Patent Document

CROSS-REFERENCES TO OTHER APPLICATIONS 
       [0001]    This is a divisional application to U.S. Ser. No. 10/555,895 filed on Nov. 2, 2006, the national stage of PCT/US2004/14368 filed on May 7, 2004. 
     
    
     FIELD OF INVENTION 
       [0002]    This invention relates to methods and devices for transporting nutrients and waste into and out of the intervertebral disc to halt or reverse the degeneration of the intervertebral disc. 
       BACKGROUND 
       [0003]    Low back pain is a leading cause of disability and lost productivity. Up to 90% of adults experience back pain at some time during their lives. For frequency of physician visits, back pain is second only to upper respiratory infections. In the United States the economic impact of this malady has been reported to range from $50-$100 billion each year, disabling 5.2 million people. Though the sources of low back pain are varied, in many cases the intervertebral disc is thought to play a central role. Degeneration of the disc initiates pain in other tissues by altering spinal mechanics and producing non-physiologic stress in surrounding tissues. 
         [0004]    The intervertebral disc  100  absorbs most of the compressive load of the spine, but the facet joints  142 ,  143  of the vertebral bodies  159  share approximately 16%. The disc  100  consists of three distinct parts: the nucleus pulposus  128 , the annular layers and the cartilaginous endplates  105 , as shown in  FIGS. 1 and 2 . The disc  100  maintains its structural properties largely through its ability to attract and retain water. A normal disc  100  contains 80% water in the nucleus pulposus  128 . The nucleus pulposus  128  within a normal disc  100  is rich in water absorbing sulfated glycosaminoglycans, creating the swelling pressure to provide tensile stress within the collagen fibers of the annulus. The swelling pressure produced by high water content is crucial to supporting the annular layers for sustaining compressive loads, as shown in a longitudinal view in  FIG. 2 . 
         [0005]    In adults, the intervertebral disc  100  is avascular. Survival of the disc cells depends on diffusion of nutrients from external blood vessels  112  and capillaries  107  through the cartilage  106  of the endplates  105 , as shown in  FIG. 2 . Diffusion of nutrients also permeates from peripheral blood vessels adjacent to the outer annulus, but these nutrients can only permeate up to 1 cm into the annular layers of the disc  100 . An adult disc can be as large as 5 cm in diameter; hence diffusion through the cranial and caudal endplates  105  is crucial for maintaining the health of the nucleus pulposus  128  and inner annular layers of the disc  100 . 
         [0006]    Calcium pyrophosphate and hydroxyapatite are commonly found in the endplate  105  and nucleus pulpous  128 . As young as 18 years of age, calcified layers  108  begin to accumulate in the cartilaginous endplate  105 , as shown in  FIG. 3 . The blood vessels  112  and capillaries  107  at the bone-cartilage interface are gradually occluded by the build-up of the calcified layers  108 , which form into bone. Bone formation at the endplate  105  increases with age. 
         [0007]    When the endplate  105  is obliterated by bone, diffusion between the nucleus pulposus  128  and blood vessels  112  beyond the endplate  105  is greatly limited. In addition to hindering the diffusion of nutrients, calcified endplates  105  further limit the permeation of oxygen into the disc  100 . Oxygen concentration at the central part of the nucleus  128  is extremely low. Cellularity of the disc  100  is already low compared to most tissues. To obtain necessary nutrients and oxygen, cell activity is restricted to being on or in very close proximity to the cartilaginous endplate  105 . Furthermore, oxygen concentrations are very sensitive to changes in cell density or consumption rate per cell. 
         [0008]    The supply of sulfate into the nucleus pulposus  128  for biosynthesizing sulfated glycosaminoglycans is also restricted by the calcified endplates  105 . As a result, the sulfated glycosaminoglycan concentration decreases, leading to lower water content and swelling pressure within the nucleus pulposus  128 . During normal daily compressive loading on the spine, the reduced pressure within the nucleus pulposus  128  can no longer distribute the forces evenly along the circumference of the inner annulus to keep the lamellae bulging outward. As a result, the inner lamellae sag inward, while the outer annulus continues to bulge outward, causing delamination  114  of the annular layers, as shown in  FIGS. 3 and 4 . 
         [0009]    The shear stresses causing annular delamination and bulging are highest at the posteriolateral portions adjacent to the neuroforamen  121 . The nerve  194  is confined within the neuroforamen  142  between the disc and the facet joint  142 ,  143 . Hence, the nerve  194  at the neuroforamen  121  is vulnerable to impingement by the bulging disc  100  or bone spurs. 
         [0010]    When oxygen concentration in the disc falls below 0.25 kPa (1.9 mm Hg), production of lactic acid dramatically increases with increasing distance from the endplate  105 . The pH within the disc  100  falls as lactic acid concentration increases. Lactic acid diffuses through micro-tears of annulus irritating the richly innervated posterior longitudinal ligament  195 , facet joint and/or nerve root  194 . Studies indicate that lumbar pain correlates well with high lactate levels and low pH. The mean pH of symptomatic discs was significantly lower than the mean pH of the normal discs. The acid concentration is three times higher in symptomatic discs than normal discs. In symptomatic discs with pH 6.65, the acid concentration within the disc is 5.6 times the plasma level. In some preoperative symptomatic discs, nerve roots  194  were found to be surrounded by dense fibrous scars and adhesions with remarkably low pH 5.7-6.30. The acid concentration within the disc was 50 times the plasma level. 
         [0011]    Approximately 85% of patients with low back pain cannot be given a precise pathoanatomical diagnosis. This type of pain is generally classified under “non-specific pain”. Back pain and sciatica can be recapitulated by maneuvers that do not affect the nerve root, such as intradiscal saline injection, discography, and compression of the posterior longitudinal ligaments. It is possible that some of the non-specific pain is caused by lactic acid irritation secreted from the disc. Injection into the disc can flush out the lactic acid. Maneuvering and compression can also drive out the irritating acid to produce non-specific pain. Currently, no intervention other than discectomy can halt the production of lactic acid. 
         [0012]    The nucleus pulposus  128  is thought to function as “the air in a tire” to pressurize the disc  100 . To support the load, the pressure effectively distributes the forces evenly along the circumference of the inner annulus and keeps the lamellae bulging outward. The process of disc degeneration begins with calcification of the endplates  105 , which hinders diffusion of sulfate and oxygen into the nucleus pulposus  128 . As a result, production of the water absorbing sulfated glycosaminoglycans is significantly reduced, and the water content within the nucleus decreases. The inner annular lamellae begin to sag inward, and the tension on collagen fibers within the annulus is lost. The degenerated disc  100  exhibits unstable movement, similar to a flat tire. Approximately 20-30% of low-back-pain patients have been diagnosed as having spinal segmental instability. The pain may originate from stress and increased load on the facet joints and/or surrounding ligaments. In addition, pH within the disc  100  becomes acidic from the anaerobic production of lactic acid, which irritates adjacent nerves and tissues. 
         [0013]    Resilient straightening of a super elastically curved needle within a rigid needle is described in prior art DE 44 40 346 A1 by Andres Melzer filed on Nov. 14, 1994 and FR 2 586 183-A1 by Olivier Troisier filed on Aug. 19, 1985. The curved needles of these prior art are used to deliver liquid into soft tissue. In order to reach the intervertebral disc without an external incision, the lengths of the curved and rigid needles must be at least six inches (15.2 cm). There are multiple problems when attempting to puncture the calcified endplate as described in the prior art. Shape memory material for making the curved needle usually is elastic. Nickel-titanium alloy has Young&#39;s modulus approximately 83 GPa (austenite), 28-41 GPa (martensite). Even if the handles of both the curved and rigid needles are restricted from twisting, the long and elastically curved needle  101  is likely to twist within the lengthy rigid needle  220  during endplate  105  puncturing, as shown in  FIGS. 54 and 55 . As a result, direction of puncture is likely to be deflected and endplate  105  puncture would fail. 
         [0014]    Furthermore, in the prior art, the sharp tips of their rigid needles are on the concave sides of the curved needles. When puncturing a relatively hard tissue, such as calcified endplates  105 , the convex sides of the curved needles are unsupported and vulnerable to bending, resulting in failure to puncture through the calcified endplates  105 . To minimize bending or twisting, the sizes of their curved and rigid needles are required to be large. By increasing the sizes of the curved  101  and rigid  220  needles, friction between the curved  101  and rigid  220  needles greatly increases, making deployment and retrieval of the curved needle  101  very difficult. In addition, a large opening created in the disc  100  by the large needles may cause herniation of the nucleus pulposus  128 . Similarly, a large opening at the endplate  105  may cause Schmorl&#39;s nodes, leakage of nucleus pulpous  128  into the vertebral body  159 . 
         [0015]    In essence, the support from the distal end of the rigid needle  220  in  FIGS. 62-67  of this invention is relevant to support puncturing of a relatively hard tissue, such as calcified endplate  105  with a small diameter needle  101 . Furthermore, the non-round cross-sections of the curved  101  and rigid  220  needles in  FIGS. 56-60  to prevent twisting are also relevant to ensure successful puncturing through the calcified endplate  105 . 
       SUMMARY OF INVENTION 
       [0016]    In this invention, conduits are delivered through the calcified endplates to re-establish the exchange of nutrients and waste between the disc and vertebral bodies. The conduit is delivered within an elastically curved needle. The curved needle is resiliently straightened within a rigid needle. The rigid needle punctures into a degenerating disc with calcified endplates. The elastically curved needle carrying the conduit is then deployed from the rigid needle to resume the curved configuration and puncture through the calcified endplate. By retrieving the curved needle back into the rigid needle while holding a plunger behind the conduit stationary, the conduit is deployed across the endplate to transport nutrients and waste between the disc and vertebra. 
         [0017]    The puncturing device in this invention is designed to minimize twisting and friction between the curved and rigid needles. The device also provides support to the elastically curved needle to minimize bending during endplate puncturing. In addition, the device is designed to deliver at least one conduit at the endplate to bridge between the avascular intervertebral disc and the vertebral body for exchange of nutrients, oxygen, carbon dioxide, lactate and waste. 
         [0018]    Nutrients and oxygen are abundantly supplied by peripheral blood vessels near the outer annulus. Conduits can also be deployed transverse the degenerating disc to draw nutrients from the outer annulus into the nucleus pulposus to halt disc degeneration. 
         [0019]    After nutrient and waste exchange is re-established by the semi-permeable conduits, stem cells, growth factor or gene therapeutic agents can be injected into the disc to promote regeneration. In addition, the disc with semi-permeable conduits is still immunoisolated. Donor cells injected into the disc can be nourished by nutrients through the semi-permeable conduits without triggering an immune response. These cells are selected for their capability to biosynthesize therapeutic agents, such as insulin and neurotransmitters. The therapeutic agents are transported through the semi-permeable conduits into body circulation to treat a disease. 
         [0000]    
       
