Bipolar radiofrequency ablation systems for treatment within bone

Abstract

System and methods for channeling a path into bone include a trocar having a proximal end, distal end and a central channel disposed along a central axis of the trocar. The trocar includes a distal opening at the distal end of the trocar. The system includes a curved cannula sized to be received in the central channel, the curved cannula comprising a curved distal end configured to be extended outward from the distal opening to generate a curved path extending away from the trocar. The curved cannula has a central passageway having a diameter configured to allow a treatment device to be delivered through the central passageway to a location beyond the curved path.

Claims

1. A system for navigating to and providing treatment within bone, the system comprising: an introducer having a central channel and an opening at a distal tip of the introducer; a first stylet configured to be installed in the introducer, the first stylet comprising a sharp distal tip that is configured to extend beyond the opening at the distal tip of the introducer and to pierce an outer cortical bone region of the bone; a channeling instrument configured to be inserted through the introducer after removal of the first stylet to create a predetermined-length linear path within a cancellous region of the bone toward a target treatment site; a cannula configured to be inserted through the introducer after removal of the first stylet, the cannula having a deflectable distal tip configured to form a curved path within the bone; a second stylet configured to be installed within a central passageway of the cannula and to extend beyond an opening at a distal end of the central passageway, wherein the second stylet and the cannula together form the curved path within the bone; and a bipolar radiofrequency probe configured to be inserted through the introducer after removal of the channeling instrument or the second stylet, the bipolar radiofrequency probe being configured to deliver radiofrequency energy sufficient to ablate a basivertebral nerve at the target treatment site within the bone, wherein the bipolar radiofrequency probe comprises a sensor.

2. The system of claim 1, wherein: the first stylet is straight; the bipolar radiofrequency probe comprises two spaced-apart electrodes; and the introducer and the first stylet are configured to percutaneously access the bone.

3. The system of claim 1, wherein the bone is a lumbar vertebral body or an S1 vertebral body.

4. The system of claim 1, wherein the cannula comprises a locking nut configured to engage with the introducer to stop additional advancement.

5. The system of claim 1, wherein the system is configured to treat multiple vertebrae.

6. A system for navigating to and providing treatment within bone, the system comprising: a trocar having a central channel and an opening at a distal tip of the trocar; a first stylet configured to be installed in the trocar, the first stylet comprising a sharp distal tip that is configured to extend beyond the opening at the distal tip of the trocar and to pierce an outer cortical bone region of the bone; a channeling instrument configured to be inserted through the trocar after removal of the first stylet to create a predetermined-length linear path within a cancellous region of the bone toward a target treatment site; a cannula configured to be inserted through the trocar after removal of the first stylet, the cannula having a deflectable distal tip configured to form a curved path within the bone; a second stylet configured to be installed within a central passageway of the cannula and to extend beyond an opening at a distal end of the central passageway, wherein the second stylet and the cannula together form the curved path within the bone; and a treatment device configured to be inserted through the trocar and deliver radiofrequency energy sufficient to ablate a basivertebral nerve at the target treatment site, wherein the bone is a lumbar vertebral body or an Si vertebral body; and a sensor configured to perform measurements at the treatment site.

7. The system of claim 6, wherein: the first stylet is straight; the treatment device comprises a bipolar radiofrequency probe that comprises two spaced-apart electrodes; and the trocar and the first stylet are configured to percutaneously access the bone.

8. The system of claim 6, wherein the sensor is positioned on a distal tip of a separate probe.

9. The system of claim 6, wherein the system is configured to treat multiple vertebrae.

10. The system of claim 6, wherein the cannula comprises a locking nut configured to engage with the trocar to stop additional advancement of the cannula.

11. The system of claim 6, wherein the cannula comprises a tube having a pattern of relief or cuts in a wall of the tube.

12. The system of claim 6, wherein the treatment device comprises two spaced-apart electrodes.

13. The system of claim 6, wherein the deflectable distal tip of the cannula has a preformed curvature, and wherein the second stylet comprises a distal end portion having a preformed curvature corresponding to the preformed curvature of the deflectable distal tip of the cannula.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

(1) The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:

(2) FIG. 1 is a system for generating a curved path in bone according to the present invention.

(3) FIG. 2 is a sectional view of the system of FIG. 1

(4) FIG. 3 illustrates a sectioned view of a vertebral body with a path bored through the cortical shell.

(5) FIGS. 4A-F illustrate a method for accessing the BVN with the system of the present invention.

(6) FIG. 5 shows an alternative system for generating a curved path in bone according to the present invention.

