Abstract:
This invention proposes devices and methods directed to providing rapid and complete surgical removal of the nucleus from the spine intervertebral space. In addition, the invention protects the endplate tissue of vertebrae containing the disc and limits damage to the integrity of the disc annulus.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to devices and methods for use in interventions to restore spinal function. More specifically, the invention removes nucleus pulposus from the intact spine intervertebral disc during surgical therapy to treat herniation or degenerated discs.  
       BACKGROUND OF THE INVENTION  
       [0002]     Back and spinal ailments trouble thousands of Americans every year. In 2003 approximately 11 million people had impaired movement because of back pain, resulting in $80 billion of lost work and productivity. Back pain is a top cause of health care expenditures, amounting to $50 billion in the USA alone. However, only 2 percent of patients seek current implant therapies that create spinal fusion, and they typically do so only at an advanced stage of disease.  
         [0003]     Disc degeneration is part of the natural process of aging and has been documented in approximately 30% of 30 year olds. As the population ages, it is even more common for individuals to have signs of disc degeneration. Disc degeneration is an expected finding over the age of 60.  
         [0004]     Many back problems result from failure of the annulus (also called the disc annulus or outer fibrous ring) and from herniation of the nucleus pulposus (also called the disc nucleus) through the annulus of the intervertebral disc to compress the spinal cord or nerve roots. Currently, there are a limited number of treatments for these ailments. First, if the nucleus is still relatively intact, a physician can remove the herniating portion and leave the remaining nucleus in an effort to maintain the integrity and mobility of that spinal region. Successful surgery depends on integrity of the annulus and involves the assessed risk of additional future herniation. Or, physicians can remove much of the intervertebral disc with the intention of preventing future herniations by facilitating a fusion of adjacent discs.  
         [0005]     These interventions are great advancements over treatments that were available just decades ago. But, they introduce several concerns and difficulties. One of the most difficult decisions that physicians face is to determine the amount of nucleus to remove. If too much is removed then mobility can be reduced, too little and the herniation may recur. There is also substantial risk of damage to the annulus that could impair healing. Procedures that remove the complete intervertebral disc, discectomy, damage the vertebral end plate. Due to the similar texture of the ligamentum flavum and the dura there is also concern of cutting into the dura, which could result in neurological complications. Finally, these procedures produce large amounts of scarring, which limits the scope of revision surgeries.  
         [0006]     A new treatment uses intervertebral implants to replace the nucleus with materials that restore mobility and avoid adjacent segment deterioration without the risk of herniation. Manufacturers have developed implants to the point that several forms of the prostheses are in clinical trials. Although there are associated problems and difficulties, these implants are poised to be a major breakthrough treatment of failed intervertebral discs, particularly in young people. The implants are placed within the space defined by the annulus after as much of the nucleus as possible has been removed. Because the goal of the surgery is to restore mobility, the annulus, vertebral endplates and other disc structures must be undamaged.  
         [0007]     Presently, most disc surgeries involve partial removal of the nucleus pulposus (nuclectomy). Or the nucleus is removed along with the entire intervertebral disc (discectomy). Standard surgical tools, such as curettes, bone nibblers or pituitary rongeurs, and a variety of techniques have been adapted for these procedures. All of these prior art tools were designed for purposes other than spinal surgery and are poorly suited to nucleus removal, especially when other tissues must be spared from injury. Generally, surgeons have experience and training only for procedures that require incremental extraction of small pieces of the nucleus (micro or partial nuclectomy). When applied to complete nuclectomy these tools lack the flexibility and control to remove all of the nucleus and invariably cause damage to the surrounding annulus fibrosus and vertebral end plates. In addition, substantial skill and dexterity is required to produce satisfactory results. Even in the hands of an experienced surgeon, nucleus extraction can be the most prolonged and difficult stage of the newer forms of spinal surgery.  
         [0008]     No devices or methods have been developed specifically to remove the entire nucleus while minimizing trauma to other tissues. Maintaining the integrity of surrounding tissue is necessary to hold the implant in place and allow proper support and separation of the surrounding vertebrae. Some the implants will function poorly or risk new herniation if 20% or even as little as 10% of the original nucleus is left behind. A clean bed, free of nuclear material in critical locations, within which to deploy or graft the implants will also be crucial to the success of surgery. As a result, special methods, tools, or procedures are needed that can cleanly remove the nucleus without damaging the fibers of the annulus.  
         [0009]     In an effort to address some of these limitations, physicians and researchers are searching for new methods of treatment for the herniated nucleus pulposus. They are looking at treatments that restore the function of the nucleus, regenerate the structure of the annulus, or are implanting artificial discs. Each of these proposed treatments introduces new difficulties and will need additional support mechanisms to prepare for the procedures. One of the most promising therapies is nucleus replacement. It is superior to traditional disc fusion because it restores movement and function to the disc space. It also promises to be superior to artificial disc implantation because much more of the original tissue is preserved, the procedure is faster, and there is less risk of malpositioning. Neither fusion nor artificial disc implantation are likely to ever be compatible with percutaneous access and thus carry a greater risk of infection and damage to other tissues or organs.  
         [0010]     Most approaches to nucleus replacement will require removing the entire nucleus. Currently, there are few methods of removing the nucleus to prepare for nucleus replacement. These include the use of manual surgical implements such as curettes, bone nibblers, and pituitary rongeurs. The procedure involves incremental extraction of small pieces of the damaged portion until a the surgeon judges that a sufficient amount has been removed.  
