Source: http://www.google.com/patents/US20110190772?ie=ISO-8859-1&dq=6,275,983
Timestamp: 2014-04-21 16:29:12
Document Index: 133130610

Matched Legal Cases: ['Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60', 'Application No. 60']

Patent US20110190772 - Powered tissue modification devices and methods - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA device for modifying tissue in a spine may include: a shah having a proximal portion and a distal portion, the distal portion having dimensions which allow h to be passed into an epidural space of the spine and between target and non-target tissues at least one distal force application member extending...http://www.google.com/patents/US20110190772?utm_source=gb-gplus-sharePatent US20110190772 - Powered tissue modification devices and methodsAdvanced Patent SearchPublication numberUS20110190772 A1Publication typeApplicationApplication numberUS 13/078,376Publication dateAug 4, 2011Filing dateApr 1, 2011Priority dateOct 15, 2004Also published asUS20130310837Publication number078376, 13078376, US 2011/0190772 A1, US 2011/190772 A1, US 20110190772 A1, US 20110190772A1, US 2011190772 A1, US 2011190772A1, US-A1-20110190772, US-A1-2011190772, US2011/0190772A1, US2011/190772A1, US20110190772 A1, US20110190772A1, US2011190772 A1, US2011190772A1InventorsVahid Saadat, Jeffery L. Bleich, Kenneth J. Michlitsch, John E. AshleyOriginal AssigneeVahid Saadat, Bleich Jeffery L, Michlitsch Kenneth J, Ashley John EExport CitationBiBTeX, EndNote, RefManPatent Citations (2), Classifications (6), Legal Events (1) External Links: USPTO, USPTO Assignment, EspacenetPowered tissue modification devices and methodsUS 20110190772 A1Abstract A device for modifying tissue in a spine may include: a shah having a proximal portion and a distal portion, the distal portion having dimensions which allow h to be passed into an epidural space of the spine and between target and non-target tissues at least one distal force application member extending from the distal portion of the shall and configured to facilitate application of at least one of anchoring force and tensioning force to the shaft; at least one movable tissue modifying member coupled with the shaft at or near its distal portion; at least one drive member coupled with the at least one tissue modifying member to activate the at least one tissue modifying member; and at least one power transmission member coupled with the at least one drive member to deliver power to the at least one drive member.
Images(85) Claims(21)
1. A method for modifying tissue in a spine, the method comprising,
passing a distal portion of a tissue modification device into a spine; positioning at least one tissue modifying member of the tissue modification device adjacent target tissue; urging the tissue modifying member against the target tissue by applying at least one of anchoring force or tensioning force to a guidewire coupled to a distal portion of the tissue modification device; and transmitting power to at least one drive member coupled with the at least one tissue modifying member to move the tissue modifying member and thus modify the target tissue. 2. A method as in claim 1, wherein passing the distal portion of the tissue modification device comprises passing the device into a spinal channel selected from the group consisting of an intervertebral foramen and a central spinal canal.
3. A method as in claim 1, wherein passing the distal portion of the tissue modification device comprises passing a distal portion of a tissue modification device into an epidural space of a spine.
4. A method as in claim 1, wherein passing the distal portion of the tissue modification device comprises passing a distal portion of a tissue modification device between target tissue and non-target tissue.
5. A method as in claim 1, wherein positioning at least one tissue modifying member of the tissue modification device comprises positioning at least one tissue modifying member of the tissue modification device such that the tissue modifying member faces the target tissue and does not face non-target tissue.
6. A method as in claim 1, wherein urging the tissue modifying member against the target tissue comprises applying at least one of anchoring force or tensioning force to a distal portion of the tissue modification device while applying at least one of tensioning or anchoring force to a proximal portion of the tissue modification device.
7. A method as in claim 1, wherein urging the tissue modifying member comprises applying anchoring force to the distal portion of the tissue modification device and applying tensioning force at or near the proximal end of the tissue modification device.
8. A method as in claim 1, wherein urging the tissue modifying member against the target tissue comprises deploying one or more anchoring members located at or near the distal portion of the device within a patient's body.
9. A method as in claim 1, wherein urging the tissue modifying member against the target tissue comprises deploying one or more anchoring members located at or near the distal portion of the device outside a patient's body.
10. A method as in claim 1, wherein urging the tissue modifying member against the target tissue comprises coupling a handle to the distal portion of the tissue modification device outside the patient's body and applying the force to the handle.
11. A method as in claim 10, wherein urging the tissue modifying member against the target tissue comprises coupling a handle to a guidewire coupled to the distal portion of the tissue modification device.
12. A method as in claim 1, further comprising by positioning at least one shield device coupled with the tissue modification device between the device and the non-target tissue.
13. A method for treating spinal stenosis by removing spinal tissue, the method comprising,
advancing a guidewire into a patient's spine; advancing a flexible distal portion of a tissue modification device into the patient's spine using the guidewire; urging the tissue modifying member against the target tissue by applying at least one of anchoring force or tensioning force to the guidewire outside the patient and to a proximal end of the tissue modification device; and transmitting power to at least one drive member coupled with the tissue modifying member to modify at least one of ligamentum flavum or bone tissue in the spine. 14. A method as in claim 13, wherein the step of advancing a guidewire comprises advancing a guidewire into an epidural space and through an intervertebral foramen of a patient's spine.
15. A method as in claim 13, wherein the step of advancing a guidewire comprises advancing a guidewire into a patient's spine so that opposite ends of the guidewire extend out of different regions of the patient's body.
16. A method as in claim 13, wherein the step of advancing the flexible distal portion of the tissue modification device comprises advancing a flexible distal portion of a tissue modification device into the patient's spine using the guidewire.
17. A method as in claim 13, wherein the step of advancing the flexible distal portion of the tissue modification device comprises advancing a flexible distal portion of a tissue modification device such that a tissue modifying member disposed along one side of the tissue modification device faces a target tissue and an atraumatic surface of the tissue modification device faces non-target tissue.
18. A method as in claim 13, wherein the step of urging the tissue modifying member against the target tissue comprises urging the tissue modifying member against the target tissue by applying at least one of anchoring force or tensioning force to a distal handle coupled with the guidewire outside the patient and to a proximal handle coupled with a proximal end of the tissue modification device.
19. A method as in claim 13, wherein the step of advancing the flexible distal portion of the tissue modification device comprises pulling the tissue modification device into the intervertebral foramen by pulling the guidewire.
20. A method as in claim 13, wherein the step of transmitting power comprises transmitting power to at least one drive member coupled with the tissue modifying member to cut at least one of ligamentum flavum or bone tissue in the spine.
21. A method as in claim 13, further comprising coupling the distal end of the tissue modification device to the guidewire.
CROSS REFERENCE TO RELATED APPLICATIONS The present application is a continuation-in-part of U.S. patent application Ser. No. 11/406,486, entitled �Powered Tissue Modification Devices and Methods�, filed on Apr. 17, 2006, which is a continuation-in-part of U.S. patent application Ser. No. 11/375,265, entitled �Methods and Apparatus for Tissue Modification,� filed on Mar. 13, 2006, which is a continuation-in-part of PCT Patent Application No. PCT/US2005/037136, filed Oct. 15, 2005, which claimed the benefit of: U.S. Provisional Application No. 60/619,306, filed Oct. 15, 2004, U.S. Provisional Application No. 60/622,865, filed Oct. 28, 2004, U.S. Provisional Application No. 60/681,719, filed May 16, 2005, U.S. Provisional Application No. 60/681,864, filed May 16, 2005, and U.S. Provisional Application No. 60/685,190, filed May 27, 2005, each of which is incorporated by reference herein in its entirety.
The present application is also a continuation-in-part of U.S. patent application Ser. No. 11/405,848, entitled �Mechanical Tissue Modification Devices and Methods�, filed on Apr. 17, 2006, which is a continuation-in-part of U.S. patent application Ser. No. 11/375,265, entitled �Methods and Apparatus for Tissue Modification,� filed on Mar. 13, 2006, which is a continuation-in-part of PCT Patent Application No. PCT/US2005/037136, filed Oct. 15, 2005, which claimed the benefit of: U.S. Provisional Application No. 60/619,306, filed Oct. 15, 2004. U.S. Provisional Application No. 60/622,865, filed Oct. 28, 2004, U.S. Provisional Application No. 60/681,719, filed May 16, 2005, U.S. Provisional Application No. 60/681,864, filed May 16, 2005, and U.S. Provisional Application No. 60/685,190, filed May 27, 2005, each of which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION The present invention relates to methods and apparatus for modifying tissue in a patient
BACKGROUND OF THE INVENTION Many pathological conditions in the human body may be caused by enlargement, movement, displacement and/or a variety of other changes of bodily tissue, causing the tissue to press against (or �impinge on�) one or more otherwise normal tissues or organs. For example, a cancerous tumor may press against an adjacent organ and adversely affect the functioning and/or the health of that organ. In other cases, bony growths (or �bone spurs�), arthritic changes in bone and/or soft tissue, redundant sail tissue, or other hypertrophic bone or soft tissue conditions may impinge on nearby nerve and/or vascular tissues and compromise functioning of one or more nerves, reduce blood flow through a blood vessel, or both. Other examples of tissues which may grow or move to press against adjacent tissues include ligaments, tendons, cysts, cartilage, scar tissue, blood vessels, adipose tissue, tumor, hematoma, and inflammatory tissue.
One common cause of spinal stenosis is buckling and thickening of the ligamentum flavum (one of the ligaments attached to and connecting the vertebrae), as shown in FIG. 1. Buckling or thickening of the ligamentum flavum may impinge on one or more neurovascular structures, dorsal root ganglia, nerve roots and/or the spinal cord itself Another common cause of neural and neurovascular compression within the spine is disease of one or more of the intervertebral discs (the malleable discs between adjacent vertebrae), which may lead to collapse, bulging or herniation of the disc. In FIG. 1, an intervertebral disc is shown with three solid-tipped arrows demonstrating how the disc might bulge or herniate into the central spinal canal to impinge upon the spinal cord, cauda equina and/or individual nerve roots. Other causes of neural and neurovascular impingement in the spine include: hypertrophy of one or more facet joints (also known as zygopophaseal joints, facet joints provide articulation between adjacent vertebrae�two vertebral facet superior articular processes are shown in FIG. 1); formation of osteophytes (bony growths or �bone spurs�) on vertebrae; spondylolisthesis (sliding of one vertebra relative to an adjacent vertebra); and (facet joint) synovial cysts. Disc, bone, lierament or other tissue may impinge on the spinal cord, the cauda equina, branching spinal, nerves and/or blood vessels in the spine to cause loss of function, ischemia (shortage of blood supply) and even permanent damage of neural or neurovascular tissue. In a patient, this may manifest as pain, impaired sensation and/or loss of strength or mobility.
