In other embodiments, the pressure/flow rate may be controlled by the operator via an adjustable pressure/flow rate control component 136, that can control the motor speed of the pump drive console and/or the displacement of the high pressure pump. While in
The liquid utilized for forming the liquid cutting jet can be any fluid that can be maintained in a liquid state at the pressures and temperatures contemplated for performing the surgical procedures. For applications in which the instruments are used to perform surgical procedures in a live patient, the liquid utilized should also be physiologically compatible. In typical embodiments, the liquid supplied will be a sterile surgical saline solution, or sterile water and liquid supply reservoir 132 can comprise a sterile container, such as an intravenous (IV) bag containing such fluid. In some embodiments, in order to improve the cutting or ablating character of the liquid jet, the liquid may contain solid abrasives, or the liquid may comprise a liquefied gas, for example carbon dioxide, which forms solid particulate material upon being admitted from nozzle 116 to for the liquid jet 120. In other embodiments, the liquid supplied to surgical instrument 102 may include medicaments, such as antiseptics, antibiotics, antiviral components, anesthetics, drugs, chemotherapy agents, etc., that are useful in the context of a specific surgical procedure. In other embodiments, the fluid may include a dye to improve visualization of the liquid jet when the instrument is in operation.
Evacuation tube 112 is connectable at its proximal end to an evacuation conduit 138, which can be used to transport evacuated material and debris to a drainage reservoir 140. The liquid contained in evacuation conduit 138 is under relatively low pressure and, accordingly, evacuation conduit 138 may be constructed, in certain embodiments, of a low cost flexible material, for example, polymeric tubing, such as polyvinyl chloride (PVC), silicone, polyethylene, rubber, etc. tubing. In certain embodiments, evacuation conduit 138 should have a minimum internal cross-sectional area that equals or exceeds the maximum internal cross-sectional area of the evacuation lumen. In the illustrated embodiment, surgical instrument 102 is constructed such that the evacuation lumen is capable of evacuating liquid jet 120 and ablated material and debris from the jet-receiving opening 118 to the proximal end of the evacuation lumen and through evacuation conduit 138 into drainage reservoir 140, without the need for an external source of suction. In such embodiments, evacuation conduit 138 may include a vacuum breaker 142 or a proximal end that is not couplable to an external source of suction, so that it is not possible for an operator to inadvertently couple evacuation conduit 138 to an external source of suction when the instrument is in operation.
In certain embodiments, the fluid supply path of liquid jet surgical system 100 is disposable, and sterilizable, for example by chemical methods such as exposure to ethylene oxide, or by gamma or beta irradiation, as apparent to those of ordinary skill in the art. In certain embodiments, the fluid path is supplied pre-sterilized to the user for a single use only. Those of ordinary skill in the art understand what is meant by “disposable” and “for a single use only.” Disposability of the liquid supply path, including liquid supply reservoir 132, liquid supply line 130, high pressure pump 124, high pressure liquid supply conduit 126, and pressure tube 110 is advantageous because such components can be difficult to effectively clean and sterilize between use without reducing the utility of the instrument, for example by the plugging of jet nozzle 116 with deposits during the sterilization process. In certain embodiments, all of the components of liquid jet surgical system 100 are entirely disposable after a single use except for pump drive console 128. For embodiments where the surgical liquid jet instrument is disposable after a single use, the instrument may be sterilizable, and may be provided pre-sterilized. In other embodiments, only the pressure tube and the distal end of the instrument for insertion into the patient are sterilizable or pre-sterilized.