(7) FIG. 6 shows the system of FIG. 5 being installed in a vertebral body.

(8) FIGS. 7A-7B show a curved stylet in accordance with the present invention.

(9) FIG. 8 illustrates a perspective view of a system for generating a curved path in bone according to the present invention.

(10) FIG. 9 is an exploded view of the system of FIG. 8.

(11) FIG. 10A-10E show schematic diagrams of the system of FIG. 8 at various stages of deployment during a procedure.

(12) FIG. 11 is a section view of the proximal end of the system of FIG. 8 during introduction of the system into the body.

(13) FIG. 12 is a side view of the distal end of the system of FIG. 8 during introduction of the system into the body.

(14) FIG. 13 is a section view of the proximal end of the system of FIG. 8 after deploying the curveable cannula into the body.

(15) FIG. 14 is a side view of the distal end of the system of FIG. 8 after deploying the curveable cannula into the body.

(16) FIG. 15 is a section view of the proximal end of the system of FIG. 8 with the drive nut retracted.

(17) FIG. 16 is a section view of the proximal end of the system of FIG. 8 after deploying the probe into the body.

(18) FIG. 17 is a side view of the distal end of the system of FIG. 8 after deploying the probe into the body.

(19) FIGS. 18A and 18B are side views of the distal end of the system of FIG. 8 with the curveable cannula in a stowed and deployed position respectively.

(20) FIG. 19A illustrates a perspective view of an alternative system for generating a curved path in bone according to the present invention.

(21) FIG. 19B illustrates the system of FIG. 19A in a deployed configuration.

DETAILED DESCRIPTION OF THE INVENTION

(22) Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1 through FIG. 19B. It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to the specific steps and sequence, without departing from the basic concepts as disclosed herein.

(23) Tube-In-Tube

(24) FIGS. 1 and 2 illustrate a first embodiment of the present invention comprising a system or kit 10 for forming a path through bone. The system comprises a having a needle trocar 20 (the main body of the instrument set). The trocar 20 comprises an elongate shaft 28 having a handle 24 at its proximal end 32 and a central lumen 36 passing through to the distal end 22 of the trocar 20. The central lumen 36 is generally sized to allow the other instruments in the system 10 to be slideably introduced into the patient to a treatment region. System 10 further comprises a straight stylet 80 having a sharp-tipped needle 84 at its distal end that is used with the needle trocar 20 to create the initial path through the soft tissue and cortical shell to allow access to the cancellous bone, a curved cannula 50 that is used to create/maintain the curved path within the bone/tissue. A straightening stylet 40 is used to straighten out the curve and load the curved cannula 50 into the needle trocar 20. A curved stylet 60 is used in conjunction with the curved cannula 50 to create the curved path within the bone/tissue, and a channeling stylet 90 is used to create a working channel for a treatment device (such as RF probe 100) beyond the end of the curved path created by the curved cannula 50.

(25) The surgical devices and surgical systems described may be used to deliver numerous types of treatment devices to varying regions of the body. Although the devices and systems of the present invention are particularly useful in navigating through bone, it is appreciated that they may also be used to navigate through soft tissue, or through channels or lumens in the body, particularly where one lumen may branch from another lumen.

(26) The following examples illustrate the system 10 applied to generating a curved bone path in the vertebral body, and more particularly for creating a bone path via a transpedicular approach to access targeted regions in the spine. In particular, the system 10 may be used to deliver a treatment device to treat or ablate intraosseous nerves, and in particular that basivertebral nerve (BVN). Although the system and methods provide significant benefit in accessing the BVN, it is appreciated that the system 10 of the present invention may similarly be used to create a bone path in any part of the body.

(27) FIG. 3 illustrates a cross-sectional view of a vertebra 120. Recently, the existence of substantial intraosseous nerves 122 and nerve branches 130 within human vertebral bodies (“basivertebral nerves”) has been identified. The basivertebral nerve 122 has at least one exit 142 point at a location along the nerve 122 where the nerve 122 exits the vertebral body 126 into the vertebral foramen 132.

(28) Preferably, the basivertebral nerves are at, or in close proximity to, the exit point 142. Thus, the target region of the BVN 122 is located within the cancellous portion 124 of the bone (i.e., to the interior of the outer cortical bone region 128), and proximal to the junction J of the BVN 122 having a plurality of branches 130 (e.g. between points A and B along nerve 122). Treatment in this region is advantageous because only a single portion of the BVN 122 need be effectively treated to denervate or affect the entire system. Typically, treatment in accordance with this embodiment can be effectuated by focusing in the region of the vertebral body located between 60% (point A) and 90% (point B) of the distance between the anterior and posterior ends of the vertebral body. In contrast, treatment of the BVN 122 in locations more downstream than the junction J requires the denervation of each branch 130.