In the United States, spinal stenosis occurs with an incidence of between 4% and 6% of adults aged 50 and older and is the most frequent reason cited for back surgery in patients aged 60 and older, Conservative approaches to the treatment of symptoms of spinal stensosis include systemic medications and physical therapy. Epidural steroid injections may also be utilized, but they do not provide ling lasting benefits. When these approaches are inadequate, current treatment for spinal stenosis is generally limited to invasive surgical procedures to remove vertebral ligament, cartilage, bone spurs, synovial cysts, cartilage, and bone to provide increased room for neural and neurovascular tissue. The standard surgical procedure for spinal stenosis treatment includes laminectomy (complete removal of the lamina (see FIG. 1) of one or more vertebrae) or larninotomy (partial removal of the lamina), followed by removal (or �resection�) of the ligamentum flavum. In addition, the surgery often includes partial or occasionally complete facetectomy (removal of all or part of one or more facet joints between vertebrae). In cases where a bulging intervertebral disc contributes to neural impingement, disc material may be removed
Removal of vertebral bone, as occurs laminectomy and facetectomy, often leaves the effected area of the spine very unstable, leading to a need for an additional highly invasive fusion procedure that puts extra demands on the patient's vertebrae and limits the patient's ability to move. In a spinal fusion procedure, the vertebrae are attached together with some kind of support mechanism to prevent them from moving relative to one another and to allow adjacent vertebral bones to fuse together. Unfortunately, a surgical spine fusion results in a loss of ability to move the fused section of the back, diminishing the patient's range of motion and causing stress on the discs and facet joints of adjacent vertebral segments.
Description of Background Art. Flexible wire saws and chain saws, such as threadwire saws (T-saws) and Gigli saws, have been used since the late 1800s to saw through or file/abrade bone and other tissue in the human body. See, for example. Brunori A et al., �Celebrating the Centenial (1894-1994): Leonardo Gigli and His Wire Saw,� J Neurosurg 82:1086-1090, 1995. An example of one such saw is described in U.S. Pat. No. 8250, issued to P. A. Stohlmann on Nov. 28, 1876. A description of using a T-saw to cut vertebral bone is provided in Kawahara N et al., �Recapping T-Saw Laminoplasty for Spinal Cord Tumors,� SPINE Volume 24, Number 13, pp. 1363-1370.
SUMMARY OF THE INVENTION In various embodiments, the present invention provides methods, apparatus and systems for modifying tissue in a patient, Generally, the methods, apparatus and systems may involve using an elongate, at least partially flexible tissue modification device having one or more tissue modifying members to modify one or more target tissues. The tissue modification device may be configured such that when the tissue modification member (or members) is in a position for modifying target tissue, one or more sides, surfaces or portions of the tissue modification device configured to avoid or prevent damage to non-target tissue will face non-target tissue. In various embodiments, during a tissue modification procedure, an anchoring force may be applied at or near either a distal portion or a proximal portion of the tissue modification device, either inside or outside the patient. Pulling or tensioning force may also be applied to the unanchored end of the device to urge the tissue modifying member(s) against target tissue. The tissue modifying members may then be activated to modify tissue while being prevented from extending significantly beyond the target tissue in a proximal or distal direction. In some embodiments, the tissue modifying members may be generally disposed along a length of the tissue modification device that approximates a length of target tissue to be modified.
Methods, apparatus and systems of aspects of the present invention generally provide for tissue modification while preventing unwanted modification of or damage to, surrounding tissues. Tensioning the tissue modification device by applying anchoring force at or near one end and applying tensioning or pulling force at or near the opposite end may enhance the ability of tissue modification members of the device to work effectively within a limited treatment space. Applying tensioning force to a predominantly flexible device may also allow the device to have a relatively small profile, thus facilitating its use in less invasive procedures and in other procedures in which alternative approaches to target tissue may be advantageous.
In another aspect of the present invention, a device for modifying tissue in a patient may include: an elongate, at least partially flexible body having a proximal portion and a distal portion, the distal portion having dimensions which allow it to be passed between target and non-target tissues in the patient; at least one distal force application member extending from the distal portion of the elongate body and configured to facilitate application of at least one of anchoring force and tensioning force to the elongate body; at least one proximal force application member coupled with the elongate body at or near the proximal portion and configured to facilitate application of tensioning three to the elongate body; at least one movable tissue modifying member coupled with the elongate body; at least one drive member coupled with the at least one tissue modifying member to activate the at least one tissue modifying member; and at least one power transmission member coupled with the at least one drive member to deliver power to the at least one drive member.
In one aspect of the present invention, a device for modifying one or more tissues in a patient's spine may include: an elongate, at least partially flexible body having a proximal portion and a distal portion, wherein at least the distal portion has dimensions that allow it to be passed into an epidural space and between target and non-target tissues of the spine; at least one movable blade disposed along one side of the elongate body; at least one actuator coupled with the at least one blade and disposed at or near the proximal or distal portion of the body for moving the blade(s) to modify one or more target tissues, wherein the at least one actuator is configured to move the blade(s) without significantly translating the elongate body proximally or distally; and means at or near the proximal and distal portions of the elongate body for facilitating application of at least one of anchoring force and tensioning force to the body to urge the at least one blade against the target tissue.
In another aspect of the present invention, a device for modifying one or more tissues in a patient may include: an elongate, flexible body having a proximal portion and a distal portion; at least one blade disposed along one side of the elongate body; and means at or near the proximal and distal portions of the elongate body for facilitating application of at least one of anchoring force and tensioning force to the body to urge the at least one blade against the target tissue.
In another aspect of the present invention, a method for modifying tissue in a patient may involve: advancing at least a distal portion of at least one elongate, at least partially flexible tissue modification device into a patient and between one or more target tissues and one or more non-target tissues; positioning at least one blade of the tissue modification device adjacent the target tissue such that the blade(s) face the target tissue and do not face the non-target tissue; applying at least one of anchoring and tensioning force to the tissue modification device at or near its proximal and distal portions to urge the blade(s) against the target tissue; and moving the at least one blade to cut the target tissue.
FIG. 14 is a cross-sectional view of a portion of a spine with a tissue modification device having steerable distal portion in position for modifying tissue according to one embodiment of the present invention.
FIGS. 36A and 3613 are side views of a distal portion of a tissue modification device according to an alternative embodiment of the present invention.
FIGS. 41A and 41B are side views of a portion of a bladed tissue modification device according to one embodiment of the present invention.
FIGS. 42A and 42B are perspective views of a portion of a bladed tissue modification device according to an alternative embodiment of the present invention.
FIGS. 43A and 43B are perspective views of a portion of a bladed tissue modification device according to an alternative embodiment of the present invention,
FIGS. 44A-44D are side, end-on cross-sectional, top, and lateral cross-sectional views, respectively, of a blade mechanism of a tissue modification device according to one embodiment of the present invention.
FIGS. 45A-45D are side, end-on cross-sectional, top, and lateral cross-sectional views, respectively, of the blade mechanism of FIGS. 44A-44D, shown with the blades disposed at an angle, relative to the mechanism according to one embodiment of the present invention.
FIGS. 46A-46C are side, top, and lateral cross-sectional views, respectively, of the blade mechanism of FIGS. 45A-45D, shown with the blades disposed at an angle with their cutting edges brought together according to one embodiment of the present invention,
FIGS. 47A-47D are cross-sectional end-on views of various embodiments of a blade mechanism of a tissue modification device with a track having different configurations in the various embodiments.
FIG. 47E is a cross-sectional view of a blade with means for directing cut tissue according to one embodiment of the present invention,
FIGS. 48A and 48B are top views of blades having alternative configurations of teeth according to alternative embodiments of the present invention,
FIGS. 48C-48G are side views of various blade-blade and blade-backstop combinations according to various embodiments of the present invention.
FIGS. 49A and 49B are top views of a blade and pull wire mechanism according to one embodiment of the present invention,
FIGS. 50A and 50B are top views of a blade and pull wire mechanism according to an alternative embodiment of the present invention,
FIGS. 51A and 51B are top views of a blade and pull wire mechanism according to an alternative embodiment of the present invention,
FIGS. 52A-52C are side views of a blade mechanism including a ramp and a window according to one embodiment of the present invention,
FIGS. 53A and 53B are top views of a blade and pull wire mechanism according to an alternative embodiment of the present invention.
FIGS. 54A and 54B are perspective views of a tissue modification device including flexible portions and endcaps according to one embodiment of the present invention.
FIGS. 55A and 55B are top views of a handle mechanism of a tissue modification device according to one embodiment of the present invention.
FIGS. 56A and 56B are end-on views of a blade mechanism allowing for lateral movement of one or more blades according to one embodiment of the present invention.
FIGS. 57A and 57B are end-on views of a blade mechanism allowing for lateral movement of one or more blades according to an alternative embodiment of the present invention.
FIGS. 58A and 58B are top views of a blade mechanism allowing for lateral movement of one or more blades according to an alternative embodiment of the present invention.
FIGS. 59A-59C are top views of a portion of a tissue modification device including aside wire for facilitating guiding of the portion according to one embodiment of the present invention.
FIGS. 60A and 60B are top views of a portion of a tissue modification device including side wires for facilitating guiding of the portion according to an alternative embodiment of the present invention.
FIGS. 61A and 61B are top and cross-sectional side views, respectively, of a portion of a tissue modification device including a track along which one or more blades slide according to one embodiment of the present invention.
FIG. 62 is a top view of a portion of a tissue modification device including a track along which one or more blades slide according to an alternative embodiment of the present invention.
FIGS. 63A-63C are top views of a portion of a tissue modification device including side wires for facilitating guiding of the portion according to an alternative embodiment of the present invention.
FIGS. 64A-64C are end-on views of a portion of a tissue modification device including expandable bladders for facilitating guiding of the portion according to an alternative embodiment of the present invention.
FIGS. 65A and 65B are top views of a portion of a tissue modification device including a track and deflecting member for facilitating guiding of the portion according to an alternative embodiment of the present invention.
Referring to FIG. 2, in one embodiment a tissue modification device 102 may include an elongate body 108 having a proximal portion 107 and a distal portion 109, a handle 104 with an actuator 106 coupled with proximal portion 107, one or more tissue modifying members 110, and one or more protective surfaces 112. In various embodiments, some of which are described further below, modification device 102 may be introduced into an area for performing a treatment, such as a spine, using any of a number of different introduction methods, devices and systems. In FIG. 2, for example, modification device 102 extends through an introducer device 114 placed through a first incision 240 on the patient's back and into the central spinal canal. Modification device 102 is advanced along a guide member 116, which extends through introducer member 114, through the intervertebral foramen between two adjacent vertebrae (only part of one vertebra is shown in FIG. 2), and out a second (or �distal�) incision 242 on the back. In some embodiments, as shown, guide member has a beveled distal tip 117 for facilitating advancement of guide member 116 through tissue.
Generally, tissue modification device 102 may be advanced to a position in the spine such that tissue modifying member 110 faces target tissue to be modified, such as buckled, thickened or otherwise impinging ligamentum flavum tissue as shown in FIG. 2. Modification device 102 is configured such that when tissue modifying member 110 faces the target tissue, protective surface(s) 112 face non-target tissue. Protective surface 112 may be simply a length of elongate body 108 or may have one or more protective features, such as a widened diameter, protective or lubricious coating, extendable barrier, drug-eluting coating or ports, or the like. In some instances, protective surface(s) 112 may act as �non-tissue-modifying� surfaces, in that they may not substantially modify the non-target tissue. In alternative embodiments, protective surface(s) 112 may affect non-target tissue by protecting it in some active way, such as by administering one or more protective drugs, applying one or more forms of energy, providing a physical harrier, or the like.