The present invention provides, in certain embodiments, surgical liquid jet instruments which are specifically designed and constructed for use in a particular surgical environment. Specifically, in some embodiments, the present invention provides surgical liquid jet instrument designs that are tailored to provide highly desirable performance characteristics in surgical operating environments where the liquid jet is submerged in a liquid environment when the instrument is in operation, and, in other embodiments, the present invention provides surgical liquid jet instrument designs that are tailored to provide highly desirable performance characteristics in surgical operating environments where the liquid jet is surrounded by a gaseous environment when the instrument is in operation. More specifically, the invention provides surgical liquid jet instruments including pressure tubes and evacuation tubes that are shaped, and positioned relative to each other, to establish certain predetermined geometric relationships between the jet forming components and jet-receiving components that are specifically selected to provide the desired performance characteristics of the instrument in a liquid or gaseous surgical environment. Importantly, the above mentioned geometric relationships and design characteristics may be substantially different for instruments that are designed for use in a liquid environment when compared to instruments that are designed for use in a gaseous environment.
Reference is made to
As discussed previously, the pressure of the high pressure liquid supplied to nozzle 232 for forming the liquid jet 238 depends on the particular design of nozzle 232 and the hardness/toughness of tissue or material to be cut or ablated. In certain embodiments, the liquid at high pressure is supplied to jet opening 236 at a pressure of at least 500 psig, in other embodiments at a pressure of at least about 1,000 psig, 2,000 psig, 3,000 psig, or 5,000 psig, and still other embodiments at a pressure of at least about 10,000 psig, or 15,000 psig, and still other embodiments at a pressure of at least 20,000 psig, and in yet still other embodiments at a pressure of at least about 30,000 psig, or 50,000 psig. Also as discussed previously, for embodiments where a collimated jet is desired, nozzle 232 may have a length to minimum internal diameter ratio of at least about four, about six, and in other embodiments at least about ten. Using other nozzle-forming technology, such as that described in commonly-owned International Application Publication No. WO 2004/069064, different ratios or design criteria may apply. Jet opening 236 can have a circular cross-sectional area, but may, in other embodiments, have other cross-sectional shapes, such as rectangular, oval, slit-like, etc., for forming jets having different shapes for specific desired purposes. In certain embodiments, jet opening 236 has an internal diameter of between about 0.001 and about 0.02 inches, in certain embodiments between about 0.003 and about 0.01 inches, and in certain embodiments about 0.005 inches.
Liquid jet 238, which is collimated as it exits jet opening 236, tends to create a visible, opaque entrainment region 242 surrounding liquid jet 238. Entrainment region 242 is comprised of rapidly moving liquid, which is entrained and driven by the kinetic energy of liquid jet 238. Liquid jet 238, as it rapidly moves through liquid environment 244, also tends to create a zone of low pressure, which is essentially coextensive with entrainment region 242. In certain embodiments involving high pressure liquids and rapidly moving liquid jets, the pressure in entrainment region/low pressure zone 242 will be lower than the vapor pressure of the surrounding liquid in liquid environment 244, thus causing cavitation of the liquid in entrainment region 242 and a resulting formation of an abundance of extremely small gas bubbles 246 within the liquid in the entrainment region 242, making the region visually opaque.
As discussed previously, it is desired, in certain embodiments, for safety and performance, that the instrument be designed to reduce, and preferably eliminate, undesirable effects, such as blow-by of the liquid jet, plugging of the jet-receiving opening of the evacuation tube, and inefficient tissue/debris entrainment and removal. Also, as previously mentioned, in certain embodiments, it is desirable that ablated tissue and debris be evacuated from the surgical site through the evacuation lumen, without the need for a source of external suction to be applied to the proximal end of the evacuation lumen. In order to provide the above-mentioned characteristics, the inventive surgical instruments for use in a liquid environment can include an evacuation tube having a specifically selected predetermined shape and configuration, which is positionable relative to the jet opening at a specific predetermined distance. Specifically, in certain embodiments, jet-receiving opening 234 is positioned, when the instrument is in operation, opposite jet opening 236, at a distance l therefrom, and the instrument is provided with a nozzle 232 having a length to minimum diameter ratio so that essentially all of the fluid in liquid jet 238 enters jet-receiving opening 234. As discussed above, liquid jet 238 will tend to create entrainment region 242 surrounding the liquid jet 238 when the instrument is in operation. Entrainment region 242 will typically be symmetrically disposed around liquid jet 238 and will tend to diverge in a direction from jet opening 236 to jet-receiving opening 234. In embodiments where jet opening 236 is circular in shape, entrainment region 242 will have a truncated cone shape, having a truncated apex at jet opening 236 and a base defined as a cross section of the cone at the plane of jet-receiving opening 234. In certain embodiments, the base of entrainment region 242 occupies between about 50% and about 100% of the cross-sectional area of jet-receiving opening 234 when the instrument is in operation; in certain embodiments the entrainment region occupies at least about 75%; in certain embodiments at least about 90%; in certain embodiments at least about 95% of the cross-sectional area of jet-receiving opening 234 when the instrument is in operation.
