JP2013523413A - System and method for tissue expansion and dissection - Google Patents

Abstract

A minimally invasive expansion device includes a plurality of rigid arms radially disposed about a center and an expansion member positioned between the arms. The device can be introduced into the tissue toward the targeted area during the closed configuration. The expansion member may be a balloon, and when the balloon is inflated, the arm is pressed radially outward to expand the device and expand the surrounding tissue. The expansion member may be a tube, and the arm is pressed radially outward when the tube is inserted. In order to keep the arm in an open configuration, a cannula may be inserted inside multiple arms, and the expansion member is withdrawn and opened toward the targeted area through the device. A passage may be provided. The device may be used with a neuromonitoring system.

Description

  The present disclosure relates to orthopedics, and more particularly to providing access to a surgical site in the body via an expandable minimally invasive dilator.

  Many spinal orthopedic procedures, including discectomy, motion preservation device implantation, total disc replacement and interbody device implantation, require smooth access to the targeted portion of the spine. Providing access to the targeted area requires forming a passage through muscles, fascia and other tissues. Current surgical access systems utilize a series of continuous dilators or mechanical retractor systems that include at least one dilatation cannula.

  There are several disadvantages associated with continuous dilators. Continuous dilator systems can shear the tissue to which they are advanced. These tissues include muscles, nerves, blood vessels and organs. In addition, tissue at the end of the dilator can be crushed against bone or other soft tissue rather than being properly separated. When multiple dilators are deployed to expand the space, each dilator is advanced through the same tissue so that the tissue is repeatedly injured.

  Accordingly, there is a need in the art for systems and methods that facilitate access to the spinal column while minimizing damage to surrounding tissue and avoiding time-consuming and unnecessary repetitive steps. Keeping the overall diameter of the cannula and the number of passes can minimize damage to surrounding structures. Such systems and methods can simplify surgical procedures and accelerate patient recovery. Ultimately, reducing the invasiveness of the procedure will result in earlier recovery and improved patient outcome.

  The present disclosure relates to systems and methods for tissue expansion to provide access to intervertebral spaces or other targeted areas. Those skilled in the art will appreciate that the following description is merely illustrative of principles that can be applied in various ways to provide many different alternative embodiments. This description is made for the purpose of illustrating the general principles and is not meant to limit the inventive concept to the appended claims.

  The present invention provides access to the spinal column by using a minimally invasive expandable dilator. The device can be placed in tissue with minimal contours and the expanded device is optimally sized to allow access to the targeted spinal region with minimal impact on surrounding tissue. It also has a high expansion ratio as a result of providing a passage. A single device is advanced into the tissue to be expanded and expanded from within. In this way, the additional step of continuous introduction of dilators with repeated damage to the tissue due to pushing the dilators one after the other through the tissue is avoided.

  Various embodiments will be discussed with reference to the accompanying drawings. It is understood that these drawings depict only typical embodiments and therefore should not be considered as limiting the scope of the invention as set forth in the claims.

1 is a perspective view of a tissue expansion device attached to a hub in a closed configuration, the device comprising a stylus, a balloon, a plurality of arms surrounding the stylus, an inner mesh and an outer sheath. 1B is a perspective view of the tissue dilator of FIG. 1A in a closed configuration, with the outer sheath not depicted and the dashed line representing the inner mesh. FIG. 1B is a perspective view of the tissue expansion device of FIG. 1A, with the balloon inflated and the device expanded, with the dashed line representing the outer sheath. 1B is a perspective view of the tissue expansion device of FIG. 1A in an expanded configuration, with the outer sheath not depicted and the dashed line representing the inner mesh. FIG. 1B is an enlarged longitudinal cross-sectional view of the distal end of the tissue expansion device of FIG. 1A in an expanded configuration. FIG. FIG. 4 is an enlarged cross-sectional view of the distal end of the tissue expansion device of FIG. 1A in an expanded configuration taken along line AA of FIG. 4A. FIG. 1B is a perspective view of a distal portion of the stylus of FIG. 1A, with broken lines representing internal holes. 1B is a perspective view of the outside of one of the arms of FIG. 1A. FIG. FIG. 1B is a perspective view of the inside of one of the arms of FIG. 1A. 1B is an enlarged cross-sectional view of the arms of FIG. 1A in a closed configuration. FIG. 1B is a perspective view of the tissue expansion device of FIG. 1A in a closed configuration with the distal end inserted into the lumbar muscle near the spine and the proximal end attached to the hub. FIG. 6B is a perspective view of the tissue dilator of FIG. 6A in an open configuration with the stylus, balloon, and inner mesh withdrawn and an open passage extending through the hub, dilator, and psoas. 1 is a side view of a curved tissue expansion device in a closed configuration, the device comprising a stylus, two balloons, the stylus and a plurality of curved arms that radially surround the balloon, where the arms are Releasably secured to the proximal end of the stylus, and the arms are releasably secured to one another via lateral engagement features that are fastened by a plurality of release wires. FIG. 8 is an exploded top view of the stylus and two arms of the curved tissue expansion device of FIG. 7. FIG. 8 is a partially exploded enlarged view of a distal end portion of a stylus, a balloon, and an arm of the curved tissue dilating device in FIG. 7. FIG. 8 is a perspective view of the tissue expansion device of FIG. 7 in an expanded configuration with the lure attached to the proximal end of the stylus. FIG. 8 is a perspective view of the tissue expansion device of FIG. 7 in an expanded configuration with the cannula partially inserted into the device. A stylized human body with a closed form of curved tissue expansion device inserted into the lower back muscle and coupled to a targeting system positioned to target a predetermined location along the spinal column. It is a perspective view of a cross section. The human body of FIG. 12 with the dilator in an open configuration, secured to the table mounting clamp to which the dilator and targeting system are secured, and the cannula partially inserted into the dilator. 1 is a perspective view of a targeting system and a curved tissue expansion device. FIG. FIG. 13 is a perspective view of the human body, targeting system and curved tissue dilator of FIG. 12 with the cannula fully inserted into the dilator. FIG. 13 is a perspective view of the human body and targeting system of FIG. 12 with electromyography electrodes inserted into the psoas muscle and coupled to a neuromonitoring system. FIG. 10 is a perspective view of another tissue expansion device in an open configuration. FIG. 17 is a perspective view of the hub assembly of the tissue expansion device of FIG. 16. FIG. 18 is an exploded perspective view of the hub assembly of FIG. 17. FIG. 18 is a top view of a stationary disk of the hub assembly of FIG. 17. FIG. 18 is a top view of a drive disk of the hub assembly of FIG. 17. It is a perspective view of the clamp coupling body of the hub assembly of FIG. FIG. 18 is a perspective view of a disk clamp of the hub assembly of FIG. 17. FIG. 18 is a perspective view of an arm clamp of the hub assembly of FIG. 17. It is another perspective view from the other direction of the said arm clamp of FIG. 23A. FIG. 23B is still another perspective view of the arm clamp of FIG. 23A from still another direction. FIG. 17 is a perspective view of an arm assembly of the tissue expansion device of FIG. 16. FIG. 24B is an exploded perspective view of the arm assembly of FIG. 24A. FIG. 24B is a side view of the arm assembly of FIG. 24A. FIG. 25B is a cross-sectional view of the arm assembly of FIG. 24A taken along line 25B-25B shown in FIG. 25A. FIG. 24B is a perspective view of an arm of the arm assembly of FIG. 24A. FIG. 24B is a perspective view of an arm lock of the arm assembly of FIG. 24A. It is a perspective view of a set of dilators. FIG. 3 is a perspective view of a set of cannulas. FIG. 20 is a top view of the tissue expansion device of FIG. 16 in an open configuration operably assembled to one of the cannulas of FIG. 29; FIG. 30B is a cross-sectional view of the tissue dilator and the cannula of FIG. 30A taken along line 30B-30B shown in FIG. 30A. FIG. 10 is a perspective view of yet another tissue expansion device in a closed configuration. FIG. 31B is a top view of the tissue expansion device of FIG. 31A in a closed configuration. FIG. 31B is a perspective view of the tissue expansion device of FIG. 31A in an unlocked and opened configuration. FIG. 31B is a top view of the tissue expansion device of FIG. 31A in an unlocked and open configuration. FIG. 31B is a perspective view of the tissue expansion device of FIG. 31A in a locked and open configuration. FIG. 31B is a top view of the tissue expansion device of FIG. 31A in a locked and open configuration. FIG. 31B is an exploded perspective view of the tissue expansion device of FIG. 31A. FIG. 31B is a perspective view of a stationary disk of the tissue expansion device of FIG. 31A. FIG. 35B is another perspective view from another direction of the stationary disk of FIG. 35A. FIG. 31B is a perspective view of a drive disk of the tissue expansion device of FIG. 31A. FIG. 36B is another perspective view from another direction of the drive disk of the tissue expansion device of FIG. 36A. FIG. 31B is a perspective view of an arm of the tissue expansion device of FIG. 31A. FIG. 37B is another perspective view from the other direction of the arm of FIG. 37A. FIG. 17 is a perspective view of the tissue expansion device of FIG. 16 operatively assembled to a retainer. FIG. 39 is a front view of the tissue expansion device and retainer of FIG. 38. FIG. 39 is a cross-sectional view of the tissue expansion device and retainer of FIG. 38 taken along line 39B-39B of FIG. 39A. It is a perspective view of the retainer of FIG. FIG. 39 is an enlarged detail view of a portion of the retainer of FIG. 38. FIG. 18 is a perspective view of the hub assembly of FIG. 17 operatively assembled with a plurality of arm assemblies and retainers. FIG. 41B is another perspective view of the hub assembly, arm assembly, and retainer of FIG. 41A from another direction. FIG. 41B is a front view of the hub assembly, arm assembly, and retainer of FIG. 41A. 42B is a cross-sectional view of the hub assembly, arm assembly, and retainer of FIG. 41A taken along line 42B-42B of FIG. 42A. FIG. 42B is a cross-sectional view of the hub assembly, arm assembly, and retainer of FIG. 41A taken along line 42C-42C of FIG. 42A. FIG. 42B is a cross-sectional view of the hub assembly, arm assembly, and retainer of FIG. 41A taken along line 42D-42D of FIG. 42A. FIG. 41B is an exploded perspective view of the hub assembly, arm assembly, and retainer of FIG. 41A. FIG. 41B is a perspective view of one arm of the arm assembly of FIG. 41A. FIG. 41B is a perspective view of the retainer of FIG. 41A. FIG. 41B is an enlarged detail view of a portion of the retainer of FIG. 41A. FIG. 18 is a front view of the hub assembly of FIG. 17 operatively assembled to a plurality of arm assemblies and retainers. 46B is a cross-sectional view of the hub assembly, arm assembly, and retainer of FIG. 46A taken along line 46B-46B of FIG. 46A. FIG. 46B is a cross-sectional view of the hub assembly, arm assembly, and retainer of FIG. 46A taken along line 46C-46C of FIG. 46A. FIG. 46B is a cross-sectional view of the hub assembly, arm assembly, and retainer of FIG. 46A taken along line 46D-46D of FIG. 46A. FIG. 46B is an exploded perspective view of the hub assembly, arm assembly, and retainer of FIG. 46A. FIG. 46B is a perspective view of one arm of the arm assembly of FIG. 46A. FIG. 46B is an enlarged detail view of a portion of the arm assembly of FIG. 46A. FIG. 46B is a perspective view of the retainer of FIG. 46A. FIG. 6 is a perspective view of the clamp assembly in a closed configuration. FIG. 52 is a perspective view of the clamp assembly of FIG. 50 in an open configuration. FIG. 52 is a side view of the clamp assembly of FIG. 50. FIG. 52B is a cross-sectional view of the clamp assembly of FIG. 50 taken along line 52B-52B of FIG. 52A. FIG. 52 is an exploded perspective view of the clamp assembly of FIG. 50. FIG. 52 is a perspective view of a stationary jaw of the clamp assembly of FIG. 50. FIG. 54B is another perspective view from another direction of the stationary jaw of FIG. 54A. FIG. 52 is a perspective view of a movable jaw of the clamp assembly of FIG. 50. FIG. 55B is another perspective view from the other direction of the movable jaw of FIG. 55A. FIG. 50 is a perspective view of the tissue expansion device of FIG. 16 in a closed configuration operably assembled to a pair of clamp assemblies of FIG. 50; FIG. 59 is a perspective view of the tissue dilator operatively assembled to the smallest of the dilators of FIG. 28 and the clamp assembly of FIG. 56. FIG. 59 is a perspective view of the tissue expansion device operably assembled with the two minimal dilators of FIG. 28 and the clamp assembly of FIG. FIG. 57 is a perspective view of the tissue expander operatively assembled with one of the smallest of the cannulas of FIG. 29 and a plurality of long pins and the clamp assembly of FIG. FIG. 59 is a perspective view of the tissue dilator, clamp assembly, cannula and pin of FIG. 59 operatively assembled into three of the largest of the dilators of FIG. FIG. 57 is a perspective view of the tissue expansion device operatively assembled to one of the largest of the cannulas of FIG. 29 and a plurality of long pins and the clamp assembly of FIG. 56. FIG. 6 is a perspective view of a portion of a stylized human lumbar vertebra and pelvis with the stylus positioned and oriented for a direct lateral approach to the disc. FIG. 63 is a perspective view of the stylus of FIG. 62 operatively assembled to the spine, pelvis, and tissue expansion device of FIG. FIG. 63 is a perspective view of the tissue expansion device of FIG. 63 operatively assembled to the spinal column, pelvis, stylus and minimal dilator of FIG. FIG. 63 is a perspective view of the tissue dilator of FIG. 63 operatively assembled into two of the spine, pelvis, stylus and minimal dilator of FIG. FIG. 64 is a perspective view of the tissue expansion device of FIG. 63 operatively assembled to the spine, pelvis, stylus, and the smallest cannula and multiple long pins of FIG. 29; FIG. 64 is a perspective view of the tissue expansion device of FIG. 63 operatively assembled to the spine, pelvis, stylus, and the largest of the cannula of FIG.