Turning to FIG. 3A-3I, more detailed figures of one embodiment of tissue modification device 102 are shown. Referring to FIG. 3A, tissue modification device 102 may include elongate body 108 having proximal portion 107 and distal portion 109, a window 111 disposed along elongate body 108, two tissue modifying blades 110 exposed through window 111, and handle 104 with actuator 106 coupled with proximal portion 107. In the embodiment shown, the tissue modifying members comprise blades 110, although in alternative embodiments other tissue modifying members may be added or substituted.
FIGS. 38-3D show in greater detail a portion of tissue modification device 102. In these figures, window 111 and blades 110 are more clearly seen. In one embodiment, at least a portion of elongate body 108 and blades 110 may have a slightly curved configuration. In alternative embodiments, at least a portion of elongate body 108 and blades 110 may be flat. In other alternative embodiments, tissue modification members such as blades 110 may be proud to elongate body 108.
In one embodiment, distal blade 110 a is coupled with two pull-wires 118, as seen in FIGS. 3C, 3E and 3F, Pull-wires 118 coupled to and translated by actuator 106 on handle 104 may be used to drive distal blade 110 a proximally to contact the cutting edge of proximal blade Hob, thus cutting tissue. Other alternative mechanisms for driving blades 110, such as gears, ribbons or belts, magnets, electrically powered, shape memory alloy, electro magnetic solenoids and/or the like, coupled to suitable actuators, may be used in alternative embodiments. As mentioned, in one embodiment distal blade 110 a and/or proximal blade 110 b may have an outwardly curvilinear shape along its cutting edge. Alternatively, distal blade 110 a may have a different blade shape, including flat, rectilinear, v-shaped, and inwardly curvilinear (concave vs. convex). The cutting edge of either blade 110 may have a sharp edge formed by a simple bevel or chamfer. Alternatively or in addition, a cutting edge may have tooth-like elements that interlock with a cutting edge of an opposing blade, or may have corrugated ridges, serrations, rasp-like features, or the like. In various embodiments, both blades 110 may be of equal sharpness, or alternatively one blade 110 may be sharp and the other substantially flat to provide a surface against which the sharp blade 110 may cut. Alternately or in addition, both cutting edges may be equally hard, or first cutting edge may be harder than a second, the latter of which deflects under force from the first harder edge to facilitate shearing of the target tissue.
FIGS. 3E and 3F show cross-sectional views through elongate body at lines A-A and B-B, respectively, of FIG. 3C. In some embodiments, all or a portion of elongate body 108, such as the lower surface shown in FIG. 3E, may include a lubricious surface for facilitating manipulation of the tool in the surgical space and at the anatomical site. The lubricious lower surface also provides a barrier between blades 110 and non-target tissue in the surgical space. The lower surface may include a guide member lumen 120 to accommodate a guidewire or other access device or rail. FIG. 3E shows distal blade 110 coupled with pull wires 118. FIG. 3F shows proximal blade 110 b, which is not coupled with pull wires 118 but rather fixed to body 108. In various alternative embodiments, proximal blade 110 b may be movable distally while distal blade 110 a is static, both blades may be moved toward one another, or a. different number of blades may be used such as one blade drawn toward a backstop or more than two blades, one or more of which may be mobile. In various alternative embodiments, guide member lumen 120 may be accommodated on a side surface or more centrally within elongate body 108. In further alternative embodiments, the one or more guide member lumens 120 may comprise one or more various cross sectional shapes, for example substantially round, substantially oval, or substantially rectabular, to accommodate alternative guide members, for example flat or rectangular guidewires, needles or rails. In still other alternative embodiments guide member lumen 120 may be adjustably coupled with the elongate body 108 to enable manipulation of the location of the elongate body 108 and therefore the tissue modifying members 110 relative to the guiding member.
Referring now to FIGS. 3G-3I, blades 110 are shown in their closed position. In one embodiment, when distal blade 110 a is drawn proximally to cut tissue, at least sonic of the cut tissue is captured in a hollow interior portion of elongate body 108. Various embodiments may further include a cover, a cut tissue housing portion and/or the like for collecting cut tissue and/or other tissue debris. Such collected tissue and debris may then be removed from the patient during or after a tissue modification procedure. During a given tissue modification procedure, distal blade 110 a may be drawn proximally to cut tissue, allowed to retract distally, and drawn proximally again to further cut tissue as many times as desired to achieve a desired amount of tissue cutting.
Blades 110 may be made from any suitable metal, polymer, ceramic, or combination thereof, Suitable metals, for example, may include but are not limited to stainless steel (303, 304, 316, 31614, nickel-titanium alloy, tungsten carbide alloy, or cobalt-chromium alloy, for example, Elgiloy� (Elgin Specialty Metals, Elgin. Ill., USA), Conichrome� (Carpenter Technology, Reading, Pa.. USA), or Phynox� (Imphy SA, Paris. France). In some embodiments, materials for the blades or for portions or coatings of the blades may be chosen for their electrically conductive or thermally resistive properties. Suitable polymers include but are not limited to nylon, polyester, Dacron�, polyethylene, acetal, Delrin� (DuPont, Wilmington, Del.), polycarbonate, nylon, polyetheretherketone (PEEK), and polyetherketoneketone (PEKK). In some embodiments, polymers may be glass-filled to add strength and stiffness. Ceramics may include but are not limited to aluminas, zirconias, and carbides. In various embodiments, blades 110 may be manufactured using metal injection molding (MIM), CNC machining, injection molding, grinding and/or the like, Pull wires 118 be made from metal or polymer and may have circular, oval, rectangular, square or braided cross-sections. In some embodiments, a diameter of a pull wire 118 may range from about 0.001″-0.050″, and more preferably from about 0.010″-0.020″.
In various embodiments, a number of different techniques may be used to prevent blades 110 (or other tissue modifying members) from extending significantly beyond the target tissue. In one embodiment, for example, preventing blades 110 from extending significantly beyond the target tissue involves holding tissue modification device 102 as a whole predominantly stable to prevent device 102 from translating in a direction toward its proximal portion or toward its distal portion while activating blades 110, Holding device 102 stable is achieved by anchoring one end of the device and applying tensioning force at or near the other end, as described further below.
In the embodiment shown in FIGS. 3A-3I, pull wires 118 are retracted proximally by squeezing actuator 106 proximally. In an alternative embodiment, squeezing actuator 106 may cause both blades 110 to translate inward so that they meet approximately in the middle of window 111. In a further embodiment, distal blade 110 a may be returned to it's starting position by a pulling force generated from the distal end of device 102, for example by using a distal actuator that is attached to distal wires, or by pulling on the distal guide member which is attached to distal blade 110 a, in yet another alternative embodiment, proximal blade 110 b may be moved to cut by a pulling force generated from the distal end of device 102, for example by using a distal actuator that is attached to distal wires, or by pulling on the distal guide member which is attached to proximal blade 110 b, in yet another embodiment, squeezing actuator 106 may cause proximal blade 1101) to move distally while distal blade 110 a stays fixed. In other alternative embodiments, one or more blades 110 may move side-to-side, one or more blades 110 may pop, slide or bow up out of window 111 when activated, or one or more blades 110 may expand through window. In another embodiment, one or more blades 110 and/or other tissue modifying members of device 102 may be powered devices configured to cut, shave, grind, abrade and/or resect target tissue. In other embodiments, one or more blades may be coupled with an enemy transmission device, such as a radiofrequency (RF) or thermal resistive device, to provide energy to blade(s) 110 for cutting, ablating, shrinking, dissecting, coagulating or heating and thus enhancing tissue modification. In another embodiment, a rasp or file may be used in conjunction with or coupled with one or more blades. In any of these embodiments, use of actuator 106 and one or more moving blades 110 provides for tissue modification with relatively little overall translation or other movement of tissue modification device 102. Thus, target tissue may be modified without extending blades 110 or other tissue modification members significantly beyond an area of target tissue to be treated.
Referring now to FIGS. 4A-4C, in an alternative embodiment, a tissue modification device 202 may include an elongate body 208 having a proximal portion and a distal portion 209, a handle 204 and actuator 206 coupled with proximal portion, and a window 211 and tissue modifying member 210 disposed near distal portion 209. As seen more clearly in FIGS. 4B and 4C, in the embodiment shown, tissue modifying member 210 comprises an RE electrode wire loop. Wire loop 210 may comprise any suitable RE electrode, such as those commonly used and known in the electrosurgical arts, and may be powered by an internal or external RE generator, such as the RE generators provided by Gyrus Medical, Inc. (Maple Grove, Minn.). Any of a number of different ranges of radio frequency may be used, according to various embodiments. For example, some embodiments may use RE energy in a range of between about 70 hertz and about 5 megahertz. In some embodiments, the power range for RE energy may be between about 0.5 Watts and about 200 Watts. Additionally, in various embodiments, RE current may be delivered directly into conductive tissue or may be delivered to a conductive medium, such as saline or Lactate Ringers solution, which may in sonic embodiments be heated or vaporized or converted to plasma that in turn modifies target tissue. Distal portion 209 includes a tapered tip, similar to that described above, to facilitate passage of elongate body 208 into narrow anatomical sites, Handle 204 and actuator 206 are similar to those described above, although in the embodiment of FIGS. 4A-4C, actuator 206 may be used to change the diameter of the wire loop 210. Using actuator 206, wire loop 210 may be caused to extend out of window 211, expand, retract, translate and/or the like. Some embodiments may optionally include a second actuator (not shown), such as a foot switch for activating an RF generator to delivery RE current to an electrode.
Elongate body 208 may be fabricated from any suitable material and have any of a number of configurations. In one embodiment, body 208 comprises a metal tube with a full-thickness slit (to unfold the tube into a flat form�not shown) or stiffening element (not shown). The split tube provides for a simple manufacturing process as well as a conductive pathway for hi-polar RE operation.
Referring to FIG. 4C, insulators 222 may be disposed around a portion of wire loop 210 so that only a desired portion of wire loop 210 may transfer RF current into the tissue for tissue modifying capability. Wire loop 210, covered with insulators 222 may extend proximally into support tubes 218. In various alternative embodiments, an electrode tissue modifying member (of which wire loop 210 is but one example) may be bipolar or monopolar. For example, as shown in FIG. 4C, a sleeve 224 housed toward the distal portion of window 211 may act as a return electrode for wire loop 210 in a bipolar device. Wire loop electrodes 210 may be made from various conductive metals such as stainless steel alloys, nickel titanium alloys, titanium alloys, tungsten alloys and the like. Insulators 222 may be made from a thermally and electrically stable polymer, such as polyimide, polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), polyamide-imide, or the like, and may optionally be fiber reinforced or contain a braid for additional stiffness and strength. In alternative embodiments, insulators 22.2 may be composed of a ceramic-based material.
