HK1188105B

HK1188105B - Safe cutting heads and systems for fast removal of a target tissue

Info

Publication number: HK1188105B
Application number: HK14101400.6A
Authority: HK
Inventors: J．图
Original assignee: DePuy Synthes Products, Inc.
Priority date: 2011-12-03
Filing date: 2012-08-22
Publication date: 2016-01-29

Abstract

A safe and efficient cutting heads for removing a target tissue from a subject during a surgical procedure are provided, the cutting heads composing a part of systems that address several problems, including clogging of state-of-the-art systems during removal of such tissue, for example. The target tissue can include any tissue that is accessible through a small surgical opening, for example, a joint tissue such as a meniscus or an intervertebral tissue, such as a nucleus pulposus. The devices can be referred to as orthopedic tissue removal devices having cutting heads associated with vacuum systems, making the systems useful in several procedures, including X-LIF (lateral approach to an intervertebral fusions) procedures, T-LIF (transforaminal approach to intervertebral fusions) procedures, P-LIF (posterior approach to intervertebral fusions), and a percutaneous, transforaminal approach (Kambin triangle access).

Description

Safety cutter head and system for rapid removal of target tissue

Cross Reference to Related Applications

This application claims priority from U.S. provisional application No.61/566,629, filed 2011, 12, month 3, and U.S. provisional application No.61/596,865, filed 2012, 2, month 9, the entire disclosures of both of which are hereby incorporated by reference in their entirety.

Technical Field

The teachings herein are generally directed to a safe and effective cutting head for use in resecting target tissue on a subject during a surgical procedure.

Background

Intervertebral disc disease is a major global health problem. Nearly 700,000 spinal surgeries are performed annually in the united states alone, and the total cost of treating back pain has exceeded 300 billion dollars. Age-related changes in the disc include loss of water from the nucleus and an increase in collagen content every 4 decades of life (the 4.sup. th decade). The reduction in water locked-up by the nucleus results in more compressive load on the annulus (annuus). This results in the ring being more prone to delamination (delaminations) and damage. Damage to the annulus results in accelerated disc degeneration as well as degeneration of surrounding tissue (e.g., intervertebral joints).

The two most common spinal surgeries performed are discectomy and spinal fusion. These procedures address only the symptoms of lower back pain, nerve compression, instability (instability) and deformity. The purpose of the fusion process of the intervertebral disc is to restore, maintain and stabilize the height of the intervertebral disc and/or reduce back pain. The process is typically implemented as: to stabilize the height, the intermediate disc material (e.g., cartilage on the inner annulus, nucleus, and end plates) is removed prior to replacing the bone graft and scaffold to effectively fuse the vertebral bodies within the treated disc. This removal process is known as discectomy (discectomy) and is both tedious and frequently inadequate, which can lead to poor fusion (compounded fusion), trauma, and time consumption due to the large incision and dissection required to expose the disc for discectomy.

In a typical discectomy procedure, a nuclectomy (nucleotomy) is first performed in which the nucleus is dissociated using a curette or a manual scraper (manual cutter) to shear the dissociated nucleus (nucleus iose), and the dissociated nucleus is then removed using a hard grasper called a rongeur. The surgeon must insert the rongeur through an opening in the disc called an incision (anulotomy), grasp the nucleus, and move it out of the disc and the operative corridor, clear the jaws (jaw) and reinsert repeatedly to grasp more of the disc. This process may pose safety issues for tissue (e.g., nerves) between tool channels. In addition, residual disc debris can prevent effective subsequent removal of tissue and insertion of a discectomy tool into the disc. The second step is decortication, in which the cartilage attached to the bone is removed using a rigid spatula (e.g., a curette or rasp) to help promote a secure intervertebral fusion. The stripped cartilage is scooped out by using a spatula and removed from the vertebral body by using rongeurs. Residual tissue debris may also reduce the efficiency and effectiveness of the decortication procedure, resulting in a weaker fusion. Furthermore, prior art tools are often difficult to reach corners in the disc and often leave areas of the disc insufficiently removed.

Furthermore, existing systems that utilize a combination of aspiration and cutting suffer from clogging problems due to the accumulation of excised tissue within the system. Those skilled in the art will appreciate that the above-described occlusion problem during surgical procedures is open and a solution to the above-described occlusion is highly desirable.

While a variety of advanced tools have been developed, none have addressed these tissues adequately at all. It would of course be desirable to have a discectomy system that is (i) less tedious and time consuming to use; (ii) less prone to occlusion by excised tissue; (iii) the object of operation is safer; and (iv) more effectively promote firm disc fusion.

Disclosure of Invention

The teachings provided herein are generally directed to a safe and effective cutting head for use in resecting target tissue on a subject during a surgical procedure. The target tissue may include any tissue that can be accessed through a small surgical opening, such as joint tissue (e.g., meniscus) in some embodiments, or disc tissue (e.g., nucleus pulposus) in other embodiments.

The cutting head may be tubular with a cutting surface forming at least a first face on a distal periphery of the cutting head, the cutting head being in operable communication with a suction device to resect target tissue in a manner to facilitate removal of the tissue by suction. The cutting surface may be, for example, flat, sinusoidal or serrated, and the first face of the cutting surface may form an angle θ_FPThe angle theta_FPUp to 75 from a position orthogonal to a central axis of the tool bit. In some embodiments, the cutting surface may have a second face, which may form an angle θ_SPThe angle theta_SPUp to 75 from a position orthogonal to a central axis of the tool bit. In some embodiments, the cutting head has a cutting edge and a cutting edge guard for preventing the cutting edge from cutting the surrounding tissue.

Accordingly, the present teachings include a tubular cutting head for removing a target tissue of interest. In these embodiments, the cutter head may have an outer periphery defining an internal cavity therethrough, the internal cavity having a central axis. The distal edge of the outer periphery of the cutting head may have a forward-facing cutting edge configured to (i) cut target tissue in an advancing stroke of the cutting head and (ii) direct the cut target tissue into the lumen. And, the cutting head may have a blade guard distal to the forward cutting blade and configured to prevent the forward cutting blade from cutting peripheral tissue during the forward stroke, the blade guard having a width less than a width of the cross-section of the inner lumen to facilitate entry of the target tissue into the inner lumen during the forward stroke.

In some embodiments, the cutting head may have a rearward cutting edge for cutting the target tissue during the return stroke of the cutting head, a lateral cutting edge for cutting the target tissue during the lateral stroke of the cutting head, or a combination of both. In some embodiments, a transverse cutting blade may be located on the blade guard to cut the target tissue during a transverse stroke of the cutting head.

In some embodiments, the rearward-facing cutting edge may be located on a distal edge of the outer periphery to cut the target tissue during the return stroke of the cutting head. In some embodiments, the rearward facing cutting blade may be located on the blade guard to cut the target tissue during the return stroke of the cutting head, the blade guard having a double blade tip at an angle θ greater than 90 °₂Is directed rearwardly into the lumen to grasp and/or cut tissue in the lumen during the return stroke of the cutting head.

The present teachings are also directed to a system of cutting heads that operably connect the cutting head to a cutting head of a suction assembly, as the cutting head can be designed to remove tissue by suction. Accordingly, the present teachings include a tissue removal system (a surgical) that includes a tubular cutting head for removing a target tissue of interest. The system may include a cutter head having: an outer periphery defining a suction flow through the cutter head; a lumen defined by the outer periphery, the lumen directing the suction flow and having a central axis; a forward cutting edge on a distal edge of the outer periphery, the forward cutting edge configured to (i) cut the target tissue in an advancing stroke of the cutting head and (ii) direct the cut target tissue into the lumen; and a blade guard distal to the forward cutting blade, and configured to prevent the forward cutting blade from cutting peripheral tissue (perimeter tissue) during the forward stroke of the cutting head. In some embodiments, the cutting blade guard has a width less than a width of a cross-section of the lumen to facilitate entry of the target tissue into the lumen during the forward stroke.