  FIGS. 1-6B illustrate one embodiment of the expansion device 60. The dilator 60 includes an obturator or stylus 70, a plurality of rigid arms 90, a balloon 110, a flexible inner mesh 130, and an optional flexible outer sleeve or sheath 140. Yes. A portion of the dilator can be introduced into the muscle and the dilator can be expanded from a closed configuration to an open configuration to tear and separate muscle fibers to form a passage through the muscle. After expansion, the stylus, balloon and inner mesh are removed, leaving an open passage through the muscle. Through this, instruments, implants, and other materials can be passed to perform one or more surgical procedures.

  Referring to FIGS. 1A and 1B, the expansion device 60 is shown in a closed configuration that extends partially through the hub 50. The hub 50 includes a hub body 52 and a collet 54 and is attachable to a surgical table mounting support system (not shown) that provides stability and support to the hub and expansion device during a surgical procedure. In FIG. 1A, only the outer sleeve 140, which is an option for the device 60, and only the distal ends of the arms 90 and the stylus 70 are visible. This is because the outer sleeve 140 covers most of the device. The outer sleeve 140 is securely attached to the plurality of arms and is securely attached circumferentially to the collet to form a barrier around the remainder of the device. FIG. IB depicts the device without the outer sleeve 140 and a dashed line displaying the inner mesh 130. Balloon 110 is mounted circumferentially on stylus 70 toward the distal end of the stylus and extends proximally along a portion of the stylus. The plurality of arms 90 may completely surround the balloon in a closed configuration. Thus, the balloon is not visible in FIGS. 1A and 1B. The inner mesh 130 is interposed between the balloon and the plurality of arms to surround the balloon and extends from the distal end of the plurality of arms toward the collet 54. The inner mesh may be attached to the stylus. The maximum outer diameter of the device 60 in the closed configuration ranges from 5 to 15 millimeters as measured perpendicular to the longitudinal axis of the stylus and rigid arm along the line aa.

  The device 60 may further comprise one or more holding bands 64 that are placed around the plurality of arms to help close and hold the device when the device is in a closed configuration. . The band is made of a biocompatible polymer that is bioabsorbable and has a generally circular ring shape. The band can be heat shrunk around the closed device. During expansion, the arms move radially and laterally relative to each other so that the forces of the moving arms stretch the band and ultimately break it. All of the expansion devices disclosed herein may include these retaining bands.

  FIG. 2 shows the expansion device 60 in its expanded or open configuration. The outer sleeve 140 is not depicted, but its arrangement is shown in broken lines. A distal portion 132 of the inner mesh 130 surrounds the balloon, and in this embodiment, the distal end of the mesh is attached to the stylus. The proximal end of the mesh 134 extends through a collet 54 that surrounds the stylus.

  FIG. 3 shows the expansion device 60 in an expanded configuration without an outer sleeve, and the inner mesh is indicated by a dashed line. FIG. 4A shows an enlarged longitudinal cross-sectional view of the distal portion of the device 60 in an expanded or open configuration. FIG. 4B shows a further enlarged cross-sectional view taken along line AA of FIG. 4A of the distal end of the device 60 in the open configuration. Each end of the balloon 110 is attached to the stylus 70. In order to obtain an open configuration, fluid is introduced into the balloon 110 via the stylus and inflates the balloon. When balloon 110 is actuated by inflation, it expands radially, the outer surface of the balloon presses against a plurality of rigid arms 90, and each individual arm 92 is radially outward and , Displaced laterally away from adjacent arms. The inner mesh 130 surrounding the balloon body also expands or expands radially outward and generally conforms to the shape of the balloon where it is adjacent to the balloon. The outer sleeve 140 also expands or expands with the expansion of the device. After expansion of the device to the open configuration, the stylus 70 and attached balloon 110 and inner mesh 130 may be withdrawn nearby and are armed from the hub 50 covered by the arm and outer sleeve. Leave an open passage extending to the end of 92. The device 60 has a generally cylindrical shape in both a closed configuration as seen in FIG. 1A and an open configuration as seen in FIG.

  5A-5D show details of the stylus 70 and arm 92. FIG. 3, 4A and 5A, the stylus 70 includes a proximal end 72, a distal end 74, and a shaft 76 extending between the proximal and distal ends. The stylus may be an obturator or hypotube made of stainless steel or other biocompatible metal. The stylus tip 78 may be disposed at the distal end and formed integrally with the stylus, or may be formed separately from the stylus and rigidly secured to the stylus. The tip 78 may be blunted to separate and push the muscle fibers with minimal damage to the muscle fibers as the stylus advances into the muscle. In some embodiments, the tip is conical, pointed, and / or provided with a cutting edge. In certain embodiments, the distal end of the stylus may further comprise a connecting feature that cooperates with a complementary connecting feature on the rigid arm, the connecting features being engaged with each other. The arm is then placed in a predetermined longitudinal alignment with the stylus. The stylus may be partially hollow and has an internal hole 80 extending from an opening at the proximal end to a distal end or toward it. One or more ports 82 may extend from the hole 80 to the outside of the shaft 76, through which fluid can flow to inflate the balloon upon expansion. A luer (not shown) may be communicated with the hole 80 and attached to the proximal end of the stylus to direct fluid into the hole of the stylus.

  With reference to FIGS. 3-5D, the plurality of rigid arms 90 includes four or more individual arms 92. Each of the arms 92 is the same as each other arm and includes a proximal end 94, a distal end 96, a first side edge 98, and a second side edge 100 opposite the first side edge. ing. The shaft 102 is bounded laterally by side edges 98, 100 and extends between the proximal and distal ends. An outer surface 104 that can be curved convexly covers one side of the arm, while an inner surface 106 that can be curved concavely covers the other side. The entirety of each of the arms 92 is such that when the arms are positioned in a closed configuration, their side edges are adjacent to each other to form a closed cylinder as in FIGS. 1B, 5D, and 6A. It may be curved about its longitudinal axis to contact and align. The inner diameter of the closed cylinder is sized to receive the stylus 70 and the uninflated balloon 110. The arm may include holes or other features that are used to securely attach the outer sleeve to the arm by sutures, pins or other attachment mechanisms. In the embodiment shown in FIGS. 1B-3, the arm extends along only a portion of the stylus. In other embodiments, the arms are longer, can extend the entire length of the stylus, and / or can extend out of the hub 50. Each of the arms 92 may extend outward, i.e., bend, at its distal end, which helps hold the tissue during expansion or expansion.

  The distal end portion 96 of the arm may include an arm connection feature shaped to engage a corresponding stylus connection feature to place the arm in a predetermined longitudinal alignment with the stylus. Referring to FIGS. 4A, 5A and 5B, the arm connection feature may comprise a curved end edge 97. The stylus connection feature may comprise a section of an overhanging lip 79. The lip 79 has a circular flange that protrudes outward from the stylus tip 78 at the stylus tip 78. When the curved distal end 97 of the arm is positioned against the curved section corresponding to the lip 79 so that the entire curved distal end contacts the lip section, the arm is in contact with the stylus. And in a predetermined longitudinal alignment.