         
               
             
               
               
             
           
               
                   
               
               
                 REFERENCE NUMBER 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 100 
                 Intervertebral disc 
               
               
                 101 
                 Needle 
               
               
                 102 
                 Bevel or tapering 
               
               
                 103 
                 Trocar 
               
               
                 104 
                 Lumen or channel of conduit 
               
               
                 105 
                 Endplate 
               
               
                 106 
                 Hyaline cartilage 
               
               
                 107 
                 Capillaries 
               
               
                 108 
                 Blockade or calcified layers 
               
               
                 109 
                 Plunger 
               
               
                 110 
                 Monofilament 
               
               
                 112 
                 Blood vessels 
               
               
                 113 
                 Tissue gripping flange 
               
               
                 114 
                 Annular delamination 
               
               
                 115 
                 Epiphysis 
               
               
                 116 
                 Penetration marker 
               
               
                 121 
                 Neuroforamen 
               
               
                 122 
                 Braided multi-filament 
               
               
                 123 
                 Spinal cord 
               
               
                 124 
                 Porous conduit 
               
               
                 125 
                 Tube 
               
               
                 126 
                 Conduit 
               
               
                 127 
                 Electronic cutter or laser 
               
               
                 128 
                 Nucleus pulposus 
               
               
                 129 
                 Facet joint 
               
               
                 130 
                 Handle of curve needle 
               
               
                 131 
                 Guide rail of curve needle handle 
               
               
                 132 
                 Handle of rigid sleeve 
               
               
                 133 
                 Track of rigid sleeve handle 
               
               
                 134 
                 Electronic cutting device 
               
               
                 135 
                 Electric cord 
               
               
                 140 
                 Sacrum 
               
               
                 142 
                 Superior articular process 
               
               
                 143 
                 Inferior articular process 
               
               
                 153 
                 Label indicating curved direction 
               
               
                 159 
                 Vertebral body 
               
               
                 160 
                 Tissue ingrowth indentation 
               
               
                 161 
                 Knot 
               
               
                 162 
                 Protrusion or ring 
               
               
                 163 
                 Coating 
               
               
                 184 
                 Impingement 
               
               
                 193 
                 Psoas muscle 
               
               
                 194 
                 Nerve root 
               
               
                 195 
                 Posterior longitudinal ligament 
               
               
                 121 
                 Neuroforamen 
               
               
                 217 
                 Screw entry 
               
               
                 220 
                 Rigid sleeve or needle 
               
               
                 224 
                 Puncture 
               
               
                 230 
                 Dilator 
               
               
                 268 
                 Lumen of rigid sleeve 
               
               
                 269 
                 Lumen of rigid needle 
               
               
                 270 
                 Window of rigid sleeve 
               
               
                 271 
                 Shape memory extension 
               
               
                 272 
                 Ramp in lumen of rigid needle 
               
               
                 276 
                 Syringe 
               
               
                 277 
                 Donor cells 
               
               
                   
               
             
          
         
       
     
