Patent Abstract:
In an endoscope having a working channel, an inflatable abrading device including an outer flexible sleeve, an auger arranged for controllable rotation within the sleeve, the auger arranged for rotation about a hollow shaft and a balloon having an inner surface and an outer surface, the outer surface coated with abrasive material, the balloon initially disposed within the hollow shaft and connected via a tube to a source of fluid, the balloon arranged to be extendible beyond the hollow shaft and arranged for inflation by the fluid, the tube arranged for controllable rotation.

Full Description:
FIELD 
       [0001]    The present disclosure relates generally to spinal surgery, more specifically to spinal disc removal, and, even more specifically, to an endoscopic inflatable abrading device for use in a discectomy (also known as a diskectomy). 
       BACKGROUND 
       [0002]    The spinal column, or backbone, is one of the most important parts of the body. It provides the main support, allowing us to stand upright, bend, and twist. As shown in  FIG. 1 , thirty three (33) individual bones interlock with each other to form the spinal column. The vertebrae are numbered and divided into regions. The cervical vertebrae (C 1 -C 7 ) form the neck, support the head and neck, and allow nodding and shaking of the head. The thoracic vertebrae (T 1 -T 12 ) join with the ribs to form the rib cage. The five lumbar vertebrae (L 1 -L 5 ) carry most of the weight of the upper body and provide a stable center of gravity when a person moves. Five vertebrae of the sacrum S and four of the coccyx C are fused. This comprises the back wall of the pelvis. Intervertebral discs are located between each of the mobile vertebra. Intervertebral discs comprise a thick outer layer with a crisscrossing fibrous structure annulus A that surrounds a soft gel-like center, the nucleus N. Discs function like shock-absorbing springs. The annulus pulls the vertebral bodies together against the elastic resistance of the gel-filled nucleus. When we bend, the nucleus acts like a ball bearing, allowing the vertebral bodies to roll over the incompressible gel. Each disc works in concert with two facet joints, forming a spinal motion segment. The biomechanical function of each pair of facet joints is to guide and limit the movement of the spinal motion segment. The surfaces of the joint are coated with cartilage that helps each joint move smoothly. Directly behind the discs, the ring-like vertebral bodies create a vertical tunnel called the spinal canal or neuro canal. The spinal cord and spinal nerves pass through the spinal canal, which protects them from injury. The spinal cord is the major column of nerve tissue that is connected to the brain and serves as an information super-highway between the brain and the body. The nerves in the spinal cord branch off to form pairs of nerve roots that travel through the small openings between the vertebrae and the intervertebral foramens. 
         [0003]    Various medical conditions require a surgeon to repair, remove and/or replace the aforementioned discs. For example, in one surgical procedure, known as a discectomy (or diskectomy), the surgeon removes the nucleus of the disk and replaces it with an implant. As shown in  FIG. 2 , it may be necessary, for example, for the surgeon to remove the nucleus of the disc between the L 3  and L 4  vertebrae. Disc D L3-L4  is shown in an enlarged view in  FIG. 3 . This figure also shows various anatomical structures of the spine, including facets F 3 A and F 4 A, facet joint FJ, spinous processes SP 3  and SP 4 , transverse processes TP 3 A and TP 44 A, and intervertebral foramen IF.  FIG. 4  is a top view of the section of the spinal column shown in  FIG. 3 , with the L 3  vertebra removed to expose annulus A and nucleus N of disc D L3-L4 .  FIG. 5  is an anterior perspective view of the section of the spinal column shown in  FIG. 4 .  FIG. 6  is a partial cross-sectional view of the section of the spinal column shown in  FIG. 5 , but with vertebra L 3  in place atop disc D L3-L4 . 
         [0004]    One common tool used in these spinal surgical procedures is an endoscope. A representative endoscope  30  is shown in  FIG. 7A . Endoscopes are complex biomedical devices. The complexity results from the need for fiberoptic bundles and multiple long narrow channels to be contained within a tubular structure that is constrained by the limited dimensions of the body cavity opening. As shown in  FIG. 7A , endoscope  30  broadly comprises light guide connector  31 , light guide tube  32 , control body  33 , and insertion tube  34 . As will be described infra, the inflatable abrading device of the embodiment is introduced into the disc space via insertion tube  34 . As shown in  FIG. 7B , surgeon  40  uses the endoscope both to observe and guide the procedure via monitor  41 , and to introduce and manipulate surgical instruments and tools during surgery on patient  45 . 