  The side edges 98, 102 of the arms are in contact with the arms in longitudinal alignment with each other along their first and second side edges when the arms are in a closed configuration. Complementary engagement features that cooperate with the engagement features of adjacent arms may be provided. In one embodiment, the engagement feature may comprise a flat portion comprising a flat surface 108 with a first side edge engaging a complementary flat surface of an adjacent second side edge. . In another embodiment, the engagement feature is in a groove, wherein the first side edge comprises a tongue, while the second side edge comprises a groove shaped to receive the tongue. You may provide the characteristic part of a tongue part. In yet other embodiments, the engagement feature may comprise alternating edge extensions with holes shaped to receive longitudinal members such as wires or sutures. As a result, the edges can be temporarily tied together. In the closed configuration, the longitudinal member extends through the hole and the arms are held in contact in longitudinal alignment. When the longitudinal member is removed, the arms are free to disengage and move away from each other.

  The arm may be at least partially radiolucent so as not to jeopardize the visualization of the procedure when using the device with fluoroscopy. Alternatively, the arm may be at least partially radiopaque to assist in positioning and positioning the system under fluoroscopy. The arm may comprise a metal such as aluminum, stainless steel, titanium, and other biocompatible metals. The arm may comprise high density plastics such as, among others, delrin, radel, udel, polyetheretherketone (PEEK), polycarbonate, and acrylonitrile butadiene styrene (ABS). Barium sulfate may be added to the constructed plastic material to provide increased radiopacity.

  Referring to FIG. 4A, the balloon 110 includes a proximal end 112, a distal end 114, and a substantially cylindrical balloon body 116 extending therebetween. At the proximal end 112 and the distal end 114, the balloon is circumferentially directed to the stylus so that when fluid is introduced into the balloon cavity 115, the fluid cannot escape at the point of attachment to the stylus 70. It is attached by an adhesive or other joining method. As fluid is introduced into the balloon 110 from the stylus 70 via the port 82, the balloon can expand proximally and distally. When the proximal end of the balloon is inflated, the arm 92 is pushed slightly distally, and then is pushed radially outward as the inflation continues in the distal direction. The proximal end 94 of the arm can be pressed radially outwardly before or simultaneously with the distal end 96 of the arm 92.

  The balloon may be opaque or translucent, and the balloon may be flexible or non-flexible. A flexible balloon may allow a uniform distribution of force to the rigid arm and ultimately to the surrounding tissue. Non-flexible balloons can tolerate uneven force distribution, and this is suitable for cutting tissue. The balloon shape is optimized to best suit physiology and tissue dissection. For example, a round balloon creates a uniform force distribution and creates a local open space. The elongated balloon creates a distal expansion and creates a space at the distal end of the device. The balloon may comprise polyethylene, polyethylene terephthalate (PET), polytetrafluoroethylene, (PTFE), nylon, dacron, polyurethane, and other flexible or non-flexible polymers.

  The inner mesh 130 may be secured to the stylus in a position distal to the distal end of the balloon and extends toward the proximal end of the stylus. The inner mesh 130 is generally tubular and flexible, can follow the shape of the balloon, and can be permeable or impermeable. The inner mesh may be an indeterminate shape or a pre-formed shape. The mesh comprises polypropylene, polyethylene (PE), polyethylene terephthalate (PET), polyetheretherketone (PEEK), nylon, ultra high molecular weight polyethylene (UHMWPE), or other biocompatible polymers, or combinations thereof. obtain. In some embodiments, the inner mesh is configured such that when a portion of the inner mesh is expanded by the balloon, i.e., an expansion member, the length of the inner mesh is reduced.

  In some embodiments, the dilator 60 further comprises an outer mesh or sheath 140 that can circumferentially surround the rigid arms and stylus to further retain and protect body tissue during dilation. . In other embodiments, the outer sheath may be located inside the arm, but circumferentially surrounds them outside the inner mesh, balloon and stylus. The outer sheath may prevent tissue pinching and / or movement of tissue between rigid arms during the expansion process. The outer sheath is securely attached to the arm on the inside or outside by mechanical fastening devices such as adhesives, stitching techniques and / or pins. The sheath 140 is generally tubular in shape with an open distal end and a proximal end. The sheath is attached to the plurality of arms at or toward the distal end. At its proximal end, the sheath is circumferentially attached to the collet 54 via an O-ring or other fastener. In some embodiments, the outer sheath comprises a mesh interwoven with a conductive secondary material. The conductive nature of the mesh may be used in flat tissue or in more diagnostic modes, such as neural tissue detection associated with an electromyography (EMG) device. The outer sheath may comprise the same material as the inner mesh.

  6A shows the device 60 in a closed configuration advanced into the muscle, while FIG. 6B shows the device 60 in an open configuration expanding the muscle to provide a passage through the muscle. Is shown. In FIGS. 6A and 6B, the outer sheath 140 is located inside the plurality of arms 90. Referring to FIG. 6A, the device 60 has been partially advanced into the lower back muscle adjacent to the spinal column. A stylus 70 and a plurality of closed arms 90 penetrate the muscle and cut the muscle fibers. When the device is introduced, the device may be rotated so that the outer surface 104 of the arm 92 is in a preferred orientation relative to the muscle fibers. As a result, the fibers are mainly pushed aside instead of being torn during expansion. For example, as shown in FIGS. 6A and 6B, the device is preferably placed so that the outer surface 104 of the arm 92 is approximately 45 ° to the longitudinal axis of the muscle fiber. Fluid is introduced into the holes of the stylus where it passes through the port 82 and into the balloon 110 to inflate the balloon and cause radial expansion. As the balloon expands, the surrounding inner mesh 130 expands and the arms 92 are pushed radially outward and displaced from each other radially and laterally as seen in FIGS. 6B and 4B. The The surrounding muscle fibers are cut and the muscle is expanded, creating a passage through the muscle to the spinal column.

  After the balloon 110 has been inflated by the desired amount, the stylus, balloon and inner mesh may be removed from the device 60, leaving the expanded arm 90 and the outer mesh 140 surrounding the open passage 62. Good. A rigid cannula is inserted longitudinally into the passage 62 inside the arm 90 and the outer mesh 140 to further keep the passage open before or after removal of the stylus, balloon and inner mesh. May be. The cannula forms the inner wall of the passage. Instruments, implants and other materials are passed through the passages to perform a surgical procedure. In the open configuration, the maximum outer diameter of the device 60 is in the range of 25 to 40 millimeters, measured perpendicular to the longitudinal axis of the stylus and rigid arm along the line aa in FIG. 4A. The expansion ratio of the device can be measured as the ratio of the maximum outer diameter in the open configuration of the device to the maximum outer diameter in the closed configuration of the device. The expansion ratio of the device 60 is in the range of 2.5 to 8.0. In some embodiments, the expansion ratio can range from 4.0 to 7.0, while in other embodiments, the expansion ratio can range from 5 to 6.5. In a preferred embodiment, the expansion ratio is at least 6.0.

  Figures 7-10 illustrate another embodiment of a minimally invasive expandable dilator. The dilator 160 includes a curved stylus 170, a plurality of rigid curved arms 190 disposed radially around the stylus, and two balloons attached circumferentially to the stylus. The dilator 160 can be used in a posterior lateral approach to dilate and form a passage through the lumbar muscles to gain access to the intervertebral space. In other embodiments, a balloon or balloons are attached to a curved stylus. In still other embodiments, at least one cannula is introduced into the space defined by the arm that is expanded with the arm spaced apart instead of one or more balloons. The device 170 can be used to create a curved path through the psoas muscle and / or to create a curved path through another muscle or tissue set.

  Referring to FIG. 7, a dilated device 160 is shown in a closed configuration with a plurality of curved arms 190 surrounding and blocking the balloon. The central longitudinal space is circumferentially surrounded by the arm. The plurality of bending arms 190 includes four individual bending arms 192, 194, 196, 198. Each arm is releasably secured to the end of the stylus via an attachment mechanism 200. Each arm is also releasably secured to a side edge of an adjacent arm via a lateral engagement feature 220. The release wire 226 fixes each arm to its adjacent neighbor by extending the length of the arm through an arm hole 224 extending from the proximal end to the distal end. In this embodiment, the arms are not identical to each other, but are each shaped so that when mounted simultaneously, the arms form a curved cylinder that is closed around a curved stylus. For example, arms 194 and 196 have a shorter radius of curvature than arms 192 and 198 and slightly smaller than arms 192 and 198. The maximum outer diameter of the device 160 in the closed configuration is in the range of 5 to 15 millimeters, measured perpendicular to the longitudinal axis of the stylus and rigid arm along line bb.

  Referring to FIG. 8, a top to bottom perspective view shows the stylus 170 and two arms 194,196. Attached to the stylus shaft 172 are two uninflated balloons 240,242. Each balloon extends longitudinally along a portion of the stylus and is secured to the stylus at the end of each balloon. The stylus includes an internal hole 174 that extends along the length of the stylus and communicates with two ports 176. The holes and ports provide fluid passages for inflating the balloons 240, 242. The stylus end 177 has a stylus tip 178 that is formed integrally with or separately from the stylus. The stylus tip has a point 180 that may be blunted to more gently displace the tissue as the stylus is inserted into body tissue and muscle. The stylus tip may have a distal conical surface that helps to separate tissue and muscle fibers without damaging them. The maximum diameter of the stylus tip is larger than the shaft of the stylus as in FIG. In other embodiments, the maximum diameter of the stylus tip may be the same or smaller than the stylus shaft.

  Referring to FIGS. 8 and 9, the stylus tip 178 has four individual connecting features 182 positioned adjacent to the distal end of the stylus. Each connecting feature 182 is a peg protruding radially from the stylus, each peg having an oval shape, one with a slightly rounded end on the other. . This shape ensures a snug fit to the complementary shaped receiving hole 204 at the end of each arm. When the arms are mated to the pegs, as in FIG. 7, the arms are transverse to each other until the connecting feature is removed, for example, until the holes 204 are removed from the pegs 182. The arm is longitudinally aligned with the stylus in a predetermined longitudinal alignment that cannot move in the direction. Other connecting features are possible, including but not limited to pegs and corresponding round, oval, rectangular, or polygonal holes, or other complementary projection and slot combinations. . The receiving hole may be open at both ends or may be a recess or cavity having an opening on one side shaped to receive a peg. In an alternative embodiment, the peg is located on the arm and the receiving hole or cavity is located on the stylus or stylus tip.