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  depicts a healthy disc  100  with normal swelling pressure within the nucleus pulposus  128  to support the layers of annulus during compressive loading. 
           [0021]      FIG. 2  shows a longitudinal view of a spine segment, displaying outward bulging of annular layers during compression of a healthy disc  100  between cartilaginous  106  endplates  105 . 
           [0022]      FIG. 3  shows that the calcified layers  108  of the endplates  105  hinder diffusion of nutrients between the inner disc  100  and the vertebral bodies  159 , leading to inward bulging and annular delamination  114 . 
           [0023]      FIG. 4  depicts a degenerated and flattened disc with reduced swelling pressure within the nucleus pulposus  128  and annular delamination. 
           [0024]      FIG. 5  depicts trocar  103  insertion into the disc  100  using the guiding technique similar to that used in discography. 
           [0025]      FIG. 6  shows insertion of a dilator  230  over the trocar  103 . 
           [0026]      FIG. 7  depicts withdrawal of the trocar  103 . The dilator  230  acts as a passage leading into the disc  100 . 
           [0027]      FIG. 8  shows a longitudinal view of the degenerated spinal segment with insertion of the dilator  230 . 
           [0028]      FIG. 9  depicts an elastically curved needle  101 . 
           [0029]      FIG. 10  shows the elastic needle  101  being resiliently straightened within a rigid sleeve  220 . 
           [0030]      FIG. 11  shows a round cross-section of the needle  101  within the rigid sleeve  220 . 
           [0031]      FIG. 12  depicts insertion of the resiliently straightened needle  101  within the rigid sleeve  220  into the dilator  230  leading into the disc  100 . 
           [0032]      FIG. 13  shows a longitudinal view of the needle  101  and sleeve  220  assembly inserted into the dilator  230  leading into the disc  100 . 
           [0033]      FIG. 14  depicts upward puncturing of the needle  101  into the endplate  105  (not shown) by deploying the resiliently straightened needle  101  from the rigid sleeve  220 . 
           [0034]      FIG. 15  shows endplate  105  puncturing through the calcified layers  108  by deploying the curved needle  101  from the rigid sleeve  220 . 
           [0035]      FIG. 16  depicts permeation of water, nutrients and metabolites through the puncture sites  224  of the superior and inferior endplates  105 . 
           [0036]      FIG. 17  depicts re-establishment of swelling pressure by the renewed biosynthesis of glycosaminoglycan within the nucleus pulposus  128 . 
           [0037]      FIG. 18  depicts an electronic device  134  empowering a cutter  127  to puncture, drill, abrade or cauterize through the calcified endplate  105 . 
           [0038]      FIG. 19  depicts a conduit  126  in the form of an elastic tube  125  with tissue-holding flanges  113  and longitudinal opening  104 . 
           [0039]      FIG. 20  shows insertion of the elastic tube  125  onto the elastically curved needle  101  with a sliding plunger  109  abutting the tube  125 . 
           [0040]      FIG. 21  depicts the needle  101  carrying the elastic tube  125  being resiliently straightened within the rigid sleeve  220 . 
           [0041]      FIG. 22  shows insertion of the needle  101 , elastic tube  125 , sleeve  220  and plunger  109  into the dilator  230 . 
           [0042]      FIG. 23  depicts deployment of the needle  101  delivering the tube  125  through the calcified layer  108  of the endplate  105 . 
           [0043]      FIG. 24  shows withdrawal of the needle  101  while holding the plunger  109  stationary to dislodge the tube  125  from the needle  101 . 
           [0044]      FIG. 25  shows the lower portion of the tube  125  dislodged within the nucleus pulposus  128  and the top portion deployed within the cranial vertebral body  159  (not shown) through the endplate  105  (also not shown). 
           [0045]      FIG. 26  depicts stacking of a square handle  130  of the curved needle  101  within a handle  132  of the rigid sleeve  220  to avoid rotation between the needle  101  and sleeve  220 . 
           [0046]      FIG. 27  depicts a handle  130  of the elastically curved needle  101 , containing guide rails  131  and an orientation line  153  to show the direction of the curvature. 
           [0047]      FIG. 28  shows tracks  133  on a handle  132  of the rigid sleeve  220  with orientation line  153  and penetration markers  116 . 
           [0048]      FIG. 29  depicts the assembly with the rails  131  in the tracks  133  to avoid rotation between the needle  101  and the sleeve  220 . 
           [0049]      FIG. 30  shows resumption of the curvature as the elastically curved needle  101  is deployed from the rigid sleeve  220 . 
           [0050]      FIG. 31  shows oval cross-sections of the needle  101  and the rigid sleeve  220  to prevent rotation between the needle  101  and sleeve  220 . 
           [0051]      FIG. 32  indicates square cross-sections of the needle  101  within the sleeve  220 . 
           [0052]      FIG. 33  depicts rectangular cross-sections of the needle  101  within the sleeve  220 . 
           [0053]      FIG. 34  shows triangular cross-sections of the needle  101  within the sleeve  220 . 
           [0054]      FIG. 35  depicts a conduit  126  made as a small tube  125  with a longitudinal channel  104 . 
           [0055]      FIG. 36  indicates a conduit  126  made as a braided tube  125  with a longitudinal channel  104 . 
           [0056]      FIG. 37  shows a conduit  126  made with porous material in a tubular form  125 . 
           [0057]      FIG. 38  depicts a conduit  126  made as a braided suture  122  or braided thread  122 . 
           [0058]      FIG. 39  indicates a conduit  126  made with a flexible porous or spongy fiber  124 . 
           [0059]      FIG. 40  shows a conduit  126  abutting against a plunger  109  within a lumen  269  of an elastically curved needle  101 . 
           [0060]      FIG. 41  shows a bevel  102  at the distal end of the lumen  268  of the rigid sleeve  220  to minimize friction during deployment and retrieval of the curved needle  101 . 
           [0061]      FIG. 42  depicts the elastically curved needle  101  with the conduit  126  being resiliently straightened within a rigid sleeve  220 . 
           [0062]      FIG. 43  indicates insertion of the assembly containing the needle  101 , conduit  126 , plunger  109  and sleeve  220  into a dilator  230 . 
           [0063]      FIG. 44  shows deployment of the curved needle  101  through the calcified endplate  105 . 
           [0064]      FIG. 45  depicts dislodgement of the conduit  126  by withdrawing the needle  101  while holding the plunger  109  stationary. 
           [0065]      FIG. 46  depicts insertion of the needle  101 , conduit  126 , plunger  109  and sleeve  220  assembly into the dilator  230  leading into disc  100 . 
           [0066]      FIG. 47  shows deployment of the curved needle  101  through the calcified endplate  105 . 
           [0067]      FIG. 48  depicts withdrawal of the needle  101  while the plunger  109  is held stationary to dislodge the conduit  126  through the calcified endplate  105 . 
           [0068]      FIG. 49  shows a portion of the conduit  126  within the nucleus pulposus  128  and the remaining portion within the vertebral body through the endplate (not shown). 
           [0069]      FIG. 50  depicts two conduits  126  within the lumen  269  of the needle  101 . 
           [0070]      FIG. 51  shows deployment of two conduits  126  through superior and inferior calcified endplates  105 . 
           [0071]      FIG. 52  indicates disc  100  height restoration from regained swelling pressure within the nucleus pulposus  128  following the re-establishment of nutrient and waste exchange. 
           [0072]      FIG. 53  depicts two conduits  126  extending from the nucleus pulposus  128  into superior and inferior vertebral bodies  159  through the calcified endplates  105  (not shown). 
           [0073]      FIG. 54  depicts twisting of the curved needle  101  within the rigid sleeve  220  during endplate  105  puncturing. The cross-section is shown in  FIG. 62 . 
           [0074]      FIG. 55  shows the cross-sectional view of  FIG. 61 . The elastic needle  101  twists or rotates within the rigid sleeve  220 . 
           [0075]      FIG. 56  depicts prevention of twisting by using a needle  101  and sleeve  220  with elliptical cross-sections. 
           [0076]      FIG. 57  shows a cross-sectional view of the elliptical needle  101  within the elliptical sleeve  220 , depicted in  FIG. 63 , to limit rotational movement. 
           [0077]      FIG. 58  indicates a square cross-section of the needle  101  and sleeve  220 . 
           [0078]      FIG. 59  indicates a rectangular cross-section of the needle  101  and sleeve  220 . 
           [0079]      FIG. 60  indicates a triangular cross-section of the needle  101  and sleeve  220 . 
           [0080]      FIG. 61  depicts bending or drooping of the curved needle  101  during endplate  105  puncturing. 
           [0081]      FIG. 62  shows a sharpened end or tip of the rigid needle  220  providing support beneath the convex side of the curved needle  101  to reduce bending or drooping during puncturing. 
           [0082]      FIG. 63  depicts an extended distal end of the rigid needle  220  to lengthen the support beneath the convex side of the curved needle  101  during endplate  105  puncturing. 
           [0083]      FIG. 64  shows a window  270  near the distal end of a sleeve  220  with an elliptical cross-section. The distal portion of the window  270  is slanted or sloped to conform to the curved needle  101 . 