As shown in
As mentioned above, the separation distance l between the jet opening 236 and the jet-receiving opening 234 depends upon the requirements of the particular surgical procedure for which the surgical instrument is used; however, for some typical embodiments, the distance will have a maximum value of about 1 cm, for other typical embodiments, about 5 mm, and for yet other typical embodiments, about 1 mm. The jet-receiving opening 234 may have a diameter of between about 0.01 and about 0.2 inches, in other embodiments between about 0.03 and about 0.1 inches, and in some embodiments a diameter of about 0.06 inches.
Referring again to
In order to provide a maceration region, evacuation tube 240 may include a jet-deflecting portion 248 that is located adjacent to and downstream of jet-receiving opening 234. Jet-deflecting region 248 may be either a straight surface that is angled with respect to the direction of at least a central portion of liquid jet 238, or in certain embodiments, jet-deflecting region 248 comprises a smoothly curved surface upon which at least a portion of liquid jet 238 impinges, where the curved surface is shaped to deflect at least a portion, and in certain cases, all of the liquid jet 238 and liquid comprising entrainment region 242 in a direction that is essentially parallel to the longitudinal axis 250 of the lumen of evacuation tube 240 in the region proximal to the jet-deflecting region 248. In certain embodiments, the radius of curvature of the curved surface defining jet-deflecting region 248 is essentially constant, having a value of between about 1 and 20 times the internal diameter of evacuation tube 240. It is also a feature of certain embodiments of the surgical instruments provided by the invention that the liquid jet be directed into the jet-receiving opening so that a direction of at least a central portion of the liquid jet forms an angle of no greater than 10 degrees with respect to a line normal (i.e., perpendicular) to a plane defining (i.e., co-planar to) the jet-receiving opening. In certain embodiments, the central portion of the liquid jet is essentially parallel to a line that is normal to the plane defining the jet-receiving opening.
To provide effective eductor pump action of the evacuation tube, in some embodiments, the lumen of evacuation tube 240 will have an essentially constant internal cross-sectional area from jet-receiving opening 234 to a position that is proximal to the distal end of the surgical instrument where the proximal end of the evacuation lumen is located. In other embodiments, eductor pump action can be enhanced by providing an evacuation lumen having an essentially constant cross-sectional area and having a jet-receiving opening, which has a cross-sectional area that is less than the cross-sectional area of the evacuation lumen (i.e., the internal cross-sectional area of the evacuation lumen has a minimum value at the jet-receiving opening). In yet other embodiments, eductor pump action can be enhanced by providing an evacuation lumen having an internal cross-sectional area which increases continuously from a minimum value at the jet-receiving opening to a maximum value at a position located proximal to the jet-receiving opening. In such embodiments, this maximum value of the internal cross-sectional area may be essentially constant for positions within the evacuation lumen that are proximal to the above-mentioned position. In each of the above-mentioned embodiments, there may be essentially no reductions in the internal cross-sectional area of the evacuation lumen at any position proximal and/or downstream of the maceration region described above.
b shows an alternative design embodiment for the construction of the evacuation tube for surgical instruments designed for use in a liquid surgical environment. Evacuation tube 260 includes a constriction 262 which creates a reduction in the internal cross-sectional area of the evacuation lumen. The constriction 262 is located proximal to jet-receiving opening 264, and may be positioned immediately proximal and adjacent to maceration region 266. In operation, the constriction 262 in the evacuation tube 260 will act as a venturi as liquid within the evacuation lumen flows through the constriction, thus enhancing the eductor pump action of evacuation tube. In the illustrated embodiment, constriction 262 comprises a pinch 268 in the sidewall of the tubing conduit comprising evacuation tube 260. In certain embodiments, the cross-sectional area of constriction 262 should be between about three and about eight times the cross-sectional area of jet-opening 270 in nozzle 272.