  Each arm 192, 194, 196, 198 comprises a distal end 206, a proximal end 208, and an arm shaft 210 that is laterally bounded by a first side edge 212 and a second side edge 214. Yes. Each side edge 212, 214 includes one or more recessed portions 216 that are alternately distributed with protruding portions 218. In this way, when the two arms are fitted together in the lateral direction, the protruding portion 218 of one arm fits into the recessed portion 216 of the adjacent arm. The arm hole section 222 extends longitudinally along each side edge through the entire length of each protruding portion 218. When the two arms are fitted together laterally, one continuous arm hole 224 is formed from alternating arm hole sections 222 that are now axially aligned with each other. The release wire 226 seen in FIG. 7 may be inserted along the length of each arm hole 224 to ensure that the arms are effectively pinned or stitched together. The release wire 226 may be withdrawn after the closed device 160 has been advanced into tissue and prior to expansion of the device so that the arms can be moved away from each other by expansion force. Other lateral engagement features are contemplated, including but not limited to groove and tongue features corresponding to tab and slot features and press fit features. Such features may be disengaged by removing wires, such as pins, sutures or release wires 226, or the features may be removed from each other with sufficient expansion force provided by expansion of the expansion member. You may have the friction fitting removed.

  Referring to FIGS. 8 and 9, details of the distal end of the arm and stylus are shown. The distal end 206 of each arm 192, 194, 196, 198 may include an offset portion 228 whose distal end is offset from the shaft 210. The offset 228 allows the arms to match together more precisely when the device 160 is in the closed configuration and also provides a stop surface for the distal end of the release wire 226. The distal end 206 may also include a constriction 230 and an adjacent diverging portion 232. The constriction 230 and the widened portion 232 together form a concave curved region at the distal end of the arm. It helps to hold down or hold the tissue that has been torn and pushed aside by the stylus tip 178 during advancement of the device into muscle and other tissues, and upon expansion of the device 160 It helps to hold down or hold tissue that has been moved separately. The diverging portion 232 acts as a retainer that prevents the tissue from sliding back onto the distal end of the arm once the tissue is torn apart from each other. The inner surface of the diverging portion 232 may also be shaped to complementarily match the outer surface of the stylus tip 178, a portion of which extends outward.

  An alternative embodiment of the dilator includes a stylus and an arm that includes a corresponding coupling feature, such as the peg / hole system described above, but does not have a lateral engagement feature on the arm. Another embodiment includes lateral engagement features on two or more arms, but does not include corresponding coupling features between the arms and the stylus. Yet another embodiment does not include a distal linking feature or a lateral engagement feature. Additional embodiments may include any combination of features described herein.

  The dilator 160 may further comprise an inner mesh positioned longitudinally between the balloon and the arms in a manner similar to the inner mesh 130 described in the previous embodiment. The apparatus also includes an outer sleeve that is securely attached to the arm and positioned longitudinally either inside or outside the plurality of arms in a manner similar to the outer sleeve 140 described in the previous embodiment. May be further provided. The mesh and sleeve may comprise the same materials as previously described for the inner mesh 130.

  Referring to FIG. 10, the expansion device 160 can be expanded by introducing fluid into the stylus 170. Prior to expansion, all release wires are withdrawn from the arm holes. A luer 244 at the end of the stylus provides a means for introducing a fluid, such as saline, into the stylus bore. The fluid is forced distally along the stylus to escape through port 176 and inflate balloons 242 and 240. A proximally disposed balloon 242 is inflated ahead of a distally disposed balloon 240 and this causes the arm to move slightly distally and then radially outward when both balloons are inflated. Will be pressed. As the arms 192, 194, 196, 198 move radially outward, the arm connection feature 204 is engaged from the stylus connection feature 182 by the expansion force provided by the inflation of the balloon. Canceled. Similarly, the lateral engagement features 216, 218 are also disengaged and the arms move radially and laterally away as the balloon expands. After the balloon inflation has provided sufficient expansion of the device to expand the surrounding tissue by the desired amount, fluid introduction is stopped and the stylus 170 with the attached balloons 240, 242 is removed. May leave a passage through the surrounding tissue. In the open configuration, the maximum outer diameter of the device 160 may be in the range of 25 to 40 millimeters, measured perpendicular to the longitudinal axis of the stylus and rigid arm, again along line bb. Good. The expansion ratio of the device 160 may be in the range of 2.5 to 8.0. In some embodiments, the expansion ratio may be in the range of 3.0 to 7.5. In other embodiments, the expansion ratio ranges from 4.0 to 7.0, and in yet other embodiments, the expansion ratio ranges from 5 to 6.5, and in a preferred embodiment, the expansion ratio is at least It may be 6.0.

  Referring to FIG. 11, a cannula is inserted between the stylus 170 and the curved arm 190 to keep the device in an open configuration and to prevent movement of the tissue into the longitudinal space 162 in the center. A cannula, such as an arcuate cannula 246, may be inserted along a curved path on the stylus 170 prior to withdrawal of the stylus and balloon from the device 160, as shown in FIG. Good. Alternatively, the cannula may be inserted along the inside of the arm after withdrawal of the stylus and balloon. It will be understood that the cannula is not passed along the outside of the device. It crushes or hurts neighboring tissues. Instead, the cannula is advanced along the inside of the expanded arm and within the optional outer sleeve. Following insertion of the cannula and withdrawal of the mesh inside the stylus, balloon, and option, instruments, implants, and the like to perform a surgical procedure at the end of the passage formed by the expanded device Material is passed through the cannula. The cannula may be docked to a skeletal structure such as the spine and / or a surgical table support system to provide stability during a surgical procedure.

  FIGS. 12-14 illustrate the dilation device being inserted through an opening in the skin and through the lumbar muscles to create a passage from the posterior lateral approach to the intervertebral arrangement. The device 260 is configured such that the arms are radially displaced from the stylus from a closed configuration in which each arm is in longitudinal alignment with the other two arms along their side edges and It can be transformed into an open form displaced laterally from each other. The dilator 260 includes a dilator member that is a stylus 270, a plurality of arms 280, a tubular sleeve 290, and a cannula 300. In such embodiments where the expansion member is not a balloon, the entire stylus including the distal tip may be cannulated to allow site flushing and / or k-wire passage.

  Referring to FIG. 12, the dilator 260 inserted through an incision in the skin 10 and through the psoas muscle 12 is shown in a closed configuration. The sleeve 290 is secured to the inner surface of the arm 280 and at its proximal end to the collet portion 54 of the hub 50. The stylus 270 is also releasably clamped to the hub 50. The hub 50 is described in US patent application Ser. No. 12 / 357,695, filed Jan. 22, 2009, entitled “Spine Access System and Method,” which is incorporated herein by reference in its entirety. To a targeting system 20 which is fully described in The hub 50 and / or the targeting system may be a surgical table support system known in the art to provide stability during device insertion and expansion, and during other surgical procedures. It is understood that it may be fixed to other support systems. The targeting system 20 includes a housing 22, a targeting post 24, a micrometer 26, and a swing arm 28. The targeting post 24 is advanced through the skin and fascia to the desired depth and placement near the spine 14 and a targeting depth stop 29 can regulate the depth of the targeting post. Micrometer 26 may be used to precisely adjust the position of the targeting post. An offset arm or swing arm 28 connects the housing 22 to the hub 50. The swing arm 28 is raised or lowered and rotates about the axis of the housing 22 to raise or lower the hub 50 and the associated expansion device 270. In FIG. 12, the swing arm 28 is sufficiently lowered to guide the device 260 along the arcuate curved path to the psoas muscle.

  Toward the proximal ends of the plurality of arms 280, each arm includes a longitudinal slot extending distally along a portion of the arm from the proximal ends. This slot provides a slight amount of flexibility at the proximal end of the arm when the cannula 300 is inserted to initiate deformation of the device 260 from a closed configuration to an open configuration. The slot may also be a guide that cooperates with a pin or protrusion on the cannula or on a separate guide ring that guides the insertion of the cannula into the device.

  Referring to FIG. 13, the expansion device 260 is shown in an opened form. The hub 50 and the housing 22 are connected to table mounting clamps 30 and 32 that can be adjusted in multiple axes. The post 34 is fastened to the pedicle and a slidable clamping sphere 36 is located on the post. As an option, the targeting system may be clamped to the post 34 instead of or in addition to the table mounting clamp. The stylus 270 has been withdrawn from the dilator 260 and the distal end 302 of the cannula 300 has been partially advanced within the system, ie, inside the plurality of arms 280 and sleeve 290. The proximal end 304 of the cannula is docked to the hub 50. The cannula 300 has a larger diameter than the plurality of arms 280 in the closed configuration. As the cannula 300 is advanced along a curved path inside the space in the closed arm, the arm 280 is subjected to radial and lateral forces to open the attached tubular sleeve 290. And create a passage through the tissue and the psoas muscle.

  Referring to FIG. 14, the dilator 260 is shown in an open configuration, and the distal end of the cannula 300 is shown fully advanced along a plurality of arms and through the psoas muscle. The swing arm 28 is partially rotated about the axis of the housing 22, thus lowering the hub and the docked cannula to advance the cannula completely along the curved path, and The angle between the swing arm 28 and the target post 24 is reduced. The clamp arms 30, 32 are adjusted to stabilize the device in a fully advanced position. Other instruments, implants, and materials can be passed through the passage formed by the cannula.

  FIG. 15 illustrates an electromyography (EMG) electrode 310 inserted into the lower back muscle. The electrode 310 is connected to a nerve monitoring system 320 that can detect the presence of nerve tissue. Prior to insertion of a dilator device such as device 60, 160 or 260, the electrode 310 may be advanced into the muscle or tissue to be dilated and excited, i.e. activated, to detect the presence of a nerve. . The electrode is then deactivated and / or removed, and the dilator is inserted into the muscle or tissue. If a nerve is sensed along a particular path or trajectory, the dilator can be inserted along a different path or trajectory to avoid the nerve. The electrode and nerve monitoring system can be used to detect and avoid neural tissue before insertion of the dilation device, after insertion of the device but before dilation, and following dilation. The electrode may also be activated intermittently during advancement of the expansion device. In an alternative embodiment of the device, if it is metal, a rigid arm is used as the electrode. Similarly, permeable tape and / or paint may be applied to the surface of the arm to create a surface capable of transmitting voltage.

  FIGS. 16-27 illustrate another expansion device 400. The expansion device 400 may be described as an expansion assembly because it includes several components in an operable arrangement. FIG. 16 shows the expansion device 400 in an open configuration. The expansion device 400 includes a hub assembly 500 and a plurality of arm assemblies 1300. Although alternative embodiments may include more than one arm assembly, the expansion device 400 is configured to accept up to five arm assemblies 1300. The arm assembly 1300 is supported by the hub assembly 500. In this embodiment, the arm assembly 1300 is evenly spaced around the hub assembly 500 in a circular or pentagonal pattern, although non-circular or asymmetrical arrangements are possible. The pattern of arm assembly 1300 expands and contracts synchronously with respect to hub assembly 500. In other words, each arm assembly 1300 is movable in the radial direction with respect to the center of the pattern. The center of the pattern is, in a sense, a point at the center of the pattern. Other embodiments may provide independent adjustments in different directions, such as independent adjustments in the anterior-posterior, mid-lateral, and / or head-to-tail directions.