         [0011]     There are few companies currently looking at methods for removal of the nucleus pulposus, as nucleus replacement is a fairly new treatment modality. Clarus Medical has developed the ‘cut and suction’ method of percutaneous discectomy. Their product is the Nucleotome, a mechanical device with a blunt drill passing through a cannula that enters the disc site. It uses a rounded tip, shaped like a blunt drill to decrease the risk of cutting into the annulus. Stryker Corporation offers another rigid design, the “Dekompressor”, a percutaneous discectomy probe. It has a battery-operated disposable hand piece attached to a helical probe. The cannula allows access to the disc space, and the probe rotates and removes nucleus material through a suction mechanism. Both devices are too stiff to easily remove all of the nucleus  
         [0012]     ArthroCare Corporation, has worked on coblation technology, which involves the use of low energy radio-frequency waves. This energy creates an ionic plasma field from the sodium atoms found in the nucleus. A molecular dissociation process occurs due to this low temperature plasma field, which converts this tissue into gases that exit the treatment site. The product is named the Spine Wand. It acts as drill as it is advanced into the disc. The tissue is converted into gas that exits the disc through the cannula. An accessory to the Spinal Wand is the System 2000 Controller. This accessory uses a combination of ablation, resection, coagulation and suction. A bipolar cautery is employed. However, the insertion depth up to the annulus must be predetermined and the wand is difficult to steer to remote parts of the nucleus space.  
         [0013]     Laser discectomy employs laser energy to vaporize portions of a diseased disc. It is compatible with through minimally invasive surgery. However, laser techniques are generally useful to remove only small amounts of material because of the heat generated and other limitations. In addition, vaporized material expands to a gaseous phase and must be removed.  
         [0014]     This invention proposes devices and methods directed to improving complete removal of the disc nucleus. The new process must be a relatively quick and cost effective alternative to current procedures. In addition, the new method or device must facilitate a complete and clean removal of the disc in a safe manner that does not compromise the integrity of the annulus.  
       OBJECTS OF THE INVENTION  
       [0015]     An object of the present invention is to overcome the drawbacks described above and other limitations in existing systems by providing a surgical device to remove almost the entire nucleus from a spinal intervertebral disc.  
         [0016]     Another object of the invention is to remove nucleus material with minimal or no damage to surrounding tissues or structures such as the disc annulus, vertebral endplates, spinal nerves or blood vessels.  
         [0017]     Another object of the invention is to be minimally invasive and carry a low risk of infection or discomfort to the patient.  
         [0018]     Another object of the invention is to aid imaging, by x-ray or other means, of the nuclear space and surrounding structures.  
         [0019]     Another object of the invention is to provide a system and method that removes the nucleus rapidly.  
         [0020]     Another object of the invention is to provide a system and method that allows a surgeon to remove the nucleus without prolonged training, practice or skill.  
         [0021]     Another object of the invention is to provide a system and method that removes the nucleus while allowing the surgeon fine control of the procedure.  
         [0022]     These and other objects of the invention are accomplished according to various embodiments of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]      FIG. 1  is a frontal-lateral view of the anatomy of a section of the human lumbar spine.  
         [0024]      FIG. 2  is a superior view cross section of the anatomy of a human lumbar intervertebral disc.  
         [0025]      FIG. 3  is a superior view in cross section of a herniated human intervertebral disc.  
         [0026]      FIG. 4  is a side view representation of the human spine in the vicinity of a herniated disc.  
         [0027]      FIGS. 5A and 5B  show a multiple port suction embodiment of the present invention.  
         [0028]      FIG. 6  shows another multiple port suction embodiment of the present invention.  
         [0029]      FIG. 7  shows yet another multiple port suction embodiment of the present invention.  
         [0030]      FIG. 8  shows a multiple port suction embodiment of the present invention with protrusion features.  
         [0031]      FIG. 9  shows another view of the multiple port suction embodiment of the present invention with protrusion features.  
         [0032]      FIG. 10  shows a side view of a pinching embodiment of the present invention.  
         [0033]      FIGS. 11A and 11B  show a side views of a multiple arm pinching embodiment of the present invention.  
         [0034]      FIG. 12  shows a side view of a multiple-vane collector embodiment of the present invention located in the nucleus space.  
         [0035]      FIG. 13  shows a closer view of the vane collector embodiment of  FIG. 12 .  
         [0036]      FIG. 14  shows a reciprocating and articulating plunger embodiment of the present invention.  
         [0037]      FIG. 15  shows a rotatable, multiple-vane embodiment of the present invention.  
         [0038]      FIG. 16  shows a rotatable an alternate multiple-vane embodiment of the invention in  FIG. 15 .  
         [0039]      FIG. 17  shows a scissor arm embodiment of the present invention.  
         [0040]      FIG. 18  shows a conveying embodiment of the present invention.  
         [0041]      FIG. 19  shows a spiral conveying rod embodiment of the present invention.  
         [0042]      FIG. 20  shows an expandable straining embodiment of the present invention driven by an inflatable member.  
         [0043]      FIG. 21  shows the embodiment in  FIG. 20  with arm elements.  
         [0044]      FIGS. 22A and 22B  show a spiraling plow and suction embodiment of the present invention.  