The cutting head may be configured to communicate operatively between the lumen and the suction source, and thus, the system includes a suction assembly in operative communication with the cutting head to create a suction flow for passing the target tissue through the lumen and out of the target, the suction assembly including a rigid suction tube having a central axis. In some embodiments, operatively communicating includes using one or more suction ports disposed at a proximal-most point near a distal edge of the outer periphery of the cutting head. In some embodiments, one or more ports may be located about 3mm to about 20mm from the closest point of the distal edge.

In some embodiments, the aspiration assembly includes an at least substantially rigid aspiration tube having a proximal end and a distal end, the distal end in operable communication with the cutting head, and the distal end configured to communicate with an aspiration source of the aspiration assembly. In some embodiments, the at least substantially rigid suction tube may be formed integrally with the cutting head.

In certain embodiments, the central axis of the lumen forms an angle θ with the central axis of the rigid suction tube₁The angle theta₁In the range of 5 ° to 90 ° and the forward cutting edge is located at a distance θ from the angle₁From about 3mm to about 25 mm.

The system of claim 10, said central axis of said lumen having an exit point on said forward cutting blade and said exit point being located at a transverse distance orthogonal to the central axis of said rigid suction tube of about 3mm to 25 mm.

In some embodiments, the central axis of the lumen is at an angle θ from the central axis of the aspiration flow at the distal end of the aspiration assembly₁The angle theta₁In the range of about 5 ° to about 90 ° and the forward cutting edge is positioned at an angle θ from the angle₁Are spaced apart by a distance of about 3mm to about 25 mm. In certain embodiments, the operative communication between the cutting head and the suction assembly may be an articulation, and the angle may be adjustable. In certain embodiments, the operative communication between the cutting head and the suction assembly may be rigid, the angle being fixed.

In certain embodiments, a central axis of the lumen forms an angle θ with a central axis of the aspiration flow at the distal end of the aspiration assembly₁The angle theta₁In the range of 1 ° to 180 ° and the forward cutting edge is located at a distance θ from the angle₁From 3mm to 25 mm. In these embodiments, the approach angle θ₁About 5mm to 25mm is an additional angle theta₃And angle theta₁And angle theta₃Are independently selected from the range of about 0 DEG to about 180 DEG, and the angle theta₁And angle theta₃Is (i) the central axis of the internal cavity of the cutting head and the approach angle theta₃The net angle theta between the central axes of the rigid suction pipes₄In the range of 0 ° to 90 °; and (ii) the distance between the central axis of the lumen of the cutting head and the central axis of the rigid suction tube is in the range of 2mm to 30 mm.

It should be appreciated that the cutting heads and systems taught herein have a variety of uses known to those skilled in the art. For example, in some embodiments, the target tissue may be the nucleus pulposus, and the peripheral tissue may be the annulus fibrosus.

Accordingly, the present teachings are also directed to a surgical tissue removal system for a discectomy, and may include a tubular cutting head for removing a nucleus pulposus from a target. In these embodiments, the system may include a cutter head having: an outer periphery defining a suction flow through the cutter head; an inner lumen defined by the outer periphery, the inner lumen directing the suction flow; a forward cutting edge on a distal edge of the outer periphery, the forward cutting edge configured to (i) cut the nucleus pulposus during an advancing stroke of the cutting head and (ii) direct the cut nucleus pulposus into the lumen; a backward cutting blade for cutting the nucleus pulposus in a backward stroke of the cutter head; a transverse cutting edge for cutting the nucleus pulposus in a transverse stroke of the cutter head; and a blade guard distal to the forward cutting blade and configured to prevent the forward cutting blade from cutting the annulus fibrosis during the forward stroke. Also, the blade guard may have a width, for example, less than a width of a cross-section of the lumen, to facilitate entry of the target tissue into the lumen during the forward stroke.

The teachings also include a method of removing a target tissue from a subject. In these embodiments, the method can include creating an opening in the subject for accessing the target tissue; inserting a cutting head taught herein through the opening to access the target tissue in the subject; and advancing the cutting head in a forward direction over a surface including the target tissue to remove the target tissue. The forward direction may include a force vector that moves (i) at least generally on a plane that includes a central axis of the lumen of the cutting head, (ii) at least generally on the surface that includes the target tissue, and (iii) toward the peripheral tissue that is protected by the cutting blade guard. Also, the method can include grasping the target tissue within the lumen of the cutting head and moving the target tissue through the lumen and out of the target.

In certain embodiments, the method comprises advancing a cutting head taught herein in a rearward direction over a surface comprising the target tissue to remove the target tissue. The rearward direction includes a force vector that moves (i) at least generally on a plane that includes a central axis of the lumen of the cutting head, (ii) at least generally on the surface that includes the target tissue, and (iii) away from peripheral tissue protected by the cutting blade guard.

In certain embodiments, the method comprises advancing a cutting head as taught herein in a lateral direction over a surface comprising the target tissue to remove the target tissue. The transverse direction may include a force vector that moves (i) at an angle in a range of about 15 ° to about 150 ° from a plane including a central axis of the lumen of the cutting head, (ii) at least substantially over a surface including the target tissue, and (iii) into contact with the peripheral tissue protected by the blade guard.

The present teachings are also directed to an obturator guard cannula (obturator) that protects a target when an elongated surgical cutting device having non-linearity enters and exits. In these embodiments, the protective cannula may include an inlet hub having an inner periphery, an outer periphery, and a flush port communicating between the inner periphery and the outer periphery; and a linear, elongated split-tube (split-tube) having a proximal end, a distal end, and an inner lumen. In these embodiments, the proximal end of the split-tube can (i) define at least a portion of the inner periphery of the inlet hub, and (ii) be in operable communication with the irrigation port. In these embodiments, the communication is operable to receive the irrigation fluid from the irrigation port, and delivering the irrigation fluid to the target tissue includes, for example, moving the irrigation fluid from the irrigation port to the distal end of the split-tube over the inner lumen surface of the split-tube.

The distal ends of the split-tubes can also have any configuration desired by one skilled in the art. For example, the distal end may be at least substantially pointed and/or sharp. In some embodiments, the distal end may be at least substantially blunt to avoid damaging the entry tissue when the distal end is in contact with the entry tissue. The length of the split-tube can be in the range of about 10cm to about 60cm, and the width of the split-tube can be in the range of about 5mm to about 16 mm. Further, the split (split) of the split-tube may constitute a gap having a width in the range of about 4mm to about 14mm, the split having a non-linearity in the surgical device.

As noted above, the systems taught herein may be used in a variety of surgical procedures for removing target tissue from a subject, including, for example, removal of a meniscus or discectomy. In some embodiments, the surgical cutting device utilizing the protective cannula may be a discectomy device. Also, in some embodiments, the inlet tissue comprises epithelial tissue, muscle tissue, neural tissue, connective tissue, blood vessels, bone, cartilage, or a combination thereof, of the target to the nucleus pulposus. Thus, in some embodiments, the target tissue may comprise the nucleus pulposus.

The teachings are also directed to a surgical tissue removal tool having a surgical tissue removal system and a protective cannula utilizing any combination of the system and protective cannula embodiments taught herein. In some embodiments, the surgical tissue removal tool may be a discectomy tool. Thus, in certain embodiments, the inlet tissue comprises epithelial tissue, muscle tissue, neural tissue, connective tissue, blood vessels, bone, cartilage, or a combination thereof, of the target to the nucleus pulposus. Thus, the target tissue may include the nucleus pulposus in some embodiments.