  A portion of the dilator 400 can be introduced into a muscle, other tissue, or natural passageway in a longitudinally aligned closed configuration (shown in FIG. 56). The expansion device 400 is then expanded from the closed configuration to the open configuration. When introduced into the muscle, the expansion of the expansion device 400 tears and separates the muscle fibers. The expansion of the dilator 400 forms an open passage through muscle, tissue or natural passage through which instruments, implants, and other materials are passed to perform one or more surgical procedures.

  FIGS. 17-23C illustrate the hub assembly 500 in more detail. 17-18, the hub assembly 500 includes a stationary disk 600, a drive disk 700, a basic disk clamp 800, a slotted disk clamp 900, a socket disk clamp 1000, a clamp connector 1100, an arm clamp 1200, and a dowel pin. And associated fasteners such as screws. The drive disk 700 is sandwiched between two stationary disks 600, and the three disks are secured together by disk clamps 800, 900, and 1000 that connect around the outer diameter of the disk. The stationary disk 600 and disk clamps 800, 900, and 1000 form a stationary frame in which the drive disk 700 can freely rotate. The arm clamp 1200 is connected in a circular pattern around the inner diameter of the stacked disks and is freely linearly translatable with respect to the stationary frame along the radius of the circular pattern. The rotation of the drive disk 700 and the translation of the arm clamp 1200 are related such that the force input causing the translation of the arm clamp 1200 causes the drive disk 700 to rotate and vice versa. Yes. In this way, the hub assembly 500 provides a synchronized radial expansion and contraction of the pattern relative to the arm clamp discs 600,700. At least some of the components of the hub assembly 500 may be partially or completely radiolucent.

  Referring to FIGS. 18-19, stationary disk 600 is shaped as a ring or ring with a central opening 602. The stationary disk 600 includes five pairs of linear, radially extending slots 604 that are evenly spaced around the disk. The stationary disk 600 also includes five pairs of holes 606 that are evenly spaced about the outer diameter around the disk. There may be one smaller hole 608 between each pair of holes 606. For example, one or more additional holes 610 may be present to provide easy access for weight reduction or cleaning.

  Referring to FIGS. 18 and 20, the drive disk 700 is shaped as a ring or ring with a central opening 702. The drive disk 700 includes five pairs of arcuately extending slots 704 that are evenly spaced around the disk. The drive disk 700 also has four arcuate peripheral slots 708 located at four of five evenly spaced locations around the disk. The drive disk 700 includes a tab 710 that protrudes from the outer diameter of the disk.

  Referring to FIG. 18, the basic disk clamp 800 or the bracket may have an arc shape complementary to the outer diameter of the stationary disk 600, the driving disk 700, or both. The concave side of the disc clamp 800 includes a channel 802 or groove sized to receive the combined thickness of two stationary discs 600 with clearance and one drive disc 700. The disc clamp 800 also includes a pair of through holes 806 that are sized and positioned corresponding to the holes 606 in the stationary disc 600 and that are also sized to complement the fasteners 898. For example, if the fastener 898 is a screw, the hole 806 may be screwed with a corresponding internal thread shape. The disc clamp 800 can accept up to four fasteners 898.

  With continued reference to FIG. 18, the slotted disc clamp 900 or bracket further shares a through-slot 908 as best seen in FIG. 30B, sharing some or all of the characteristics of the disc clamp 800 described above. May be characterized. The tab 710 of the drive disk 700 protrudes through the slot 908 when the hub assembly 500 is fully assembled and provides a force input arrangement that rotates the drive disk 700.

  18 and 22, the socket disc clamp 1000 or bracket may share some or all of the above characteristics, such as the recessed channel 1002 or hole 1006, for the disc clamp 800. In addition, the disc clamp 1000 may include a central protrusion 1010 extending from the convex side of the bracket. A socket 1012 extends at least partially within the protrusion 1010.

  With reference to FIGS. 18 and 21, the clamp coupling 1100 is most prominently characterized by a spherical ball 1102 from which a shaft 1104 projects. Ball 1102 may be smooth or textured. For example, FIG. 21 illustrates a textured ball 1102 having a regular pattern of grooves 1112. Other texture processing, such as knurling, dimples or sandblasting is also conceivable. The shaft 1104 may optionally have drive features 1108 such as threads 1106 and a pair of dihedral widths 1110. If threads are present, the clamp coupling 1100 can be screwed into the socket 1012 threaded corresponding to the disc clamp 1000. Alternatively, the clamp assembly 1100 may be pinned, press-fit, welded or articulated to the disc clamp 1000 by some other means. The clamp assembly 1100 is also integrally formed with the disc clamp 1000 in some embodiments.

  Referring to FIGS. 18 and 23A-C, an arm clamp 1200 or bracket is shown with an hourglass profile in a top view, as seen in FIGS. 19 and 23A. Other contours are also conceivable for their function or decorative appeal. A dovetail slot 1206, visible in FIG. 23A, is formed at one widened end of the hourglass shape and extends completely across. A pocket 1208 is formed at the bottom of the dovetail slot 1206 as seen in FIG. 23C. The arm clamp 1200 also includes a pair of through holes 1204 sized and positioned corresponding to the slot 604 of the stationary disk 600 and the slot 704 of the drive disk 700. The hole 1204 is also sized and configured to complement the fastener 1298. For example, if the fastener 1298 is a dowel pin, at least some of the holes 1204 may be sized and errored to receive the fastener 1298 with a press-fit or interference fit. In side view, arm clamp 1200 includes a channel 1202 or groove sized to receive the combined thickness of two stationary disks 600 and one drive disk 700 with clearance. The channel 1202 extends across the hourglass-shaped constriction in the illustrated embodiment with the bottom of the channel 1202 adjacent to the dovetail slot 1206. Arm clamp 1200 also includes a hole 1210 passing through dovetail slot 1206 opposite pocket 1208. The hole 1210 may be sized and configured to complement the fastener 1296.

  The hub assembly 500 can be assembled with a drive disk 700 sandwiched between two stationary disks 600. The three disks may optionally pass a fastener 698 through each hole 608 in one of the stationary disks 600, a corresponding slot 708 in the drive disk 700, and a corresponding hole 608 in the second stationary disk 600. May be fixed together. Alternatively or in combination, the three disks may be secured together with disk clamps 800, 900, 1000, and fasteners 898. In this situation, the disk clamp 900 is positioned at the outer periphery of the three disks such that the tab 710 of the drive disk 700 protrudes through the slot 908 and the hole 906 is aligned with the hole 606 of the stationary disk 600. May be. The disc clamp 900, stationary disc 600, and drive disc 700 may be secured together by inserting four fasteners 698 through the holes 906, 606. Similarly, two disk clamps 1000 may be located on either side of the disk clamp 900. Four fasteners may be inserted through the holes 1006, 606 to secure the disk clamp 1000, stationary disk 600, and drive disk 700 together. Similarly, the two disc clamps 800 can be fixed in the remaining positions with a total of eight fasteners 698 inserted through the holes 806,606. Each arm clamp 1200 may be prepared by inserting a fastener 1296 through the hole 1210, and then on the edge of the opening 602, 702 centered on the arm clamp 1200, the slot 604 corresponding to the hole 1204. , And are attached to stationary disk 600 and drive disk 700 by inserting two fasteners 1298 through holes 1204 and slots 604, 704. In the illustrated embodiment, all of the arm clamps 1200 are oriented with their fasteners 1296 near the same stationary disk 600, as understood in FIG.

  Referring to FIGS. 24A-27, arm assembly 1300 may include an arm 1400, an arm lock 1500, and a fastener 1498.

  FIGS. 24A-26 illustrate an arm 1400 or blade with an elongate shaft 1402 extending between a base 1404 and a tip 1406. FIG. One side of the arm 1400 has a groove 1408 or a depression extending over the entire length. The base portion 1404 includes a pigeon-shaped protrusion 1410 on the opposite side of the groove portion 1408. The dovetail projection 1410 is sized and shaped to complement the dovetail slot 1206 of the arm clamp 1200. The slot 1412 extends completely across the end of the base 1404 between the groove 1408 and the dovetail-shaped protrusion 1410. A hole 1414 is formed at the bottom of the slot 1412 in parallel with the dovetail-shaped protrusion 1410. The hole 1414 is intersected by a through hole 1416 near its bottom. The hole 1416 is sized to complement the fastener 1498. The tip 1406 includes a constriction 1418 and an adjacent widened portion 1420. The constriction 1418 and the diverging portion 1420 together form a concavely curved region at the tip 1406 that helps to hold or hold tissue that has been torn and pushed aside by the expansion device 400. The tip 1406 includes docking features (not shown) such as spikes or pin holes to allow the arm 1400 to be stabilized relative to the structure surrounding the surgical site. May be.

  The arm 1400 may be at least partially radiolucent so as not to jeopardize the visualization of the procedure when using the device with fluoroscopy. Alternatively, the arm 1400 may be at least partially radiopaque to assist in positioning and positioning the system under fluoroscopy. The arm 1400 may be rigid, semi-rigid, or flexible. The arm 1400 may comprise a metal such as aluminum, stainless steel, titanium, and other biocompatible metals. The arm 1400 may also comprise high density plastics such as, among others, Delrin, Radel, Udel, polyetheretherketone (PEEK), polycarbonate, and acrylonitrile butadiene styrene (ABS). Barium sulfate may be added to the component plastic material to provide increased radiopacity. The arm may guide light, i.e. function as a light guide or light guide.

  Referring to FIGS. 24B, 25B, and 27, arm lock 1500 or latch has an elongated shaft 1502 that extends between a base 1504 and a head 1506. The base 1504 has a through hole 1508 that is sized and positioned corresponding to the hole 1416 of the arm 1400 and that is also sized and configured to complement the fastener 1498. The arm lock 1500 has a slot 1510 that leaves the base 1504 intact and separates the shaft 1502 and head 1506 into two parts. Each portion of the head 1506 includes an enlarged portion 1512 that is tapered on one side and flat on the other side. From FIG. 25B, it is understood that the tapered sides of the two head portions can be oriented in opposite directions. At least one portion of the head 1506 may include another enlarged portion 1514 that can serve as an input arrangement of forces to deflect the head portion.

  The arm assembly 1300 slides the base 1504 of the arm lock 1500 into the hole 1414 of the arm 1400 so that the enlarged portion 1514 is close to the dovetail-shaped protrusion 1410 and the side enlarged portion 1512 is in the slot 1412. And may be assembled by rotating arm lock 1500 and inserting fasteners 1498 into holes 1416 and 1508.