(29) In one approach for accessing the BVN, the patient's skin is penetrated with a surgical instrument which is then used to access the desired basivertebral nerves, i.e., percutaneously. In one embodiment, a transpedicular approach is used for penetrating the vertebral cortex to access the BVN 122. A passageway 140 is created between the transverse process 134 and spinous process 136 through the pedicle 138 into the cancellous bone region 124 of the vertebral body 126 to access a region at or near the base of the nerve 122. It is appreciated that a postereolateral approach (not shown) may also be used for accessing the nerve.

(30) FIGS. 4A-F illustrate a preferred method for accessing the BVN with the system 10 of the present invention. First, the straight stylet 80 is inserted in aperture 26 at the proximal end 32 of needle trocar 20. The straight stylet 80 is advanced down the central lumen 36 (see FIG. 2) of the trocar 20 until the proximal stop 82 abuts against handle 24 of the trocar 20, at which point the distal tip 84 of straight stylet protrudes out of the distal end 22 of the trocar 20. The tip 84 of the straight stylet 80 preferably comprises a sharp tip for piercing soft tissue and bone.

(31) Referring now to FIG. 4A, the assembly (trocar 20 and straight stylet 80) is advanced through soft tissue to the surface of the bone. Once the proper alignment is determined, the assembly is advanced through the cortical shell of pedicle 138 and into the cancellous interior 124 of the bone.

(32) After the proper depth is achieved, the straight stylet 80 is removed from the trocar 20, while the trocar 20 remains stationary within the vertebrae 120. The straightening stylet 40 is inserted into proximal aperture 52 (see FIG. 2) of the curved cannula 50 and advanced along the central lumen of the curved cannula 50 until the stop 42 of the stylet 40 abuts up to the proximal end of the curved cannula. This forces the distal tip of the straight stylet through the curved section 56 of the curved cannula 50 to straighten out the curve 56. It is contemplated that the straight stylet comprise a hard, non-compliant material and the distal end 56 of the curved cannula 50 a compliant, yet memory retaining material (e.g. Nitinol, formed PEEK, etc.) such that the curved 56 section yields to the rigidity of the straightening stylet 40 when installed, yet retains its original curved shape when the stylet 40 is removed.

(33) As shown in FIG. 4B, once the straightening stylet 40 is secure and the curved cannula 50 is straight, they are inserted into the needle trocar 20 and secured. Proper alignment (e.g. prevent rotation, orient curve direction during deployment) is maintained by aligning a flat on the upper portion 58 of the curved cannula 50 to an alignment pin secured perpendicularly into the needle trocar 20 handle 24. Once the curved cannula 50 is secure, the straightening stylet 40 is removed, while the curved cannula 50 remains stationary within the trocar 20.

(34) Referring to FIG. 4C, the curved stylet 60 is then straightened out by sliding the small tube 68 proximally to distally on its shaft towards the distal tip 64 or from the distal tip 64 proximally on its shaft towards the proximal end 62. Once the curved distal tip 66 is straightened out and fully retracted inside the small tube 68, the curved stylet 60 is inserted into the proximal aperture 52 of the curved cannula 50, which still resides inside the needle trocar 20. As the curved stylet 60 is advanced into the curved cannula 50, the small tube 68 is met by a stop 55 (see FIG. 4C). As the curved stylet 60 continues to advance the small tube 68 is held inside the handle of the curved cannula 50. This allows the curve of the stylet 60 to be exposed inside the curved cannula 50. To create the maximum force the curve of the two parts (50 & 60) must be aligned. To ensure alignment the cap on the curved stylet 60 has an alignment pin 70 which engages with alignment notch 52 on the proximal end of the curved cannula 50.

(35) Once the stylet 60 is fully seated and aligned with the curved cannula 50 the tip of the curved stylet 60 will protrude from the tip of the curved cannula 50 by about 1/16 to 3/16 inches. This protrusion will help to drive the curve in the direction of its orientation during deployment.

(36) Referring now to FIG. 4D, with the curved stylet 60 and the curved cannula 50 engaged, the locking nut 58 at the top of the curved cannula 50 is rotated counter clockwise to allow the cannula 50 and stylet 60 to be advanced with relation to the needle trocar 20 such that the proximal end 52 about against 58, advancing the curved cannula 50 and stylet 60 beyond the distal opening of trocar 20 to generate a curved path in the cancellous bone region 124. As the curved cannula 50 and stylet 60 are advanced they will preferably curve at a radius of 0.4 to 1.0 inches through cancellous bone and arc to an angle between 5 and 110 degrees. Once the curved cannula 50 and stylet 60 are deployed to the intended angle, the locking nut at the top of the curved cannula 50 is engaged with the needle trocar 20 to stop any additional advancement of the curved stylet cannula assembly.