The teachings also refer to a method of removing a target tissue using the tool. In some embodiments, the method includes creating an opening in the subject for access to the target tissue; inserting a cutting head of the tool through an inlet hub and an elongated split-tube of a protective cannula of the tool; inserting the tool through the opening to access the target tissue in the subject while protecting the entry tissue with the blunt distal end of the split-tube. In other aspects, methods of using the tissue removal system are the same as or similar to those taught herein. It will be appreciated by those skilled in the art that such a tool may be used in a discectomy, for example, where the target tissue may be the nucleus pulposus and the peripheral tissue may be the annulus fibrosus. It will also be appreciated by those skilled in the art that the tool is provided with a protective cannula that helps protect the target epithelial tissue, muscle tissue, nerve tissue, connective tissue, blood vessels, bone, cartilage, or combinations thereof, leading to the nucleus pulposus in such procedures.

Those skilled in the art will appreciate that the embodiments taught herein are provided for the purpose of generally teaching concepts and that those skilled in the art will also appreciate that the teachings provided herein include a variety of other embodiments and can be derived from the teachings provided herein.

Drawings

FIGS. 1A-1D illustrate various tubular bit structures that may be fabricated from tubing (stock tube), according to some embodiments;

fig. 2A-2E illustrate cutting edge configurations according to some embodiments;

3A-3C illustrate cross-sections of individual cutting edge profiles according to certain embodiments;

FIGS. 4A-4C illustrate a cutter head according to certain embodiments;

FIGS. 5A and 5B illustrate an angle (alignment) of a tool tip 500 according to some embodiments;

FIG. 6 illustrates an obturator protective cannula according to certain embodiments;

FIG. 7 illustrates a surgical tissue removal tool according to certain embodiments;

figures 8A-8C illustrate a surgical tissue removal system or tool that can be irrigated while suction is being used and does not require an obturator protective cannula to be installed in place, according to some embodiments;

FIGS. 9A-9G illustrate tested tool tip designs according to certain embodiments;

fig. 10A to 10E illustrate a modification (advance) of the cutter head according to some embodiments;

fig. 11A-11C illustrate bayonet-type communication between a cutting head and a suction assembly according to certain embodiments.

Detailed Description

The teachings provided herein are generally directed to a safe and effective cutting head for use in surgical procedures to remove target tissue from a subject. The target tissue may include any tissue that may be accessed through a small surgical opening, such as joint tissue (e.g., meniscus) or intervertebral disc tissue (e.g., nucleus pulposus). In certain embodiments, the device taught herein may be referred to as an orthopedic tissue removal device (orthopedics tissue removal device). In certain embodiments, the devices taught herein are useful in an X-LIF (lateral approach to intervertebral fusion) procedure, a T-LIF (transforaminal to intervertebral fusion) procedure, a P-LIF (posterior approach to intervertebral fusion) procedure, or a percutaneous intervertebral access (a percutaneous, transforaminal approach).

In certain embodiments, the terms "target" and "patient" are used interchangeably, and "target" and "patient" refer to an animal, e.g., a mammal, including, but not limited to, a non-primate (such as a cow, pig, horse, cat, dog, murine) and a primate (such as a monkey or human). Thus, the terms "target" and "patient" may also apply to non-human biological contexts, including but not limited to disease animals, pets, commercial livestock, and the like.

The cutting head may be tubular with a cutting surface forming at least a first face on a distal periphery of the cutting head, the cutting head being in operable communication with a suction device to resect target tissue in a manner to facilitate removal of the tissue by suction.

The cutting surface may be, for example, flat, sinusoidal, or serrated, and the first face of the cutting surface may form an angle θ_FPThe angle theta_FPUp to 75 from a position orthogonal to a central axis of the tool bit. In some embodiments, the cutting surface may have a second face, which may form an angle θ_SPThe angle theta_SPUp to 75 from a position orthogonal to a central axis of the tool bit. In some embodiments, the cutting head has a cutting edge and a cutting edge guard for preventing peripheral tissue from being cut by the cutting edge. In certain embodiments, the angle θ_FPAnd angle theta_SPMay be independently selected from the range of 0 ° to about 75 °, about 5 ° to about 75 °, about 10 ° to about 70 °, about 15 ° to about 65 °, about 10 ° to about 60 °, about 5 ° to about 55 °, about 15 ° to about 50 °, about 20 ° to about 45 °, about 15 ° to about 40 °, about 25 ° to about 35 °, or may be independently selected from any angle or any angular range herein increased by 1 °.

FIGS. 1A-1D show a rootAccording to some embodiments of the various tubular bit configurations, the bit configuration may be made from tubing (stock tube). FIG. 1A shows a bit tube 100 having a first face 105, the first face 105 forming an angle θ_FPThe first face 105 is orthogonal to the central axis 110 of the lumen of the tubing 100. FIG. 1B shows a bit tube 100 having a first face 105, the first face 105 forming an acute angle θ with a central axis 110 of the lumen of the tube 100_FPThe acute angle theta_FPIn the range of 1 deg. to about 75 deg.. FIG. 1C illustrates a tool bit tube 100 having a first face 105, the first face 105 forming an acute angle θ with a central axis 110 of the lumen of the tube 100_FPThe acute angle theta_FPIn the range of 1 ° to about 75 °; and the bit tube has a second face 105, the second face 105 forming an angle theta_SPThe second face 105 is orthogonal to the central axis of the inner cavity 110 of the tubing 100. FIG. 1D illustrates a bit tube 100, the bit tube 100 having a first face 105, the first face 105 forming an acute angle θ with a central axis of the inner cavity 110 of the tube 100_FPThe acute angle theta_FPIn the range of 1 ° to about 75 °; and the cutting head tube has a second face 105, the second face 105 forming an acute angle θ with a central axis 110 of the lumen of the tube 100_SPThe acute angle theta_SPIn the range of 1 deg. to about 75 deg..

The cutting head may be fabricated from any material known to those skilled in the art to be suitable for the surgical environment in which the teachings herein are used. For example, hard materials having a hardness greater than Rockwell C30 or a hardness greater than Rockwell C45 may be suitable in certain embodiments. In some embodiments, the cutting head may comprise a composition selected from the group consisting of: tempered steel, stainless steel, high carbon steel, titanium or titanium alloys, ceramics, diamond and obsidian. In certain embodiments, the stainless steel may comprise 304 stainless steel, 316 stainless steel, 17-4PH stainless steel, 400 series stainless steel, or any stainless steel material known to those skilled in the art suitable for the cutting function taught herein. In some embodiments, the cutting tip may be made of cobalt chromite (cobalt chromium), tungsten carbide (tungsten carbide), or a ceramic material.

The wall thickness of the tube forming the tool tip may be, for example, between 0.003 "and 0.020", more specifically between 0.005 "and 0.012". The cross-sectional area of the tool tip may be in the range of 0.120 square inches to 1.5 square inches, or, in some embodiments, the cross-sectional area of the tool tip may be in the range of 0.180 square inches to 0.400 square inches. The width in any direction may range from 0.080 "to 0.400" or greater, and in certain embodiments, may range from 0.160 "to 0.250". In some embodiments, the maximum cross-sectional dimension of the tool tip is between 3.0mm and about 20.0mm, between 4.0mm and about 15mm, between about 4.0mm and about 12.0mm, between about 5.0mm and about 10.0mm, between about 5.0mm and about 8.0mm, or any range therein increased by 0.1 mm. In some embodiments, the diameter of the cutting head is about 4.8mm, about 5.0mm, about 5.2mm, about 5.4mm, about 5.8mm, about 6.0mm, about 6.2mm, about 6.4mm, about 6.6mm, about 6.8mm, about 7.0mm, about 7.2mm, about 7.4mm, about 7.6mm, about 7.8mm, about 8.0mm, about 8.2mm, and any diameter 0.1mm added thereto.