           [0084]      FIG. 65  depicts the sharp tip of the elastically curved needle  101  located on the concave side of the curvature for ease of protrusion through the window  270 . 
           [0085]      FIG. 66  shows support of the convex side of the curved needle  101  by the distal pocket of the window  270  to strengthen the needle  101  to puncture endplate  105 . 
           [0086]      FIG. 67  shows a rigid needle  220  with the window  270 . 
           [0087]      FIG. 68  depicts the elastically curved needle  101  within a curved shape memory extension  271 . Both curved needle  101  and extension  271  are housed within a rigid sleeve  220 . 
           [0088]      FIG. 69  shows resilient straightening of the shape memory extension  271  within the rigid sleeve  220 . 
           [0089]      FIG. 70  shows endplate  105  puncturing by the fortified curved needle  101  without increasing the size of the endplate  105  puncture. 
           [0090]      FIG. 71  shows a sharpened shape memory extension  271  to support endplate  105  puncturing. 
           [0091]      FIG. 72  shows a longitudinal cross section of a curved needle  101  with non-uniform outer diameter, supported by a ramp  272  within the lumen  268  of the rigid needle  220 . 
           [0092]      FIG. 73  depicts a conduit  126  containing a multi-filament  122  section and a tubular  125  section. 
           [0093]      FIG. 74  shows a multi-filament  122  with a tube  125  at the mid-portion to prevent mineralization or clotting, especially around the endplate  105 . 
           [0094]      FIG. 75  depicts a monofilament  110  within the multi-filament  122  to assist deployment. 
           [0095]      FIG. 76  shows degradable tubes (shaded)  125  covering both ends of a multi-filament  122  to prevent bunching during deployment from the curved needle  101 . 
           [0096]      FIG. 77  shows the needle  101  carrying the conduit  126  transverse the degenerating disc  100 . 
           [0097]      FIG. 78  depicts a longitudinal view of  FIG. 84  to deliver a conduit  126  transverse a degenerating disc  100 . 
           [0098]      FIG. 79  depicts withdrawal of the needle  101  while holding the plunger  109  stationary to deploy or dislodge the conduit  126  within the degenerating disc  100 . 
           [0099]      FIG. 80  depicts drawing of nutrients from the outer annulus into the nucleus pulposus  128  through capillary action or convection flow within the conduit  126 . 
           [0100]      FIG. 81  depicts a radiopaque, echogenic or magnetic coating  163  on the needle  101  to indicate the location of the conduit  126  within the needle  101 . 
           [0101]      FIG. 82  shows two conduits  126  inserted through the disc  100  to exchange nutrients and waste between the outer annulus and the nucleus pulposus  128 . 
           [0102]      FIG. 83  depicts the distal tip of the needle  101  penetrating beyond the intervertebral disc  100 . 
           [0103]      FIG. 84  shows the length of the conduit  126  extending beyond the disc  100  to maximize exchange of nutrients and waste. 
           [0104]      FIG. 85  depicts restoration of swelling pressure within the nucleus pulposus  128  enabling it to sustain compressive loading. 
           [0105]      FIG. 86  shows a conduit  126  extending into the Psoas major muscle  193  for nutrient and waste exchange to nourish and/or regenerate the disc  100 . 
           [0106]      FIG. 87  depicts two conduits  126  extending into both Psoas major muscles  193  to expedite nutrient and waste exchange to nourish and/or regenerate the disc  100 . 
           [0107]      FIG. 88  depicts a series of knots  161  tied on a multi-filament  122  to prevent or minimize conduit  126  migration with time. 
           [0108]      FIG. 89  shows rings  162  or protrusions on the conduit  126  to prevent or minimize migration with time. 
           [0109]      FIG. 90  shows indentations  160  to promote tissue ingrowth and prevent or minimize conduit  126  migration with time. 
           [0110]      FIG. 91  shows injection of donor cells  277  through a syringe  276  into a disc  100  containing conduits  126  through cranial and caudal endplates  105 . 
           [0111]      FIG. 92  shows injection of donor cells  277  through a syringe  276  into a disc  100  with conduits  126  transverse the disc  100  and extending into muscles  193 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0112]    Since diffusion from the endplate  105  is crucial for maintaining the intervertebral disc, effort is made to re-establish nutrient and waste exchange between the nucleus pulposus and circulation within the vertebral body. Guided by anteroposterior and lateral views from fluoroscopes, a trocar  103  enters posteriolaterally, 45° from mid-line into the disc  100 , as shown in  FIG. 5 . This guiding technique is similar to the one used in diagnostic injection of radiopaque dye for discography or chymopapain injection for nucleus pulposus digestion. A dilator  230  is inserted over the trocar  103 , as shown in  FIG. 6 . The trocar  103  is then withdrawn. The dilator  230  remains as a passage leading into the disc  100 , as shown in  FIG. 7 .  FIG. 8  shows the distal end of the dilator  230  near the nucleus pulposus  128  of the degenerating disc  100 . 
         [0113]    An elastically curved needle  101 , as shown in  FIG. 9 , is resiliently straightened in a rigid sleeve  220  indicated in  FIG. 10 . The round cross section of the straightened needle  101  and sleeve  220  is shown in  FIG. 11 . The resiliently straightened needle  101  within the rigid sleeve  220  is inserted into the dilator  230  and the disc  100 , as shown in  FIG. 12 . A longitudinal view of the needle  101  insertion into the degenerating disc  100  is indicated in  FIG. 13 . The elastically curved needle  101  is deployed by holding the rigid sleeve  220  stationary while pushing the needle  101  inward. The needle  101  resumes the curved configuration as it exits the distal opening of the sleeve  220 , puncturing upward as shown in  FIG. 14 , through the cartilage  106  and calcified layers  108  into the vertebral body  159 , as indicated in  FIG. 15 . 
         [0114]    Multiple endplate  105  punctures  224  can be accomplished to re-establish the exchange of nutrients and waste between the disc  100  and bodily circulation. After retrieving the elastically curved needle  101  into the sleeve  220 , the assembly of needle  101  and sleeve  220  can be further advanced into or slightly withdrawn from the disc  100  to puncture more holes  224  through the calcified cranial endplate  105 . By turning the assembly of needle  101  and sleeve  220  180°, the caudal endplate  105  can also be punctured, as shown in  FIG. 16 , to re-establish the exchange of nutrients, oxygen and waste through the superior and inferior endplates  105 .  FIG. 17  indicates restoration of swelling pressure within the nucleus pulposus  128  enabling the disc  100  to sustain compressive loads. With the presence of oxygen within the disc  100 , production of lactic acid may also decrease and ease chemical irritation and pain. 
         [0115]    Endplate  105  puncturing can also be accomplished by electronic devices  134 , such as a laser, cutting or abrading device.  FIG. 18  depicts an electronic device  134  powering a cutter  127  to puncture, drill, abrade or cauterize the endplate  105  to re-establish the exchange of nutrients and waste. The electronic device  134  can be a cautery, laser, or drill. 
         [0116]    Re-establishing the exchange of nutrients and waste through the calcified endplate  105  can also be accomplished using a conduit  126 . A conduit  126  can be an elastic tube  125  with a lumen or channel  104  and tissue-holding flanges  113  at both ends, as shown in  FIG. 19 . The orientations of the flanges  113  located at both ends of the conduit  126  are counter gripping to anchor onto the endplate  105 . The tube  125  is inserted over the elastically curved needle  101  and abutting a sliding plunger  109 , as shown in  FIG. 20 . The needle  101  carrying the elastic tube  125  is resiliently straightened within the rigid sleeve  220 , as depicted in  FIG. 21 . The assembly of the straightened needle  101 , tube  125 , sleeve  220  and plunger  109  is inserted into the dilator  230 , as shown in  FIG. 22 , and into the disc  100 . As the resilient needle  101  carrying the tube  125  is deployed from the rigid sleeve  220 , the curvature of the needle  101  resumes and punctures through the calcified endplate  105 , as shown in  FIG. 23 . The needle  101  is withdrawn while the plunger  109  is held stationary to dislodge the tube  125  from the needle  101  into the endplate  105 , as shown in  FIG. 24 . The lumen  104  of the tube  125  acts as a passage for exchanging nutrients, gases and waste between the vertebral body  159  and the inner disc  100 . A portion of the tube  125  is in the nucleus pulposus  128  or inner disc  100 , while the remaining portion is within the vertebral body (not shown) in  FIG. 25 . 