(37) Referring to FIGS. 7A-7B illustrate the tip of the curvet stylet 60, which has been formed with two angles. To help the curve deployment in the proper direction the curve 66 of the curved stylet 60 is shaped in a predetermined orientation. The angle on the inside of the curve 72 is less than the angle on the outside of the curve 74. This disparity in angle helps the stylet cannula assembly 50 & 60 curve in the bone as bone pushes against outside curve face 74 ensuring the curve radius is maintained during deployment.

(38) Referring now to FIG. 4E, the curved stylet 60 is then removed and replaced by the channeling stylet 90. The tip 94 of the channeling stylet 90 is advanced beyond the end 54 of the curved cannula 50 towards the intended target treatment zone.

(39) Referring now to FIG. 4F, once the channeling stylet 90 reaches the target treatment zone, it is removed creating a working channel 146. Channel 140 will generally have a first section 142 that crosses the cortical bone of the pedicle 138, followed by a curved path 144. These sections are occupied by curved cannula 50 such that a treatment device fed through the cannula 50 will have to follow the curve of the cannula 50 and not veer off in another direction. The channel may further comprise the linear extension 146 in the cancellous bone 124 to further advance the treatment device toward the treatment site T.

(40) With the trocar 20 and curved cannula 50 still in place, a treatment device (e.g. treatment probe 100 shown in FIG. 2, with an active element 102 on the distal end 104 of elongate flexible catheter 110 is delivered to the target treatment location T to perform a localized treatment.

(41) In a preferred embodiment, the active element 102 is delivered to the treatment site and activated to delivery therapeutic treatment energy. The treatment probe may comprise an RF delivery probe having bipolar electrodes 106 and 108 that deliver a therapeutic level of heating to stimulate or ablate the nerve 122.

(42) It is appreciated that any number of treatment modalities may be delivered to the treatment site for therapeutic treatment. For example, treatment may be affected by monopolar or tripolar RF, ultrasound, radiation, steam, microwave, laser, or other heating means. Additionally, the treatment device may comprise a fluid delivery catheter that deposits an agent, e.g. bone cement, or other therapeutic agent, to the treatment site T. Alternatively, cryogenic cooling may be delivered for localized treatment of the BVN. Furthermore, treatment may be affected by any mechanical destruction and or removal means capable of severing or denervating the BVN. For example, a cutting blade, bur or mechanically actuated cutter typically used in the art of arthroscopic surgery may be used to affect denervation of the BVN.

(43) In addition to or separate from treating the BVN, a sensor may be delivered to the region to preoperatively or postoperatively measure nerve conduction at the treatment region. In this configuration, the sensor may be delivered on a distal tip of a flexible probe that may or may not have treatment elements as well.

(44) The goal of the treatment may be ablation, or necrosis of the target nerve or tissue, or some lesser degree of treatment to denervate the BVN. For example, the treatment energy or frequency may be just sufficient to stimulate the nerve to block the nerve from transmitting signal (e.g. signals indicating pain).

(45) Once the treatment is complete, the probe 100 is withdrawn. The curved cannula 50 is then withdrawn into the needle trocar 20. The needle trocar 20 with the curved cannula 50 is then removed and the access site is closed as prescribed by the physician.

(46) In the above system 10, the design of the curves 56 and 66 of the curved cannula 50 and curved stylet 60 is such that the flexible element (e.g. carrying the treatment device) can navigate through the angular range of deployment of the Nitinol tube of the curved cannula 50. The curved nitinol tube 50 allows the flexible element to navigate through a curve within bone without veering off towards an unintended direction. Cancellous bone density varies from person to person. Therefore, creating a curved channel within varying density cancellous bone 124 will generally not predictably or accurately support and contain the treatment device as it tries to navigate the curved channel.

(47) With the system 10 of the present invention, the treatment device 100 is deployed into the bone through the curved Nitinol tube of the curved cannula 50, which supports the element as it traverses through the curve. When it departs from the tube, it will do so in a linear direction along path 146 towards the target zone. This allows the user to predictably and accurately deploy the treatment device towards the target zone T regardless of the density of the cancellous bone.