         [0005]    The endoscope is only one element of the system. Other required elements are a light source, video processor, monitor and water bottle. For the purpose of describing an endoscope in this disclosure, we refer to videoscopes, which represent a newer technology in endoscope development as compared to fiberoptic endoscopes. In videoscopes, the “viewing” fibre bundle is replaced by a miniature charged coupled device (CCD) video camera chip that transmits signals via wires. 
         [0006]    Videoscopes include three major sections: connector  31  (sometimes referred to as the “umbilical” section), control body  33  and insertion tube  34 . Endoscopes require a watertight internal compartment integrated through all components for electrical wiring and controls, which protects them from exposure to patient secretions during use and facilitates the endoscope being submerged for cleaning and subsequent disinfection. Example embodiments are not intended to be limited to any particular type of endoscope. 
         [0007]    Control body  33  provides connections for four systems: the electrical system, the light system, the air and water system, and the suction system. A cable with video signal, light control, and remote switching from the video processor is connected in the electrical system. A watertight cap is required for leak testing and reprocessing. The electrical connector is the only opening to the internal components. The connector is inserted into the light source and directs light via the fiberoptic bundle in the light guide to the distal end of the insertion tube. Air pressure is provided from a pump to the air pipe, and the water bottle is also connected here (there is no water channel or water connection for bronchoscopes). In some endoscope models, the separate air and water channels merge just prior to the distal end where they exit through a single channel. In other models, the air and water channels are totally separate and do not merge. The air and water channels are usually of one millimeter internal diameter, which is too small for brushing. A portable or wall suction system is connected to the suction port. The Universal cord encases the electrical wiring and air, water and suction channels from the connector to the control section. Teflon® (PTFE) tubing is commonly used for channels, and advances in technology have led to more pliable and smooth materials for instrument channels with better anti-adhesion properties. The suction channel size can vary from two to 4 millimeters internal diameter depending on scope make and model. There is a biopsy port on the side of the insertion tube that allows instruments to be passed down the insertion tube to the distal end (referred to as the instrument channel or biopsy/suction channel). 
         [0008]    Control body  33  has moveable knobs that allow the physician to control all scope functions. The angulation control knobs drive the angulation wires and control the bending section at the distal end of the insertion tube, thereby providing two-dimensional angulation. Locking mechanisms are provided to hold the bending section in a specific position. The suction cylinder and valve connects the suction channel to the instrument channel in the insertion tube. By pressing the valve button, suction can be provided to the instrument channel. The air/water cylinder and valve are similar to the suction cylinder/valve except that a two-way button valve is used in a dual channel cylinder thereby providing air or water to the lens at the distal end to wash and insufflate for better vision. Both valves are removable for cleaning. The air and water channels also require a cleaning adapter valve that is to be used at the end of each procedure. Insertion of the cleaning adapter initiates air flow through both air and water channels, and once activated, water is pumped through both channels. The instrument channel port (often referred to as the “biopsy port”) is located on the lower part of the control section. It enters the instrument channel at a Y-piece union with the suction channel. A valve is required to close the port so that suctioning may be facilitated. Remote switches present on the top of the control section are usually programmable, allowing control of the video processor (i.e., contrast, iris and image capture functions). 
         [0009]    Most disc removal instruments have included grasping tools with alligator like jaws designed to bite and tear tissue pieces which are then withdrawn from the endoscopic working channel whereupon the disc material is removed and the instrument is reintroduced. U.S. Pat. No. 5,772,578 (Heimberger, el al.) discloses such a device which, while flexible, allows only one small piece of disc to be removed at a time. Such piece-meal removal is laborious and time consuming. 