  The arm assembly 1300 may be coupled to the hub assembly 500 by sliding the dovetail protrusion 1410 into the dovetail slot 1206 such that the side enlargement 1512 engages the pocket 1208. In certain embodiments, the dovetail connection may be configured to allow the arm assembly 1300 to be adjustably connected to the hub assembly 500. For example, the pigeon tail slot 1206 may be extended and provided with multiple pockets 1208. This arrangement will allow the dilator 400 to approach the surgical site at an angle while allowing the distal end 1406 of the arm 1400 to closely engage the structure surrounding the surgical site. Let's go.

  FIG. 28 illustrates a set of dilators 1600, 1660, 1670, 1680, 1690. The dilator 1600 includes an elongated shaft 1602 that extends between a base 1604 and a tip 1606. A through hole 1608 extends the length of the dilator 1600. The hole 1608 is sized to complement a guide wire, K-wire, Beath pin, stylus or other small diameter rod. The base 1604 may be smooth or textured. For example, FIG. 28 illustrates a textured base 1604 having a regular pattern of grooves 1610. Other texture processes such as knurling, dimples or sandblasting are also conceivable. The tip 1606 includes a region 1612 that is tapered toward the end to reduce the outer diameter. Other dilators 1660, 1670, 1680, 1690 in the set may share some or all of the characteristics described for dilator 1600. However, the outer and inner diameters of each dilator are selected so that all of the dilators are nested together with a clearance. In this situation, these dilators may be described as a set of continuous dilators, since each of the gradually increasing dilators slides over a smaller sized dilator. The dilators may be color-coded for communicating their relative size information.

  FIG. 29 illustrates a set of cannulas 1700, 1770, 1780, 1790. Cannula 1700 has an elongate shaft 1702 that extends between a base 1704 and a tip 1706. A central through hole 1708 extends the length of the cannula 1700. Hole 1708 may be sized to complement one of dilators 1600, 1660, 1670, 1680, 1690, such as dilator 1660, for example. One or more peripheral through-holes 1710 may extend the length of cannula 1700. One or more outer longitudinal grooves 1712 may be positioned to intersect or interrupt at least a portion of the length of the hole 1710. For example, FIG. 29 shows a groove 1712 interrupting the middle portion of the hole 1710. Cannula 1700 may also include one or more outer longitudinal grooves 1714 that are spaced from hole 1710. FIG. 29 shows a cannula 1700 comprising a pattern of alternating five evenly spaced grooves 1714 with five evenly spaced holes 1710. Cannula 1700 may also include one or more windows 1716 at the bottom of each groove 1714, as best shown in FIG. 30B. For example, cannula 1700 has a pattern of 20 closely spaced windows at the bottom of each groove 1714. The base 1704 may be smooth or textured. For example, FIG. 29 illustrates a smooth base 1704. The tip 1706 includes a region 1718 that is tapered toward the end to reduce the outer diameter. Other cannulas 1770, 1780, 1790 in the set may share some or all of the properties described for cannula 1700. However, the inner diameter of each cannula may be selected such that the cannula slides with clearance over the corresponding dilator. For example, cannula 1700 may slide over dilator 1660, cannula 1770 may slide over dilator 1670, cannula 1780 may slide over dilator 1680, and cannula 1790 may slide over dilator 1690. Further, the inner diameter of at least one cannula in the set may be selected to correspond to the outer dimensions of the instrument or implant that must fit through the cannula. For example, the inner diameter of cannula 1780 may be selected to correspond to the outer dimensions of a spinal implant such as a fusion cage, while the inner diameter of cannula 1700 may be selected to correspond to the outer dimensions of a spinal disc resection instrument. Good. Obviously, when such a selection is made for the cannula, a corresponding selection in the dilator will be necessary. The cannulas may be color coded for communication of their relative sizes or their corresponding dilators. In some embodiments, the inner diameter at the tip 1706 corresponds to the outer diameter of the dilator, but one or more cannulas may be tapered such that the inner diameter at the base 1704 is larger. In still other embodiments, one or more cannulas may be shorter than the arm 1400. The cannula may be as short as a ring. Such a cannula can be inserted between the tips 1406 of the arm 1400.

  The dilators 1600, 1660, 1670, 1680, 1690 and / or cannulas 1700, 1770, 1780, 1790 may be at least partially radiolucent. Alternatively, the dilator and / or cannula may be at least partially radiopaque. The dilator and / or cannula may comprise a metal such as aluminum, stainless steel, titanium, and other biocompatible metals. The dilator and / or cannula may also comprise high density plastics such as, among others, delrin, radel, udel, polyetheretherketone (PEEK), polycarbonate, and acrylonitrile butadiene styrene (ABS). The dilator and / or cannula may be manufactured by machining, molding, casting, or other manufacturing process. Barium sulfate may be added to the constructed plastic material to provide increased radiopacity. The dilator and / or cannula may be reusable or disposable. The dilator and / or cannula may direct light or function as a light guide, or may be a light guide. The dilator and / or cannula may accept a reusable light ring, collar, or cap, fiber optic cable or other light source. For example, the reusable light collar may snap into the base 1704 of the cannula 1700 and key into the groove 1714 to distribute light through the transparent cannula. In another embodiment, a disposable battery-operated light source may be at least partially inserted into one or more holes 1710 to distribute light to the tip 1706 of the cannula.

  FIGS. 30A-30B illustrate an expansion device 400 operatively assembled with a cannula 1700. FIGS. The dilator 400 is in an open configuration and the cannula 1700 is in the middle of the circular pattern of the arm assembly 1300. Each arm 1400 rests in a corresponding groove 1714 and the enlarged portion 1512 on the side of each arm lock 1500 rests in a corresponding window 1716. Groove 1714 and side enlargement 1512 may cooperate to guide insertion of the cannula 1700 into the dilation device 400. The tapered and flat orientations of the side enlargement 1512 and the inherent elastic or spring-like properties of the slotted shaft 1502 facilitate passage of the cannula 1700 in one direction. It is understood that it acts to enable and to prevent the cannula 1700 from passing in the opposite direction. Referring to FIG. 30B, the cannula 1700 passes easily to the right, but is prevented from passing to the left. In this way, the cannula 1700 can be prevented from unintentional exclusion of the resistance of the tissue in which it resides.

  FIGS. 31A-37B illustrate another expansion device 1800. FIG. The expansion device 1800 can also be described as an expansion assembly because it includes several components in an operable arrangement. 31A-31B show the expansion device 1800 in a closed configuration. 32A-32B show the expansion device 1800 in an unlocked configuration that is open. Figures 33A-33B show the expansion device 1800 in an open and locked configuration. The expansion device 1800 includes a stationary disk 1900, a drive disk 2000, and three arms 2100. Alternative embodiments may include more than one arm. The arm 2100 is supported by a stationary disk 1900 and a drive disk 2000. In this embodiment, the arms 2100 are evenly spaced in a circular or triangular pattern around the disks 1900, 2000, although non-circular or asymmetrical arrangements are also conceivable. The pattern of the arm 2100 expands and contracts synchronously with respect to the two disks 1900 and 2000. In other words, each arm 2100 is movable in the radial direction with respect to the center of the pattern.

  A portion of the dilator 1800 can be introduced into a muscle, other tissue, or natural passageway in a closed configuration, and the dilator 1800 can be expanded from a closed configuration to an open configuration. When introduced into the muscle, the expansion of the expansion device 1800 gently tears and separates the muscle fibers. The expansion of the dilator 1800 forms an open passage through muscle, tissue or natural passage through which instruments, implants, and other materials pass to perform one or more surgical procedures. Can be done.

  FIGS. 35A-35B illustrate a stationary disk 1900 shaped as a ring or ring with a central opening 1902. The stationary disk 1900 has a concave side 1914 and a convex side 1916 as shown, and may include a peripheral flange 1918. The stationary disk 1900 includes three slots 1904. Each slot 1904 may include a radial portion 1906 and a locking portion 1908. The locking portion 1908 of the stationary disk 1900 may be described as an “L” or “U” dog leg. Other locking parts such as obliquely angled parts or tapered parts are also conceivable. For example, there may be one or more additional windows 1910 to provide easy access for weight reduction or for cleaning. The stationary disk 1900 may include one or more peripheral recesses 1912 or other grip features, such as grooves or textures.

  36A-36B illustrate a drive disk 2000 shaped as a ring or ring with a central opening 2002. FIG. The drive disk 2000 has a concave side 2004 and a convex side 2006 as shown. The drive disk 2000 includes slots 2008 that are evenly spaced around three arcuately extending disks.

  FIGS. 37A-37B illustrate an arm 2100 or blade with an elongated shaft 2102 extending between a base 2104 and a tip 2106. The shaft 2102 has a concave side 2108 and an opposite convex side 2110. Base 2104 includes a dog leg portion 2112, ie, an L-shaped portion that projects laterally from shaft 2102. A pair of bosses 2114 protrude from the dog leg portion 2112 substantially parallel to the shaft 2102. In other embodiments, the boss 2114 may be replaced with a pin secured to the hole in the L-shaped portion 2112.

  Referring to FIG. 34, the expansion device 1800 moves the boss 2114 of the arm 2100 through the drive disk 2000 such that the dog leg portion 2112 is on the concave side 2004 and the shaft 2102 passes through the central opening 2002. It may be assembled by inserting it into the slot 2008. The remaining two arms 2100 can be assembled to the drive disk 2000 in a similar manner. The stationary disk 1900 may be oriented so that the convex side 1916 faces the concave side 2004 and the boss 2114 is in each slot 1904. The stationary disk 1900 may be fixed to the drive disk 2000 in the axial direction while maintaining the freedom to rotate at least within an angular limit with respect to the drive disk 2000. For example, the stationary disk 1900 may be connected to the drive disk 2000 by a holding ring (not shown).

  Referring to FIGS. 38-40B, an expansion device 400 is shown operably assembled to a modified dilator 2200. FIG. Compared to the dilators 1600, 1660, 1670, 1680, 1690 of FIG. 28, the dilator 2200 is provided with an arm 1400 to help close and hold the dilator 400 when inserted into tissue or natural passageway. It has been modified to interact positively with.

  Referring to FIGS. 40A-40B, dilator 2200 has an elongated shaft 2202 that extends between a base 2204 and a tip 2206. A through hole 2208 extends the length of the dilator 2200. The hole 2208 may be sized to complement a guide wire, K-wire, Beath pin, stylus, or other small diameter rod. One or more ribs 2210 extend the length of the dilator 2200. As illustrated in FIG. 40B, dilator 2200 includes five evenly spaced ribs 2210. The base 2204 may be smooth or textured. For example, FIG. 28 illustrates a textured base 2204 having a pattern of regular recesses 2212. Other texture processes such as knurling, dimples or sandblasting are also conceivable. The tip 2206 includes a region 2214 that tapers toward the end to reduce the outer diameter.