         [0117]    The handle  130  of the curved needle  101  and the handle  132  of the rigid sleeve  229  are used to maintain the direction of needle  101  deployment. The square handle  130  of the curved needle  101  is stacked within the handle  132  of the rigid sleeve  220 , as shown in  FIG. 26 , to avoid rotation between the needle  101  and sleeve  220 . The handle  130  of the needle  101  can also contain guide rails  131 , as shown in  FIG. 27 . The guide rails  131  are sized and configured to fit within the sunken tracks  133  on the handle  132  of the rigid sleeve  220 , as indicated in  FIG. 28 . Direction of the needle&#39;s curvature is indicated by the orientation lines  153  on the handle  130  of the needle  101 , as shown in  FIG. 27 , and on the rigid sleeve  220  as shown in  FIG. 28 . To indicate depth of insertion into the body, penetration markers  116  are labeled on the sleeve  220 , as shown in  FIG. 28 . The guide rails  131  within the tracks  133  keep the handles  130 ,  132  from rotating around each other, as shown in  FIG. 29 . As the resiliently straightened needle  101  advances and protrudes from the rigid sleeve  220 , the curvature of the needle  101  resumes, as shown in  FIG. 30 . Since the handle  130  of the needle  101  and the handle  132  of the sleeve  220  are guided by the rails  131  in tracks  133 , the direction of needle  101  puncturing is established and predictable for the operator or surgeon. 
         [0118]    Non-circular cross-sections of the needle  101  and rigid sleeve  220  can also prevent rotation.  FIG. 31  shows a needle  101  and a sleeve  220  with oval cross-section.  FIG. 32  indicates a square cross-section.  FIG. 33  depicts a rectangular cross-section.  FIG. 34  shows a triangular cross-section. 
         [0119]    Conduits  126  can also be made small enough to fit within the lumen of the elastically curved needle  101 . A conduit  126  can be a small tube  125  with a longitudinal channel  104 , as shown in  FIG. 35 , for transporting nutrients, oxygen and waste dissolved in fluid. The tubular conduit  126  with a lumen  104  can be braided or weaved with filaments, as shown in  FIG. 36 . The fluid can be transported through the lumen  104  as well as permeated through the braided filaments of the tube  125 . The tubular conduit  126  can also be molded or extruded with porous or spongy material, as shown in  FIG. 37 , to transport nutrients, oxygen and waste dissolved in fluid through the lumen  104  as well as through the pores. 
         [0120]    Nutrients, oxygen, lactate, metabolites, carbon dioxide and waste can also be transported in fluid through capillary action of multi-filaments or braided filaments  122 , as shown in  FIG. 38 . A conduit  126  may not require the longitudinal lumen  104  as mentioned. A strand of braided filaments  122  can be a suture with channels formed among weavings of the filaments, capable of transporting fluid with nutrients, gases and waste. The braided filaments  122  can be coated with a stiffening agent, such as starch, to aid deployment using the plunger  109 . Similar to the channels formed by the braided filaments  122 , a conduit  126  made as a spongy thread  124 , as shown in  FIG. 39 , can also transport fluid with nutrients, gases and wastes through the pores and channels formed within the porous structure. 
         [0121]    A conduit  126  is inserted into a longitudinal opening  269  of an elastically curved needle  101  abutting a plunger  109 , as shown in  FIG. 40 . To minimize friction between the curved needle  101  and the rigid sleeve  220 , the distal end of the lumen  268  of the sleeve  220  is angled or tapered with a bevel  102  or an indentation, conforming to the concave curvature of the needle  101 , as shown in  FIG. 41 . A lubricant or coating to lower friction can also be applied on the surface of the elastically curved needle  101  and/or within the lumen  268  of the rigid sleeve  220 . The elastically curved needle  101  carrying the conduit  126  is resiliently straightened within a rigid sleeve  220 , as shown in  FIG. 42 . The assembly is then inserted into a dilator  230 , as indicated in  FIG. 43 , which leads into the disc  100 . As the resiliently straightened needle  101  is deployed from the sleeve  220 , the needle  101  carrying the conduit  126  resumes the curved configuration and punctures into the cartilaginous endplate  105  through the calcified layers  108 , as shown in  FIG. 44 . The elastically curved needle  101  is then retrieved into the sleeve  220  while the plunger  109  is held stationary to deploy the conduit  126  at the calcified endplate  105 , as shown in  FIG. 45 . 
         [0122]      FIG. 46  depicts insertion of the needle  101 , conduit  126 , plunger  109 , sleeve  220  and dilator  230  into the disc  100 . The resiliently straightened needle  101  carrying the conduit  126  is deployed from the sleeve  220 , resumes the curvature and punctures through the endplate  105  and calcified layers  108 , as shown in  FIG. 47 . While the plunger  109  behind the conduit  126  is held stationary, the elastically curved needle  101  is withdrawn from the calcified endplate  105  and retrieved into the sleeve  220  to deploy, expel or dislodge the conduit  126  at the calcified endplate  105 , as shown in  FIG. 48 . The conduit  126  acts as a channel or a passage, bridging between the bone marrow of the vertebral body  159  and the disc  100  to re-establish the exchange of fluid, nutrients, gases and wastes.  FIG. 49  shows the general location of the conduit  126  between the disc  100  and the vertebral body through the calcified endplate (both not shown). 
         [0123]    Multiple conduits  126  can be loaded in series into the curved needle  101 , as shown in  FIG. 50 . Each conduit  126  is deployed sequentially at the calcified endplate  105  by retrieving the curved needle  101  and holding the plunger  109  stationary. In essence, the plunger  109  is advanced toward the distal end of the needle  101  one conduit-length at a time. After deploying the first conduit  126  at the cranial endplate  105 , the rigid sleeve  220  is rotated 180° to deploy the second conduit  126  into the caudal endplate  105 , as shown in  FIG. 51 . Multiple conduits  126  within the elastically curved needle  101  allow surgeons to implant multiple conduits through calcified endplates  105  without having to withdraw the needle  101  assembly, reload additional conduits  126  and re-insert the assembly into the disc  100 . 
         [0124]    In the supine position, disc pressure is low. During sleep, fluid is drawn in by the water absorbing glycosaminoglycans within the nucleus pulposus  128 . By bridging the calcified endplate  105 , the glycosaminoglycans draw fluid with sulfate, oxygen and other nutrients through the conduits  126  into the nucleus pulposus  128  during sleep by (1) capillary action, and (2) imbibing pull of the water-absorbing glycosaminoglycans. The flow of sulfate, oxygen and nutrients is channeled within the conduit  126  unidirectionally toward the nucleus pulposus  128 , rather than via the dispersion mechanism in diffusion. 
         [0125]    It is generally accepted that disc  100  degeneration is largely related to nutritional and oxygen deficiency. By re-establishing the exchange, a renewed and sustained supply of sulfate may significantly increase the production of sulfated glycosaminoglycans and restore swelling pressure. Restoration of swelling pressure within the nucleus pulposus  128  reinstates the tensile stresses within the collagen fibers of the annulus, thus reducing the inner bulging and shear stresses between the layers of annulus, as shown in  FIG. 52 . Similar to a re-inflated tire, disc  100  bulging is reduced and nerve impingement is minimized. Thus, the load on the facet joints  129  is also reduced to ease pain, the motion segment is stabilized, and disc  100  space narrowing may cease. The progression of spinal stenosis is halted and/or reversed, as shown in  FIG. 53  to ease pain. 
         [0126]    In daily activities, such as walking and lifting, pressure within the disc  100  greatly increases. Direction of the convective flow then reverses within the conduit  126 , flowing from high pressure within the disc  100  to low pressure within vertebral bodies  159 . The lactic acid and carbon dioxide dissolved in the fluid within the nucleus pulposus  128  is slowly expelled through the conduit  126  into the vertebral bodies  159 , then to bodily circulation. As a result, the lactic acid concentration decreases, and pH within the disc  100  is normalized. 
         [0127]    Furthermore, due to the abundance of oxygen in the disc  100  supplied through the conduit  126 , lactic acid normally produced under anaerobic conditions may drastically decrease. Hence, the pain caused by acidic irritation at tissues, such as the posterior longitudinal ligament  195 , superior  142  and inferior  143  articular processes of the facet joint, shown in  FIG. 53 , is anticipated to quickly dissipate. Buffering agents, such as bicarbonate, carbonate or others, can be loaded or coated on the conduits  126  to neutralize the lactic acid upon contact and spontaneously ease the pain. 
         [0128]    The elasticity of the curved needle  101  still can twist within the rigid sleeve  220  during endplate  105  puncturing, as shown in  FIG. 54 . The likelihood of twisting increases with the length of the elastic needle  101 . The twisting is depicted in a cross-sectional view of the sleeve  220 , needle  101  and conduit  126  in  FIG. 55 . The elastic twisting between the shafts of the needle  101  and sleeve  220  allows directional shift at the tip of the needle  101  during contact with the calcified endplate  105 . As a result, puncturing of the endplate  105  may fail. 
         [0129]    To avoid twisting, the cross-sections of the needle  101  and sleeve  220  can be made non-round, such as oval in  FIG. 56  with a cross-sectional view in  FIG. 57 . A square cross-section is shown in  FIG. 58 . A rectangular cross-section is shown in  FIG. 59 . A triangular cross-section is in  FIG. 60 . 