(48) In some embodiments, a radius of curvature that is smaller than that which can be achieved with a large diameter Nitinol tube may be advantageous. To achieve this, the curved tube of the curved cannula 50 may take one of several forms. In one embodiment, the tube 50 is formed from a rigid polymer that can be heat set in a particular curve. If the polymer was unable to hold the desired curve, an additional stylet (e.g. curved stylet 60) of Nitinol, or other appropriate material, may also be used in conjunction with the polymer tube to achieve the desired curve. This proposed combination of material may encompass and number or variety of materials in multiple different diameters to achieve the desired curve. These combinations only need to ensure that the final outside element (e.g. trocar 20) be “disengageable” from the internal elements and have an inner diameter sufficient to allow the desired treatment device 100 to pass to the treatment region T.

(49) In an alternative embodiment, of the curved cannula 50 may comprise a Nitinol tube having a pattern of reliefs or cuts (not shown) in the wall of the tube (particularly on the outer radius of the bend). The pattern of cuts or reliefs would allow the tube to bend into a radius tighter than a solid tube could without compromising the integrity of the tubing wall.

(50) FIG. 5 illustrates a second embodiment of the system or kit 200 of the present invention that may be used to reduce the number of steps required for the procedure. The second embodiment includes a needle trocar 20, straightening stylet 40, used with the needle trocar 20 and the curved cannula 50 to create the initial path through the soft tissue and cortical shell to allow access to the cancellous bone, curved stylet 60 used in conjunction with the curved cannula 50 to create the curved path within the bone/tissue, and channeling stylet 90 used to create a working channel for the probe beyond the end of the curved path created by the curved stylet.

(51) In one method according to the present invention, the straightening stylet 40 is inserted into the curved cannula 50 and secured. In this embodiment, the straightening stylet 40 has a sharp tip 46 designed to penetrate bone. Once the straightening stylet 40 is secure and the curved cannula 50 is straight, they are inserted into the needle trocar 20 and secured. In this embodiment, the curved cannula 50 and straightening stylet 40 are inserted into the shaft 28 of the trocar 20 only as far as to have sharp tip 46 of the straightening stylet 40 protrude from the distal end 22 of the trocar 20. Proper alignment is maintained by aligning a flat on the upper portion of the curved cannula 50 with a pin secured perpendicularly into the needle trocar 20 handle.

(52) Referring now to FIG. 6, once the curved cannula 50 is secure, the assembly (trocar 20, curved cannula 50, and straightening stylet 40) is advanced through soft tissue to the surface of the bone. After finding the proper alignment at the pedicle 138 of vertebrae 120, the assembly (trocar 20, curved cannula 50, and straightening stylet 40) is advanced through the cortical shell 128 and into the cancellous interior 124 of the bone.

(53) After the proper depth is achieved, the straightening stylet 40 is removed. The curved stylet 60 is then straightened out by sliding the small tube 68 on its shaft towards the distal tip 64. The curved distal tip 66 is straightened out and fully retracted inside the small tube 68, and then the curved stylet 60 is inserted into the curved cannula 50 which still resides inside the needle trocar 20. Once the curved stylet 60 is inserted into the curved cannula 50, the small tube 68 is met by a stop 55 (see FIG. 4C). As the curved stylet 60 continues to advance, the small tube 68 is held inside the handle of the curved cannula 50. This allows the curve of the stylet 60 to be exposed inside the curved cannula 50.

(54) To create the maximum force, it is preferred that the curves of the two parts (50 & 60) are aligned. To ensure alignment the cap on the curved stylet 60 has an alignment pin, which engages with a notch on the top of the curved cannula 50.

(55) When the stylet 60 is fully seated and aligned with the curved cannula 50, the tip of the curved stylet 60 will protrude from the tip of the curved cannula 50 by about 1/16 to 3/16 inches. This protrusion will help to drive the curved cannula 50 in the direction of its orientation during deployment. Once the curved stylet 60 and the curved cannula 50 are engaged, the lock nut at the top of the curved cannula 50 is rotated counter clockwise to allow the cannula 50 and stylet 60 to be advanced with relation to the needle trocar 20 (as shown in FIG. 4D). As the curved cannula and stylet are advanced they generate a curved path toward the treatment location T. Once the curved cannula 50 and stylet 60 are deployed to the intended angle, the lock nut at the top of the curved cannula 50 is engaged with the needle trocar 20 to stop any additional advancement of the curved stylet cannula assembly.

(56) The curved stylet 60 is then removed and replaced by the channeling stylet 90. The channeling stylet 90 is advanced beyond the end of the curved cannula 50 (see FIG. 4E) towards the intended target treatment zone creating a working channel for the active element to be inserted. Once the channeling stylet 80 reached the target treatment zone it is removed and replaced by the treatment device 100, which is delivered to the treatment site T and activated.