         [0045]      FIG. 23  shows an inflatable member and suction embodiment of the present invention.  
         [0046]      FIG. 24  shows a second inflatable member and suction embodiment of the present invention.  
         [0047]      FIG. 25  shows a third inflatable member embodiment of the present invention.  
         [0048]      FIG. 26  illustrates deployment of a deployable straining and suction embodiment of the present invention.  
         [0049]      FIG. 27  shows combined inflatable and directional suction members as an embodiment of the present invention.  
         [0050]      FIG. 28  shows the inclusion of further elements to the embodiment in  FIG. 27 .  
         [0051]      FIG. 29  shows a detail of one embodiment of the distal portion of the suction member of  FIG. 28 .  
         [0052]      FIG. 30  shows a further detail of one embodiment of the distal portion of the suction member of  FIG. 28 .  
         [0053]      FIG. 31  shows a another view of the distal portion of the suction member of  FIG. 30 .  
         [0054]      FIG. 32  shows another detail and element of the distal portion of the suction member of  FIG. 29 .  
         [0055]      FIGS. 33A, 33B  and  33 C show a positioning device to aid deployment of the various embodiments of this invention.  
         [0056]      FIG. 34  shows an oscillating member and suction embodiment of the present invention.  
         [0057]      FIG. 35  shows the embodiment of  FIG. 34  with multiple oscillating members.  
         [0058]      FIG. 36  shows a distal translational motion control mechanism for use in the present invention.  
         [0059]      FIG. 37  shows another embodiment of motion control with suction elements.  
         [0060]      FIGS. 38A and 38C  show a plowing vane embodiment of the invention in perspective and cross-section views.  
         [0061]      FIG. 38B  shows an alternate embodiment of the plowing vane. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0062]     This invention overcomes various limitations of prior art means to remove nucleus pulposus from spinal intervertebral discs.  FIG. 1  shows a section of the lumbar spine with major anatomic features labeled. Vertebrae are the bones that provide essential strength and stiffness to the spine and afford protection to the spinal cord, spinal nerve roots and major blood vessels (the blood vessels are not shown but are located opposite the spinal cord). The discs located between vertebra provide the spine with the ability to articulate by lubricating and separating the vertebrae.  
         [0063]      FIG. 2  is a superior sectional view through an intervertebral disc  24  of the lumbar spine, the front of the body is upward in this view. Spinal nerves  22  radiate from the spinal cord  23 , located posterior to the spine, to provide control and sensation to various segments and organs of the body. The disc  24  is roughly kidney shaped and defined by the annulus fibrosus  21 . The annulus is composed of concentric layers of fibrous tissue that seal the space between vertebra located above and below the disc (not shown). Each layer of annulus  21  connective tissue is comprised of type I collagen oriented at approximately 30°. Successive annulus  21  layers alternate the 30° angle to provide substantial resistance to pressure from inside the disc  24 . Within the space defined by the annulus  21  is the nucleus pulposus  20 . The nucleus is avascular and comprised of hydrated mucoprotein gel and type II collagen fibers.  
         [0064]     The intervertebral disc functions somewhat like a water bed to allow articulation of the spine. When a person is upright substantial hydrostatic pressure is developed within the disc  24  and this pressure increases at lower portions of the spine, particularly the lumbar and sacral region. The annulus  21  serves to contain nucleus  20  that is under pressures in the range of 690 to 2000 kPa (100 to 300 psi). Articulation of the spine is accommodated by displacement of nucleus material from one side of the nucleus space to another. In a normal, healthy spine the vertebrae are prevented from contacting each other even at maximal angles of articulation.  
         [0065]     In young adults the intervertebral disc  24  is approximately 7 to 9 mm thick. With age and disease the hydration level of the nucleus  20  decreases. This thickens the nucleus from a soft gel-like consistency to become relatively stiff. Further degeneration with age and disease can occur to both the nucleus  20  and the annulus  21 . This may allow the thickness of the disc  24  to decrease until, in the final stages, the vertebrae are in contact during some or all postures and movement. Contact between vertebrae damages these bony structures and generates substantial pain. Disc thickness greater than approximately 4 mm is presently considered suitable for nucleus replacement therapy. At lesser thickness treatment will usually involve removal of the disc  24  for spinal fusion or implantation of an artificial disc.  
         [0066]     Because the nucleus  20  is avascular there are no living cells and exchange of fluids is through the cartilaginous endplates (not shown) covering the vertebral body. The endplates are a thin layer of primarily hyaline cartilage. The endplates are important to proper function of the intervertebral disc. In traditional therapies of fusion and disc replacement the endplates are not preserved so surgical techniques generally disregarded protection of the endplates. With motion restoration implantation of nucleus replacements the endplates must be protected from damage.  
         [0067]     Similarly, with age and disease the annulus  21  may become weakened. This is a frequent cause of herniation, as illustrated in  FIG. 3 . As shown, the annulus  21  has weakened under pressure exerted by the nucleus  20  (in response to compression from the vertebrae) and compresses spinal nerve root  22 .  FIG. 4  is lateral view of a disc  41  herniation impacting spinal nerve  42  caused by annular failure  30 . Similarly, the annulus  21  can fail such that nucleus material  20  exits the annulus and causes a direct effect on the nerve. In addition to being one of the major causes of disc therapy, degeneration of the annulus makes it vulnerable to damage during nucleus removal. The various embodiments of the present invention provide means of protecting the annulus from penetration or disruption.  