In an alternative embodiment (not shown), tissue modification device 202 may include multiple RF wire loops 210 or other RE members. In another embodiment, device 202 may include one or more blades as well as RF wire loop 210. In such an embodiment, wire loop 210 may be used to remove or otherwise modify soft tissues, such as ligamentum flavum, or to provide hemostasis, and blades may be used to modify hard tissues, such as bone. In other embodiments, as described further below, two separate tissue modification devices (or more than two devices) may be used in one procedure to modify different types of tissue, enhance modification of one type of tissue or the like.
In other alternative embodiments, tissue modification devices 202 may include tissue modifying members such as a rongeur, a curette, a scalpel, a scissors, a forceps, a probe, a rasp, a file, an abrasive element, one or more small planes, a rotary powered mechanical shaver, a reciprocating powered mechanical shaver, a powered mechanical burr, a laser, an ultrasound crystal a cryogenic probe, a pressurized water jet, a drug dispensing element, a needle, a needle electrode, or some combination thereof in some embodiments, for example, it may be advantageous to have one or more tissue modifying members that stabilize target tissue, such as by grasping the tissue or using tissue restraints such as barbs, hooks, compressive members or the like. In one embodiment, soft tissue may be stabilized by applying a contained, low-temperature substance (for example, in the cryo-range of temperatures) that hardens the tissue, thus facilitating resection of the tissue by a blade, rasp or other device. In another embodiment, one or more stiffening substances or members may be applied to tissue, such as bioabsorbable rods.
Referring to FIG. 5C, once device 102 is positioned in a desired location, anchoring force may be applied at or near the distal portion of elongate body 108. In one embodiment, applying anchoring force involves a user 244 grasping body 108 at or near its distal portion. In alternative embodiments, as described further below, anchoring force may be applied by deploying one or more anchor members disposed at or near the distal portion of body 108, or by grasping a guidewire or other guide member extending through at least part of body 108. Once the anchoring force is applied, proximally-directed tensioning force may be applied to device 102, such as by pulling proximally on handle 104 (one-directional, diagonal arrows). This tensioning force, when applied to the substantially anchored device 102, may help urge the tissue modifying member(s) against the target tissue (one-directional, vertical arrows near target tissue), thus enhancing contact with the target tissue and facilitating its modification, With the tissue modifying member(s) contacting the target tissue, actuator 106 may be squeezed or pulled (two-headed arrow) to cause the tissue modifying member(s) to modify tissue. (Alternative actuators may be activated in different ways in alternative embodiments.)
Referring now to FIG. 6A, tissue modification device 102 is shown with one embodiment of a distal anchoring member 250 deployed at the patient's skin. In various embodiments, anchoring members may include hut are not limited to one or more handles, barbs, hooks, screws, toggle bolts, needles, inflatable balloons, meshes, stents, wires, lassos, backstops or the like. In some embodiments, anchoring members 250 may be disposed at the extreme distal portion 109 of elongate body 108, while in other embodiments anchoring members 250 may be located more proximally. In the embodiment shown, anchoring members 250 are deployed at the patient's skin. In an alternative embodiment, anchoring may be achieved outside the patient by deploying one or more anchoring members 250 above the skin and having a user grasp the anchoring members 250. In an alternative embodiment, anchoring may be achieved outside the patient by deploying one or more anchoring members 250 above the skin and having a user grasp anchoring members 250, after tissue modification device 102 has been anchored to the guide member. In another alternative embodiment, anchoring may be achieved outside the patient by attaching anchoring member 250 to an external device, for example one that is mounted on the patient or on the procedure table. In a further alternative embodiment, anchoring may be achieved outside the patient by attaching the guide member to an external device, for example one that is mounted to on the patient or on the procedure table, after tissue modification device 102 has been anchored to the guide member. Anchoring members 250 generally are deployable from a first, contracted configuration to facilitate delivery of device 102, to a second, expanded configuration to facilitate anchoring. This change in configuration may be achieved, for example, by using shape memory or super-elastic materials, by spring loading anchoring members 250 into body 108 or the like. In most embodiments, anchoring members 250 may also be collapsed down into the first, contracted configuration after a tissue modification procedure has been performed, to facilitate withdrawal of device 102 from the patient. In an alternative embodiment, anchoring members 250 may detach from body 108 and may be easily removable from the patient's skin.
FIG. 6B shows tissue modification device 102 with an alternative embodiment of a distal anchoring member 260. Here, distal anchoring member 260 includes multiple hooks or barbs extended out the distal portion 109 of elongate body 108 within the patient's back. In using such an embodiment, may not be necessary to pass guide member 117 through a second, distal incision on the patient, although in some embodiments guide member 117 may extend significantly beyond distal portion 109. Anchoring member(s) 260, according to various embodiments, may be deployed so as to anchor to bone, ligament, tendon, capsule, cartilage, muscle, or any other suitable tissue of the patient. They may be deployed into vertebral bone or other suitable tissue immediately adjacent an intervertebral foramen or at a location more distant from the intervertebral foramen. When a tissue modification procedure is complete, anchoring members 260 are retracted within elongate body for removal of device 102 from the patient.
Referring to FIG. 7A, in one embodiment a device delivery method first involves advancing an introducer cannula 300 coupled with a stylet 302 into the patient's back. Cannula 300 and stylet 302 are then passed between adjacent vertebrae and into the ligamentum flavum or an adjacent spinal ligament, as shown further in FIG. 7B. As shown in 7C, when the distal tip of cannula is positioned as desired, stylet 302 is removed. Referring to FIGS. 7D and 7E, a loss of resistance syringe 304 including a plunger 310, barrel 308 and fluid and/or air 306, is coupled with the proximal portion of cannula 300, The distal portion of cannula 300 is advanced through the ligamentum flavum until it enters the central spinal canal where a loss of resistance to pressure placed on plunger 310 is encountered, and fluid and/or air 306 is injected into central spinal canal to confirm correct placement of cannula 300 as shown in fig, 7E. Syringe 304 is then removed, as in FIG. 7F, and a guidewire 312 with a non-rigid, atraumatic tip is advanced through cannula 300 into the central spinal canal, as in FIG. 7G. Next, cannula 300 is removed, as in FIG. 7H, leaving behind guidewire 312. As shown in FIGS. 7I and 7J, an introducer sheath 114, coupled with a dilator 314, is then advanced over guidewire 312 to position a distal portion of sheath 114 at a desired location within the spine, Dilator 314 and guidewire 312 are then removed, as in FIG. 7K.
In sonic embodiments, tissue modification device 102 is inserted through one or more hollow devices as described above (such as introducer sheath 114, as shown, or cannula 300 in an alternative embodiment) in such a way that device 102 expands upon extending out of a distal portion of the hollow delivery device thereby assuming a wider profile for modifying a greater amount of target tissue from a single location. In an alternative embodiment, device 102 retains the same overall profile during insertion and during use. In some embodiments, one or more delivery devices will remain in the patient during use of tissue modification device 102, while in alternative embodiments all delivery devices are removed from the patient when tissue modification device 102 is operating. In some embodiments, tissue modification device 102 may be slidably coupled with one or more delivery devices during delivery and/or during use. In one embodiment, tissue modification device 102 is advanced through introducer sheath 114 and sheath 114 is used as an irrigation and evacuation lumen to irrigate the area of the target tissue and evacuate removed tissue and other debris, typically by applying a vacuum. In alternative embodiments, tissue modification device 102 may include an irrigation and/or evacuation lumen to irrigate an area of the target tissue and evacuate removed tissue and other debris.
Some embodiments of an access system for facilitating tissue modification may further include one or more visualization devices (not shown). Such devices may be used to facilitate placement of the access system for introducing the tissue modification device, to facilitate tissue modification itself, or any combination of these functions. Examples of visualization devices that may be used include flexible, partially flexible, or rigid fiber optic scopes, rigid rod and lens endoscopes, CCD or CMOS chips at the distal portion of rigid or flexible probes, LED illumination, fibers or transmission of an external light source for illumination or the like. Such devices may be slidably couplable with one or more components of an access system or may be slidably or fixedly coupled with a tissue modification device, In other embodiments, additional or alternative devices for helping position, use or assess the effect of a tissue modification device may be included. Examples of other such devices may include one or more neural stimulation electrodes with EMG or SSEP monitoring, ultrasound imaging transducers external or internal to the patient, a computed tomography (CT) scanner, a magnetic resonance imaging (MRI) scanner, a reflectance spectrophotometry device, and a tissue impedance monitor disposed across a bipolar electrode tissue modification member or disposed elsewhere on a tissue modification device or disposed on the access system.
Referring now to FIGS. 10A-10E, in the embodiments described above, the tissue modification devices 102, 202 include at least one non-tissue-modifying (or �protective�) portion, side or surface. The non-tissue-modifying portion is located on tissue modification device 102, 202 so as to be positioned adjacent non-target tissue when tissue modifying members 110, 210 are facing the target tissue. The non-tissue-modification surface of the device is configured so as to not modify or damage tissue, and thus the non-target tissue is protected from unwanted modification or damage during a tissue modification procedure. Alternatively, in some embodiments, a protective surface or portion of tissue modification device 102, 202 may actually modify non-target tissue in a protective manner, such as by delivering a protective drug, coating, fluid, energy or the like to the non-target tissue.
Optionally, in some embodiments, tissue modification devices or systems may further include one or more tissue barriers (or �shields�) for further protecting non-target tissues. Such barriers may be slidably coupled with, fixedly coupled with, or separate from the tissue modification devices with which they are used. In various embodiments, a barrier may be delivered between target and non-target tissues before delivering the tissue modification device, may be delivered along with the tissue modification device, or may be delivered after delivery of the tissue modification device but before the device is activated or otherwise used to modify target tissue. Generally, such a barrier may be interposed between the non-target tissue and one or more tissue modification devices to prevent unwanted damage of the non-target tissue.
FIG. 10A shows a distal portion of an introducer device 514 through which a barrier may be introduced. FIGS. 10B and 10C show one embodiment of a barrier 500 partially deployed and in cross-section, respectively. Typically, barrier 500 will have a first, small-profile configuration for delivery to an area near non-target tissue and a second, expanded configuration for protecting the non target tissue, in various embodiments, some of which are described more fully below, barrier 500 may be configured as one piece of super-elastic or shape-memory material, as a scaffold with material draped between the scaffolding, as a series of expandable wires or tubes, as a semicircular stent-like device, as one or more expandable balloons or bladders, as a fan or spring-loaded device, or as any of a number of different devices configured to expand upon release from delivery device 514 to protect tissue. As shown in FIGS. 10B and 10C, barrier 500 may comprise a sheet of material disposed with a first end 502 a abutting a second end 502 b within introducer device 514 and unfurling upon delivery. In an alternative embodiment, as shown in FIGS. 10D and 10E, opposite ends 522 a and 522 b of a barrier 520 may overlap in introducer device 514. Generally, barrier 500, 520 may be introduced via introducer device 514 in one embodiment or, alternatively, may be introduced via any of the various means for introducing the tissue modification device, such as those described in conjunction with FIGS. 7A-7S, 8A-8F and 9A-9B. In some embodiments, barrier 500, 520 may be fixedly coupled with or an extension of a tissue modification device. Barrier 500, 520 may also include one or more lumens, rails, passages or the like for passing a guidewire or other guide member, for introducing, removing or exchanging any of a variety of tissue modification, drag delivery, or diagnostic devices, for passing a visualization device, for providing irrigation fluid at the tissue modification site, and or the like. In some embodiments, barrier 500, 520 is advanced over multiple guidewires and the guidewires remain in place during a tissue modification procedure to enhance the stability and/or maintain positioning of barrier 500, 520.