Referring again to
d and 2e illustrate certain arrangements for liquid jet surgical instruments designed for use in a surrounding gaseous environment. Referring to
Of concern for certain applications employing liquid jet surgical instruments in a gaseous environment is minimizing, and in certain cases eliminating, misting and back spray of the liquid jet from the jet-receiving opening. Such misting or back spray can cause poor visualization of the surgical field, in addition to potentially creating infectious and/or undesirable aerosolization of material into the surrounding gaseous environment. In order to avoid back spray or misting from the evacuation lumen, evacuation tube 282, in certain embodiments, is essentially straight at its distal end so that an axis 294 defining the direction of at least a central region of liquid jet 288 is essentially co-linear with the longitudinal axis of the distal end of the evacuation lumen.
As mentioned above, liquid jet 288 is in certain embodiments, a diverging jet, which diverges as it travels from jet opening 290 to jet-receiving opening 296. Diverging jet 288 may have an apex at jet opening 290 and, for essentially circular jet opening shapes, may have a truncated cone shape, where the truncated apex of the cone is located at jet opening 290 and the base of the cone is defined as the planar cross section of the cone at jet-receiving opening 296. As was previously the case for surgical instruments designed for use in a liquid environment, certain embodiments of surgical instruments designed for use in a gaseous environment provide an evacuation tube shaped and positioned relative to the jet opening, when the instrument is in operation, so that the base of the liquid jet entrainment region occupies between about 50% and about 100% of the cross-sectional area of the jet-receiving opening; in certain embodiments the entrainment region occupies at least about 75%; in certain embodiments at least about 90%, and in certain embodiments at least about 95% of the cross-sectional area of the jet-receiving opening. As was previously described in the context of instruments for use in a liquid environment, the size of jet-receiving opening 296 can be selected based upon the desired separation distance between jet opening 290 and jet-receiving opening 296 and the length to minimum internal diameter ratio of nozzle 286, which may dictate the degree of divergence of liquid jet 288. Analogous to the geometrical relationships discussed previously in the context of
In some embodiments, it is also desirable to shape and position evacuation tube 282 with respect to jet opening 290 so that the cross-sectional shape and area of liquid jet 288 at a given location 298 within the evacuation lumen is essentially the same as the internal cross-sectional shape and area of the evacuation lumen at given location 298. Given location 298 may coincide with jet-receiving opening 296 or may be located proximal to jet-receiving opening 296. For embodiments where given location 298 is located proximal to jet-receiving opening 296, the given location 298 may be selected to be no greater than about 5 mm proximal to jet-receiving opening 296. By shaping and positioning evacuation tube 282 in this fashion, liquid jet 288 can completely fill the cross-sectional area of the evacuation lumen at a position at or near its jet-receiving opening, thus essentially eliminating back spray and misting and improving evacuation via eductor pump action.