The distal perimeter of the cutting tip may be on the first face or the second face, or a combination thereof, and the cutting surface may be any cutting surface known to those skilled in the art, for example, in some embodiments, the cutting surface may be a razor surface, a serrated surface, or a sinusoidal surface. There are many cutting edge designs known to those skilled in the art, and any of these configurations may be utilized. For example, the cutting surface may have teeth and gullets between the teeth. The spacing between the plurality of teeth may be equal or may vary, and the depth of the gullets may be equal or may vary, and any combination of teeth and gullets may be utilized. In some embodiments, the direction of the projection of the tooth may be offset from the direction of the remainder of the wall (remainder) of the cutter head. In some embodiments, the teeth are in the same direction as the remainder of the wall of the cutter head, such that the teeth are simply extensions of the wall of the cutter head and do not change direction toward or away from the internal cavity of the cutter head. In some embodiments, there is a pattern of alternating directions of the teeth away from or toward the interior cavity of the cutter head. For example, the pattern may be in the order of facing, away, no offset, and this order repeats around the distal edge of the outer periphery of the cutting head. In some embodiments, all of the teeth are directed toward the lumen, and in some embodiments, all of the teeth are directed away from the lumen. In some embodiments, each tooth of the plurality of teeth is alternately directed toward and away from the lumen. Also, in certain embodiments, each of the plurality of teeth tapers toward and away from the lumen at progressively increasing and decreasing angles to create a wavy appearance as the teeth encircle the distal edge of the outer periphery. The order may also be completely random.

Fig. 2A-2E illustrate cutting edge configurations according to some embodiments. Fig. 2A shows a 5-tooth shift pattern with repeated facing, away, and no change. Fig. 2B shows a random transformation pattern. Fig. 2C shows a wave-shaped transformation pattern. Fig. 3D shows a 3-tooth shift pattern that repeats away, toward, and no change. Also, FIG. 3E shows a simple repeated far and far, direction transition pattern.

In some embodiments, the configuration of the cutting edge may be selected in conjunction with selecting the profile of the cutting edge. Those skilled in the art of designing cutting edges will appreciate that the tool tips taught herein may have a variety of cutting actions, such as, for example, a chisel action, a sawing action, a slicing action, and a cleaving action. Thus, the profile of the cutting edge selected may be modified to use any cutting edge profile known to those skilled in the art. In certain embodiments, the teeth are beveled. In some embodiments, the cutting head may have a rearward facing tooth and a forward facing tooth to include a forward facing cutting surface in addition to a rearward facing cutting "spur".

Thus, the teachings include a tubular cutting head for removing a target tissue on a subject. Also, the tube may be an elongated, tubular structure having any shape (e.g., round, square, rectangular, elliptical, pentagonal, hexagonal, heptagonal, octagonal, etc.), such that in some embodiments, any number of sides, curves, or a combination thereof of tubes may be utilized. In certain embodiments, a round tube is utilized.

The cutting head may have a combination of various types of cutting edges (e.g., forward, rearward, and lateral cutting edges, as well as projections, hooks, etc.) to grasp, cleave, or otherwise remove tissue. In some embodiments, the cutting head has: a rearward cutting edge for cutting the target tissue in a backward stroke of the cutter head; a transverse cutting edge for cutting the target tissue in a transverse stroke of the cutting head; or a combination of a backward cutting edge and a transverse cutting edge. In some embodiments, a transverse cutting blade may be located on the blade guard for cutting the target tissue during a transverse stroke of the cutting head.

Fig. 3A-3C illustrate cross-sections of individual cutting edge profiles according to some embodiments. Figure 3A shows a planar-concave cutting edge profile. Figure 3B shows a wedge-shaped cutting edge profile. Also, fig. 3C illustrates a chisel cutting edge profile. Likewise, it should be understood that the cutting edge may be designed with any configuration (including single sided, double sided, single barb, double barb, straight tip, barbed tip, etc.) to aid in any form of tissue removal (including cutting, slicing, chiseling, scraping, planing, sawing, grinding, and cleaving of tissue) to effectively remove the tissue, for example, during a surgical procedure.

Fig. 4A-4C illustrate a tool tip according to some embodiments. Fig. 4A shows an oblique view of the cutter head, and fig. 4B shows a side view of the cutter head. The tool bit 400 may have an outer periphery 405, the outer periphery 405 defining an internal cavity 410 through the tool bit 400, the internal cavity 410 having a central axis 415. The cutting head 400 may also have a forward cutting edge 420, the forward cutting edge 420 being located on a distal edge 425 of the outer periphery 405, the forward cutting edge 420 being configured to (i) cut a target tissue (not shown) during the forward stroke of the cutting head 400 and (ii) direct the cut target tissue into the lumen 410. Also, the cutting head 400 may have a cutting blade guard 430 located distal of the forward cutting blade 420 and configured to prevent peripheral tissue (not shown) from being cut by the cutting blade 420 during the forward stroke, the cutting blade guard 430 having a width 433 less than a width 422 of the cross-section of the inner lumen 410 to facilitate entry of the target tissue into the inner lumen 410 during the forward stroke. Also, as shown in fig. 4A-4C, the side surfaces 409 of the blade guard may be serrated, or otherwise shaped sharp cutting surfaces for transverse cutting.

Since the cutting-head can be designed to remove tissue by using suction 444, the teachings also refer to a system of cutting-heads that operatively connects the cutting-head to a suction assembly 484 (only the distal end is shown). Thus, fig. 4C also illustrates a surgical tissue removal system that includes a tubular cutting-head 400, the cutting-head 400 being used to remove a target tissue of interest (not shown). The surgical tissue removal system can include a cutting head 400, the cutting head 400 having: an outer periphery defining a suction flow 444 through the cutter head 400; a lumen 410, the lumen 410 being defined by the outer periphery 405, the lumen 410 directing a suction flow 444 and having a central axis 415; a forward cutting edge 420, the forward cutting edge 420 being on a distal edge 425 of the outer periphery 405, the forward cutting edge 420 being configured to (i) cut the target tissue during the forward stroke of the cutting head 400 and (ii) direct the cut target tissue into the lumen 410; and a blade guard 430, the blade guard 430 being located distally relative to the forward cutting blade 420 and configured to prevent peripheral tissue (not shown) from being cut by the forward cutting blade 420 during the forward stroke.

The cutting head can be configured to operably communicate between the lumen 410 and the suction source 444, and thus, the system 400 includes a suction assembly 484, the suction assembly 484 operably communicating with the cutting head 400 to generate a flow of suction 444 to remove the target tissue out of the target through the lumen 410, the suction assembly 484 including a rigid suction tube 488, the suction tube 488 having a central axis. In some embodiments, the operative communication includes the use of one or more suction ports 466, the suction port 466 being located at a proximal-most point proximate a distal-most edge of the bit periphery. In some embodiments, the one or more suction ports 466 can be located approximately 3mm to 20mm proximal to the closest point of the distal edge 425. Without being bound by any theory or mechanism of action, those skilled in the art will appreciate that an additional source of air may be useful when suctioning within an area where a vacuum may be created that may otherwise impede or terminate the suction flow that transports excised tissue away from the surgical field during removal of tissue. The suction port 466 may be used to provide additional air to avoid creating a vacuum in the surgical field.