         [0130]    The elastic property of the curved needle  101  may bend and fail to penetrate through the calcified endplate  105 , as shown in  FIG. 61 . The direction of the bend or droop is at the convex side of the curvature of the needle  101 . To minimize the droop, the distal end of the rigid sleeve  220  is cut at an angle, providing an extension to support the convex side of the curved needle  101  during endplate  105  puncturing, as shown in  FIG. 62 . The angled cut of the rigid sleeve  220  functions as a rigid needle  220  with a sharp tip supporting the convex side of the curved needle  101 , as shown in  FIG. 62 . The supporting structure can be further extended by cutting an indentation near the distal end of the rigid needle  220 , as shown in  FIG. 63 , to increase support of the convex side of the curved needle  101  during endplate  105  puncturing. 
         [0131]    To further support the elastically curved needle  101 , a window  270  may be located near the distal end of the rigid sleeve  220  with an oval cross-section, as shown in  FIG. 64 . The distal side of the window  270  is open slanted at an angle. The slant can also be formed with multiple angles into a semi-circular-like pocket, sized and configured to fit the convex side of the elastically curved needle  101 .  FIG. 65  shows protrusion of the elastically curved needle  101  from the window  270  of the rigid sleeve  220 . The sharp tip of the curved needle  101  is located on the concave side of the curvature to avoid scraping or snagging on the distal portion of the window  270  during deployment.  FIG. 66  shows deployment of the elastically curved needle  101  from the window  270  of the rigid sleeve  220 . The semi-circular pocket of the distal window  270  supports and brackets around the base of the convex curvature to minimize bending, twisting and/or deflection of the curved needle  101  during endplate  105  puncturing. In essence, the slanted portion of the window  270  provides a protruded pocket to direct and support the curved needle  101 . The distal end of the rigid sleeve  220  can be sharpened to function as a rigid needle  220  with the window  270 , as shown in  FIG. 67 . 
         [0132]    When a substantial amount of bone is formed, puncturing through the bony endplate  105  with a small curved needle  101  can be challenging. Increasing the size of the needle  101  and creating a large hole  224  at the endplate  105  may cause leakage of nucleus pulposus  128  into the vertebral bodies  159 . To support a small curved needle  101 , a shape memory extension  271  containing a curvature similar to the curved needle  101  is added to strengthen and support the elastically curved needle  101 , as shown in  FIG. 68 . The shape memory extension  271  can be indented, as shown in  FIG. 68 , or tubular at the distal end. The curved needle  101  and shape memory extension  271  are capable of sliding independently within the rigid sleeve or needle  220 .  FIG. 69  shows resiliently straightening of both the curved needle  101  and shape memory extension  271  within the rigid sleeve  220 . Both the curved needle  101  and shape memory extension  271  apply stresses on the rigid sleeve  220 . To minimize potential bending of the rigid sleeve  220 , the stresses are distributed over a larger area by positioning the tip of the needle  101  proximal to the curvature of the shape memory extension  271 , as shown in  FIGS. 68-69 . Spreading of the stresses also helps to ease the deployment and retrieval of both the needle  101  and shape memory extension  271 . 
         [0133]    For tissue puncturing, the shape-memory extension  271  is deployed from the rigid sleeve  220 , as shown in  FIG. 68 , followed by the curved needle  101  gliding along the curvature of the shape-memory extension  271  and puncturing into the calcified endplate  105 , as shown in  FIG. 70 . The shape memory extension  271  provides support to the needle  101  to minimize bending and twisting during puncturing without increasing the size of the puncture. The shape memory extension  271  can also be non-indented and sharpened to facilitate tissue piercing, as shown in  FIG. 71 . To dislodge the conduit  126  at the endplate  105 , the plunger  109  behind the conduit  126  is held stationary, while the curved needle  101  is retrieved into the shape memory extension  271 . The shape memory extension  271  is then withdrawn into the rigid sleeve  220 . 
         [0134]    The outer diameter of the curved needle  101  can be made non-uniform, being small at the distal end for creating a small opening, as shown in  FIG. 72 . The adjoining curved portion of the needle  101  contains a thick wall and a larger outer diameter to support and strengthen the process of endplate  105  puncturing. The transition between the small and large outer diameters is gradual, as shown in  FIG. 72 , or in steps. The curved needle  101  with varying outer diameters can be made by grinding, machining or injection molding. 
         [0135]    The lumen  268  of the rigid needle  220  may have a bevel  102  and a double-sided ramp  272 , as shown in  FIG. 72 . The bevel  102  or tapering at the distal end of the lumen  268  minimizes friction against the concave side of the curved needle  101  during deployment and retrieval. The double-sided ramp  272  is protruded at the side opposite to the bevel  102  with the distal side in continuation with the sharp tip or extended end of the rigid needle  101 . The proximal side of the ramp  272  or protrusion can be shaped to conform to and support the convex side of the curved needle  101  during endplate  105  puncturing. The ramp  272  can be made with epoxy, solder or other hardened material, then shaped by machining. The ramp  272  can also be created during a molten process to seal the lumen  268  at the distal end. The sealed end is then cut, the ramp  272  and bevel  102  are shaped, and the lumen  268  is re-opened by machining. 
         [0136]    Sections of the conduit  126  are made to optimize the exchange of nutrients and waste.  FIG. 73  shows a conduit  126  with braided filaments  122  connected to a porous tube  125  with a lumen  104 . The tubular  125  portion acts as a funnel, collecting nutrients from capillaries within the vertebral body  159  and funneling the nutrients into braided filaments  122  within the nucleus pulposus  128 . 
         [0137]    Especially at the endplate  105 , mineralization within the pores or channels of the conduit  126  may occlude or block the exchange of nutrients and waste between the vertebral body  159  and disc  100 .  FIG. 74  shows a tube  125  covering or wrapped around the mid-section of the conduit  126  to prevent ingrowth of minerals or tissue into the pores or channels. The material for making the tube  125  can also have swelling, expanding or sealing characteristics to seal the puncture at the endplate  105  and prevent formation of Schmorl&#39;s node. The swelling, expanding or sealing material can be polyethylene glycol, polyurethane, silicon or others. An anti-ingrowth film or coating at the mid-section of the conduit  126  may also discourage mineralization or occlusion within the channels or pores to ensure long lasting exchange of nutrients and waste. 
         [0138]    Especially within the vertebral body  159  or outer annulus, formation of fibrous tissue over the conduit  126  may occur, hindering the exchange of nutrient and waste. A portion of the conduit  126  can be coated, grafted, covalently bonded or ionic bonded with a drug to minimize fibrous formation. The drug can be actinomycin-D, paclitaxel, sirolimus, cell-growth inhibitor or fibrous tissue inhibitor. 
         [0139]    Due to the soft or pliable characteristic, conduits  126  made with braided filaments  122  are difficult to deploy with the retrieving needle  101  and stationary plunger  109 . A conduit  126  made with braided filament can be stiffened with water soluble agents, such as starch, collagen, hyaluronate, chondroitin, keratan or other biocompatible agents. After deployment, the soluble stiffening agent dissolves within the body, exposing the filaments to transport nutrients, oxygen and waste.  FIG. 75  shows a monofilament  110  used as a stiff core within the braided conduit  126  to assist deployment. The monofilament  110  can be made with degradable material to maximize transport area after deployment of the conduit  126 . Degradable tubes  125 , indicated in the shaded area of  FIG. 76 , can also be used to wrap and stiffen the braided filaments  122 . The degradable tube  125  or the degradable monofilament  110  can be made with poly-lactide, poly-glycolide, poly-lactide-co-glycolide or others. 
         [0140]    Since nutrients are relatively abundant within the peripheral 1 cm of the disc  100 , the conduit  126  can also draw nutrients from the outer annulus through capillary action into the nucleus pulposus  128 . A needle  101  carrying the starch-stiffened conduit  126  (not shown) and a plunger  109  is punctured into a disc  100  with calcified endplates  105 , as shown in  FIG. 77 . The needle  101  guiding technique is similar to the one used in diagnostic injection of radiopaque dye for discography or chymopapain injection for nucleus pulposus  128  digestion to treat herniated discs  100 . Guided by anteroposterior &amp; lateral views from fluoroscopes, the needle  101  enters posteriolaterally, 45° from mid-line into the disc  100 . A longitudinal view of the needle  101  carrying the stiffened conduit  126  puncturing through the disc  100  with calcified endplates  108  is shown in  FIG. 78 . 