Evacuation tube 282 may have an essentially constant internal cross-sectional area, may have an essentially constant cross-sectional area with a jet-receiving opening having a cross-sectional area that is less than the cross-sectional area of evacuation tube 282, or may have an internal cross-sectional area which increases continuously from a minimum value at jet-receiving opening 296 to a maximum value at a position proximal to jet-receiving opening 296, which then remains essentially constant for positions proximal to this position. Alternatively, as shown in
It should be understood that while certain embodiments of the inventive liquid-jet surgical instruments for use in a liquid environment have been described as including an evacuation tube wall constructed and positioned to provide a jet-deflecting surface upon which a liquid jet impinges, and while certain embodiments of the inventive liquid-jet surgical instruments for use in a gaseous environment have been described as providing an evacuation tube that is essentially straight and does not include a wall providing a jet-deflecting surface, the liquid jet surgical instruments within the scope of the present invention are not so limited. Specifically, configurations such as those shown in
b and 3c show two embodiments of the distal end of a surgical liquid jet instrument according to the invention where the distal end of sheath 320 essentially completely surrounds both pressure lumen 322 and evacuation lumen 324. The liquid jet path length is created in the instruments by providing a notch 326 at the distal end of sheath 320 where the proximal surface of notch 326 includes a jet-receiving opening 328, and the distal end of notch 326 includes a jet opening 330. In some embodiments, sheath 320 may be constructed from a flexible material, such as a polymeric material. The configuration shown in
The invention also provides various embodiments of surgical liquid jet instruments having distal ends for insertion into a surgical operating space that have a selected contour and size that are selected to facilitate inserting the distal end into the confined surgical operating space. Certain embodiments of such surgical instruments provided by the invention may include mechanisms for creating relative motion between the pressure tube and evacuation tube in order to change the orientation, positioning, and/or configuration of the tubes with respect to each other, for example to increase a separation distance between the jet opening and the jet-receiving opening. Embodiments of surgical liquid jet instruments having actuating mechanisms, as provided by the invention, can enable the distal end of the instruments to be inserted into a surgical operating space in an undeployed configuration, and subsequently deployed by an operator to provide a desired separation distance between the jet opening and the jet-receiving opening in order to yield a desired liquid jet path length. Embodiments involving deployable liquid jet surgical instruments may be directed to surgical applications involving confined regions within the body of a patient, such as joint capsules or intervertebral discs. In certain such embodiments, the surgical environment surrounding the distal end of the instrument, when it is in operation, is a liquid environment. Such embodiments are described in further detail in commonly-owned U.S. Pat. No. 6,375,635, which is herein incorporated by reference in its entirety.
One aspect of the invention involves the discovery that certain problems may arise when certain conventional surgical liquid jet instruments are used in surgical procedures, especially in a confined space within the body. For example, when an instrument is designed for use within a confined body space, the dimensions of components at the distal end of the instrument may be selected to be small to enable the instrument to fit into the confined space. When dimensions are reduced, the thickness of some components of the instrument, e.g. the wall thicknesses of evacuation and/or pressure tubes, may also be reduced, causing the instrument to present sharp and/or rough edges, which may damage the surrounding tissue when the instrument is inserted into the body.
To further demonstrate an example of this problem,
To prevent and/or reduce trauma to the surrounding tissue during surgical procedures utilizing liquid jet instruments, in certain embodiments of the invention, the terminal tip of the wall of the evacuation tube and/or the pressure tube is modified to reduce exposure of surrounding tissue to sharp corners or edges that could gall or cut tissue undesirably and that may be present on surgical liquid jet instruments manufactured with an essentially planar cut made perpendicular to the center axis of the evacuation/pressure tube at the terminal tip. As mentioned above, forming the terminal tip of the wall of the evacuation tube and/or the pressure tube with a planar cut perpendicular to the center axis of the lumen at the terminal tip can leave edges of the terminal tip of the wall of the tube that may inadvertently damage and/or cut tissue regions where it is not desirable. Accordingly, in certain embodiments of the invention, the walls of either or both of the evacuation tube and the pressure tube are provided with a blunted terminal tip. “Blunted” as defined previously is meant to encompass any treatment in which the terminal tip of a tube is less sharp in comparison to the terminal tip of an untreated tube with a planar cut perpendicular to the center axis of the tube at the terminal tip to the extent necessary so as to be substantially non-traumatic to tissue against which the terminal tip(s) of the tube(s) may be brought into contact during normal usage for procedures for which the instrument is indicated. As discussed in further detail below, in one embodiment, the blunted terminal tip of the tube wall may be formed by smoothly curving or bending the edges of the walls inwardly or outwardly with respect to the center axis of the tube at its terminal tip. In other embodiments, the blunted terminal tip may be formed by mechanically or chemically altering the terminal tip of the tube wall, and/or with heat treatment. In yet other embodiments, the blunted terminal tip may be formed by an attachment secured to the terminal tip of the tube wall.