         [0068]     A first embodiment of the present invention  50  illustrated in  FIGS. 5A and 5B  contemplates a hollow tube  51  terminating at the distal end in a plurality of shorter tubes  52  and  53 . Vacuum applied to the proximal end of tube  51  provides suction through lumen  54  at the opening of tubes  52  to remove nucleus  20  material. The hollow tube  51  preferably has a smaller cross-section area than the sum of cross-section areas of shorter tubes  52  and  53  yet has a larger cross section than any of the single tubes  52  or  53 . The hollow tube  51  may be manipulated to move shorter tubes  52  through the nucleus space and remove substantially all of the nucleus material.  
         [0069]      FIG. 6  shows another embodiment of the present invention  60  where hollow tube  62  terminates in a plurality of openings  61  in a roughly spherical plenum  63  with a diameter larger than the diameter of tube  62 . Vacuum applied to the proximal end of tube  62  provides suction at each of the openings  61  to remove nucleus  20  material. An advantage of the present embodiment  60  is that the spherical conformation of the plenum  63  serves in preventing injury to the annulus.  
         [0070]      FIG. 7  shows another embodiment comprising a hollow tube  70  providing suction to distal side openings  71  and distal tip opening  72  when a vacuum is applied to a proximal end of tube  70 . The illustrated distal portion of tube  70  is navigated throughout the nucleus  20  space to remove nucleus material. Tube  70  preferably has a terminal radius approximately the same as the inner radius of the annulus  21  of a human intervertebral disc.  
         [0071]      FIG. 8  shows an embodiment of the present invention  80  comprising a hollow tube  83  employing suction through openings  81  located on the distal side and tip. Features  82  are in the shape of fibers or short ridges that can be employed to disrupt the nucleus  20  material as the tube  83  is moved through the nucleus space.  FIG. 9  is a proximal side view of embodiment  80  comprising illustrating the lumen  54  in tube  83  through which suction is applied to the openings  81 .  
         [0072]      FIG. 10  illustrates a further embodiment of the present invention  100  comprising a hollow tube  103  terminating at the distal end in a grasping mechanism. The grasping mechanism comprises arms  102  that may be opened and closed by pivoting about pin  104  when activated by mechanisms operated at the proximal end of tube  103  (not shown). The grasping mechanism serves to liberate pieces of nucleus material  20  which are then removed from the nucleus space through tube  103  by suction or carried out of the disc space by removing the mechanism  100  with the arms  103  together.  
         [0073]     The embodiment of the present invention  112  shown in  FIGS. 11A and 11B  is comprised of an outer tube  111  containing a plurality of extensible tips  110  at the end of rods  114 . The rods are threaded through at least part of the length of tube  111  and attached to inner tube  115  so that as inner tube  115  is controllably advanced from the proximal end the tips are moved away from the end of tube  111 . Spring force in rods  114  cause the tips to move apart when advanced while ring apparatus  113  serves to define the point at which the diverging spring force is constrained. A cycle of advancing the rods into nucleus material and retracting them causes pieces of the nucleus material to be brought into proximity with the distal opening of tube  111 . The tube  111  may removed from the nucleus space and each piece of nucleus material discarded or a vacuum may be applied to the proximal end of tube  111  through lumen  54  to remove nucleus  20  by suction. An optional guide ridge on the exterior of inner tube  115  matches a channel (not shown) on the inside of outer tube  111  to limit rotation and assure positioning of inner tube  116  within the outer tube  111 .  
         [0074]      FIGS. 12 and 13  show another embodiment  120  of the present invention that comprises a hollow tube  121  with a distal opening  123  and a plurality of partially curled circumferential ridges  122 . The ridges may be moved with one or more control rods  124  from a position substantially perpendicular to the tube  120  to an angle of approximately 30° to 45° (not shown). The ridges are preferably softer than the annulus to prevent injury to the annulus but disrupt the softer nucleus material and allow pieces of nucleus to be removed by suction through distal tip opening  130  or side openings (not shown), or entrapped and removed when the device is withdrawn from the nucleus space.  
         [0075]     In a further embodiment of the present invention, the distal portion of a reciprocating apparatus is shown in  FIG. 14 . Hollow tube  140  comprises a collar  141  attached to the tube  140  by angleable joint  142  which further comprises a distal opening  146  that allows a vacuum applied to the proximal end of tube  140  (not shown) to produce suction at opening  146 . Rod  143  passes through opening  146  and can be reciprocally advanced and retracted. One or more blades  144  are attached to the distal tip of rod  143  and are used to bring pieces of nucleus material into proximity with the opening  146  to be removed by the suction. Further, the blades  144  may be flexed in a manner shown by arrows  145  to increase mobilization of nucleus material. Joint  142  enables the collar  141  to be directed in various directions to reach each portion of the nucleus space.  
         [0076]      FIG. 15  shows an embodiment  150  of the invention that employs a hollow tube  156  to support and multiple arms that disrupt the nucleus when the device  150  is rotated. Each arm is comprised of two or more segments  151  and  152 . First arm  151  is attached at one end to the tube  150  by a second pin joint or a flexural hinge. The second end of arm  151  is attached to arm  152  at flexural hinge  154 , while the second end of arm  152  is attached at the distal tip of the apparatus to other arms  152 . Control arms  155  can be extended longitudinally to expand arms  151  and  152 . Nucleus material dislodged by motion of the arms may be extracted by suction through tube  150 .  