  FIG. 39B illustrates how the dilator 2200 positively engages the arm 1400 to close and hold the dilator 400 during insertion. In the dilator 2200, the rib 2210 is located between the adjacent arms 1400 and fits in the center of the pattern of the arm 1400. The rib 2210 supports the arm 1400 so that the arm 1400 remains straight when inserted. The arm 1400 is prevented from being twisted or bent laterally while being supported by the ribs 2210.

  Referring to FIGS. 41A-45B, a hub assembly 500 that is operatively assembled to a modified arm assembly 2300 and an arm retaining clip 2400 is shown. Compared to the arm assembly 1300 of FIG. 24A, the arm assembly 2300 actively interacts with the arm retaining clip 2400 to assist in closing and holding the expansion device upon insertion into the tissue or natural passageway. It has been modified to work. The arm retaining clip 2400 may be coupled to the hub assembly 500 with the arm assembly 2300 prior to introducing the dilator into tissue or natural passageway and removed after the dilator is fully introduced. Good.

  FIG. 44 illustrates an arm 2500 or blade with an elongate shaft 2502 extending between a base 2504 and a tip 2506. Arm 2500 may share some or all of the characteristics of arm 1400 of FIG. One side of the arm 2500 has a full length groove 2508 or recess that is interrupted by a deeper groove 2518 located centrally along the length of the shaft 2502. The base portion 2504 includes a pigeon-shaped protrusion 2510 on the opposite side of the groove portion 2508. The dovetail shaped protrusion 2510 may be sized and shaped to complement the dovetail slot 1206 of the arm clamp 1200. The tip 2506 includes a constriction 2512 and an adjacent widened portion 2514. The constriction 2512 and the diverging portion 2514 together form a concavely curved region at the tip 2506 that helps to hold down or hold the tissue that has been torn and pushed aside by the dilator. Yes.

  45A-45B illustrate an arm retaining clip 2400 that includes a body 2402, one or more short protrusions 2404, one or more intermediate length protrusions 2406, and a central shaft 2408, ie, a stylus. . The body may include protrusions 2410, 2406 and a protrusion 2410 opposite the shaft 2408. The protrusion 2410 serves as a handle. The shaft 2408 includes one or more laterally projecting tabs 2412 that can be located at a distance from the body 2402. The tab 2412 may be sized and shaped to complement the groove 2518 of the arm 2500 at least in cross section. The shaft 2408 may also include a through-hole 2414 or intubation that can be sized to accept a guide wire, K-wire, Beath pin, stylus or other small diameter shaft.

  When the clip 2400 is connected to the hub assembly 500 and the arm assembly 2300, the central shaft 2408 is positioned at the center of the pattern of the arm 2500 (FIGS. 42B-42C), and the protrusion 2406 is of the pattern of the arm 2500. It is located at least partially on the outside and between adjacent arms 2500 (FIG. 42C), and the protrusion 2404 is positioned where the adjacent arm clamp 1200 is touching (FIG. 42D). Further, as can be seen from FIG. 42B, the tabs 2412 are positioned in corresponding grooves 2518 such that the arms 2500 are supported against lateral bending and twisting within the pattern of arms. ing. Groove 2518 and tab 2412 are shown with parallel sides so that tab 2412 can slide laterally in and out of groove 2518, although other shapes are contemplated. For example, the groove 2518 and the tab 2412 may have a dovetail shape so that the tab 2412 can only slide axially in and out of the groove 2518. Groove 2518 and tab 2412 may be described as a connecting feature that cooperates to place the arm 2500 in a predetermined longitudinal alignment with the shaft 2408 when the connecting feature is engaged with each other.

  Referring to FIGS. 46-49, a hub assembly 500 and an arm retaining clip 2700 that are operatively assembled to a modified arm assembly 2600 are shown. Compared to the arm assembly 1300 of FIG. 24A, the arm assembly 2600 is more proactive with the arm retention clip 2700 to assist in closing and holding the expansion device upon insertion into the tissue or natural passageway. It has been modified to interact. The arm retaining clip 2700 may be coupled to the hub assembly 500 with the arm assembly 2600 prior to introducing the expansion device into the tissue or natural passage and removed after the expansion device is fully installed. May be.

  FIG. 48A illustrates an arm 2800 or blade with an elongate shaft 2802 extending between a base 2804 and a tip 2806. Arm 2800 may share some or all of the characteristics of arm 1400 of FIG. One side of the arm 2800 has a groove 2808 or a depression extending over the entire length. The base portion 2804 includes a pigeon-shaped protrusion 2810 on the opposite side of the groove portion 2808. The dovetail-shaped protrusion 2810 may be sized and shaped to complement the dovetail slot 1206 of the arm clamp 1200. The tip 2806 includes a constriction 2812 and an adjacent widened portion 2814. The constriction 2812 and the diverging portion 2814 together form a concavely curved region in the tip 2806 that helps to hold down or hold the tissue that has been torn and pushed aside by the dilator 400. . The side of the tip 2806 includes a protruding tab 2820. The opposite side of the tip 2806 includes a recessed slot 2822 or socket. Slot 2822 is sized and sized to receive tabs 2820 of adjacent arms 2800, as can be seen in FIG. 48B, showing an enlarged detail view of the pattern of arms 2800 in a partially open configuration. Tabs 2820 and slots 2822 may be described as coupling features that cooperate to hold arms 2800 in a predetermined longitudinal alignment. Tabs 2820 and slots 2822 also cooperate with adjacent arms to place the arms in longitudinal alignment with each other along their sides when the arms are in a closed configuration. May be described as complementary engagement features.

  FIG. 49 illustrates an arm retaining clip 2700 that includes a body 2702, one or more short protrusions 2704, and one or more intermediate length protrusions 2706. The main body may include a protrusion 2710 opposite to the protrusions 2704 and 2706. The protrusion 2710 can serve as a handle. Clip 2700 may also include a through-hole 2714 or intubation that may be sized to accept a guide wire, K-wire, Beath pin, stylus, or other small diameter shaft.

  When the clip 2700 is coupled to the hub assembly 500 and the arm assembly 2600, the protrusion 2706 is located outside the pattern of the arm 2500 and at least partially between adjacent arms 2500 (FIG. 46C), and The protrusion 2704 is located at a location where the adjacent arm clamp 1200 is touching (FIG. 46D). Further, as can be seen from FIG. 46B, the tabs 2820 are positioned in corresponding slots 2822 so that the arms 2800 are self-supported against side bending and twisting bias.

  50-55B illustrate the clamp 30 in more detail. Clamp 30 may also be described as a clamp assembly because it includes several components in an operable arrangement. Clamp 30 includes stationary jaw 3100, movable jaw 3200, lever 3300, link 3400, optional spring 3500, shaft 3600, and fasteners 3198, 3398. FIG. 50 shows the clamp 30 in a closed configuration. 51-52B show the clamp 30 in the open configuration. The clamp 30 may be designed to releasably lock the spheres 36, 1102. For example, the stationary jaw 3100 may include a partial sphere surface 3102 and the movable jaw may include a partial sphere surface 3202. The surfaces 3102, 3202 may be sized to complement the spheres 36, 1102. The surfaces 3102, 3202 may have a non-spherical shape, for example, a conical shape or a stepped cylindrical shape. Surfaces 3102 and 3202 may also include macro or micro-texture processing. Clamp 32 may share some or all of the characteristics of clamp 30.

  Hub assembly 500 comprising dilators 400, 1800, or arm assemblies 2300 or 2600 is described as an access point for the device where a nerve retractor can be inserted into the device to move the nerve out of the way. One or more nerve retractor ports may be included.

  With reference to FIGS. 56-61, a method of use for expansion device 400 will be described. Similar methods of use apply to the hub assembly 500 in combination with the expansion device 1800 or the arm assembly 2300 or 2600.

  Referring to FIG. 56, the expansion device 400 is shown in a closed configuration. The clamp 30 is locked to the sphere 1102. Clamp 32 is positioned on sphere 1102 but is shown in an open configuration. The shaft 3600 of the clamps 30, 32 locks to an external support (not shown) that can provide stability and support to the hub and expansion device during a surgical procedure, such as a surgical table mounting support system. May be. As an option, a stylus, guide wire, K-wire, beespin or other small diameter shaft or tube may be inserted through or into the tissue before inserting the dilator 400 through the tissue or into the natural passage. The position of the stylus tip and the shaft trajectory may be confirmed, for example, by imaging or other detection means to ensure that the desired surgical site is targeted. In this situation, the dilator 400 can be inserted onto the stylus by sliding the stylus into the central central space of the arm pattern. Depending on whether a stylus was used to locate the surgical site and trajectory, arm holding means may be used when inserting the expansion device 400 or other expansion device. For example, the retaining band 64 may be provided around the constriction 1418 of the arm 1400. In another embodiment, an expansion device can be introduced with an arm retaining clip 2400 or 2700 coupled to the device. In this situation, the retaining clip 2400 or 2700 is removed after the expansion device is satisfactorily introduced. Some embodiments may include a lock or clip to keep the drive disk 700 with the expansion device 400 in a closed configuration from moving, such as by interacting with the tab 710. Other embodiments may replace the manually operated tab 710 with a geared linkage that makes the expansion device 400 operate more smoothly.

  Referring to FIG. 57, a dilator 400 is shown with a dilator 1600 inserted in the center of the arm pattern. If used, the stylus is received in the hole 1608 of the dilator 1600. When the dilator 1600 is inserted into the dilator 400, the arm 1400 is pressed radially outward from the center of the pattern. The base portion 1404 of the arm 1400 is pressed outward in the radial direction before or simultaneously with the distal end portion 1406. In other words, the arms 1400 may be straight or they may be toe out or toe in. The surrounding tissue or passage is pressed radially outward by the arm. In at least the direction of advancement of the dilator 1600, no shear, tension, or drag force is applied to the tissue. In this way, the effects of direct continuous expansion on potentially problematic tissues are avoided. Furthermore, because the dilator 1600 presses against the arm assembly 1300 instead of tissue, it requires significantly less effort and therefore less time to insert each dilator. Alternatively, the dilator 400 may be initially introduced with a dilator 2200 inserted in the center of the arm pattern, and an optional stylus may also be used.

  Referring to FIG. 58, the dilator 400 after insertion of the dilator 1660 covering the dilator 1600 is shown. When the dilator 1660 is inserted into the dilator 400, the arm is pressed further radially outward from the center of the pattern, and as a result, the surrounding tissue is biased radially outward.