Referring now to FIGS. 11A and 11B, in an alternative embodiment, a powered tissue modification device 1000 suitably includes an elongate shaft 1001 having a proximal portion 1002, a distal portion 1003 and a longitudinal axis 1008, one or more tissue modifying members 1004 coupled with shaft 1001 at or near distal portion 1003, and a handle 1006 coupled with shaft 1001 at or near proximal portion 1002. Optionally, some embodiments may also include one or more power connectors 1010 for connecting device 1000 with one or more power sources. In some embodiments, shaft 1001 has a size and shape that facilitate passage of at least distal portion 1003 into an epidural space of the spine and between target tissue, such as ligamentum flavum, and non-target tissue, such as neural and/or neurovascular tissue. In some embodiments, shaft 1001 may include one or more bends or curves at or near its distal portion 1003 to farther facilitate passage and positioning of device 1000. In some embodiments, for example, a bend or curve may facilitate passage of at least part of distal portion 1003 at least partway into an intervertebral foramen.
In various embodiments, handle 1006 may have any suitable configuration and features. In some embodiments, handle 1006 includes one or more actuators for activating tissue modifying member(s) 1004. Power connector 1010 may have any suitable configuration and may deliver any suitable type of energy from an external power source (not shown) to device 1000 in various embodiments, such as but not limited to electric, radiofrequency, ultrasound, laser or conductive energy, In alternative embodiments, device 1000 may be battery operated or use any other suitable source of internal power or energy, and such internal energy source may be housed in handle 1006, for example. From whatever source, power is typically transmitted to tissue modifying member(s) 1004 to activate them and thus modify tissue.
Referring now to FIG. 13A, in an alternative embodiment, a tissue modification device 1040 includes an elongate shaft 1041, one or more tissue modifying member(s) 1044, a handle 1046 and a power connector 1050. Additionally, device 1040 may include a guidewire lumen (not shown) extending through all or part of shaft 1041, which may allow passage of a guidewire 1048 having proximal 1049 and distal 1047 ends therethrough. In one embodiment, for example, guidewire 1048 may extend from a proximal end of shaft 1041, through a distal end of shaft 1041 and out the patient. In some embodiments, as described previously above, anchoring and/or tensioning force may be applied at or near distal end 1047 and/or proximal end 1049 to help urge tissue modifying member(s) 1044 against target tissue.
In the embodiment shown in FIG. 13A, tissue modifying member 1044 is shown having relatively fiat configuration. In many of the subsequent embodiments described herein, various embodiments of tissue modifying members are also shown as having flat configurations, primarily for ease of description. In alternative embodiments, however, and with reference now to FIG. 13B, tissue modification device may include a curved and/or flexible tissue modifying member 1045 (or multiple curved and/or flexible members), having a curved/flexible surface for contacting target tissue, Device 1040 may also include a curved and/or flexible shaft 1042. Such curved and/or flexible tissue modifying members 1045 (or tissue modifying surfaces) and shafts 1042 may facilitate tissue modification in some embodiments, in that tissue modifying members 1045 may more readily conform to target tissue. In alternative embodiments, many if not all of the devices described in the present application may have such curved and/or flexible tissue modifying member(s).
Referring now to FIG. 14, in some embodiments a tissue removal device 1100 may include an elongate shaft 1104 having proximal 1106 and distal 1105 portions, one or more tissue modifying members 1108, a movable handle 1103 coupled with proximal portion 1106, and a power connector 1107, In the embodiment shown, distal portion 1105 is at least partially steerable (shown in FIG. 14 as two, overlapping distal portions), and movable handle 1103 may be used (two-headed, straight arrow) to steer distal portion 1105 while holding shaft 1104 relatively stationary. A steerable distal portion 1105 may enhance the ability of tissue modifying members 1108 to contact and apply force against target tissue. In some embodiments, the location of tissue modifying members 1108 may be adjusted, using steerable distal portion 1105, without significantly moving shaft 1104. In some embodiments, steerable distal portion 1105 may move in multiple directions, such as laterally and up-and-down., relative to the longitudinal axis of shaft 1104. Movable handle 1103 may operate with a piston-like motion, in one embodiment, where a distal portion of handle 1102 is attached to the shaft and a proximal portion handle 1103 is attached to a tensioning member. The tensioning member may translate tension to steerable distal end 1105 when handle 1103 is actuated, which in turn deflects distal end 1105. In various alternative embodiments, any other handle steering mechanisms and/or other steering mechanisms, many of which are known in the art, may be used.
In some embodiments, optical cable 1090 may include fiber optics. Some or all of the fiber optics may comprise or may be coupled with illuminating elements 1092. Alternatively or additionally, some or all of the fiber optics may be connected to a camera (not shown). For example, such a camera may be attached to the proximal end of tissue modification device 1080. Optical cable 1090 may alternatively include one or more electrical wires connected to a power source (e.g., to power LED(s)) and/or an image capturing element 1094. Lenses, fiber optics, LED(s), or combinations thereof may be used for illumination with lenses, fiber optics. CCD CMOS, or combinations thereof used for image capturing, according to various embodiments.
FIGS. 17A-17E show cross-sectional views of various embodiments of shaft 1132, from the perspective of line A-A in FIG. 16. In the embodiment shown in FIG. 17A, for example, shaft 1132 may include a tissue modifying drive 1134 within a tissue modifying drive lumen 1140, and a guidewire 1136 within a guidewire lumen 1138. Tissue modifying drive 1134 may be configured to translate or rotate with respect to tissue modifying drive lumen 1140. Examples of tissue modifying drives 1134 include, but are not limited to, a drive shall, one or more conductive wires, one or more optical -fibers, or the like. Various embodiments may also include a motor, which may be located in the handle of the device, near the device distal end, in a separate drive apparatus, or the like.
In an alternative embodiment, as shown in FIG. 17B, shaft 1132 may include tissue modifying drive 1134 within tissue modifying drive lumen 1140, guidewire 1136 within guidewire lumen 1138, conductive elements 1146 within a visualization lumen 1144, and suction/irrigation lumen 1142. Suction/irrigation lumen 1142 may be used, for example, to deliver gas, fluid or pushable solids (e.g., granular solids) from outside the patient to the distal end of the device or to aspirate gas, fluids, tissue and/or other material from the targeted tissue region to the outside of the patient. Suction/irrigation lumen 1142 may also be used, in some embodiments, to slidably pass instruments, such as a long flexible needle or biopsy forceps. Visualization lumen 1144, in some embodiments, may be configured to receive conductive elements 1146, such as elements to power LEDs at the distal end of the device, and/or to carry the signal from a CCD or CMOS chip located at the distal end of the device that has captured a visual image and converted it into an electronic signal to a display device located outside the patient
FIG. 18 is an end-on cross-sectional view of tissue modification device 1120 of FIG. 16, shown from the perspective of line B-13, in this embodiment, visualization device 1122 and illuminating elements 1158 are located proximal to tissue modifying member 1130. In the embodiment shown, tissue modifying member 1130 includes a rotating disc mounted on a post in a bearing 1160, with multiple raised cutting edges 1131 on the disc. Two suction/irrigation lumens 1142 allow for introduction and suction of gas, fluid and/or pushable solids from an area of tissue modification.
FIGS. 19-40F illustrate a number of embodiments of a distal end of a tissue modification device having various different tissue modifying members. Referring to FIG. 19, in one embodiment, a tissue modification device 1170 may include multiple tissue modifying members 1172, each including a. cup 1174 attached to a drive shaft 1173 and having a cutting edge 1175. Tissue modifying members are located within an open chamber 1176 formed by multiple walls 1178, 1180, 1182, 1184, 1186. Cups 1174 may be rotated and/or translated to cut target tissue disposed in open chamber 1176, as shown by the curved and straight arrows.
In another embodiment, as in FIG. 22, a tissue modification device 1210 may include two rotating tissue modification members 1212 a, 1212 b, each comprising a disc with raised cutting members, The discs may rotate in the same directions or opposite directions in various embodiments. Rotating members 1212 a, 1212 b in opposite directions may help balance forces between the two members 1212 a, 1212 b and target tissue, thereby helping stabilize tissue modification device 1210 and enhance tissue modification procedures.
FIG. 23 illustrates that, in some embodiments, a tissue modifying member 1224 of a tissue modification device 1220 may be angled relative to a longitudinal axis of a distal portion 1126 of a shaft 1222. Angling tissue modifying member 1224 away from the long axis of distal portion 1126 may allow tissue modifying member 1224 to extend out of a an open chamber or window, for example, to facilitate tissue modification. The angle of tissue modification member 1224 may be fixed or adjustable in various embodiments. Angling tissue modifying member 1224 may also enhance contact of tissue modifying member 1224 with target tissue, thus enhancing tissue modification.
FIG. 25 shows another embodiment of a tissue modification device 1240, which includes tissue modifying members 1242, each including a rotating shaft 1244, 1246 and a helical cutting blade 1248, Device 1240 also may include one or more irrigation ports 1250 and one or more suction ports 1252. In various embodiments, cutting blades 1248 may be configured to remove both hard and/or soft tissue. Cutting blades 1248 may also be configured to transport separated tissue proximally toward and/or into the shall of device 1240, and/or suction port 1252, so that such tissue may be removed from the patient, Rotating shafts 1244 may be configured to rotate in opposite directions, in some embodiments, thus helping balance forces exerted by tissue modifying members 1242 on target tissues.
Referring to FIG. 28, in another alternative embodiment, a tissue removal device 1280 may include a tissue modifying member 1286 comprising one or more wires that move along multiple transverse guide rails 1282, 1284. In one embodiment, tissue modifying member 1286 may move laterally along guide rails 1282, 1284 and may also translate over guide rails 1282, 1284. In various embodiments, the tissue modifying member(s) 1286 (i.e., the wire(s)) may translate, rotate, reciprocate and/or oscillate. In some embodiments, the wire(s) may be coated (e.g., on the outer surface) with an abrasive material, and/or have a high friction outer texture. In some embodiments, the wires may be coupled to an energy (e.g. RF current, thermal) generator. In alternative embodiments, wires may be solely at or within the shaft distal portion or may extend from the shaft distal end to a more proximal location along shaft.
FIG. 29 illustrates another embodiment of a tissue modification device 1290, in which a tissue modifying member 1292 is coupled with rotating drive post 1294 and two free posts 1296, 1298. Drive post 1294 is coupled with a drive shaft 1302, which turns drive post 1294, thus translating tissue modifying member 1292 to modify tissue. Tissue modifying member 1292 may be elevated above a floor 1300 of the device shall, so as to more easily contact target tissue. In various embodiments, tissue modifying member 1292 comprises a cutting wire or abrasive wire and may be translated either in one direction or in both directions. In some embodiments, drive shaft 1302 may be advanced and retracted to further move and/or change the configuration of tissue modifying member 1292.