Any pumping assembly configuration known to those skilled in the art may be utilized in many embodiments. In certain embodiments, suction assembly 484 includes an at least substantially rigid suction tube 488, suction tube 488 having a proximal end (not shown) and a distal end 499, distal end 499 being operably in communication with cutting-head 400, and distal end 499 being configured to communicate with suction source 444 for suction assembly 484. In some embodiments, an at least substantially rigid suction tube 488 can be formed integrally with cutting-head 400. The phrase "at least substantially rigid" may refer to an element that is rigid, or sufficiently rigid, such that a desired function is achieved under the forces generated by normal use. For example, the desired function may be to prevent or prevent the rigid element from creating a bending moment at one or more points along the length of the rigid suction tube when the cutting head is used on the target.

The following table describes the dimensional ratios of the cutting head 400 that have been found to achieve rapid and effective tissue removal in a discectomy. "labels" are used to show the elements and measures that form the dimensional ratios described on small and large devices.

The rigid suction tube may comprise any material known to those skilled in the art to be suitable for use in the teachings herein. For example, the rigid suction tube may comprise any surgical steel, plastic or resin deemed necessary by those skilled in the art for the devices taught herein. In some embodiments, the rigid suction tube may comprise the same or similar material as the cutting head. In certain embodiments, the rigid suction tube may comprise stainless steel, Polyetheretherketone (PEEK), polyimide, or carbon fiber. The wall thickness of the shaft can be any thickness where the selected material will have the desired physical properties. In certain embodiments, the wall thickness may be, for example, in the range of 0.003 "to 0.020", and, in certain embodiments, may be in the range of 0.005 "to 0.010". The inner lumen surface of the aspiration tube may be coated with polytetrafluoroethylene (TEFLON), a hydrophobic coating (e.g., parylene), or a hydrophilic coating (e.g., polyvinyl alcohol or polyethylene glycol).

In some embodiments, the rigid suction tube may comprise a metal braided wire reinforced polymer tube, coiled tube, or tube with transverse grooves to facilitate articulation in some embodiments where articulation is desired. In these embodiments, the cutting head can be angled relative to the axis of the rigid suction tube by, for example, pulling a tendon (tendon) attached to one side of the cutting head that extends along a guide (guide) on one side of the rigid suction tube.

Fig. 5A and 5B illustrate angles of a tool tip 500 according to some embodiments. FIG. 5A illustrates that the central axis 515 of the lumen 510 may be in communication with the suction flow 544 at the distal end 599 of the suction assembly (partially shown) 584The central axis 555 forms an angle θ₁The angle theta₁In the range of about 5 to about 90, and the forward cutting edge 520 may be at a distance angle θ₁From about 2mm to about 25 mm. In some embodiments, θ₁May be in the range of about 2mm to about 30mm, about 2.5mm to about 25mm, about 3mm to about 25mm, about 4mm to about 20mm, about 5mm to about 15mm, about 3mm to about 25mm, about 7mm to about 12mm, about 8mm to about 10mm, or any range there between increased by 0.5 mm.

In certain embodiments, the angle θ between the central axis of the lumen and the central axis of the rigid suction tube₁In the range of about 5 ° to about 90 °, and the forward cutting edge distance angle θ₁From about 3mm to about 25 mm. Also, in certain embodiments, the central axis of the lumen has an exit point on the forward cutting blade, and the exit point is located at a transverse distance of about 3mm to about 25mm, the transverse distance being orthogonal to the central axis of the rigid suction tube.

In certain embodiments, the angle θ between the central axis of the lumen and the central axis of the aspiration flow at the distal end of the aspiration assembly₁In the range of 1 DEG to 180 DEG, and a forward cutting edge distance angle theta₁3mm to 25 mm. In these embodiments, the additional angle θ₃At approach angle theta₁At a position of 5mm to 25mm, and an angle theta₁And angle theta₃Are independently selected from the range of about 0 DEG to about 180 DEG and are limited to (i) the central axis of the cutting head and the approach angle theta₃The net angle theta between the central axes of the rigid suction pipes₄Between 0 ° and 90 °; and (ii) the distance between the central axis of the lumen of the cutting head and the central axis of the rigid suction tube is between 2mm and 30 mm. Thus, at the angle θ₁And angle theta₃May be between about 5mm and about 30mm, between about 5mm and about 25mm, between about 5mm and about 20mmBetween about 6mm and about 18mm, between about 7mm and about 15mm, or any range there increasing by 1 mm.

In some embodiments, the operative communication between the cutting head 500 and the suction assembly 584 may be articulated through an angle θ₁May be adjustable. In some embodiments, the operative communication between the cutting head 500 and the suction assembly 584 can be rigid, with an angle θ₁May be fixed. In certain embodiments, the angle θ₁May be in the range of 0 ° to about 45 °, in the range of about 1 ° to about 40 °, in the range of about 5 ° to about 35 °, in the range of 10 ° to about 35 °, in the range of 15 ° to about 40 °, in the range of 20 ° to about 30 °, or any range increased by 1 ° herein. In certain embodiments, the angle θ₁May be about 3 °, about 5 °, about 10 °, about 15 °, about 20 °, about 25 °, about 30 °, about 35 °, about 40 °, about 45 °, or any angle herein increased by 1 °.

In some embodiments, the rearward-facing cutting edge can be located on the distal edge 525 of the outer perimeter 505 to cut the target tissue during the return stroke of the cutting head 500. In some embodiments, a rearward facing cutting blade 531 can be positioned on the blade guard 530 to cut the target tissue during the return stroke of the cutting head 500. Fig. 5B illustrates a guard 530 having a dual-edged tip as a rearward-facing cutting edge 531 at an angle θ of greater than 90 ° from the central axis 515 of the lumen 500₂Is directed rearwardly toward the internal cavity 515 to grasp and/or cut tissue in the internal cavity 510 during the return stroke of the cutting head 500. Since the function of the rearward-facing cutting edge may be to grasp, shear, and hook tissue to be removed, in certain embodiments, the rearward-facing cutting edge 531 may be referred to as a "claw (talon)" or a "pincer (pincer)".

It should be understood that the cutting heads and systems taught herein have numerous applications known to those skilled in the art. In certain embodiments, for example, the target tissue may be the nucleus pulposus, and the peripheral tissue may be, for example, the annulus fibrosus.

A surgical tissue removal system for a discectomy is provided and may include a tubular cutting head for removing a nucleus pulposus from a target. In these embodiments, the surgical tissue removal system may comprise: a tool bit having: an outer periphery defining a suction flow through the cutter head; a lumen defined by the outer periphery and directing the suction flow; a forward cutting edge on a distal edge of the outer periphery, the forward cutting edge configured to (i) cut the nucleus pulposus during an advancing stroke of the cutting head and (ii) direct the cut nucleus pulposus into the lumen; a backward cutting blade for cutting the nucleus pulposus in a backward stroke of the cutter head; a transverse cutting edge for cutting the nucleus pulposus in a transverse stroke of the cutter head; and a blade guard distal to the forward cutting blade and configured to prevent the forward cutting blade from cutting the annulus fibrosus during the forward stroke.