(57) Once the treatment is complete, the treatment device 100 is withdrawn. The curved cannula 50 is then withdrawn into the needle trocar 20. The needle trocar 20 with the curved cannula 50 is then removed and the access site is closed as prescribed by the physician.

(58) FIGS. 7A and 7B illustrate detail views of a Nitinol wire for the curved stylet 60 (proximal end not shown). The wire comprises a shaft 78 having constant diameter D and a length Ls that may vary according to the application and desired depth to the treatment location. The wire has a preformed distal tip that is curved to have a radius r that redirects the distal tip 64 at an angle Θ with the shaft. As shown in FIG. 7A, angle Θ is shown to be approximately 110°. However, it is appreciated that the preformed tip may have an angle ranging from a few degrees (slight deflection off axis), to up to 180° (e.g. directing back toward the proximal end).

(59) As shown in FIG. 7B detailing the distal tip 64, the tip may have a distal extension LT that extends away from the shaft 78. To promote channeling along a path that follows radius r, the distal tip 64 is configured with dual-plane bevels 74 and 72. Plane 74 is offset at angle β, and plane 72 is offset at angle α. This configuration of the leading—allows for the stylet and/or curved cannula to travel through bone in a path correlating to the specified curve in the stylet and/or cannula.

(60) In the example illustrated in FIGS. 7A and 7B, the curved stylet 60 has a shaft length Ls of approximately 3.6 in., diameter D of approximately 0.040 in., and a distal tip length L.sub.T of 0.125 in., radius r of 0.40 in., and angle β=35° and angle α=31°. It should be noted that the above dimensions are for illustration only, and may vary depending on the anatomy and tissue type.

(61) It is appreciated that all the above embodiments may be provided as a kit of instruments to treat different regions of the body. For example, the location, orientation and angle of the treatment device with respect to the trocar 20 may be varied by providing a set of instruments at varying increments. This may be achieved by varying the curvature (56, 66) in the curved cannula 50 and curved stylet 60. The curvature may be varied by varying the radius of curvature r, the insertion depth (shaft length Ls and tip length L.sub.T, and/or the final exit angle Θ with respect to the trocar 20 central bore. Thus, the physician may select a different kit for treating a lumber spine segment as opposed to a cervical spine segment, as the anatomy will dictate the path that needs to be channeled.

(62) Thus, when treating different spine segments, a set out of the kit may be selected to match the vertebra (or other region being treated). For example, delivering the treatment device at or near the BVN junction for a lumbar vertebra may have a different angle than for a cervical vertebra, and may vary from patient to patient. The set may be selected from the kit intra-operatively, or from a pre-surgery diagnostic evaluation (e.g. radiographic imaging of the target region).

(63) Tube in Windowed Tube

(64) FIGS. 8-18B illustrate a system 201 for generating a curved path in bone according to the present invention. FIG. 8 shows a perspective view of system 201 in a configuration ready for deployment within a patient's body. System 201 comprises an introducer/trocar 210 having a proximal end housing 202 coupled to an elongate delivery tube 204. The distal end tip 208 has a sharpened and/or beveled tip to facilitate entry into and delivery through at least a portion of a bony mass such as the vertebral body.

(65) The proximal end of the assembly (drive nut 270), may comprise a hard, rigid material to allow the trocar 210 to be tapped into place with a mallet or the like.

(66) The tube body 204 comprises a laterally positioned radial opening or window 212 disposed just proximal or at the distal tip 208. The window 212 provides radial access from the central channel 218 of tube 204 so that an instrument or probe (e.g. probe 250 distal end) may be delivered at an angle (e.g. non-axial) with respect to the tube axis or central channel 218.

(67) FIG. 9 illustrates an exploded view of system 201 prior to delivery within a patient. While it is preferred that the trocar 210 is introduced to a location near the target treatment site as a whole assembly shown in FIG. 8, it is also appreciated that the trocar may be introduced to the location by itself, with the additional components being positioned once the trocar 210 is in place. In such a configuration, a stylet (not shown) may be positioned down the central channel 218 of the trocar 204 so as to block the aperture 212 from bone fragments or other tissue matter entering in channel 218. The stylet may have a hard, widened proximal end to allow the trocar 210 to be tapped into place.