         [0010]    U.S. Pat. No. 8,109,957 (Stad et al.) discloses a disc nucleus removal device with cutting members in its side wall near the tip deployed by virtue of slits in the side wall sheath. Since the cutting members are actuated from the side wall of the elongate member, the blunt tip impedes the ability of the device to cut tissue directly in front of it and hence is better suited to end plate preparation than de novo disc removal. Furthermore, since the elongate member does not contain an auger, the lumen is prone to clogging, since disc fragments are well known to plug simple suction cannula because of the adhesiveness and consistency of the disc nuclear material. 
         [0011]    Therefore, there is a long-felt need for an instrument for endoscopic disc removal which is capable of cutting and removing disc material not only on the lateral edges of the insertional axis of the device, but also on its distal most aspect where the bulk of cutting is expected to be done. Additionally, there is a long-felt need for a device not solely dependent on suction to evacuate disc material to avoid the annoying and inevitable plugging that occurs with pure single lumen suction cannula already utilized in the art. An endoscopic disc removal device that combines a retractable abrading balloon capable of cutting in 360 degrees with a controllably flexible shaft containing an auger and suction device to allow for rapid removal of disc nuclear material is needed. 
       SUMMARY 
       [0012]    According to aspects illustrated herein, there is provided a tool for an endoscope. The tool includes an auger having a hollow shaft, and an inflatable abrading device insertable through the augur hollow shaft. The auger is arranged for rotation within an outer flexible sheath, and the abrading device is similarly arranged for independent rotation by a rotating shaft within the hollow shaft. In one embodiment, the abrading device is an inflatable balloon having an inner surface and an outer surface, the outer surface coated with abrasive material. The balloon is initially disposed within the hollow shaft and connected via a tube to a source of fluid, the tube arranged for controllable rotation within the hollow shaft. In operation the balloon is moved external to the hollow shaft of the auger and arranged for rotation in a part of a body (e.g., in a disc space where it may function to morcellate tissue). 
         [0013]    According to aspects illustrated herein, there is provided an inflatable abrading device for an endoscope having a working channel, the inflatable abrading device including: an outer flexible sheath arranged to be introduced within the working channel, a rotatable flexible member arranged for controllable rotation within the sheath, a hollow shaft arranged within the sheath, and a rotatable tube arranged to extend and retract within the hollow shaft, the rotatable tube having an inflatable abrasive member secured to a first end of said rotatable tube, the inflatable abrasive member arranged to be inflated by a source of fluid. 
         [0014]    According to aspects illustrated herein, there is provided a method of performing a discectomy including an endoscope having a working channel, including: introducing the working channel proximate to a nucleus, removing at least a portion of the nucleus, introducing an inflatable abrading device through the working channel, the inflatable abrading device including an outer flexible sheath, an auger arranged for controllable rotation within the outer flexible sheath, the auger arranged for rotation about a hollow shaft, extending a balloon initially disposed within the hollow shaft into the nucleus, inflating the balloon, the balloon coated with abrasive material, and controllably rotating the balloon to morcellate the nucleus. 
         [0015]    A primary object of the disclosure is to provide an inflatable abrading device for use in discectomy (diskectomy), and in other surgical procedures. It is a primary object of this disclosure to provide for an endoscopic disc removal instrument capable of being deployed down the working channel of an endoscope. It is also an object that the cutting element be both inflatable and retractable and capable of cutting directly at the tip and at the circumference of its sides. It is a further objective that the tip be steerable with simple steering wires already known in the art. Finally, it is an objective that the instrument shaft contains both a suctioning mechanism as well as a flexible auger to facilitate rapid disc tissue removal and prevent plugging known to affect present suction devices employed in disc surgery. 
         [0016]    To achieve these objects an instrument is provided comprising an elongated central flexible core similar to a metal K-wire, around which is wound a spiral blade (flight) similar to an auger. Both the central core and spiral blade (flight) are made of metal or plastic having the ability to flex, especially near the tip. 
         [0017]    Around the auger mechanism is a flexible sheath designed to contain and protect the auger mechanism when the mechanism is inserted or removed and especially when it is being operated by rotational force. Within the walls of the sheath are steering wires to flex the tip of the sheath similar to controllable mechanisms already known in the art and practiced in flexible cystoscopes and gastroscopes. 