Another valuable feature is that the device of the teachings described herein can be operated without substantial obstruction to the flow of tissue being resected by the cutting head and by design to achieve this. Without being bound by any theory or mechanism of action, it will be found that the cross-sectional area of the distal end of the cutting head will be at least approximately equal to or less than the cross-sectional area of any point near the distal end of the cutting head that causes (leading to) the flow of tissue that the cutting head resects to converge. These points will include, for example, any point along the cross-section of the rigid suction tube, or any other element of the suction assembly that causes a collection point for the excised tissue, e.g., in some embodiments, a pressure differential that dumps the excised tissue to the nearest orifice in a collection canister (collecting vessel). In certain embodiments, the term "at least approximately equal" means that there may be a smaller cross-sectional area, as long as it is limited to a smaller range. In some embodiments, the cross-sectional area can be at least approximately equal to the cross-sectional area of the cutting head if the cross-sectional area is less than the cross-sectional area of the cross-section at the proximal end by no more than 20%. In some embodiments, the cross-sectional area can be at least approximately equal to the cross-sectional area of the cutting head if the cross-sectional area is less than the cross-sectional area at the proximal end by no more than about 3%, about 5%, about 7%, about 9%, about 11%, about 13%, about 15%, about 17%, about 19%, or about 21%. The amount of smaller cross-sectional area than the proximal cross-section may here be any percentage increase of 1%.

The teachings also include a method of removing a target tissue from a subject. In these embodiments, the method can include fabricating an opening in the subject for access to the target tissue; inserting a cutting head as taught herein through the opening to access a target tissue in the subject; imaging the depth of the tip of the tool tip using a suitable imaging technique (e.g., fluoroscopy); and advancing the cutting head in a forward direction over a surface including the target tissue to remove the target tissue while activating a vacuum to aspirate adjacent excised tissue. The forward direction may include a force vector that moves (i) at least generally on a plane that includes a central axis of the lumen of the cutting head, (ii) at least generally on a surface that includes the target tissue, and (iii) toward the peripheral tissue that is protected by the cutting blade guard. Also, the method can include grasping target tissue within a lumen of the cutting head and passing the target tissue through the lumen and out of the target.

The term "at least approximately at … …" may refer to a position or movement that is sufficiently close to an exact desired position that the desired function may be achieved under the forces and conditions that would normally be generated using the system taught herein. For example, "at least substantially on a plane including the central axis of the lumen of the cutting head" or "at least substantially on a surface including the target tissue" may refer to a position or movement parallel or substantially parallel to the plane or surface, but the position may deviate from the actual plane or surface by about 1um to about 15mm, or the direction of movement may deviate from about 0.1 ° to about 20 °. An "at least approximately" measurement is used in an approximation context where an exact measurement or an exact position cannot be obtained, but one of ordinary skill in the art can obtain the desired functionality. For example, a diminished result, when compared to the best possible result, can be used to determine what is the "at least approximate" desired result. In certain embodiments, the desired result is at least approximately achieved where the best possible result is reduced by less than 10%, less than 15%, less than 20%, less than 30%, less than 40%, or less than 50%. In certain embodiments, the desired result is at least approximately achieved at a location within any range of about 5% to about 30%, about 7% to about 35%, about 10% to about 25%, or an increase of 1% therein, of the reduction in the best possible result.

In a discectomy, the opening in the target may be altered according to the disc height of the target, which is typically in the range of about 5mm to 7 mm. In certain embodiments, the size of the opening in the target may be in the range of about 4mm x 4mm to about 14mm x 14 mm. In some embodiments, the opening may be about 10mm by 7 mm.

In certain embodiments, the method comprises advancing a cutting head taught herein in a rearward direction over a surface comprising the target tissue to remove the target tissue. The rearward direction may include a force vector that moves (i) in a plane that is at least generally in a plane that includes a central axis of the lumen of the cutting head, (ii) in a plane that includes at least generally the target tissue, and (iii) away from the peripheral tissue protected by the cutting blade guard.

In certain embodiments, the method comprises advancing a cutting head as taught herein in a lateral direction over a surface comprising the target tissue to remove the target tissue. For example, the transverse direction may include a force vector that moves (i) at an angle in a range of about 15 ° to about 165 ° from a plane including a central axis of the lumen of the cutting head, (ii) at least substantially over a surface including the target tissue, and (iii) into contact with peripheral tissue protected by the blade guard.

The blades taught herein are sharp and may be harmful to tissue as the blade enters or exits through the surgical opening. In some embodiments, an obturator canula (guard canula) is provided to protect the target when the non-linear elongated surgical cutting device is advanced or withdrawn.

Figure 6 illustrates an obturator protective cannula according to certain embodiments. The obturator guard cannula 600 may include: an inlet hub 605, the inlet hub 605 having an inner periphery 615, an outer periphery 625, and a flush port 635, the flush port 635 communicating between the inner periphery 615 and the outer periphery 625; and a linear, elongated split-tube 650, the split-tube 650 having a proximal end 655, a distal end 665, and a lumen 675. In these embodiments, the proximal end 655 of the split-tube 650 can (i) define at least a portion of the inner circumference 615 of the inlet hub 605 and (ii) be in operable communication with the irrigation port 635. In these embodiments, the communication is operable to receive the irrigation fluid 690 from the irrigation port 635, and the delivery of the irrigation fluid 690 to the target tissue (not shown) includes, for example, the irrigation fluid 690 moving on the inner lumen surface 680 of the split-tube 650 from the irrigation port 635 to the distal end 665 of the split-tube 650.

One skilled in the art will appreciate that the "flushing fluid" may be any fluid desired by one skilled in the art, including liquids and gases. In certain embodiments, the flushing fluid may be aqueous (aqueous). In certain embodiments, the flush fluid may be non-aqueous (non-aqueous). Also, in certain embodiments, the irrigation fluid may be an emulsion. In certain embodiments, the flushing fluid may comprise a gas. Examples of aqueous rinse fluids may include water, saline (saline), or aqueous surfactants including liquids (aqueous surfactants). Examples of non-aqueous fluids may include any oil-based liquid that may be helpful in achieving tissue extraction during surgery. Examples of gases may include carbon dioxide, nitrogen, air, and any inert or at least substantially non-reactive gas. In certain embodiments, the flushing fluid may include a lubricant, such as glycerin, silicone oil, and the like. The irrigation fluid may serve as a carrier to aid in the removal of the resected tissue or to prevent the creation of a vacuum at the surgical site that may interfere with the removal of the resected tissue. An example of such a vacuum is that generated when suction is applied within a closed cavity (e.g., an intervertebral space within the annulus) during a discectomy.

The distal end 665 of the split-tube 650 can also have any configuration desired by one skilled in the art. For example, the distal end 665 can be at least generally pointed and/or non-blunt. In some embodiments, distal end 665 can be at least substantially blunt to avoid injuring the entry tissue when distal end 665 is in contact with the entry tissue. The length of the split-tube 650 can also be in the range of about 10cm to about 60cm, and the width of the split-tube 650 can be in the range of about 5mm to about 16 mm. Further, the slit (split) in the split-tube 650 constitutes a gap 667, the gap 667 having a width in the range of about 4mm to about 14mm, the slit having a non-linearity in the surgical device. In some embodiments, the diameter of the cutting head taught herein may be smaller than the diameter of the portion of the suction assembly that passes through the lumen of the obturator guard cannula, such that the obturator guard cannula retains the suction assembly 484 but allows the cutting head 400 to pass through the gap 667. Thus, the width of the gap 667 can exceed the diameter of the cutting head 400, but be less than the diameter of the rigid suction tube 488, and the diameter of the lumen of the obturator protective cannula 600 is greater than the diameter of the rigid suction tube 488.

As noted above, the systems taught herein may be used in a variety of surgical procedures for removing target tissue from a subject, including, for example, removal of a meniscus or discectomy. In some embodiments, the surgical resection device used with the protective cannula may be a discectomy device. Also, in some embodiments, the inlet tissue comprises epithelial tissue, muscle tissue, neural tissue, connective tissue, blood vessels, bone, cartilage, or a combination thereof on the target leading to the nucleus pulposus. Thus, in some embodiments, the target tissue may comprise the nucleus pulposus.