         [0077]     Deployment of the present embodiment  150  into the nucleus  20  space defined by the annulus  21  is portrayed in  FIG. 16 . Also portrayed in  FIG. 16  is a particular embodiment with an inner hollow tube  155  used in place of the control arms in  FIG. 15 . Inner tube  155  contains one or more openings  166  to remove nucleus  20  material by suction.  
         [0078]      FIG. 17  shows a scissoring arm embodiment  170  of the present invention. Arm  171  is attached to hollow tube  175  at a pin joint  173 . Tethers  174  and  176  are operated to rotate arm  171  from a position perpendicular to a parallel position with respect to tube  175  and disrupt nucleus material. In this view, rotation brings the nucleus material to a plurality of openings  172  in hollow tube  175  where the nucleus material may be removed from the nucleus space by suction.  
         [0079]      FIG. 18  shows a conveying embodiment  180  of the present invention. The conveying apparatus is attached to hollow tube  186  by connector  181  that allows the belt  185  of the conveying system to move through tube  186 . A plurality of paddles  184  are attached to a belt  185  that may be guided in a loop in two direction, as indicated by the two-headed arrows  182 . Nucleus  20  material are moved with the paddles  184  to an opening in the hollow tube for removal from the tube  186 .  
         [0080]      FIGS. 19A and 19B  shows a spiral-formed apparatus  190  comprising a wire  192  that coils inward when extended from a hollow tube  194  through a distal opening  191 .  FIG. 19B  shows the wire  192  retracted into the tube  194 . Fingers  193  on wire  192  capture nucleus material and carry it through the tube  194 . Vacuum applied to the tube  194  may be employed to aid removal of nucleus  20  material by suction. Tube  194  is manipulated by advancing and retraction and changing the angle of the tube  194  to reach substantially all of the nucleus space. A rigid rod  196  may be attached at the proximal end of the wire  192  to control deployment of the wire.  
         [0081]      FIG. 20  shows a cutting balloon apparatus comprising an inflatable balloon  202  and cutting mesh  203  comprised of an elastic material containing a plurality of openings  205  attached to the distal end of tube  206 . Tube  206  contains a plurality of lumens  201  (not shown) that are employed to inflate the balloon  204  and remove nucleus  20  material when controlled pressure and vacuum, respectively, are applied to separate lumens at the proximal end (not shown) of tube  206 . When the balloon  202  is inflated the cutting mesh (resembling a strainer or screen)  203  is forced through the nucleus space to disrupt nucleus material that may be removed by suction through a lumen of tube  206  or with the cutting balloon apparatus as the balloon is deflated.  
         [0082]      FIG. 21  is another embodiment  210  of the invention comprising a cutting mesh  211  that is expanded into the nucleus space defined by the annulus  21  by spring force as the mesh is advanced from the distal end of tube  210 . The mesh  211  may incorporate hooks or other features  213  on the outside that further aid in disrupting the nucleus. As the mesh  211  is advanced through the nucleus space disrupted nucleus material passes through to the interior  212  of the mesh  211 . Suction applied through hollow tube  215  removes nucleus material along the indicated path  214 . The distal mesh and balloon combination may preferably provide a flat and smooth surface  212  that helps to prevent injury to the end plate tissue of vertebrae  40 .  
         [0083]      FIGS. 22A and 22B  illustrate yet another embodiment  220  of the invention comprising insertion tube  221  that enters the nucleus  20  space through an opening in the annulus  21 . A flexible tube  225  is advanced from the tube  221  and employs an outward spring force  226  to follow the inside edge  224  of the annulus  21  defining the nucleus space. When the flexible tube  225  has passed around the periphery of the nucleus space it begins to follow an inwardly spiraling path as more of the flexible tube is advance from the insertion tube  221  until the desired amount of nucleus material is removed.  FIG. 22B  is a detail of the distal portion of flexible tube  225 . An approximately cylindrical scoop  222  is formed at the distal end of the flexible tube  225  that captures nucleus  20  material that is removed from the nucleus space by suction through flexible tube. The scoop  222  is comprised of soft material, preferably in the range of Shore A hardness 30 to 60, that prevents damage to the annulus.  
         [0084]     According to the embodiment of the invention illustrated in  FIG. 23  tube  232  is placed within the nucleus space  20  of an intervertebral disc defined by annulus  21 . A balloon  234  located at the end of the tube  232  is inflated with fluid from a collapsed shape  234   a  to progressively displace nucleus  20  material into a suction lumen  235  of tube  232  placed in communication with the nucleus space. Suction lumen of the tube  232  preferably has a vacuum or suction applied to its lumen at the proximal end and removes displaced nucleus entering the distal end from the body and prevents nucleus from exiting the disc and remaining inside the patient. The suction lumen  235  of tube  232  may incorporate a collar or other feature  233  that aids in sealing the opening in the annulus  21  to prevent escape of nucleus material and the balloon and allow a greater negative pressure to be developed. The physician or operator may manipulate the tube  232  by changing the angle that they enter the nucleus space and advancing or retracting the tubes within the nucleus space to navigate the geometry of the nucleus space so as to remove the desired quantity of nucleus.  