         [0018]    The central core of the auger mechanism is hollow, and allows for transport and insertion of an inflatable abrading device, i.e., a balloon coated with abrasive particles. When deployed, the balloon may be inflated to form a predetermined cutting size and shape such that cutting can occur in every direction except at the junction from the hollow shaft from which it is deployed. 
         [0019]    When the central core is rotated, the balloon is rotated and cuts disc nuclear material into pieces which are then drawn toward the lumen of the external sheath by suction. At the opening of the lumen they encounter the spiral blade (flight) of the auger which engages them and assists in their transit along the lumen and their ultimate evacuation from the body. The central core, in essence, drives the auger and the cutting tip such that tissue morcelization and tissue evacuation can occur simultaneously with minimal risk of obstruction of the central lumen. Suctioning force is applied as well through the auger channel within the endoscope. 
         [0020]    These, and other objects and advantages will be readily appreciable from the following description of preferred embodiments of the invention and from the accompanying drawings and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0021]    The nature and mode of operation of the present disclosure will now be more fully described in the following detailed description of the embodiments taken with the accompanying figures, in which: 
           [0022]      FIG. 1  is an anterior perspective view of spinal column  10 ; 
           [0023]      FIG. 2  is an anterior perspective view of the lumbar section of spinal column  10 ; 
           [0024]      FIG. 3  is a lateral perspective view of L 3 , L 4  vertebrae and disc D L3-L4  and related spinal anatomy; 
           [0025]      FIG. 4  is a top view of a section of the spinal column, taken generally along line  4 - 4  in  FIG. 3 ; 
           [0026]      FIG. 5  is an enlarged anterior perspective view of the spinal column shown in  FIG. 2 , except with vertebra L 3  and all other structure above L 3  removed; 
           [0027]      FIG. 6  is a partial cross-sectional view of the L 4  vertebra and D L3-L4  disc taken generally along line  6 - 6  in  FIG. 5 , and also shows L 3  in cross-section; 
           [0028]      FIG. 7A  is a view of a typical endoscope; 
           [0029]      FIG. 7B  illustrates use of the endoscope shown in  FIG. 7A  by a surgeon performing a discectomy (diskectomy); 
           [0030]      FIG. 8  illustrates a preliminary step in a discectomy (diskectomy) procedure, namely, introduction of a needle to pierce the annulus and nucleus of a disc; 
           [0031]      FIG. 9  illustrates another preliminary step in a discectomy (diskectomy) procedure, namely, introduction of a first dilator into the disc; 
           [0032]      FIG. 10  illustrates a further preliminary step in a discectomy (diskectomy) procedure, namely, introduction of a larger dilator into the disc; 
           [0033]      FIG. 11  illustrates the working tube of the endoscope proximate the disc just prior to introduction of surgical instruments into the disc; 
           [0034]      FIG. 12  illustrates introduction of a rongeur into the nucleus of the disc; 
           [0035]      FIG. 13  is a view similar to that of  FIG. 12  showing introduction of the inflatable abrading device (prior to inflation) of the present disclosure into the disc space, with line  14 - 14  representing the cross-sectional view depicted in  FIG. 14 ; 
           [0036]      FIG. 14  is a cross-sectional view of working channel  35 , taken generally along line  14 - 14  in  FIG. 13 , showing the endoscope and auger tube  70 ; 
           [0037]      FIG. 15  is a view similar to that of  FIG. 13 , except showing the inflatable device in an inflated state and rotating to morcellate the disc material for removal by the auger; 
           [0038]      FIG. 16A  is a perspective view of the auger tube of the device; 
           [0039]      FIG. 16B  is a view similar to that of  FIG. 16A , but showing part of the auger tube cut away to expose the auger of the device; 
           [0040]      FIG. 16C  is a view similar to that of  FIG. 16B , but showing part of the spiral blade (flight) of the auger in phantom to show the hollow auger shaft of the device; 