A surgical tissue removal tool having a surgical tissue removal system and a closed-cell protection cannula is provided that utilizes any combination of the embodiments of the system and the protection cannula taught herein. In some embodiments, the tool may be a discectomy tool. Thus, in certain embodiments, the inlet tissue comprises epithelial tissue, muscle tissue, neural tissue, connective tissue, blood vessels, bone, cartilage, or a combination thereof on the target leading to the nucleus pulposus. Thus, in some embodiments, the target tissue may comprise the nucleus pulposus.

Fig. 7 illustrates a surgical tissue removal tool according to some embodiments. The tool 700 includes a cutting head 400, a suction assembly 484, and a obturator guard cannula 600. Suction flow 444 from the suction assembly 484 enters the cutting head 400 to remove the target tissue excised by the cutting head. Irrigation water 690 may enter the irrigation valve 795 and/or the irrigation port 635, with the irrigation water 690 from the irrigation valve 795 being utilized when the suction 444 is closed, and with the irrigation water 690 from the irrigation port 635 being utilized when the suction 444 is open, during which the suction 444 directs the irrigation water 690 between the luminal surface of the obturator guard cannula 600 and the suction assembly 484 into the surgical field (not shown). The protective cannula 600 serves to protect the portal tissue (not shown) as the cutting-head 400 and suction assembly 484 are moved relative thereto during a procedure, such as when the cutting-head 400 is moved forward, backward, and/or laterally to resect and remove a target tissue.

A method of removing a target tissue using the surgical tissue removal tool is provided. In certain embodiments, the method comprises: making an opening in the target for accessing the target tissue; inserting a cutting head of the surgical tissue removal tool through an entry hub and an elongated split-tube of a protective cannula of the surgical tissue removal tool; inserting the cutting tip of the surgical tissue removal tool through the opening to access target tissue in the target while protecting the entry tissue with the blunt distal end of the split-tube. In other aspects, methods of using the tissue removal system are the same as or similar to those taught herein. It will be appreciated by those skilled in the art that the surgical tissue removal tool described above is used, for example, in a discectomy in which the target tissue may be the nucleus pulposus and the surrounding tissue may be the annulus fibrosus. It will also be appreciated by those skilled in the art that the surgical tissue removal tool is provided with a protective cannula that helps protect the target epithelial tissue, muscle tissue, neural tissue, connective tissue, blood vessels, bone, cartilage or combinations thereof that are passed to the nucleus pulposus during such procedures.

Figures 8A-8C illustrate a surgical tissue removal system or tool that can apply suction while irrigating and that does not require an obturator protective cannula to be installed in place, according to some embodiments. Fig. 8A illustrates a complete discectomy system 800, the discectomy system 800 including a cutting head 400, a tool for providing aspiration flow through an aspiration assembly 884, a control handle 886 and vacuum attachment 892, an irrigation tube 804, irrigation controls 802, and optional vacuum controls 888.

In embodiments where the angle of the cutting head is adjustable, handle 886 may have a knob (not shown) that is turned to tension a pull cord (pull cable) to retract or straighten the cutting head relative to the rigid suction tube, or handle 886 may have a slide that tensions the pull cord to retract or straighten the cutting head relative to the rigid suction tube. The pull cords for retraction or straightening may be located on opposite sides of a shaft constrained by small side cavities attached to the outer surface of the shaft to retract and straighten the cutter head.

Fig. 8B illustrates a cross-sectional view of the irrigation tube 804 relative to a rigid suction tube 894. Also, fig. 8C shows a cross-sectional view of the control handle 886 and the inner tube.

Those skilled in the art will appreciate that the teachings and examples provided herein refer to a basic concept that may be extended beyond any specific embodiment or embodiments, or one or more of the accompanying drawings. It should be understood that any of the examples are for illustrative purposes and are not to be construed as limiting other aspects of the teachings.

Example 1 test tool tip design

Multiple heads were tested on 28 discs from 3 cadaver experiments (cadover laboratories). The results are compared to determine the most efficient bit design. The ideal cutting head is designed to cut all of the targeted tissue including the nucleus pulposus, vertebral end plates (verterbral endplates) and the inner annulus tissue well. However, the cutting head should also cut the target tissue in a desired manner without providing damage to the surrounding tissue, including the surrounding annulus fibrosus, which should be preserved as a desired surrounding structure. Furthermore, the blade design should remove tissue quickly under suction, and therefore the blade configuration enables the tissue removal under suction.

Fig. 9A-9G illustrate tested tool tip designs according to some embodiments. The bit design in fig. 9A cuts well, but is less safe for the annulus than other bit designs. The bit design in fig. 9B is safe for the annulus, but does not cut tough tissue well and exhibits too much resistance. The design in fig. 9C also did not penetrate tough tissue well. The design in fig. 9D does cut and exfoliate well, but the design is clogged on soft/elastic tissue. The design in fig. 9E cuts tough tissue very well without clogging, and the design peels very well. The design is also safe for the ring. However, the device is not shaped to reach the distal side of the nucleus pulposus. The design in fig. 9F shows the bend (a bend) of the introduced device that enables the blade of fig. 9E to reach the distal side of the nucleus pulposus. However, the design in fig. 9G and 9H demonstrates the most effective insert performance verified in the test, with the design in fig. 9G and 9H removing 23cc of material in 5 minutes.

Example 2

This embodiment further expands the design of the cutter head. The designs in fig. 8G and 8H were further studied in 7 cadaver experiments and 28 discs.

Fig. 10A-10E illustrate improvements in the cutter head according to certain embodiments. The design in fig. 10A shows a head with a bevel angle on the outer surface of the cutting tooth and a device that cuts poorly and requires cutting (gouge) cartilage. The design in fig. 10B shows an oval shaped cutting head with no bevel angle on the outer surface of the cutting teeth and a device that produces inconsistent cuts and requires cutting of cartilage. The design in fig. 10C shows the comparison results with the use of a ring curette and the device used to cut cartilage. The design in fig. 10D shows a short bit with one "claw" or clamp and a device that shows the most attractive results and achieves the best cut without the need for excavation. Fig. 10E is another preferred design configured to function as the design of fig. 10D, with the design of fig. 10E also having a second jaw that curves away from the internal cavity of the bit to act as an additional jaw and cutting edge guard.

The method used in this example is as follows:

1. cutting guide holes with the height and width dimensions of 5mm to 8 mm;

2. a 15 deg. tip parallel to the vertebral endplates is pointed to cut and expand the cavity centrally and laterally.

3. Gradually shaving the vertebral endplates to hard tissue (cartilage or bone); confirming the depth of the tip by fluoroscopy; shaving along the curve of the vertebral endplate with the tip; stopping shaving when bone (hard, rough, sticky and red aspirate identified as the end point) is exposed; and the handle of the device is tilted (i) centrally to strip the side edges and (ii) laterally to strip the medial side.

4. Pushing the blade medially-laterally against the anterior annulus as needed to remove the nucleus attached to the annulus and inner annulus;

5. directing the 40 ° tip to the opposite side and starting to shave from the posterior annulus while tilting the handle laterally to remove most of the nucleus pulposus; and

6. the handle is rotated toward the vertebral endplate for further ablation.