         [0085]     In a second embodiment of the invention  240 , illustrated in  FIG. 24 , one or more balloons  230 , or a single donut-shaped balloon is attached to the end of a first tube  243  containing lumen  241  that collects nucleus  20  displaced by the balloon  230 . A vacuum may applied to the proximal end of lumen  241  to aid in removal of nucleus  20  through one or more openings  242 .  
         [0086]     An example of deployment of a single balloon  230  from a tube  243  within the kidney-shaped nucleus  20  space defined by annulus  21  is illustrated in  FIG. 25 . Balloon  230  may be partially inflated and deflated one or more times to progressive mobilize nucleus  20  into the tube  243  or otherwise out of the disc. Tube  243  may be angled and repositioned one or more times in coordination with inflation of balloon  230  to optimize nucleus  20  removal. Balloon  230  is preferably inflated with an incompressible fluid having radio-opaque properties to aid visualization of the nucleus space and anatomy of the disc.  
         [0087]      FIG. 26  shows deployment of an expand and capture apparatus  260 . A one  262  or two-piece strap ( 262  and  263 ) is advanced into the nucleus space from tube  261  until it is in contact with the annulus circumscribing generally the entire nucleus space. The strap is comprised of a plurality of equally spaced openings each with a diameter of between 50% and 85% of the width of the strap. The strap preferably has a width approximately equal to the narrowest gap between vertebrae defining the sides of the nucleus space. Or, the width of the band may be between 2.5 and 5 mm and further comprise soft wipers or ridges to aid in forming a loose seal against the surfaces of the vertebrae. Alternatively, the strap  262  may be comprised of a plurality of hinged links each with an opening in the same range as described above. This embodiment of the strap resembles a bicycle chain. The chain-like band contains features at the link joints, such as tabs mating with slots, that constrain the strap to a generally convex shape as it is being advanced from the tube  261  (under compression) and provide for flexion in any direction when it is retracted.  
         [0088]     As a strap  262  or  263  of apparatus  260  is advanced into the nucleus space nucleus  20  material is disrupted and forced through the openings in the strap. The width of the strap, or the wipers described above, ensure that essentially all of the nucleus material is forced through the openings in the strap and is prevented from escaping around the strap. Once a quantity of nucleus material is captured with the region defined by the strap the strap and be withdrawn into tube  261  carrying with it the entrained nucleus. Suction applied through the tube  261  can aid in removing material from the nucleus space  264 . The strap may be repeatedly advanced and retracted until the desired quantity of nucleus material has been removed  263 . The strap will preferably contain radiopaque material or features that help describe its outline and location when imaged by x-ray. When fully deployed the strap will aid in imaging the nucleus space.  
         [0089]     Apparatus  260  may further comprise a second strap associated with the first strap. The second strap would have a width equal to or less than the first band and contain roughly the same number and size of openings as the first band. As the straps are advanced they are arranged so that the openings in both straps are aligned which allows nucleus material to pass through both straps. To prepare for retraction, the second strap is moved relative to the first strap sufficiently so that the openings in the two straps a no longer aligned and nucleus material is further disrupted and entrapped within the space defined by the straps. One or both straps  262  and  263  may be attached  265  at one end to the distal opening of tube  261 .  
         [0090]      FIG. 27  illustrates a directional balloon and tube apparatus  270  of the present invention. One or more balloons  271  are attached to one side of the distal portion of a tube  273  containing a plurality of lumens  275  that provide proximal fluid communication to the balloons  271  and distal openings  272 , and to respective pressure and vacuum sources at the proximal end (not shown) of tube  273 . Openings  272  at the distal end and side of the tube allow nucleus  20  to be removed from the disc through one of the tube lumens. The tip  274  of tube  273  is made of a soft material, rounded or otherwise adapted to prevent damage to the annulus  21  as the tube is inserted and manipulated in the nucleus space.  
         [0091]     By one preferred method, apparatus  270  is advanced into the nucleus space along the lateral wall defined by the annulus closest to the location that the apparatus penetrates the annulus (usually the location of annular failure in herniation). Suction is applied to the distal openings  272  through a lumen  275  while the apparatus  270  is advanced and throughout the nucleus extraction procedure. The apparatus  270  may be turned through 180° in alternate directions or 360° from its initial orientation so that nucleus  20  material to all sides is removed. At any time during the procedure the apparatus may be partially or completely retracted and re-advanced, with or without rotation, so that the distal openings  272  come into contact with a maximum of nucleus  20  material.  
         [0092]     Once initial placement of the apparatus  270  is complete the apparatus is rotated to position the distal openings  272  toward the nucleus  20  space that still contains nucleus material. Suction continues on distal openings  272  while one or more balloons  271  are inflated to push the openings into contact with, and through, the nucleus material. During balloon  271  inflation the apparatus may continue to be manipulated by rotation and further advancement or retraction, as allowed by the position of the balloon, to bring the openings  272  into contact with remaining material and to navigate the apparatus through the nucleus  20  space. Inflation of balloon  271  also serves to displace nucleus  20  material around the tube  273  and into proximity with the openings  272  so that it can be removed from the nucleus space. Balloon  271  further contributes to removal of nucleus material by increasing the static pressure within the nucleus  20  space so that the net pressure across the openings  272  is higher relative to the applied vacuum. The process of balloon  271  inflation and manipulation of the apparatus continues until the desired quantity of nucleus material is removed.  