           [0041]      FIG. 16D  is a perspective view similar to that of  FIG. 16A , showing the inflatable abrading device extending outwardly from the hollow auger shaft of the device; 
           [0042]      FIG. 17  is a phantom perspective view of a part of the working tube of an endoscope, showing placement of the auger tube and the endoscope tube; 
           [0043]      FIG. 18  is a fragmentary front perspective view of the auger tube and inflatable abrading device; 
           [0044]      FIG. 19  is a fragmentary rear perspective view of the auger tube and inflatable abrading device shown in  FIG. 18 ; 
           [0045]      FIG. 20  is an enlarged side view of the inflatable abrading device shown in  FIG. 18 ; 
           [0046]      FIG. 21  is an enlarged front view of the inflatable abrading device shown in  FIG. 18 ; 
           [0047]      FIG. 22  is a cross-sectional view of the inflatable abrading device, taken generally along line  22 - 22  in  FIG. 20 ; 
           [0048]      FIG. 23  is a cross-sectional view similar to the view in  FIG. 22  but illustrating an alternative embodiment of the inflatable abrading device; 
           [0049]      FIG. 24  is a fragmentary front perspective view of the auger tube and an alternative embodiment of the inflatable abrading device; and, 
           [0050]      FIG. 25  is a cross-sectional view of the alternate inflatable abrading device of the embodiment, taken generally along line  25 - 25  in  FIG. 24 . 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0051]    At the outset, it should be appreciated that like drawing numbers on different. drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred aspects, it is to be understood that the invention as claimed is not limited to the disclosed aspect. The present invention is intended to include various modifications and equivalent arrangements within the spirit and scope of the appended claims. 
         [0052]    The term “balloon” as used in the present disclosure is intended to mean any inflatable member which can be elastomeric or non-elastomeric and made of any material. 
         [0053]    Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and, as such, may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims. 
         [0054]    Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described. 
         [0055]    Adverting now to the Figures, and as described previously,  FIGS. 1-6  depict various parts and sections of spinal anatomy, and  FIGS. 7A and 7B  depict a typical endoscope for use by a surgeon on a patient. We now focus on the discectomy (diskectomy) procedure itself, first with reference to  FIG. 8 , which shows first dilator  50 , having shaft portion  51  and point portion  52  piercing annulus A and nucleus N of disc D L3-L4 . 
         [0056]    Once the surgeon has pierced the annulus and entered disc D L3-L4  with dilator  50 , he enlarges the entry channel with a plurality of increasingly larger dilators, as best shown in  FIG. 9 . This figure shows dilators  53  and  54  being introduced down shaft portion  51  (shown in  FIG. 8 ), and eventually into annulus A and the center of nucleus N of disc D L3-L4 . 
         [0057]      FIG. 10  illustrates a further preliminary step in a discectomy (diskectomy) procedure, namely, introduction of larger dilators  53  and  54  into nucleus N of disc D L3-L4  along shaft portion  51 . Dilator  55  is introduced as well to further dilate nucleus N. This is done to increase the size of the opening in annulus A and the size of disc cavity  58  for the eventual introduction of insertion tube  34  (shown in  FIG. 11 ) proximate to nucleus N. Once the dilators have made the opening large enough, insertion tube  34  is introduced over the dilators. 
         [0058]      FIG. 11  illustrates introduction of insertion tube  34  with endoscopic working channel  35  of the endoscope through annulus A of disc D L3-L4  proximate to nucleus N just prior to introduction of surgical instruments into disc cavity  58 . When insertion tube  34  is in place proximate to nucleus N, all dilators are removed. 
         [0059]      FIG. 12  illustrates introduction of rongeur  57  through endoscopic working channel  35  of insertion tube  34  into disc cavity  58  in nucleus N of disc D L3-L4 . Rongeur  57  is used to remove portions of nucleus N to enlarge disc cavity  58  for introduction of inflatable abrading device  60 . Endoscope tube  76  transmits a video feed to monitor  41  to assist physician  40 . 