  Additional dilators can be continuously inserted into the dilator 400 to increase the diameter of the working channel. However, in order to minimize damage to surrounding tissue, surgical treatment through a relatively small diameter cannula, such as cannula 1700, by at least reducing the length of time that the tissue is maximally expanded. It is possible to carry out at least a part. The cannula 1700 may be introduced into the dilator covering the dilator 1660 with care to align the groove 1714 with the side enlargement 1512. When the cannula 1700 is inserted into the dilator 400, the arm is further pressed radially outward from the center of the pattern and, as a result, the surrounding tissue is biased radially outward. In this way, cannula 1700 can function as a dilator. After the cannula 1700 is inserted, it is prevented from being eliminated by the action of the side enlargement 1512 in the window 1716. The cannula 1700 may be further stabilized by inserting a fastener 1798 into the structure surrounding the through hole 1710 and the surgical site. The fastener 1798 may be a pin threaded at the tip that can be screwed into the bone with a hexagonal head, as shown. After the cannula 1700 has been properly stabilized, the stylus (if used) and dilators 1600, 1660 can be removed to open the interior of the cannula 1700 for instrument or implant passages.

  Referring to FIG. 59, an expansion device 400 is shown comprising a cannula 1700 inserted in the middle of the pattern of arms and secured in place with a pin 1798. Cannula 1700 may provide a suitable working space for the instrument or implant. For example, cannula 1700 may be sized appropriately for a minimally invasive discectomy instrument passage. Alternatively, the dilator 1660 can function as a cannula.

  A dilator 1670 may be inserted over the cannula 1700 to further expand the tissue. When the dilator 1670 is introduced between the cannula 1700 and the arm assembly 1300, the side enlargement 1512 is automatically pushed out of the window 1716, causing the cannula 1700 to disengage from the dilator 400. If further expansion is required, the dilators 1680, 1690 can be used in succession over the dilator 1670.

  Referring to FIG. 60, the dilator 400 is shown with the cannula 1700 secured in place with a pin 1798 and dilators 1670, 1680, 1690 nested over the cannula 1700.

  The cannula 1790 may be introduced into the dilator over the dilator 1690 with care to align the cannula groove 1714 with the side enlargement 1512. As the cannula 1790 is introduced into the dilator 400, the arm is pushed further laterally. In this way, cannula 1790 can function as a dilator. After cannula 1790 is inserted, it is prevented from being eliminated by the action of side enlargement 1512 in window 1716. Cannula 1790 can be further stabilized by inserting fastener 1798 through hole 1710 and into the structure surrounding the surgical site. After cannula 1790 is properly stabilized, cannula 1700 and dilators 1660, 1670, 1680 may be removed to open the interior of cannula 1790 for instrument or implant passages. Alternatively, cannula 1770 may be introduced after dilator 1670 or cannula 1780 may be introduced after dilator 1680. In yet another alternative, dilators 1670, 1680, 1690 can function as cannulas.

  Referring to FIG. 61, an expansion device 400 is shown comprising a cannula 1790 inserted in the middle of the pattern of arms and secured in place with a pin 1798. Cannula 1790 may provide a suitable working space for the instrument or implant. For example, cannula 1790 may be sized appropriately for the passage of a spinal implant such as a full disc implant or a fusion cage.

  62-67 illustrate the steps in the method of use for the dilator 400 in the spinal column. Similar methods of use may be applied to the expansion device 1800 or the hub assembly 500 in combination with the arm assembly 2300 or 2600.

  In FIG. 62, a stylus 71 has been introduced into the lumbar disc by a direct lateral approach. In FIG. 63, the expansion device 400 is introduced so as to cover the stylus 71. The expansion device 400 may be stabilized with clamps 30, 32 (not shown). Alternatively, the circular nature of the hub assembly 500 of the dilator 400 provides an opportunity for it to be used in the practice of targeting the initial stylus to the intervertebral space. In FIG. 64, the dilator 1600 is introduced over the stylus 71 and into the pattern of the arm 1400. In FIG. 65, a dilator 1660 is introduced over the dilator 1600. In FIG. 66, cannula 1700 has been introduced and stabilized with fasteners 1798, and stylus 71 and dilators 1600, 1660 have been removed. A discectomy is performed with a minimally invasive instrument that works through cannula 1700. In FIG. 67, a cannula 1790 has been introduced and stabilized with fasteners 1798, and cannula 1700 and dilators 1670, 1680, 1690 have been removed. The spinal implant can be inserted with a minimally invasive instrument that works through cannula 1790. At the end of the surgical procedure, the cannula 1790 is released from the dilator 400 by moving the tab 710 laterally to expand the pattern of the arm and thus disengaging the side enlargement 1512 from the window 1716. Can be done.

  One way to consider the above teaching is to characterize a structure as a connecting means for placing each arm in a predetermined longitudinal alignment with the stylus. In the various embodiments described above, the coupling means are shown in elements 79 and 97 as shown in FIGS. 4A, 5A and 5B, elements 182 and 204 as shown in FIGS. 8 and 9, and shown in FIGS. 38-40B. Elements 1400 and 2210 as shown, elements 2518 and 2412 as shown in FIGS. 41A-45B, and elements 2820, 2822 and 2700 as shown in FIGS. 46A-49. Other coupling means including, but not limited to, pegs and rounds, oval, rectangular, or polygonal corresponding holes, or other complementary projection and slot combinations are also contemplated. The receiving hole may be open on both ends to receive the peg, or it may be a recess or cavity with an opening shaped on one side. In an alternative embodiment, the peg may be located on the arm and the receiving hole or cavity located on the stylus or stylus tip.

  Certain aspects of the above teachings can be characterized as side engagement means for placing the arms in contact in longitudinal alignment with each other along their first and second side edges. Structures for the side engagement means are shown in elements 108 in FIGS. 5C and 5D, elements 216, 218, 224 and 226 in FIGS. 7-9, elements 2518 and 2412 in FIGS. 41A-45B, and FIGS. 49 at elements 2820, 2822, and 2700. Other side engaging means including, but not limited to, groove inner tongue features, corresponding tab and slot features, or press fit features are also contemplated. Such features may be disengaged by removing wires, such as pins, sutures or release wires 226, or the features may be connected to each other by sufficient expansion force provided by expansion of the expansion member. You may have a friction fitting removed from.

  Some aspects of the above teachings can be characterized as expansion means. In the various embodiments described above, the expansion means includes element 110 in FIGS. 3, 4A and 4B, elements 240 and 242 in FIGS. 8-11, element 300 in FIGS. 14 and 15, and element in FIG. 1600, 1660, 1670, 1680, and 1690, elements 1700, 1770, 1780, and 1790 in FIG. 29, and element 2100 in FIGS. 37A-37B. Other possible expansion means include expansion devices such as retractors and other mechanical expanders.

  Some aspects of the above teachings can be characterized as means for circumferentially surrounding at least a portion of the expansion member. In the various embodiments described above, the means for circumferentially surrounding at least a portion of the expansion member is the elements 130 and 140 in FIGS. 1-4B and 6A-6B, the element 246 in FIG. 14, element 1400 in FIG. 26, element 2500 in FIG. 44, and element 2800 in FIG. 48A.

  The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. It will be appreciated that the various features of the embodiments described above may be mixed and matched to form other various alternatives. For example, the expansion member may comprise a balloon and / or a cannula. Embodiments can include various features for coupling between the stylus and multiple arms and engagement features between individual arms. This system is not limited to creating a passage through muscles, but can be used to create a passage through any flexible tissue, or to expand and hold a naturally occurring passage. Is also understood. Thus, the described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims (15)

A system for opening a passage in the body,
The system includes an expansion device having a plurality of arms arranged in a pattern, each arm being radially movable with respect to the center of the pattern,
The expansion device is deformed from a closed configuration to an open configuration in response to the insertion of the shaft into the center of the array of arms, and the arms are in contact, longitudinally aligned and in the closed configuration. A system characterized in that it is close to the center and the arm is in the open configuration and away from and far from the center. The system comprises at least one dilator, the dilator being insertable in the middle of the pattern of arms,
The system of claim 1, wherein the dilator is deformed from a closed configuration to an open configuration in response to insertion of the dilator arm into the center of the array. The system includes a clip, the clip is connectable to the expansion device,
The expansion device is held in a closed configuration when the clip is coupled to the expansion device,
The system according to claim 1 or 2, wherein the expansion device is deformable from a closed configuration to an open configuration when the clip is disconnected from the expansion device. The system comprises at least one cannula, the cannula being insertable in the middle of the pattern of arms,
When the cannula is in the middle of the pattern of arms, the cannula is held in a fixed rotational alignment with the dilator, the cannula is movable in the insertion direction with respect to the dilator, and 4. A system according to claim 1, wherein the cannula is releasably immovable in a removal direction opposite to the insertion direction.   5. The system according to claim 1, wherein the insertion of the shaft pushes the arm away from the center of the pattern in the radial direction.   Inserting the shaft into the center of the pattern of the arm means that the expansion device is deformed from a closed configuration to an open configuration by pressing the arm radially away from the center of the pattern. The system according to claim 1, wherein the system is characterized in that   The system of claim 3, wherein the clip at least partially surrounds the arm when the clip is coupled to the expansion device.   The system according to claim 3 or 7, wherein the clip comprises a band, and the band is decoupled from the expansion device by destroying the band.   The clip includes a main body and a plurality of protrusions extending from the main body, and the protrusion is positioned outside the pattern of the arm when the clip is connected to the expansion device, 9. A system according to claim 3, 7 or 8, wherein the clip is decoupled from the expansion device by sliding the clip axially along the arm.   The clip includes a central shaft 2408, the shaft includes a plurality of laterally extending tabs, the first side of each arm faces the center of the pattern, and each arm 10. A slot on the first side, each tab being in a corresponding slot engagement when the clip is connected to the expansion device. A system according to any of the above. The cannula has an inner diameter,
The shaft has an outer diameter, the outer diameter being smaller than the inner diameter of the cannula,
5. The system of claim 4, wherein the cannula is insertable in the middle of the pattern of arms over the shaft. The system comprises a plurality of nested dilators and a plurality of cannulas,
12. A system according to claim 3 or 11, characterized in that each cannula is insertable in the middle of the pattern of arms over a corresponding one of the dilators. The dilator includes a lock that automatically allows the cannula to move in the insertion direction and automatically prevents the cannula from moving in the removal direction;
12. A system according to claim 4 or 11, wherein further moving the arm radially from the center of the pattern releases the lock to allow the cannula to move in the removal direction.   13. A system according to claim 4 or 11 or 12, wherein the cannula comprises a plurality of peripheral longitudinal holes.   14. A system according to any of claims 4 or 11 to 13, wherein at least a portion of the cannula is a light guide.

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