         [0093]     A further embodiment of the balloon and tube arrangement  270  is illustrated in  FIG. 28 . A plurality of openings  272  are formed on the side of the tube  273  opposite the balloon. Preferably, the number and size of openings define a longitudinal distance substantially equal to the co-linear dimension of the nucleus  20  space. It may also be advantageous to have openings  272  only on the side of tube  273  and not provide a distal opening. A further preferable configuration would permit certain openings  272  to be closed by advancing outer sheath  281  when they are not in contact with nucleus  20  material. This permits maximum vacuum pressure to be applied to the openings best able to remove nucleus.  
         [0094]      FIG. 29  shows details of a possible arrangement of the tip of a directional suction apparatus  290  that can be used alone or with the balloon and tube arrangement  270 . Side openings  272  and distal opening  293  in tube  291  provide fluid communication between suction lumen  294  and nucleus  20  material outside the apparatus  290 . Ridges  292  are a flexible material that conforms to the shape of the surrounding vertebrae and endplates to form a partial seal separating the two sides of the apparatus. When used in the balloon and tube arrangement  270  the ridges  292  aid in collecting nucleus  20  material to the openings  272  as the apparatus is moved through the nucleus  20  space. As well, ridges  292  aid in holding the balloon to one side of the tube  291  so that it does not interfere with movement of arrangement  270  or openings  272  and  293 .  
         [0095]      FIG. 30  shows one embodiment  300  of a soft tip  302  formed on tube  301 . Tip  302  may be molded directly from tube  301  with a forming tool. Alternatively, tip  302  may be created from a different material, preferably with a lower Shore hardness than the material of tube  301 , and attached to tube  301  with adhesive or heat / chemical welding. Tip  302  allows for distal opening  273  to communicate with lumen  303 .  
         [0096]      FIG. 31  presents a top view of a tip configuration  310  of balloon and tube arrangement  270 . The tube  311  contains suction lumen  273  and inflation lumen  312 . Side openings  272  communicate with suction lumen  273 . Inflation opening  313  is located on the side of tube  311  opposite side openings  272  and communicates with inflation lumen  312 . A balloon  271  is formed of a membrane sealed  314  to tube  311  around inflation opening  313 . Fluid supplied under pressure to inflation lumen  312  passes out of inflation opening  313  and enters and enlarges balloon  271 .  
         [0097]      FIG. 32  illustrates the tip of a suction tube  321  that contains a second tube  322  that allows openings  272  in tube  321  to be selectively opened or closed. The second tube  322  has an outside diameter approximately equal to the inside diameter of suction tube  321  that provides a relatively close seal between the tubes  321 ,  322 . Second side openings  323  in second tube  322  are preferably at least as large as the side openings  272  in tube  321 . The second openings  323  are positioned at the same longitudinal positions as the side openings  272  but at different radial positions. Rotation of the second tube  322  within the suction tube  321  allows the side openings  272  to be selectively closed by orienting the associated second opening  323  away from the side opening  272 . Various arrangements of second openings  323  within the second tube  322  may be made to provide different combinations of open and closed side openings  272  by rotation of second tube  322 . A further use of second tube  322  is to cut nucleus  20  material that enters a side opening  272  into segments that aid removal of the nucleus material by suction.  
         [0098]      FIGS. 33A, 33B  and  33 C show three views of a sheath  330  to aid in inserting and positioning the various nucleus  20  removal embodiments of this invention. Tube  332  comprises a lumen  331 , flange  337 , tip  334  and flange extensions  338 . The lumen  331  is sized to accommodate passage of a nucleus removal apparatus and guide it to the opening in the annulus  21 . The sheath  330  protects the nucleus removal apparatus from damage and kinking as it is inserted and manipulated. Similarly, the sheath protects the annulus and other tissues from injury by the nucleus removal device. The distal tip  334  of the sheath  330  is tapered to ease insertion through an existing opening in the annulus  21 . The tip  334  may also be comprised of a soft material and be further shaped to prevent injury to the annulus during insertion.  
         [0099]     An important objective of the sheath  330  is to seal the opening in annulus  21  and prevent nucleus  20  or other materials from escaping the disc and being released into the body. Taper  333  on the flange  337  assists in providing a tight fit in the contact region  335  with the annulus  21 . Further, the tapered or soft tip  334  will form a partial seal around the nucleus removal device. Flange  337  has an oblong shape defined by flange extensions  338  that allows a large contact area with the annulus  21  while fitting between the vertebrae  40 . This shape of the flange  337  also keeps the sheath  330  oriented (rotation is prevented). A key  339  may be incorporated into the sheath so that a matching keyway on a nucleus removal device will serve to keep both devices oriented. Alternatively, markings on the proximal end of the sheath  330  (not shown) can be provided to indicate orientation.  