As illustrated in the embodiment shown in
It should be appreciated that although
The blunted terminal tip 703 of the tube illustrated in
A representative example of a “cupping” method that may be employed in certain embodiments of the invention is illustrated in
Another representative example of a “cupping” method that may be employed in certain embodiments of the invention involves a mandrel or pin inserted into the tube, where the mandrel may help to define the curvature at the terminal tip of the tube. The mandrel and the tube may both be placed in the chuck of a lathe or other rotating machine, or otherwise caused to rotate. Then, a cupping device, which may simply be a piece of slanted or curved material, such as a metal, is pressed against the rotating tube to bend it against the mandrel to form the curvature of the terminal tip of the tube. After the desired contour is achieved, the mandrel is removed from the tube.
The inwardly angled/curved terminal tip modification of the evacuation tube may be configured to be functionally essentially the same as the above described evacuation tube embodiments. Therefore, it may be implemented in essentially any of the above described surgical liquid jet instrument embodiments. For example,
Further, as described above and illustrated in
The inventive surgical liquid jet instruments having a blunted terminal tip on components of the instrument, such as the evacuation tube wall or pressure tube wall may be well suited for insertion into the spine of a patient for spinal surgery applications. The spinal column is made up of the vertebrae bones which are connected in the anterior (front) portion of the spine by intervertebral discs. The intervertebral discs provide support and cushioning to the spine, serving as the spine's shock absorbing system. The discs also allow for some spinal motion, although individual disc movement is very limited. Many ligaments and muscles are also attached to the posterior (back) portion of the spine to provide power for spine movement. Each intervertebral disc is composed of an outer ring-like component made up of concentric sheets of collagen fibers, called the annulus fibrosus, and an inner semi-gelatinous tissue, called the nucleus pulposus. The radial structure of the annulus fibrosus prevents the nucleus pulposus from protruding from the disc. In the spinal column, there are four segments of spinal curvatures. From the superior (top) to the inferior (bottom) portions of the spinal column, these curvatures include the cervical, thoracic, lumbar, and sacral portions.
Surgical procedures on intervertebral discs in the lumbar, cervical, or thoracic portions of the spine are performed for a variety of reasons, which include treatment of tears in the annulus fibrosus, herniation of the nucleus pulposus, and significant disc height loss. Herniation results when the annulus fibrosus weakens such that the soft central nucleus pulposus bulges through the layers of the annulus fibrosus. The nucleus pulposus may bulge or leak posteriorly towards the spinal cord and major nerve roots, causing significant pain and discomfort.
One of the most common surgical procedures for treating a disc herniation is a discectomy. This procedure involves the removal of portions of the disc which impinge on the nerve roots or spinal cord posterior to the disc. All or portions of the nucleus pulposus may be removed to minimize the risk of additional herniations. The nucleus pulposus may be accessed by a variety of recognized surgical techniques. In certain embodiments, the nucleus pulposus is accessed directly through the annulus fibrosus. For example, the nucleus pulposus may be accessed by an incision through either the anterior portion or the posterior portion of the annulus fibrosus. In other embodiments, where an opening has already formed within the annulus fibrosus, it may be desirable to access the nucleus pulposus through this opening. In yet other embodiments, the nucleus pulposus is accessed via the vertebral body or through an end plate. For example, in certain embodiments, the nucleus pulposus may be accessed by penetrating into the spinal column through the sacral portion. It should be appreciated that in certain embodiments, the inventive surgical instruments may be inserted into the spine using a variety of techniques known for entering the spine, as would be recognized by one skilled in the art.