         [0060]      FIG. 13  illustrates the introduction of inflatable abrading device  60  or balloon (prior to inflation) through auger channel  74 . Inflatable abrading device  60  is made of a material with a one to nine micron thick outer surface  62  covered with stainless steel abrasive particles  63  adhered to inflatable abrading device surface  62 . Device can also be made of a para-aramid synthetic fiber, such as Kevlar brand para-aramid synthetic fiber, polytetrafluoroethylene (PTFE), polyether ether ketone (PEEK), fabric, or other hard plastic or metal which is inexpensive so that it is disposable, or biodegradable material. Particles  63  can also be pre-formed or molded within device  60 . Device  60  can be elastomeric or non-elastomeric. Particles  63  can also be made of steel, titanium, diamond, or other abrasive metal. Inflatable abrading device  60  is positioned in disc cavity  58 . Auger tube  70  is introduced through endoscopic working channel  35 . Auger  71  and spiral blade (flight)  72  are not yet rotating in auger tube  70 . Both auger shaft  73  and spiral blade (flight)  72  are made of metal or plastic having the ability to flex, especially near the tip. 
         [0061]      FIG. 14  is a cross-sectional view taken generally along line  14 - 14  in  FIG. 13 , illustrating the inside of insertion tube  34  and endoscopic working channel  35 . Endoscope tube  76  is proximate to auger tube  70 . Auger tube  70  contains auger  71  coiled around auger shaft  73 . Inflatable abrading device  60  (not shown in  FIG. 14 ) is introduced through auger channel  74 . 
         [0062]      FIG. 15  depicts the present disclosure performing a discectomy (diskectomy). Inflatable abrading device  60  is connected to rotatable tube  64 , through which inflatable abrading device  60  is initially inflated with saline or Conray® media for fluoroscopic visualization, for example. The media is introduced into inflatable abrading device  60  by a hydraulic pump, for example. Once the media has inflated inflatable abrading device  60  to the desired level, the inflation is maintained and inflatable abrading device  60  is rotated to morcellate disc D L3-L4 . While disc D L3-L4  is being morcellated, saline is introduced into the disc space, and disc material  61  is evacuated through auger tube  70  by rotating auger  71  and applying a suctioning force from the other end of auger tube  70 . Once disk D L3-L4  is morcellated, media may be removed from inflatable abrading device  60  by a hydraulic pump, for example. Inflatable abrading device  60  and auger  71  may rotate in the same or in different directions, and each can reach a maximum speed of approximately three hundred surface feet per minute, for example. In practice, physician  40  is able to adjust the speed at which both inflatable abrading device  60  and auger  71  rotate. In the preferred embodiment, inflatable abrading device  60  rotates at a faster rate than auger  71 . 
         [0063]      FIG. 16A  is a perspective view of auger tube  70  of the device, with auger  71  partially exposed.  FIG. 16B  is a view similar to that of  FIG. 16A , but showing a portion of auger tube  70  in phantom to expose auger  71  and spiral blade (flight)  72 .  FIG. 16C  is a view similar to that of  FIG. 16B , but showing part of spiral blade (flight)  72  in phantom to expose the hollow auger shaft  73  of the device. Inflatable abrading device  60  is introduced through auger channel  74 .  FIG. 16D  is a perspective view similar to that of  FIG. 16A , showing inflatable abrading device  60  inflated and attached to rotatable tube  64  and extending outwardly from auger shaft  73  of the device. It should be understood that although a particular auger and blade are illustrated, other auger and blade configurations are contemplated. For example, spiral blade  72  can include apertures or protrusions. Alternatively, spiral blade  72  can include a tapering blade or a non-continuous blade or a fan-like component. Auger  71  can include multiple blades as well. 
         [0064]      FIG. 17  is a phantom perspective view of insertion tube  34  of the endoscope, showing the placement of auger tube  70  and endoscope tube  76 . Endoscope tube  76  transmits video to monitor  41  to assist physician  40 . Auger channel  74  is concentrically arranged within auger tube  70 . Device  60  connected to rotatable tube  64  is arranged to extend through auger channel  74 . 
         [0065]      FIG. 18  is a fragmentary front perspective view of auger tube  70  and inflatable abrading device  60  of the embodiment, similar to the one depicted in  FIG. 16D . 
         [0066]      FIG. 19  is a fragmentary rear perspective view of auger tube  70  and inflatable abrading device  60  of the embodiment. Device  60  is connected to rotatable tube  64  by an o-ring for example, or any tonic joint or mechanical gasket. In an example embodiment, rotatable tube  64  includes a groove for the o-ring or an alternative. 