         [0100]     A further embodiment of a nucleus removal device  340  is illustrated in  FIG. 34 . It is comprised of a whip  342  located within the nucleus  20  space and attached to a vibration transmission rod  341 . Vibrational motion is delivered to the rod  341  at the proximal end of the device  340  (not shown). The mechanical characteristics of the rod  341  are arranged so that the vibrational motion is transmitted efficiently from the proximal end to the distal end of the rod  341  with minimal actual motion within tube  343 . Whip  342  has different mechanical characteristics that convert the vibrational motion transmitted through the rod  341  to substantial motion of the whip  341 . The vibrational frequency and displacement delivered to the proximal end of the rod  341  is tuned to produce substantially more motion of the whip  342 . Preferably, a standing wave motion  344  would be produced in the whip  342  by the vibrational motion. More preferably, the standing wave would only be present when the whip  342  is in contact with nucleus  20  material and would degenerate to smaller amplitude motion where the whip is in contact with annulus  21  or other material with different characteristics. The tip  345  of the whip  342  incorporates a button or other feature to limit injury to the annulus  21  or endplates. The tube  343  contains a lumen surrounding the rod  341  to which a vacuum may be applied at the proximal end for the purpose of removing nucleus  20  material by suction.  
         [0101]     Vibrational motion  344  of the whip  342  of device  340  disrupts the structure of nucleus  20  so that it may be more easily removed by suction through tube  343 . Tube  343  may be manipulated and whip  342  may be extended or retracted so that whip  342  can be directed to all parts of the nucleus  20  space. Tube  343  may also be advanced into nucleus space  20  to aid removal of nucleus material by suction.  
         [0102]     An alternate embodiment to a vibrational whip  350  is portrayed in  FIG. 35 . Instead of one long whip, as in the whip  342  in  FIG. 34 , there are two symmetrically configured whips  352  extending from the rod  341 . In addition, rod  341  may be extended or retracted separately from tube  353  so that the whips  352  may be directed throughout the nucleus  20  space.  
         [0103]     Various of the embodiments, such as illustrated by  150  in  FIG. 15  and  190  in  FIG. 19 , require an operator or surgeon to manipulate mechanisms located in the disc nucleus from the proximal end of an outer tube such as tube  168  in  FIG. 16 .  FIG. 36  shows one mechanism  360  to provide translational motion from a proximal location to the distal end of a tube or sheath. A first grip  363  is connected to inner tube  362  which can be slid forward and back within outer tube  364 . A second grip  365  is connected to outer tube  364  to hold it immobile while inner tube  362  is moved. Second grip  365  also aids the operator to position the distal end (not shown) of the outer tube  364  within the nucleus  20 . Outer tube  364  may be contiguous with or connected to other outer tubes in several embodiments of the invention such as  111  in  FIG. 11B and 168  in  FIG. 16 . Grips  363  and  365  are shown with radial knurls in  FIG. 36  as an example of an aid in handling the mechanism while an operator is wearing gloves in a wet environment. Grips  363  and  365  may be bonded chemically (e.g. by adhesive or chemical welding) or mechanically (e.g. by heat, interference fit or ultrasonic welding) to respective tubes  362  and  364 . Or the grips may be formed integrally with the tubes by injection molding or a similar technique.  
         [0104]      FIG. 37  illustrates another mechanism  370  to provide controlled translational motion at the proximal end of an invention as described herein. Handles  371  and  372  fit within the palm of an operators hand. Thumb guide  374  helps to ensure proper positioning while wearing gloves or in a moist environment. When the operator closes her hand the handles  371  and  372  rotate about a pivot  375  drawing inner tube  362  through outer tube  364  and partially or completely withdraws the distal end of the mechanism at the distal end of inner tube  362  from the space defined by the disc annulus  21 . A spring  373  forces the handles  371  and  372  apart when the operator releases hand pressure. Inner tube  362  provides a vacuum pathway to the mechanism within the annulus space  21 . A reservoir  376  to capture material evacuated through the inner tube  362  is connected at the distal end of inner tube  362  and to a flexible tube  377 . The flexible tube is connected to an inlet port  378  on a vacuum pump  379 .  
         [0105]     In an alternative embodiment  380  of the invention, shown in  FIGS. 38A and 38C , a wiper is advanced into the nucleus space from the distal end of a hollow insertion tube. The wiper is comprised of plow blades  382  that are reinforced by shorter, support blades  386  and deployed by a wire  384 . The plow blades  382  are preferably formed of a soft polymer that will not harm the annulus  21  or vertebral endplates. The support blades  386  are preferably formed with reinforcing tabs and a narrowed front edge. As illustrated in  FIG. 38C , the support blade  386  may be formed with tabs spaced along the wiper rather than being continuous to facilitate easier advancement. As the wiper is advanced into the nucleus space with a wire  384  the plow blades  382  are drawn together allowing easier passage of the wiper. After the wiper is fully deployed in the nucleus space it will be in contact with essentially all of the inside edge of the annulus. The nucleus space may then be readily imaged by x-ray because the wire  384  or some other portion of the wiper is deliberately radiopaque.  
         [0106]     Retraction of the wiper into the into an insertion tube  385  causes the blades on the wiper to spread and make continuous contact with the vertebral endplates. The support blade  386  serves to prevent the plow blade  382  from collapsing in the distal direction. Nucleus material is pulled toward the insertion tube  385  by retraction of the wiper and removed through the tube by suction.  
         [0107]     Characteristics and advantages of the invention covered by this document have been set forth in the foregoing description. This disclosure is only illustrative in many respects. Changes can be made in details without exceeding the scope, or departing from the spirit, of the invention. The inventors&#39; scope is defined in the language in which the claims are expressed.