(68) The proximal end 206 of trocar housing 202 comprises a centrally-located, counter-bore or recess 216 that is in communication with trocar channel 218. Trocar recess 216 allows placement and reciprocation of curveable cannula 230 within the trocar recess 216 and trocar central channel 218. The curveable cannula 230 may be held in place at a specified location within the trocar recess 216 via a stop nut 240 that is threaded about proximal body 246 of the curveable cannula 230. The curveable cannula 230 also comprises a central recess 268 within proximal body 246 that is centrally aligned with cannula channel 245. Central recess 268 and cannula channel 245 are configured to receive and allow reciprocation of probe 250, which is threaded into drive nut 270.

(69) FIGS. 10A-10E schematically illustrate the system 201 in various stages of deployment in accordance with the present invention. FIGS. 11, 13, 15 and 16 illustrate section views of the proximal end of system 201 through the various stages embodied in FIGS. 10A-E. Correspondingly, FIGS. 12, 14, illustrate close-up views of the distal end of system 201 through various the stages embodied in FIGS. 10A-E.

(70) FIG. 11 illustrates a sectional view of the proximal end of system 201 in an un-deployed state prior to or during insertion of the trocar 210 to the desired treatment location in the patient. For delivery into a vertebral body 120 (e.g. to access the BVN), the trocar 210 may be delivered through pedicle 138 via channel 140 (as shown in FIG. 3). Channel 140 may be a pre-drilled hole, or may be generated by insertion of the sharpened tip 208 into the bone. To facilitate insertion, the proximal surface 292 of cap 290 of the drive nut 270 may comprise a rigid material (e.g. stainless steel or the like) so that a mallet or similar device may strike surface 292 to tap the trocar body 204 into place.

(71) During insertion of the trocar 210, the stop nut 240 is threaded distally along external threads 248 of the proximal body 246 of the curveable cannula 230 to restrict motion of the cannula 230 distally down trocar recess 216. This restrained motion keeps the distal end 232 of the cannula 230 from prematurely deploying while the trocar 210 is being delivered.

(72) As shown in FIG. 12, the distal tip 233 of the curveable cannula 230 comprises a series of tubular mating links 234 each having a central bore to provide a continuous cannula channel 245 along with cannula tube 244. Cannula channel 245 extends from central cannula recess 268 of the proximal body 246 to the distal link 232 at tip 233. Distal link 232 comprises a beveled tip 233 to facilitate the curveable cannula 230 generating a path through bone as detailed below. Distal link 232 may also comprise a hard material, e.g. stainless steel or the like to provide a rigid leading edge for the curveable cannula 230.

(73) The mating links 234 are held together with a cord 242 that runs from the proximal body 246 of the curveable cannula 230, and terminates at an aperture 236 in the distal link 232. The distal end of cord 242 terminates at a ball 238 that is disposed in a counter-bore, countersink, or like retaining surface of the aperture 236 to retain the cord within the distal link 232.

(74) Referring now to FIG. 10B, once the trocar 210 is in place, stop nut 240 is threaded proximally along external threads 248 of the proximal end 246 of the curveable cannula 230 to allow motion of the cannula 230 distally downward in recess 214.

(75) The proximal body 246 of curveable cannula 230 may then be deployed downward within trocar recess 216, as shown in section view in FIG. 13. As there may be resistance from the bony mass of the vertebral body (or other bony mass), the cannula 230 may be tapped downward by striking the proximal surface of cap 290 (e.g. with a mallet or the like) while holding the trocar at housing 202. The motion of proximal body 246 pushes tube 244 distally within channel 218 of the trocar body 204. This forces the leading edge 232 and trailing mating links 234 out of the radial window 212 in tube 204, as shown in FIG. 14. The distal end of opening or window 212 comprises a ramp 209 to facilitate the leading edge 232 out the window 212 at the proper angle with respect to the trocar tube 204 central axis, and without catching or getting stuck at the distal end of the trocar.

(76) In addition to the ramp 209, the curved path of the distal tip 233 is facilitated by tension provided by cord 242, which forces the mating links 232, 234 to arch upon the applied tension. The cord 242 is coupled to male-threaded dial 212 (see FIG. 8) to act as a pull cord to apply said tension. The dial 212 may be turned clockwise or counterclockwise within internal—threaded arm 214 to increase or relieve the tension on the cord 242, thereby providing steering of the distal tip 233 while the curved cannula 230 is advanced down trocar body 204 and out window 212 (e.g. increased tension provides a sharper radius, decreased tension provides a more relaxed or no radius.)

(77) Alternatively, cord 242 may comprise a memory material such as a Nitinol wire that fastens the tube 244 and links 232, 234 in a preformed curved-shape. The cord 246 in this configuration stretches to allow the curveable cannula 230 to be delivered into and stowed in a linear form within channel 218, and retracts when not restrained in channel 218 to drive a curved path when exiting window 212.