Referring to FIG. 32, in another embodiment a tissue modification device 1330 includes multiple tissue modifying members 1332, each including a movable platform 1333 with an abrasive surface attached to a drive shaft 1334. Tissue modifying members may move back and forth relative to one another and to the device shaft in any suitable pattern, Moving tissue modifying members 1332 back and forth relative to one another may help them apply tensioning forces to target tissue, thereby enhancing the ability of tissue modifying members 1332 to cut, shear, tear and/or otherwise modify target tissues.
As shown in FIG. 33, in another alternative embodiment, a tissue modification device 1340 may suitably include tissue modifying members comprising one or more blades, such as a distal blade 1344 a and a proximal blade 1344 b, each having a cutting edge 1345 a-1345 b. In the embodiment shown, proximal blade 1344 b is movable and may translated distally toward the opposing distal blade 1344 a. In alternative embodiments, distal blade 1344 a may be movable or both blades 1344 a, 1344 b may be movable. Alternative embodiments may include one movable blade. more than two movable blades facing in one direction, more that two movable blades facing in different directions, a movable blade and a backstop against which the blade may be driven, or any other suitable combination of movable and/or immobile blades. Furthermore, any blade of any given embodiment may have any suitable shape, size and overall configuration. In some embodiments, blades may be flat, while in others they may be curved. squared off, ridged, bent, serrated or the like. Blades may be long or short, multiple blades may be aligned closely one after the other, such as in a typical multi-blade razor used for shaving a face, multiple blades may be disposed apart from one another by several millimeters or even centimeters, and/or the like. Blades may have any suitable amount of sharpness or dullness, and in some embodiment a combination of sharper and duller blades may be used. Therefore, although exemplary embodiments of blades are described in detail above and below, any other suitable blades or combinations of blades may be substituted in various embodiments, without departing from the scope of the present invention.
Blades 1344 a, 1344 b, or any other blades described in alternative embodiments herein, may be fabricated from metals, polymers, ceramics, any other suitable material or combination of materials, According to various embodiments, suitable metals for blades may include, but are not limited to, stainless steel (303, 304, 316, 316L), nickel-titanium alloy, or cobalt-chromium alloy, for example, Elgiloy� (Elgin Specialty Metals, Elgin. Ill. USA), Conichrome� (Carpenter Technology, Reading, Pa., USA), or Phynox� (Imphy SA, Paris. France), Polymer materials include nylon, polyester, Dacron�, polyethylene, acetal, Delrin� (DuPont), polycarbonate, nylon, polyetheretherketone (PEEK), and polyetherketoneketone (PEKK). In some embodiments where polymers are used, such polymers may be glass-filled or carbon-filled to add strength and stiffness. Ceramics may include, but are not limited to, aluminas, zirconias, and carbides. Blades may be manufactured using skills known in the art, for example, metal injection molding (MIM), CNC machining, injection molding, grinding, EDM, sheet metal bending, etching, or the like. Other portions of a tissue modification device, such as a cover over one or more blades or other features, may be made of any suitable material now known or hereafter discovered. A blade cover, for example, may be fabricated in various embodiments of one or more polymeric materials, such as nylon, silicone, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polytetrafluoroethylene (PTFE), polyurethane (Tecothane,), Pebax (co. USA), polycarbonate, Delrin (co. USA), high-density polyethylene (HDPE), low-density polyethylene (LDPE), HMWPE, UHMWPE, or the like.
Referring now to FIG. 34A, in one embodiment a tissue modification device 1350 may have a substantially cylindrical, circular, or otherwise curved shaft 1352 as well as one or more substantially cylindrical, circular, or otherwise curved blades 1354. In the embodiment shown, blade 1354 protrudes out of a window 1358 of shaft 1352. When blade 1354 is moved proximally (arrow), its cutting edge 1356 moves toward and perhaps engages with an opposing cutting edge 1356 of shall 1352,
In an alternative embodiment, as in FIG. 34B, a tissue modification device 1360 may have a substantially cylindrical, circular, or otherwise curved shaft 1362 as well as one or more substantially cylindrical, circular, or otherwise curved blades 1364. In the embodiment shown, blade 1364 protrudes out of a window 1368 of shaft 1362. Blade 1364 may be rotated (arrows), to cause its cutting edges 1366 cut target tissue. In some embodiments, one or more curved blades 1364 may be translated as well as rotated. In either of the embodiments shown in FIGS. 34A and 34B, out target tissue may optionally be removed through the inside of curved shaft 1352 or curved blade 1364.
Referring now to FIGS. 35A and 35B, in some embodiments, a tissue modification device may include one or more anchoring members 1374 coupled with a distal shaft portion 1370 of the device. In various embodiments, any of a number of suitable anchoring members may be used. Some embodiments of anchoring members have been previously described above, and others will be described further below. In one embodiment, for example. anchoring members 1374 may comprise multiple needles. as shown in FIGS. 35A and 35B. Needles 1374 may act not only to anchor distal shaft portion 1370 to tissue, but may also change one or more characteristics of the tissue. For example, in some embodiments, inserting multiple needles into tissue may stiffen the tissue and thus enhance the ability of one or more tissue modifying members 1372 to cut or otherwise modify the tissue. In one embodiment, anchoring members/needles 1374 may be deployable out of distal shaft portion 1370 (arrow), such that needles 1374 are retracted during delivery of the device into the patient and then deployed into the target tissue when in a desired position. In various embodiments, anchoring members/needles 1374 may extend out of distal shaft portion 1370 in an orientation substantially perpendicular to the longitudinal axis of distal shaft portion 1370 or in any other suitable orientation relative to distal shaft portion 1370, or otherwise non-parallel to the longitudinal axis. During use, the tissue stiffening projections can extend into the target tissue. Needles 1374 will typically have a modulus of elasticity greater than the modulus of elasticity of the target tissue, and thus may stiffen (i.e., increase the effective modulus of elasticity) of the target tissue,
As shown in FIG. 35B, when anchoring members 1374 are in place within target tissue, tissue modifying member 1372. (a blade in the embodiment shown) may be translated out of distal shaft portion to cut or otherwise modify tissue. Tissue modifying member 1372 may advance out of distal shaft. portion 1370 in a direction perpendicular or otherwise non-parallel to anchoring members 1374. In some embodiments, anchoring members/needles 1374 may retain target tissue after cutting, so that it may be removed from the patient.
With reference now to FIG. 38A, an end-on view of one embodiment of a tissue modification device 1400 shows that anchoring members 1406 may alternatively comprise one or more deployable support members, which may be extended laterally out of a distal shaft. portion 1402 to anchor in tissue and support distal shaft portion 1402 and a tissue modifying member 1404. Any desired number, size, shape and configuration of lateral anchoring members 1406 may be used in various embodiments.
Referring now to FIGS. 39A-39D, in another alternative embodiment, a tissue modification device 1430 may suitably include a shaft 1432 and a semicircular tissue modifying member 1434. Tissue modifying member 1434 may include multiple cup-shaped blades 1435, each having a cutting edge 1436, and may rotate about a central axle 1440 that defines a central axis of rotation 1438. In some embodiments, as shown in FIG. 39B, tissue modifying member 1434 may be hollow and may include a chamber 1442 which may collect cut tissue for removal from the patient. Cups 1435 may be in fluid communication with chamber 1442 such that at least some of the tissue removed by cups 1435 enters chamber 1442. Suction may be applied to enhance the capture of tissue in chamber 1442 and/or to remove tissue from chamber 1442 proximally through shaft 1432,
Each cup 1435 may be spaced apart from adjacent cups 1435 at regular angle intervals, for example, in longitudinal and/or latitudinal direction around tissue modifying member 1434. Cups 1434 may be disposed on all or part (FIGS. 39C and 39D) of the perimeter of tissue modifying member 1434. Tissue modifying member 1434 may rotate, in various embodiments, either clockwise, counterclockwise or both. In some embodiments, tissue modifying member 1434 may have clockwise and/or counterclockwise rotational limits. For example, such rotational limits may comprise from about −180� to about 180�, or alternatively from about −90� to about 90�, or alternatively from about −45� to about 45�, In some embodiments, tissue modification device 1430 may be counterbalanced (e.g., to minimize vibrations caused by the oscillating or otherwise rotating tissue modifying member 1434 during use). For example, shaft 1432 may comprise an offset-weighted rotating balance shaft.
Referring now to FIGS. 40A-40F, another alternative embodiment of a tissue modification device 1440 may include a shaft 1442, and a tissue modifying member 1444 including multiple cutting members 1445. On alternative embodiments, tissue modifying member 1444 may include an abrasive surface in place of cutting members 1445.) As shown in FIGS. 40B and 40C, tissue modifying member 1444 may include a platform 1448, multiple cutting members 1445, an axle 1456 defining an axis of rotation 1458, a bottom plate 1450, a drive groove 1452, a cross beam 1454, and a base plate 1460, Device 1440 may further include a tissue modifying drive shaft 1462. Base plate 1460 may be rigidly attached to a mount 1464 (FIG. 40C). Platform 1448 may be integrated with and/or attached to bottom plate 1450 at cross beam 1454 or, in an alternative embodiment, at a center shaft (not shown). Cross beam 1454 may include a stress relief channel 1466 (FIG. 40C). Mount 1464 may be rotatably attached to stress relief channel 1466. For example, mount 1464 may have one or more protruding beams that may extend into stress relief channel 1466. Mount 1464 may be on one or both sides of the tissue modifying member 1444, Mount 1464 may be biased with respect to stress relief channel 1466, for example, to force cross beam 1454 to a configuration (e.g., perpendicular) with respect to base plate 1460 and bottom plate 1450, as shown in FIGS. 40B and 40C.
Referring now to FIGS. 41A and 41B, an alternative embodiment of a tissue modification device suitably includes an elongate body 1005 having a distal portion 1007, a distal cutting blade 1008 a, and a proximal cutting blade 1008 b, each blade 1008 having a cutting edge 1008 c, 1008 d, In this embodiment, distal cutting blade 1008 a. and proximal cutting blade 1008 b may be rotated away from elongate body 1005 to further expose cutting edges 1008 c, 1008 d. The height of cutting edges 1008 c, 1008 d relative to the elongate body 1005 may be used, for example, to control the depth of the cut into hard and/or soft target tissue.
The embodiment shown in FIGS. 41A and 41B, as well as many of the embodiments described below, include two movable, opposing blades 1008 a, 1008 b, which may be moved toward one another to cut tissue. Alternative embodiments, however, may include two immobile blades, one movable blade and one immobile blade, one movable blade, one immobile blade, more than two immobile blades facing in one direction, more that two immobile blades facing in different directions, a movable blade and a backstop against which the blade may be driven, or any other suitable combination of movable and/or immobile blades. Furthermore, any blade of any given embodiment may have any suitable shape, size and overall configuration. In some embodiments, blades may be flat, while in others they may be curved, squared off, ridged, bent or the like. Blades may be long or short, multiple blades may be aligned closely one after the other, such as in a typical multi-blade razor used for shaving a face, multiple blades may be disposed apart from one another by several millimeters or even centimeters, and/or the like. Blades may have any suitable amount of sharpness or dullness, and in some embodiment a combination of sharper and duller blades may be used. Therefore, although exemplary embodiments of blades are described in detail above and below, any other suitable blades or combinations of blades may be substituted in various embodiments, without departing from the scope of the present invention.