Various devices may be used to replace portions of the removed nucleus pulposus and/or annulus fibrosus, or the disc entirely. For example, when only the nucleus pulposus is replaced, a prosthetic device may be inserted through a hole created in the annulus fibrosus. Once the prosthetic device is within the confines of the annulus fibrosus, the device may expand, inflate, or deploy to fill the area of the disc that was removed.
In certain surgical applications, it may be desirable to remove all or portions of the inner nucleus pulposus, leaving the annulus fibrosus as intact as possible. However, conventional surgical instruments that are used to remove portions of the intervertebral disc suffer from not being able to distinguish between the two components of an intervertebral disc. As mentioned previously, because the inventive surgical liquid jet instruments can be configured and operated to provide for selective tissue differentiation in cutting and removal, they may, according to certain embodiments of the invention, be advantageously utilized in surgical procedures to remove all or portions of the inner nucleus pulposus while leaving the annulus fibrosus and/or other portions of the spine, such as the cartilage of the end plates, as intact as possible. Moreover, in certain embodiments, surgical liquid jet instruments including the inventive blunted terminal tip of the evacuation and or pressure tube wall may be used advantageously for such applications. If surgical liquid jet instruments lacking such blunted terminal tips are used to attempt to remove only the nucleus pulposus, portions of such a surgical instruments comprising sharp edges that abut either the annulus fibrosus or surrounding cartilage may tend to cause injury to such tissue due to the sharp corners/edges at the periphery of the terminal tip of either the evacuation lumen wall or the pressure lumen wall pressing against such tissue during use. Consequently, portions of the annulus fibrosus and/or surrounding cartilage may be undesirably cut or damaged. This may be compounded by the fact that there may be limited visibility when performing procedures within the intervertebral discs. Not only may this contribute to additional post-surgical scar tissue, added pain, and a longer recovery time, but the annulus fibrosus has been shown to have a very limited healing capacity. Healing of the annulus fibrosus typically results in the formation of a thin fibrous film along the perimeter of the annulus fibrosus that does not ever reach the original strength of the annulus pulposus.
However, in certain embodiments of the present invention, a surgical liquid jet instrument is provided with a modified evacuation tube wall and/or a modified pressure tube wall providing a blunted terminal tip, which may be used in inventive spinal surgical procedures to remove the nucleus pulposus without injuring, or with reduced injury to, the surrounding annulus fibrosus. When the terminal tip of the evacuation tube wall and/or the pressure tube wall is blunted, undesirable trauma to the intervertebral disc may be reduced or minimized when the surgical liquid jet instrument is used to remove portions of the disc. When the terminal tip of the evacuation tube wall and/or the pressure tube wall is blunted, the outer edges and surfaces of the tube walls of the instrument will tend to not harm or cause less harm to the surrounding tissue. Therefore, the tissue cutting/ablation/removal can be more readily limited to only the desirable regions which contact the liquid jet.
In certain embodiments, the pressure of the liquid jet may further be selected and/or adjusted to limit trauma to the tissue surrounding the excised tissue. As described above, the nucleus pulposus has a gel-like consistency. In contrast, the annulus fibrous is a much more rigid collagen lamellae structure. Therefore, one can adjust the pressure of the liquid jet to be sufficient to cut and ablate the nucleus pulposus, while not sufficient to damage the more rigid annulus fibrosus.
In certain embodiments of the invention, a surgical liquid jet instrument is employed for use in a surgical method involving the cutting or ablating of a first tissue within the spine of a patient, for example the nucleus pulposus within the intervertebral disc of a patient, while not cutting or ablating an underlying, adjacent, surrounding, and/or interdigitating tissue, e.g. the annulus fibrous, desired to be preserved from damage. An exemplary method comprises use of a surgical liquid jet instrument having a blunted terminal tip of the evacuation tube wall and/or the pressure tube wall for such a procedure.