         [0141]    By holding the plunger  109  stationary while the needle  101  is being withdrawn, the conduit  126  is dislodged from the lumen of the needle  101  and deployed across the disc  100 , as shown in  FIGS. 79-80 . At least one end of the conduit  126  is placed less than 1 cm from the periphery of the disc  100  to draw nutrients and drain lactic acid. To enhance imaging, the section of the needle  101  containing the conduit  126  can be coated with a radiopaque, echogenic or magnetic coating  163 , as shown in  FIG. 81 . Multiple conduits  126  can be safely and accurately deployed into different areas of a degenerating disc  100 .  FIG. 82  shows two conduits  126  deployed across a degenerating disc  100 , exchanging nutrients and waste between the inner and outer disc  100 . 
         [0142]    In locations lacking any major blood vessel and organ, the tip of the needle  101  can be guided beyond the disc  100 , as shown in  FIG. 83 , to deploy the conduit  126  beyond the disc  100 , as shown in  FIG. 84 . The extended conduit  126  may draw significantly more nutrients into the disc  100 . In addition, the extended conduit  126  may be more effective in disposing the waste generated within the disc  100  and expediting the repair and/or regeneration of the disc  100 , as shown in  FIG. 85 . 
         [0143]    Psoas major muscles  193  are located adjacent to the lumbar segment of the spine. The needle  101  carrying the conduit  126  can puncture beyond the disc  100  into the muscle  193 . As a result, the conduit  126  can draw nutrients from the muscle  193  into the disc  100 , as shown in  FIG. 86 . Muscles  193  are well supplied with nutrients and oxygen, and muscles  193  dissipate lactic acid well. By extending into the muscles  193 , the conduits  126  can draw an abundant amount of nutrients and safely deposit the waste from the inner disc  100  to repair or regenerate the degenerating disc  100 , as shown in  FIG. 87 . The supple and tensionless conduits  126  are expected to be free from interfering with the functions of the disc  100  and muscles  193 . 
         [0144]    Methods and devices for conduit  126  deployments can also be in various combinations. The conduits  126  can be delivered into the endplates  105 , as shown in  FIG. 53 , and transverse the annulus, as shown in  FIG. 82  or  87 . 
         [0145]    An accelerated disc degeneration model was developed using rat tails. A tail section involving three discs was twisted or rotated 45° and held for 2 weeks. The section was then compressed by coil springs and held for an additional period of time. All discs within the section degenerated. Discs that had received additional nucleus pulposus from donor discs by injection experienced a delay in degeneration. Furthermore, insertions of the additional nucleus pulposus prior to the destructive loads provided the longest delay against disc degeneration. 
         [0146]    After lumbar fusion procedures, the intervertebral discs  100  of adjacent free motion segments degenerate quickly. The degenerative process leads to more pain and possibly more surgery; following each new fusion is a new vulnerable segment adjacent to it. Accelerated degeneration of segments adjacent to a lumbar fusion may be the result of additional post-fusion stress and load. In the rat model, the added volume within the nucleus pulposus had a protective function against the destructive load. In conjunction with spinal fusion procedures, implanting conduits  126  within discs  100  adjacent to the fused segment may provide adequate swelling pressure contributed by an abundant supply of sulfate and oxygen to delay and hopefully prevent adjacent disc  100  degeneration. Device migration with time is always a concern. The average age of patients undergoing back surgery is 40-45 years old. The conduit  126  is expected to remain in place within the patients for fifty or more years. Migration of the tensionless conduits  126  may result in loss of effectiveness, but it is not likely to be detrimental to nerves, ligaments, muscles or organs. To minimize migration, knots  161  can be tied on the braided conduit  126 , as shown in  FIG. 88 , to anchor within the annulus, endplate  105  and/or muscle  193 . Similar to knots  161 , rings  162  or protruded components  162  can be crimped on the conduit  126 , as shown in  FIG. 89 . Both the knots  161  and the protrusions  162  are small enough to fit within the needle  101 . Tissue ingrowth can also limit or prevent device migration. Indentations  160  or tissue ingrowth holes  160  can be created on the conduit  126 , as shown in  FIG. 90 , to discourage migration with time. 
         [0147]    The conduit  126  can also be used as a delivery vehicle to introduce healing elements for maintaining or regenerating the disc  100 . The conduit  126  can be coated or seeded with growth factor, stem cells, donor cells, nutrients, buffering agent or minerals. Cells sensitive to sterilization can be loaded aseptically. Installations of conduits  126  can be in multiple stages, separated by days, weeks, months or even years. Initial conduit  126  deployment prepares the biological conditions, including pH, electrolytic balance and nutrients, to favor cell proliferation. Subsequent deployments may contain seeded cells within the conduit  126 . 
         [0148]    Since cellularity within the inner disc  100  is low, cell migration from the outer annulus or vertebral bodies  159  can be helpful in regenerating the degenerating disc  100 . Cells can be transported along the convective flow within the conduit  126  into the nucleus pulposus  128 . The channels or pores within the conduit  126  need to be sufficiently large, about 50 to 200 microns. For minerals, nutrients, lactic acid and gas exchange alone, the channels or pore size can be much smaller. Hence, the useful range of the channel or pore size of the conduit  126  is about 200 microns to 10 nanometers. 
         [0149]    Potentially useful coating for the conduit  126  include antibiotic, anti-occlusive coating, lubricant, growth factor, nutrient, sulfate, mineral, buffering agent, sodium carbonate, sodium bicarbonate, alkaline, collagen, hydroxyapatite, analgesic, sealant, humectant, hyaluronate, proteoglycan, chondroitin sulfate, keratan sulfate, glycosamino-glycans, heparin, starch, stiffening agent, radiopaque coating, echogenic coating, cells or stem cells. 
         [0150]    The tube  125  for preventing occlusion from mineralization or tissue ingrowth can be made with a biocompatible polymer, such as polytetrafluoroethylene, polypropylene, polyethylene, polyamide, polyester, polyurethane, silicon, poly-ether-ether-ketone, acetal resin, polysulfone, polycarbonate or polyethylene glycol. Similar material can be used to coat or partially coat the conduit  126  to prevent blockage of nutrient and waste transport. The coating should be able to withstand sterilization by gamma, electron beam, autoclave, ETO, plasma or UV light to prevent infection. 
         [0151]    Especially for investigative purposes, a biodegradable conduit  126  may provide evidence within weeks or months. Since the conduit  126  degrades within months, any unforeseen adverse outcome would be dissipated. If the investigative-degradable conduit  126  shows promise, a permanent conduit  126  can then be installed to provide continuous benefits. The biodegradable conduit  126  can be made with polylactate, polyglycolic, poly-lactide-co-glycolide, polycaprolactone, trimethylene carbonate, silk, catgut, collagen, poly-p-dioxanone or combinations of these materials. Other degradable polymers, such as polydioxanone, polyanhydride, trimethylene carbonate, poly-beta-hydroxybutyrate, polyhydroxyvalerate, poly-gama-ethyl-glutamate, poly-DTH-iminocarbonate, poly-bisphenol-A-iminocarbonate, poly-ortho-ester, polycyanoacrylate or polyphosphazene can also be used. Similar biodegradable material can be used to make the biodegradable monofilament  110  in  FIG. 75 . 
         [0152]    A wide range of non-degradable materials can be used to fabricate the conduit  126 . Biocompatible polymers, such as polytetrafluoroethylene, polypropylene, polyethylene, polyamide, polyester, polyurethane, silicon, poly-ether-ether-ketone, acetal resin, polysulfone, polycarbonate, silk, cotton, or linen are possible candidates. Fiberglass can also be a part of the conduit  126  to provide capillarity for transporting nutrients and waste. Conduits  126  can also be made with metal, such as nickel-titanium alloy or stainless steel. Both non-degradable and degradable conduits  126  can be formed by molding, extruding, braiding, weaving, coiling, spiraling or machining. The conduits  126  can have a longitudinal lumen  104 , pores and/or channels for fluid exchange. The conduit  126  can be a suture with a proven safety record. The conduit  126  can also be called or classified as a shunt, wick, tube, braided suture, braided filaments, thread or sponge. The disc  100  with the conduits  126  installed can be called the shunted disc  100 . 
         [0153]    The rigid needle  101 , trocar  103 , dilator  230  and plunger  109  can be made with stainless steel or other metal or alloy. The elastically curved needle  101 , shape memory extension  271  and plunger  109  can be formed with nickel-titanium alloy. The needle  101 , rigid needle  220 , dilator  230 , shape memory extension  271  and plunger  109  can be coated with lubricant, tissue sealant, analgesic, antibiotic, radiopaque, magnetic and/or echogenic agents. 