In the embodiments described previously or in any other embodiments described herein, blades may be fabricated from metals, polymers, ceramics, composites or any other suitable material or combination of materials. According to various embodiments, suitable metals for blades may include, but are not limited to, stainless steel (303, 304, 316, 316L), nickel-titanium alloy, or cobalt-chromium alloy, for example, (Elgin Specialty Metals, Elgin, Ill. USA), Conichrome� (Carpenter Technology, Reading, Pa. USA), or Phynox� (Imphy SA, Paris, France). Polymer materials include nylon, polyester, Dacron�, polyethylene, acetal, Delrin� (DuPont), polycarbonate, nylon, polyetheretherketone (PEEK), and polyetherketoneketone (PEKK). In some embodiments where polymers are used, such polymers may be glass-filled or carbon-filled to add strength and stiffness. Ceramics may include, but are not limited to, aluminas, zirconias, and carbides. Blades may be manufactured using skills known in the art, for example, metal injection molding (MIM), CNC machining, injection molding, grinding, electrodischarge madhining (EDM), sheet metal bending, etching, electrodeposition, or the like. Pull wires 1011 may similarly be fabricated from any suitable material and may have any of a number of suitable shapes and dimension. In some embodiments, for example, pull wires 1011 may be made from metal or polymer and may have substantially circular, oval, rectangular or square cross sections, although this is by no means a comprehensive list. In some embodiments, pull wires 1011 may range in diameter from about 0.001 inches to about 0.10 inches, and more preferably between about 0.010 inches and 0.020 inches. Other portions of a tissue modification device, such as a cover over one or more blades or other features, may be made of any suitable material now known or hereafter discovered. A blade cover, for example, may be fabricated in various embodiments of one or more polymeric materials, such as nylon, silicone, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polytetrafluoroethylene (PTFE), polyurethane (Tecothane), Pebax (co. USA), polycarbonate, Delrin (co. USA), high-density polyethylene (HDPE), low-density polyethylene (LDPE), HMWPE, UHMWPE, or the like. In some embodiments, one or more materials may be chosen for their compatibility with one or more imaging techniques or systems, such as magnetic resonance imaging (MRI), for example.
In various embodiments, elongate body 1005 may include one or more hollow chambers (not shown) at or near a distal portion of body 1005. Such hollow chamber(s) may serve any of a number of suitable functions. In some embodiments, for example, a chamber may be located distal and/or proximal to one or more blades 1008 a, 1008 b and may serve to collect removed tissue during and/or after a tissue modification procedure. In some embodiments, one or more blades 1008 a, 1008 b may help push removed tissue into such a chamber or chambers. In some embodiments, one or more chambers may house one or more blades 1008 a, 1008 b, such that blades 1008 a, 1008 b are housed within the chamber(s) while elongate body 1005 is passed into a patient and between target and non-target tissues. Once elongate body 1005 is in a desired position, blades 1008 a, 1008 b may then be deployed out of one or more windows or similar openings in the chamber(s) to remove or otherwise modify tissue. Such chambers may include, in various embodiments, a hollow distal portion or nosecone of elongate body 1005, a hollow portion of elongate body 1005 just proximal to proximal cutting blade 1008 b, and/or the like.
Another embodiment, as shown in FIGS. 42A and 42B, suitably includes a thin distal cutting blade 1010 a and a thin proximal cutting blade 1010 b, each blade 1010 having a cutting edge 1010 c, 1010 d and both blades 1010 being attached to two parallel pull wires 1011. In FIG. 42A, blades 1010 a, 1010 b are shown their flat configuration. In one embodiment, as shown in FIG. 42B, when a load is applied that is planar to pull wires 1011 and normal to the long axis of pull wires 1011, thin blades 1010 a, 1010 b flex or bow out of plane to increase the height of the cutting edges 1010 c, 1010 d,
Referring now to FIGS. 43A and 43B, another alternative embodiment of a blade 1012 that changes shape as it translates along a device is shown. Blade 1012 includes multiple flat members 1024 joined at edges 1025, which may form bends, creases, folds, or hinges that allow blade 1012 to widen (FIG. 43A) and contract (FIG. 43B). Blade 1012 includes a cutting edge 1014, which may be formed using methods known in the art, for example, grinding, molding, cutting, EDM machining, etching, laser cutting, electropolishing, electrodeposition, etc. In various embodiments, blade 1012 may be made from metal, polymer, or a combination of both. In sonic embodiments, blade 1012 may be translated along a central member 23 that causes blade 1012 to widen and contract at various locations along central member 23. When blade 1012 is located over a wider section of central member, as in FIG. 43A, blade 1012 has a flatter, wider configuration. When blade 1012 slides or otherwise translates along central member 1023 to a narrower section, as in FIG. 43B, blade 1012 assumes a taller, narrower configuration. Such a taller configuration may facilitate cutting tissue with blade edge 1014, in some embodiments. Edges 1025 of blade 1012 allow it to change shape more readily between the wider and narrower configurations, and the bends or ridges formed in blade 1012 in the narrower configuration (FIG. 43B) may help limit the amount of material that is removed with each pass of blade 1014 along a surface of target tissue.
Referring now to FIGS. 44A-44D, one embodiment of a blade system for a tissue modification device is shown. FIG. 44A is aside view showing distal cutting blade 1008 a and proximal cutting blade 1008 b, each of which is free to pivot about an external pin 1031 that may be rigidly fixed to an external support block 1026 that is free to slide along a pull wire 1011 An internal pin 1032 may be contained within an angled slot 1033 (shown in FIG. 44D) in an internal support block 1028 that freely slides along pull wire 1011. A wire stop 1030 is securely fixed to the end of pull wire 1011 to prevent pull wire 1011 from pulling through distal external support block 1026 as axial force is applied to pull wire 1011. In various embodiments, wire stop 1030 may include hut is not limited to a mechanical squeeze-type clamp. a ball formed at the end using a laser, TIG welder, or torch, a crimped hypo-tube, a sleeve with a set-screw, a loop, bend or twist in the wire, or the like. A pair of external springs 1027 may maintain blades 1008 a, b in a low-profile (or �flat�) configuration. An internal spring 1029 may act to separate blades 1008 a, 1008 b. FIG. 44B provides a cross-sectional view alone: the line A-A in FIG. 44A, Proximal cutting blade 1008 b is shown to have a curved profile, and centrally located pull wire 1011 and internal spring 1029 are also shown. Internal support block 1028 and external support block 1026 remain within the profile of proximal cutting blade 1008 b. Cutting blade edge 1008 c is positioned in a low profile configuration.
As shown in FIG. 44C, in one embodiment, the width of distal blade 1008 a and proximal blade 1008 b may be approximately the same as the width of external support block 1026. Pull wire 1011 may be centrally located to facilitate uniform movement of the cutting blade 1008 a and therefore uniform cutting with cutting blade edge 1008 c. In the cross-sectional view of FIG. 44D, an angled slot 1033 is shown that constrains internal pin 1032 that controls the height of blades 1008 a, 1008 b at a given axial displacement of internal support block 1028 relative to external support block 1026, in some embodiments, a baffle 1034 may be used as a one-way mechanism for debris transport down the open channel of blade 1008 a, 1008 b. Referring now to FIGS. 45A-45D, in one embodiment, as proximal external support block 1026 is driven distally towards wire stop 1030, external springs 1027 compress to increase the height of the proximal and distal cutting blades 1008 a, 1008 b, as shown in side view in FIG. 45A, External springs 1027 may have a lower spring rate (lb./in.) than that of internal spring 1029, such that external springs 1027 displace more readily than internal spring 1029 during the initial loading of the mechanism in order to preferentially drive blades 1008 a, 1008 b upward. This increase in blade height may help control the amount of tissue material that will be removed during a cutting cycle. The blade height can be adjusted by adjusting the length, angle, and endpoint positions for angled slot 1033. To help support blades 1008 a, 1008 b during the cutting process, blades 1008 a, 1008 b may stop at the limits of the angled slot 1033 and may also be limited by the angled cut on the sides of external support blocks 1026 near external pin 1031,
With reference now to FIGS. 46A-46C, in one embodiment blades 1008 a, 1008 b may be made to rotate to a desired height, such as their maximum height, and may then be driven toward one another by applying an additional load to further compress internal spring 1029. as depicted in side-view in FIG. 46A. In some embodiments, blades 1008 a, 1008 b are driven together until cutting blade edges 1008 c contact each other to complete a cutting cycle. In some embodiments, relative spring rates for external spring 1027 and internal spring 1029 may be customized/selected to provide a desired cutting action and penetration behavior for blades 1008 a, 1008 b into target tissue. After a cutting cycle is complete, blades 1008 a, 1008 b may be driven apart and further pushed into a low profile state by internal spring 1029 and external springs 1027. Baffle 1034 may be displaced as debris is driven into the blade channel, and baffle 1034 then may return to its original position to hold the debris in place. In some embodiments, for example, baffle 1034 may include a metal tab or a polymer flap molded into blade 1008 a, 1008 b. An alternative debris capture mechanism is shown in the cross-sectional view of blade 1008 depicted in FIG. 47E. Multiple ramps 1034 a and stops 1034 b allow debris to slide away from cutting edge 1008 c but prevent the debris from sliding back.
Referring to FIG. 47A, in one embodiment, to prevent a cutting blade 1008 a from rotating about the axis of a single pull wire 1011 and/or to allow for more force or more distributed force along cutting edge 1008 c, multiple pull wires 1011 may be used to actuate the blade mechanism. In addition, external support block 1026 may optionally include ridge features 1035 that slidably engage with a track 1036 that may serve as an anti-rotation mechanism and may also provide additional strength and stiffness along the length of the blade mechanism. In various embodiments, orientation of such ridge features 1035 may be varied. For example, ridge feature 1035 may be folded inward as in FIG. 47B, flat as in FIG. 47C or folded outward as in FIG. 47D. In various embodiments, ridge feature 1035 have any suitable shape or configuration, such as but not limited to a round, square, dove-tailed, rectangular, or triangular cross-sectional shape.
With reference now to FIGS. 48A and 48B, in various embodiments the cutting edges of blades 1008 a, 1008 b may have teeth 1037 that facilitate engagement with a smooth, curved, and/or hard target tissue, such as bone. One embodiment, as in FIG. 48A, may include pointed teeth 1036, while an alternative embodiment, as in FIG. 48B, may include rounded teeth 1037. Of course, any other suitable configuration may be substituted in various alternative embodiments.