Example 3

This example describes an alternative embodiment for testing, referred to as a bent or bayonet configuration(s), in which the rigid suction tube 488 may have at least two angles: angle theta₁And angle theta₃。

Fig. 11A-11C illustrate bayonet-type communication between a cutting head and a suction assembly according to some embodiments. It has been found that the distal end of the rigid suction tube 488 can be redirected in a bayonet or curved manner to bring the cutting head closer to the target tissue in, for example, a discectomy. As shown in fig. 11A to 11C, the angle θ₁And angle theta₃May each be independently selected from the range of about 0 to about 180 and limited to (i) the central axis of the lumen 410 of the cutting head 400 and (ii) the central axis 497 of the rigid suction tube 488 (extending toward proximally)Angle theta₁) Net angle θ realized therebetween₄The net angle theta₄In the range of 0 ° to 90 °; and (ii) the distance 498 between the central axis 415 of the lumen 410 of the cutting head 400 and the central axis 497 of the rigid suction tube 488 can be in the range of about 2mm to about 30 mm. Also, in these embodiments, the central axis of the lumen may have an exit point at the forward cutting edge and the exit point is located at a lateral distance of about 3mm to about 25 mm.

In certain embodiments, the distance 498 is between about 2.5mm to about 25mm, between about 3mm to about 25mm, between about 4mm to about 20mm, between about 5mm to about 15mm, between about 3mm to about 25mm, between about 7mm to about 12mm, between about 8mm to about 10mm, or any range there between increased by 0.5 mm. Accordingly, the distance 498 may be approximately 2mm, approximately 3mm, approximately 4mm, approximately 5mm, approximately 6mm, approximately 7mm, approximately 8mm, approximately 9mm, approximately 10mm, approximately 12mm, approximately 14mm, approximately 16mm, approximately 18mm, approximately 20mm, approximately 22mm, approximately 24mm, approximately 26mm, approximately 28mm, approximately 30mm, and any distance or range there between that is increased by 0.5 mm. In certain embodiments, the angle θ₃May be between about 5mm and about 25mm, between about 6mm and about 20mm, between about 7mm and about 15mm, or any range therein increased by 1 mm.

Claims

1. A surgical tissue removal system for removing a target tissue of a subject, the surgical tissue removal system comprising a tubular cutting head having:

an outer periphery defining an inner cavity through the cutter head, the inner cavity having a central axis;

a forward cutting edge at a distal edge of the outer periphery, the forward cutting edge configured to (i) cut a target tissue during an advancing stroke of the cutting head and (ii) direct the cut tissue to the lumen;

a rearward-facing cutting edge configured as a claw for cutting tissue and hooking tissue to be removed in a return stroke of the blade head; and

a blade guard distal to the forward cutting blade and configured to prevent the forward cutting blade from cutting peripheral tissue during the forward stroke, the blade guard having a width less than a width of a cross-section of the internal cavity to facilitate entry of the target tissue into the internal cavity during the forward stroke; the rearward facing cutting blade is located on the blade guard for cutting the target tissue on a return stroke of the cutting head, the blade guard having a double blade tip at an angle θ greater than 90 °₂Is directed rearwardly into the lumen to grasp and/or cut tissue in the lumen during the return stroke of the cutting head.

2. The system of claim 1, wherein the cutting head further has a transverse cutting edge for cutting the target tissue in a transverse stroke of the cutting head.

3. The system of claim 1, wherein the cutting head further has a transverse cutting blade on the blade guard for cutting the target tissue in a transverse stroke of the cutting head.

4. The surgical tissue removal system of claim 1, wherein the cutting head is further configured to operably communicate between the lumen and a suction source;

and the combination of (a) and (b),

a suction assembly in operable communication with the cutting head, the suction assembly including an at least substantially rigid suction tube having a central axis, and the suction assembly creating a suction flow for passing the target tissue through the lumen and out of the target.

5. The surgical tissue removal system of claim 4, wherein the at least substantially rigid suction tube is formed as one piece with the cutting head.

6. The system of claim 4, wherein the cutting head further has a transverse cutting edge for cutting the target tissue in a transverse stroke of the cutting head.

7. The surgical tissue removal system of claim 4, wherein a central axis of the lumen forms an angle θ with a central axis of the rigid suction tube₁The angle theta₁In the range of about 5 ° to about 90 ° and the forward cutting edge is located at a distance θ from the angle₁From about 3mm to about 25 mm.

8. The surgical tissue removal system of claim 7, wherein the operative communication between the cutting head and the suction assembly is articulated and the angle θ₁Is adjustable.

9. The surgical tissue removal system of claim 7, wherein the operative communication between the cutting head and the suction assembly is rigid, and the angle θ₁Is stationary.

10. The surgical tissue removal system of claim 7, wherein the central axis of the lumen has an exit point at the forward cutting blade and the exit point is located at a transverse distance of about 3mm to about 25mm that is orthogonal to the central axis of the rigid suction tube.

11. According to the rightThe surgical tissue removal system of claim 4, wherein a central axis of the lumen forms an angle θ with a central axis of the rigid suction tube₁The angle theta₁In the range of 1 ° to 180 ° and the forward cutting edge is located at a distance θ from the angle₁3mm to 25mm of apex; wherein the content of the first and second substances,

additional angle theta₃The additional angle theta₃At approach angle theta₁5mm to 25 mm;

angle theta₁And angle theta₃Independently of each other, selected from the range of about 0 DEG to about 180 DEG, angle theta₁And angle theta₃The limitation is:

(i) the central axis and the approach angle theta of the inner cavity of the cutter head₃Has a net angle theta between the central axes of said rigid suction pipes₄The net angle theta₄In the range of 0 ° to 90 °; and

(ii) the central axis of the lumen has an exit point at the forward cutting blade and the exit point is at a transverse distance of about 3mm to about 25mm, the transverse distance being orthogonal to the central axis of the rigid suction tube.

12. The surgical tissue removal system of claim 4, wherein the target tissue is a nucleus pulposus and the peripheral tissue is an annulus fibrosus.

13. The surgical tissue removal system of claim 12, the cutting head further having:

a transverse cutting edge for cutting the nucleus pulposus in a transverse stroke of the cutter head; and

wherein the cutting head is configured to operably communicate between the lumen and a suction source;

and the combination of (a) and (b),

a suction assembly in operable communication with the cutting head, the suction assembly being provided with the suction source and including an at least substantially rigid suction tube having a central axis, and the suction assembly creating a suction flow for passing the nucleus pulposus through the lumen and out of the target.

14. The surgical tissue removal system of claim 13, wherein the at least substantially rigid suction tube is formed as one piece with the cutting head.

15. The surgical tissue removal system of claim 13, wherein a central axis of the lumen forms an angle θ with a central axis of the rigid suction tube₁The angle theta₁In the range of about 5 ° to about 90 ° and the forward cutting edge is located at a distance θ from the angle₁From about 3mm to about 25 mm.

16. The surgical tissue removal system of claim 13, wherein the central axis of the lumen has an exit point at the forward cutting blade and the exit point is located at a transverse distance of about 3mm to about 25mm that is orthogonal to the central axis of the rigid suction tube.

17. The surgical tissue removal system of claim 15, wherein the operative communication between the cutting head and the suction assembly is articulated and the angle θ₁Is adjustable.

18. The surgical tissue removal system of claim 15, wherein the operative communication between the cutting head and the suction assembly is rigid, and the angle θ₁Is stationary.

19. The surgical tissue removal system of claim 13, wherein a central axis of the lumen forms an angle θ with a central axis of the rigid suction tube₁The angle theta₁In the range of 1 ° to 180 ° and the forward cutting edge is located at a distance θ from the angle₁3mm to 25mm of apex; wherein the content of the first and second substances,

angle theta₁And angle theta₃Independently of each other, selected from the range of about 0 DEG to about 180 DEG, angle theta₁And angle theta₃Is limited to

20. The system of claim 13, wherein the transverse cutting blade is located on the blade guard for cutting the target tissue in a transverse stroke of the cutting head.