         [0154]    Since nutrients and oxygen are extremely low particularly in degenerating discs  100 , cell death is common, and healthy cells capable of producing glycosaminoglycans are few. Healthy cells  277  can be drawn from another disc  100  within the patient to inject with a syringe  276  into the degenerated disc  100 , as shown in  FIG. 91 . Exchange of nutrients and waste is re-established through the newly installed conduits  126  through the cranial and caudal endplates  105  to nourish both the donor cells  277  and the remaining cells within the degenerating disc  100 . Similarly, donor cells  277  can also be injected into the disc  100  with transverse conduits  126  to revitalize the disc  100 , as shown in  FIG. 92 . Since cellularity within the degenerative disc  100  is low, introduction of donor cells  277  may expedite the process of halting or reversing disc degeneration. 
         [0155]    The avascular disc  100  is well sealed. Even small ions, such as sulfate, and small molecules, such as proline, are greatly limited from diffusing into the nucleus pulposus  128 . The well sealed disc  100  may be able to encapsulate donor cells  277  from a disc  100  of another person, cadaver or animal without triggering an immune response. For disc  100  regeneration, the donor cells  277  can also be stem cells  277 , notochord  277  or chondrocytes  277 . The semi-permeable conduits  126  are permeable to nutrients and waste but impermeable to cells, proteins, glycoproteins and/or cytokines responsible for triggering an immune reaction. The cells of the immune system include giant cells, macrophages, mononuclear phagocyts, T-cells, B-cells, lymphocytes, Null cells, K cells, NK cells and/or mask cells. The proteins and glycoproteins of the immune system include immunoglobulins, IgM, IgD, IgG, IgE, other antibodies, interleukins, cytokines, lymphokines, monokines and/or interferons. 
         [0156]    The molecular weights of nutrients and waste are usually much smaller than the immuno-responsive cells, proteins and glycoproteins. The transport selectivity can be regulated or limited by the size of the pores or channels within the semi-permeable conduit  126 . The upper molecular weight cut-off of the conduit  126  can be 3000 or lower to allow the passage of nutrients and waste but exclude the immuno-responsive cells, proteins, immunoglobulins and glycoproteins. The semi-permeable conduit  126  may also contain ionic or affinity surfaces to attract nutrients and waste. The surfaces of the semi-permeable conduit  126  can be selected or modified to repel, exclude or reject immuno-responsive components. 
         [0157]    In recent years, cell transplants from cadavers or live donors have been successful in providing therapeutic benefits. For example, islet cells from a donor pancreas are injected into a type I diabetic patient&#39;s portal vein, leading into the liver. The islets begin to function as they normally do in the pancreas by producing insulin to regulate blood sugar. However, to keep the donor cells alive, the diabetic patient requires a lifetime supply of anti-rejection medication, such as cyclosporin A. In addition to the cost of anti-rejection medication, the long-term side effects of these immuno-suppressive drugs are uncertain. The benefit of cell transplant may not out weigh the potential side effects. 
         [0158]    The intervertebral disc  100  with semi-permeable conduits  126  can be used as a semi-permeable capsule to encapsulate therapeutic donor cells  277  or agents, as shown in FIGS.  91  and  92 , and evade the immune response; hence no life-long immuno-suppressive drug would be required. A variety of donor cells  277  or agent can be harvested and/or cultured from the pituitary gland (anterior, intermediate lobe or posterior), hypothalamus, adrenal gland, adrenal medulla, fat cells, thyroid, parathyroid, pancreas, testes, ovary, pineal gland, adrenal cortex, liver, renal cortex, kidney, thalamus, parathyroid gland, ovary, corpus luteum, placenta, small intestine, skin cells, stem cells, gene therapy, tissue engineering, cell culture, other gland or tissue. The donor cells  277  are immunoisolated within the discs  100 , the largest avascular organs in the body, maintained by nutrients and waste transport through the semi-permeable conduits  126 . The donor cells  277  can be from human, animal or cell culture. In the supine sleeping position, nutrients and oxygen are supplied through the conduits  126  to the donor cells  277 . During waking hours while the pressure within the disc  100  is high, products biosynthesized by these cells  277  are expelled through the conduit  126  into the vertebral bodies  159 , outer annulus or muscle  193 , then into the veins, bodily circulation and target sites. 
         [0159]    The product biosynthesized by the cells  277  within the shunted disc  100  can be adrenaline, adrenocorticotropic hormone, aldosterone, androgens, angiotensinogen (angiotensin I and II), antidiuretic hormone, atrial-natriuretic peptide, calcitonin, calciferol, cholecalciferol, calcitriol, cholecystokinin, corticotropin-releasing hormone, cortisol, dehydroepiandrosterone, dopamine, endorphin, enkephalin, ergocalciferol, erythropoietin, follicle stimulating hormone, γ-aminobutyrate, gastrin, ghrelin, glucagon, glucocorticoids, gonadotropin-releasing hormone, growth hormone-releasing hormone, human chorionic gonadotrophin, human growth hormone, insulin, insulin-like growth factor, leptin, lipotropin, luteinizing hormone, melanocyte-stimulating hormone, melatonin, mineralocorticoids, neuropeptide Y, neurotransmitter, noradrenaline, oestrogens, oxytocin, parathyroid hormone, peptide, pregnenolone, progesterone, prolactin, pro-opiomelanocortin, PYY-336, renin, secretin, somatostatin, testosterone, thrombopoietin, thyroid-stimulating hormone, thyrotropin-releasing hormone, thyroxine, triiodothyronine, trophic hormone, serotonin, vasopressin, or other therapeutic products. 
         [0160]    The products (hormones, peptides, neurotransmitter, enzymes, catalysis or substrates) generated within the shunted disc  100  may be able to regulate bodily functions including blood pressure, energy, neuro-activity, metabolism, activation and suppression of gland activities. Some hormones and enzymes govern, influence or control eating habits and utilization of fat or carbohydrates. These hormones or enzymes may provide weight loss or gain benefits. Producing neurotransmitters, such as dopamine, adrenaline, noradrenaline, serotonin or γ-aminobutyrate, from the donor cells  277  within the shunted disc  100  can treat depression, Parkinson&#39;s disease, learning disability, memory loss, attention deficit, behavior problems, metal or neuro-related disease. 
         [0161]    Release of the products biosynthesized by the donor cells  277  within the shunted disc  100  is synchronized with body activity. During activities of daily living, the pressure within the shunted disc  100  is mostly high to expel the products biosynthesized by the donor cells  277  into circulation to meet the demands of the body. In the supine position, the flow within the shunts  126  is reversed, bringing nutrients and oxygen into the disc  100  to nourish the cells  277 . Using islets of Langerhans from the donor&#39;s pancreas as an example, production of insulin is induced in the shunted disc  100  during sleeping hours when glucose enters into the disc  100 . During waking hours when disc pressure is high, insulin is expelled through the conduits  126  into circulation to draw sugars into cell membranes for energy production. At night, the insulin released from the shunted disc  100  is minimal to prevent the hypoglycemia. In essence, products biosynthesized by the donor cells  277  are released concurrent with physical activity to meet the demands of the body. 
         [0162]    Some biosynthesized products from the donor cells  277  are appropriately deposited through the vertebral body  159 , as shown in  FIG. 91 , then into bodily circulation. Other products may be more effectively transported through the outer annulus, as in  FIG. 82 , and diffused through the abdomen into bodily circulation. Some other products may be far more effective by entering into the muscles  193 , as shown in  FIG. 92 . 
         [0163]    Growth factors, buffering agents, hormones, gene therapeutic agents, nutrients, minerals, analgesics, antibiotics or other therapeutic agents can also be injected into the shunted discs  100 , similar to  FIGS. 91-92 . 
         [0164]    It is to be understood that the present invention is by no means limited to the particular constructions disclosed herein and/or shown in the drawings, but also includes any other modification, changes or equivalents within the scope of the claims. Many features have been listed with particular configurations, curvatures, options, and embodiments. Any one or more of the features described may be added to or combined with any of the other embodiments or other standard devices to create alternate combinations and embodiments. The conduit  126  can also have a gate to regulate rate and/or flow direction of nutrient, gas and waste exchange. It is also possible to connect a pump to the conduit  126  to assist the exchange between the disc  100  and the bodily fluid. A pH electrode may be exposed near the tip of the rigid needle  220  to detect the acidity within the disc  100 . 
         [0165]    It should be clear to one skilled in the art that the current embodiments, materials, constructions, methods, tissues or incision sites are not the only uses for which the invention may be used. Different materials, constructions, methods or designs for the conduit  126  can be substituted and used. Nothing in the preceding description should be taken to limit the scope of the present invention. The full scope of the invention is to be determined by the appended claims. For clarification in claims, sheath is a rigid tubular member. The elastically curved needle  101  can be called the elastic needle.

Technology Category: 1