For example, in one embodiment, the terminal tip of the evacuation lumen wall is blunted such that the outer surface of the terminal tip of the evacuation lumen wall curves/angles inwardly towards the jet-receiving opening, as provided by the invention, e.g. such as illustrated in
The method may include varying and/or selecting the pressure of the liquid jet to be sufficient to cut and/or ablate portions of the nucleus pulposus, yet not high enough to damage the surrounding annulus fibrosus. In certain embodiments, the pressure required to cut and/or ablate portions of the nucleus pulposus, while not damaging the surrounding annulus fibrosus may be dependent upon several factors. For example, this pressure may depend on the extent to which the annulus fibrosus has stiffened, and/or the nucleus pulposus has dehydrated, both of which generally increase with age. This pressure may also be dependent upon whether abnormal calcification is present. In certain embodiments, a pressure between about 2,000 psig and about 15,000 psig will provide a sufficient degree of differentiation to cut and/or ablate portions of the nucleus pulposus without damaging the healthy portions of the annulus fibrosus. However, this value may vary based upon the condition of the patient's spine, and on the configuration of the particular surgical instrument. A skilled operator of the surgical instrument could readily determine a more specific desirable pressure range. More particularly, by making adjustments to the pressure, such as by increasing the pressure until reaching a pressure that cuts and/or ablates the nucleus pulposus.
The above described cupping method is one method for forming a liquid jet surgical instrument which minimizes or eliminates the tendency of a terminal tip of a tube, and in particular a tube with a small thickness, to gouge tissue. However, several other treatments or procedures for blunting the terminal tip of the tubes used to construct surgical liquid jet instruments may alternatively be used in the context of the present invention.
Another approach to forming a blunted terminal tip is shown in
As mentioned above, another approach to forming a blunted terminal tip is to secure an attachment to the terminal tip of the tube walls. For example, as shown in
As mentioned above, the blunted terminal tip of the tube may be formed by smoothly curving or bending the edges of the tube 802 walls inwardly or outwardly with respect to the center axis of the lumen at the terminal tip.
Turning to
Furthermore,
In certain embodiments, portions of the material forming the blunted terminal tip may also be removed from the inner periphery of the evacuation tube 802. For example, portions of the terminal tip, such as the inside portion of the terminal tip 805 illustrated in
d illustrates yet another approach to forming a blunted terminal tip of an evacuation tube 802. In this embodiment, the tube has been blunted at its terminal tip 818, to form a less aggressive edge, by a mechanical force, such as hammering. To assist in the formation of this blunted terminal tip, the metal of the tube may be softened by heating.
e and 9f show the formation of a blunted terminal tip 819 of an evacuation tube 802 by the addition of an attachment, such as an external collar 822. As shown in more detail in
While several embodiments of the invention have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and structures for performing the functions and/or obtaining the results or advantages described herein, and each of such variations, modifications and improvements is deemed to be within the scope of the present invention. More generally, those skilled in the art would readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that actual parameters, dimensions, materials, and configurations will depend upon specific applications for which the teachings of the present invention are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the invention may be practiced otherwise than as specifically described. The present invention is directed to each individual feature, system, material and/or method described herein. In addition, any combination of two or more such features, systems, materials and/or methods, provided that such features, systems, materials and/or methods are not mutually inconsistent, is included within the scope of the present invention.
In the claims (as well as in the specification above), all transitional phrases or phrases of inclusion, such as “comprising,” “including,” “carrying,” “having,” “containing,” “composed of,” “made of,” “formed of,” “involving” and the like shall be interpreted to be open-ended, i.e. to mean “including but not limited to” and, therefore, encompassing the items listed thereafter and equivalents thereof as well as additional items. Only the transitional phrases or phrases of inclusion “consisting of” and “consisting essentially of” are to be interpreted as closed or semi-closed phrases, respectively. The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”
This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Ser. No. 60/636,421 entitled “Fluid Jet Surgical Instruments,” filed on Dec. 14, 2004, which is herein incorporated by reference in its entirety.
Number | Date | Country | |
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60636421 | Dec 2004 | US |