Referring now to FIGS. 48C-48G, in various embodiments, the interaction of cutting edges of two blades or one blade and a backstop may effectively modify tissue with any number of different actions. FIG. 48C depicts the cross section of two opposing blades 1118 a, 1118 b, which are slightly offset with their respective bevels angled opposite of each other. This may create a shearing action when blades 1118 a, 1118 b are brought together and pass each other as shown in the lower portion of the FIG. 48C. In FIG. 48D two blades 1148 a, 1148 b are in plane with similar bevels. The cutting edges of these blades 1148 a, 1148 b come in contact to bite tissue when blades 1148 a, 1148 b are brought together. In another embodiment, as in FIG. 48E, one blade 1158 may be brought into contact with a backstop 1160, which in one embodiment comprises a hard flat plane. FIG. 48F depicts a single blade 1162 brought into contact with a compliant flat plane backstop 1164. Contact of blade 1162 with such a backstop 1164 may create both a pinching and a shearing effect on tissue, in yet another embodiment, as in FIG. 48G, a single blade 1166 may be brought against the a backstop 1168 having a concave pocket 1169. This may also create both a shearing and a pinching action on targeted tissue.
Referring to FIGS. 49A and 49B, in one embodiment, distal cutting blade 1008 a and proximal cutting blade 1008 b (or external support blocks 1026 that in turn are fitted with blades that pivot about the external pin 1031) may be slidably engaged in a track 1036, two pull wires 1011 may be mounted in opposite directions, and wire stops 1030 may be located on the outside of opposite blades 1008 a, 1008 b, as shown in top-view in. FIG. 49A. By applying a force to the pull wires 1011, blades 1008 a, 1008 b are drawn toward the center of track 1036, as depicted in FIG. 49B.
In an alternative embodiment, as in FIGS. 50A and 50B, two pull wires 1011 may be actuated from one end of a tissue modification device. In such an embodiment, a pulley 1038 (or capstan) may be used to redirect one of the wires 1011, as shown in top-view in FIG. 50A, so that the two pull wires 1011 are aligned. As depicted in FIG. 50B, actuating pull wires 1011 from the one end causes blades 1008 a, 1008 b to move toward the center of track 1036.
In one alternative embodiment (not pictured), similar to that in FIGS. 50A and 50B, a first pull wire may be constrained on one side of a blade by a wire stop to provide a closing motion of the blade toward a stationary blade. A second pull wire may be constrained on an opposite side of the blade by a wire stop and guided around a pulley or capstan to direct the pull wire in the same direction as the first pull wire. This second pull wire may be used to provide an opening motion of the blade away from stationary blade.
Referring now to FIGS. 51A and 51B, in another alternative embodiment, to balance or distribute the applied load on blades 1008 a, 1008 b more evenly (to prevent blades 1008 a, 1008 b from binding while sliding with or without the track) and still have pull wires 1011 actuate from one end of the device, the two pull wires 1011 may both be redirected around a double grooved pulley 1038 (or capstan), as shown in top-view in FIG. 51A. Two additional wire stops 1030 may be added to an edge of each blade 1008 a, 1008 b. Applying force to the pull wires 1011 causes blades 1008 a, 1008 b to move toward one another.
As depicted in FIGS. 52A-52C, in another embodiment, distal cutting blades 1008 a and proximal cutting blades 1008 b may be housed within an enclosure 1039 that has an opening 1041 and a ramp 1042 to facilitate deployment of blades 1008 a, 1008 b out of window. Blades 1008 a, 1008 b are shown in their undeployed positions in FIG. 52A. In FIG. 52B, as blades 1008 a, 1008 b are driven inward by an applied force via one or more wires, flexures, or mechanisms, blades 1008 a, 1008 b rotate about a base pivot 1040 and are driven through opening 1041 along ramp 1042 and are exposed out of enclosure 1039. FIG. 42C shows blades 1008 a, 1008 b in contact with one another as enclosures 1039 are driven inward to complete a cutting cycle. In some embodiments, springs (not shown) may be used to drive the mechanism apart, similar to the mechanism described in FIG. 4A, such that blades 1008 a, 1008 b would lay flush within enclosure 1039 once the applied force is removed.
In some embodiments, as in FIGS. 53A and 53B, blades 1008 a, 1008 b may also be directed to translate along an axis normal to pull wire 1011 by having pull wire 1011 change its applied direction by 90 degrees by means of a pulley 1038 (or capstan).
Referring to FIGS. 54A and 54B, in one embodiment, a tissue modification device 1001 may include endcaps 1043 on each end of an elongate body 1005, which endcaps 1043 are attached to pull wires 1011 in order to actuate the distal and proximal cutting blades 1008 a, 1008 b. In addition, as depicted in FIG. 44B, elongate body 1005, in some embodiments, may be partially flexible at various locations along its length or, in some embodiments, along its entire length. The embodiment depicted in FIG. 44B shows two flexion points where elongate body 1005 may be flexed to bend around anatomical structures, in some embodiments, encaps 1043 may be tapered to facilitate passage of device 1001 through a small. Encaps 1043 and elongate body 1005 may also optionally be configured to accommodate a guidewire for over-the-wire advancement to target tissue.
In one embodiment, and with reference now to FIGS. 55A and 55B, endcaps 1043 may nest within a simple T-handle mechanism 1044 that is fitted within a handgrip 1045, as demonstrated in FIG. 55A. T-handle mechanism 1044 may be displaced to pull endcap 1043 that is in turn connected to pull wire 1011, as handgrip 1045 provides counter-traction to elongate body 1005. Other quickly attached and separated handle mechanisms that allow tensioning and wire actuation and/or wire constraint may alternately be used.
Referring now to FIGS. 56A and 56B, some embodiments may optionally provide for lateral movement and/or control of lateral movement of one or more cutting blades. As shown in front-view in FIG. 56A, in one embodiment a cam 1046 may be rigidly fixed to a rotatable control rod 1048 that freely rotates within a support block 1049. Support block 1049 has raised features 1047 that constrain cam 1046. Support rods 1050 prevent axial displacement of support block 1049 while allowing it to translate from side to side. A support frame 1051 may contain the mechanism and may be fitted to the body of the tissue modification device. Support block 1049 may translate to the left, for example, as depicted in FIG. 56B, as control rod 1048 is rotated counter-clockwise. According to various embodiments, any of the previously disclosed cutting mechanisms may be fitted to support block 1049 to facilitate controlled lateral displacement of the cutting mechanism as actuated by control rod 1048 for cutting tissue.
FIGS. 57A and 57B show an alternative embodiment including a rotatable control rod 1048 that freely rotates within support frame 1051. Control rod 1048 is rigidly fixed to a fork or yoke 1052 that captures a positioning pin 1053. As yoke 1052 is rotated counterclockwise, for example, support block 1049 may be displaced to the right, as depicted in FIG. 57B.
Referring to top-view FIGS. 58A and 58B, in one alternative embodiment, instead of rotating a rod about the long axis of a tissue modification device, control wires 1011 may be secured to a base pulley 1054 that is rigidly fixed to a control linkage 1055. By pulling on a control wire 1011, support block 1049 may be translated to the left, as in FIG. 58B, or to the right, as in FIG. 58A.
With reference now to FIGS. 59A-59C, in some embodiments it may be advantageous to include one or more guiding or steering features on an elongate body of a tissue modification device, to facilitate guiding or steering of the body and/or one or more tissue modification members. In some embodiments, such guiding or steering features may be located adjacent or near tissue modifying members and may facilitate moving such members laterally back and forth or in any of a number of directions and/or may facilitate urging the tissue modifying members into target tissue. In other embodiments, guiding or steering members may be located along an elongate body at one or more locations distant from the tissue modifying members.
As shown in FIGS. 59A-59C, in one embodiment, a tissue modifying portion 1056, such as a blade mechanism, may be coupled with a deployable wire loop 1058 that may facilitate guiding or directing portion 1056 by bowing outward to press against tissue. Atop-view depicted in FIG. 59A shows tissue modifying portion 1056 (possibly polymer or hypotube), which may contain a push wire 1057 constrained at the distal end. When a force is applied to push wire 1057, the portion of the wire contained in tissue modifying portion 1056 bows out to create a side-loop 1058, as depicted in FIG. 59B. A small feature on the end of the wire like a formed ball (or clamp) 1059 can be constrained at distal end of tissue modifying portion 1056. Alternately, as in FIG. 59C, wire 1057 may be pulled to bow out a portion of side loop 1058. In either case, side loop 1058 may push against tissue on one side to force tissue modifying portion 1056 laterally to the other side.
Referring to FIGS. 60A and 60B, in some embodiments, side-loop 1058 may be toggled from side to side by means of a distal tip 1060 to facilitate control and/or steering of tissue modifying portion 1056.
In yet another embodiment, as depicted in FIGS. 61A and 61B, a mechanism to provide lateral position control of a. cutting blade mechanism 1063 may include a track (or monorail) 1061 fixed to a backing plate 1062. Cutting blade mechanism 1063 may be advanced and retraced along track 1061 to provide different lateral positions, as depicted in top view in FIG. 61A. FIG. 61B shows a cross-sectional view of track 1061 and backing plate 1062.
In an alternative embodiment, as shown in FIG. 62, a track 1061 may include a junction, which may facilitate directing cutting blade mechanism 1063 from one side to another of backing plate 1062.
Top-view FIGS. 63A-63C further demonstrate one embodiment of a tissue modifying portion 1056 (here a cutting blade mechanism). These figures show how using push wires 1057 and side-loop wires 1058 on opposite sides of tissue modifying portion 1056, a user may move, guide or steer tissue modifying portion 1056 from side to side (FIGS. 63B and 63C).
In yet another embodiment, as shown in end-on views in FIGS. 64A-64C, lateral displacement control of a tissue modification device may use one or more fillable bladders 1063, which may be filled or emptied of water, saline, air, or other fluid or gaseous medium to direct one or more components of a tissue modification device to one side or another. In one embodiment, for example, bladders 1063 may be aligned on either side of a track 1061, as depicted in FIG. 64A. As shown in FIGS. 64B and 64C, one bladder 1063 may be deflated or emptied while the other bladder 1063 is filled to move track 1061 to one side, and then the emptied bladder 1063 may be filled and the filled bladder 1063 emptied to move track 1061 to the opposite side.
In yet another embodiment, and with reference now to FIGS. 65A and 65B, a track 1061 is fixed to proximal and distal ends of a backing plate 1062, and the position of track 1061 in between the proximal and distal ends is controlled by a lateral displacer 1064, as shown in top-view in FIG. 65A. When force is applied to move lateral displacer 1064, track 1061 may be shifted relative to backing plate 1062, as shown in FIG. 65B. A cutting blade mechanism advanced or retracted along track 1061 may be controllably displaced from side to side by controlling lateral displacer 1064.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS7189240 *Aug 1, 2000Mar 13, 2007Disc-O-Tech Medical Technologies Ltd.Method and apparatus for spinal proceduresWO2001008571A1 *Aug 1, 2000Feb 8, 2001Disc O Tech Medical Tech LtdMethod and apparatus for spinal procedures* Cited by examinerClassifications U.S. Classification606/79International ClassificationA61B17/56Cooperative ClassificationA61B17/1671, A61B17/1659European ClassificationA61B17/16R, A61B17/16S4Legal EventsDateCodeEventDescriptionAug 11, 2011ASAssignmentOwner name: BAXANO, INC., CALIFORNIAFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SAADAT, VAHID;BLEICH, JEFFERY L.;MICHLITSCH, KENNETH J.;AND OTHERS;SIGNING DATES FROM 20110418 TO 20110426;REEL/FRAME:026738/0209RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google