         [0067]      FIG. 20  is an enlarged side view of inflated inflatable abrading device  60  in an inflated state, attached to rotatable tube  64  with inflatable abrading device surface  62  and abrasive particles  63 . Line  22 - 22  represents the cross-section of inflatable abrading device  60  presented in  FIG. 22 . 
         [0068]      FIG. 21  is a front view of inflatable abrading device  60 , with inflatable abrading device surface  62  and abrasive particles  63 . 
         [0069]      FIG. 22  is a cross-sectional view of the image depicted in  FIG. 20 . This shows the inside of the inflated inflatable abrading device  60 . Media is introduced into inflatable abrading device  60  through the opening at the end of rotatable tube  64 . Abrasive particles  63  on inflatable abrading device  64  in this embodiment are adhered or formed on inflatable abrading device surface  62 . 
         [0070]      FIG. 23  is similar to  FIG. 22 . However,  FIG. 23  shows an alternative embodiment of the abrading particles, alternative abrading particles  67 . Abrading particles  67  are stainless steel, or equivalent, studs that are inserted through the inside of inflatable abrading device  60 , and protrude through inflatable abrading device surface  62 . Particles  67  can also be adhered on inflatable abrading device surface  62 . 
         [0071]      FIG. 24  is similar to  FIG. 18 . However,  FIG. 24  depicts alternative inflatable abrading device  80 , with alternative abrading vanes  82 . All properties of alternative inflatable abrading device  80  are the same as inflatable abrading device  60 , except for the parallel helical line pattern of alternative abrading vanes  82 . Although a particular configuration of vanes are illustrated, other configurations of vanes may be used. The vanes can also be more or less pronounced. 
         [0072]      FIG. 25  is similar to  FIGS. 22 and 23 . However,  FIG. 25  is taken generally along line  25 - 25  in  FIG. 24 , and depicts alternative inflatable abrading device  80 , with alternative abrading particles  81  adhered or otherwise affixed onto alternative abrading device surface  82 . Alternative inflatable abrading device  80  is also attached to rotatable tube  64 . 
         [0073]    Thus it is seen that the objects of the invention are efficiently obtained, although changes and modifications to the invention should be readily apparent to those having ordinary skill in the art, which changes would not depart from the spirit and scope of the invention as claimed. 
       LIST OF REFERENCE NUMBERS 
       [0000]    
       
           10  Spinal column 
         C 1 -C 7  Cervical vertebrae 
         T 1 -T 9  Thoracic vertebrae 
         L 1 -L 5  Lumbar vertebrae 
         S Sacrum 
         C Coccyx 
         D L1-L2  Disc 
         D L2-L3  Disc 
         D L3-L4  Disc 
         D L4-L5  Disc 
         F Facet 
         FJ Facet joint 
         SP Spinous process 
         TP Transverse process 
         IF Intervertebral foramen 
         A Annulus 
         N Nucleus 
         DH Disc height 
           30  Endoscope 
           31  Light guide connector 
           32  Light guide tube 
           33  Control body 
           34  Insertion tube 
         d 34  Diameter of Insertion tube 
           35  Endoscopic working channel 
           40  Surgeon 
           41  Monitor 
           45  Patient 
           50  Dilator 
           51  Shaft portion 
           52  Point portion 
           53  Dilator 
           54  Dilator 
           55  Dilator 
         d 50  Diameter of dilator 
         d 53  Diameter of dilator 
         d 54  Diameter of dilator 
           57  Rongeur 
           58  Disc cavity 
           60  Inflatable abrading device 
           61  Disc particle 
           62  Inflatable abrading device surface 
           63  Abrasive particles 
           64  Rotatable tube 
           66  Alternative abrasive particles 
           70  Auger tube 
           71  Auger 
           72  Spiral blade (flight) 
           73  Auger shaft 
           74  Auger channel 
           76  Endoscope tube 
           80  Alternative inflatable abrading device 
           81  Alternative inflatable abrading device surface 
           82  Alternative abrasive vanes

Technology Classification (CPC): 0