(78) As shown in FIGS. 13 and 14, the curveable cannula 230 is fully deployed, with the proximal end 246 disposed at the bottom of recess 216, and the distal tip 233 in a deployed orientation forming a curved path (along with trailing links 234) through the bone at the treatment site. In this configuration, the probe 250 is restrained from axial motion (in the distal direction) with respect to the curved cannula 230, because it is threaded inside drive nut 270, which is restrained from distal motion by stop 258 in the proximal end 246.

(79) As shown in FIG. 15, the drive nut 270 may be raised (proximally advanced out of cavity 268) with respect to the curveable cannula 230 and probe proximal body 254 by rotating the drive nut. The proximal body 254 of the probe 250 comprises a male thread 256 that mates with the female internal threads 262 in a distal recess of the drive nut 270. The thread pattern 256/262 may preferably be opposite of the thread pattern between the stop nut 240 and proximal end 246 of the curveable cannula 230 (e.g. right-handed thread vs. left-handed thread), so that rotation of the drive nut 270 does not result in rotation of the curveable cannula 230.

(80) Furthermore, the proximal end 254 of the probe 250 comprises a plurality of vertical groves 264, at least one of which interfaces with key 266 of the curveable cannula 230. This interface only allows axial motion of the proximal body 264 with the curveable cannula 230, and restricts rotation of the proximal body 264 with the curveable cannula 230. Thus, rotation of the drive nut 270 only results in proximal translation of the drive nut 270. As seen in FIG. 15, the probe proximal body 254 is now free to move downward in cavity 268.

(81) Referring now to FIGS. 16 and 17, the system 201 is shown in a fully deployed state, with the probe 250 distal shaft advanced beyond distal end 233 of the curveable cannula central channel 245. This is achieved by advancing the proximal body 254 within the cavity 268 of the curveable cannula 230. The proximal body 254 and drive nut 270 are advanced as a unit within cavity 268, preferably by tapping the cap 290, thereby providing an impact force to advance the probe tip 274 out of the cannula 230 and through tissue/bone to reach the desired treatment or diagnostic location within the body.

(82) In an alternative embodiment, a channeling stylet (such as stylet 90 shown in kit 10 of FIG. 1) may also be used to create a working channel beyond the end of the curved path created by the curveable cannula 230 prior to deploying a probe for treatment or diagnostic device.

(83) Once the distal tip 274 of the probe 250 is positioned at the desired location, treatment of the target tissue may be performed. As shown in FIG. 17, probe distal end 274 may comprise a first electrode 274 configured to deliver a therapeutic amount of RF energy to the target location. In the configuration shown in FIG. 17, the probe preferably comprises a bipolar probe with return electrode 276, however it is appreciated that the probe 250 may comprise any treatment instrument described herein.

(84) Cap 290 may further be configured to include (e.g. a self contained unit) a power source (e.g. battery) and receptacles (not shown) to couple to the probe 250, thereby supplying the energy to deliver a therapeutic level of energy to the tissue. In this configuration, the cap 290 may have sufficient power to deliver one or more metered doses of energy specifically measured to denervate the BVN of a vertebral body in accordance with the present invention.

(85) The cap 290 is preferably treaded (or otherwise releasable coupled) into drive nut 270 to be interchangeable depending on the application or step the procedure of the present invention. For example, a cap 290 having a reinforced/hardened surface 292 used for driving the system 201 into the bone may be replaced by another cap having couplings (not shown) for probe 250, an internal power supply (not shown), or couplings for an external power supply/controller (not shown) for delivering energy for treatment and/or diagnosis of a region of tissue. For embodiments wherein a fluid and/or agent is delivered to the target tissue, the cap 290 may be configured to facilitate delivery of the fluid through a probe having one or more fluid delivery channels.

(86) FIGS. 18A and 18B are side views of the distal end of the system 201 with the curveable cannula 230 in a stowed and deployed position respectively. The distal link 232 and trailing links 234 are configured to have mating/interlocking surfaces that allow the distal end of the cannula to curve in one direction. The more distal link of a mating pair will have an extension 235 that mates with a correspond depression 237 in the link proximal to it. This allows the links to rotate with respect to each other to create a curved distal end as shown in FIG. 18B.

(87) FIGS. 19A and 19B illustrate an alternative system 300 for generating a curved channel through bone. System 300 comprises a tubular trocar body 302, the proximal end (not shown) of which may comprise a portion or all of any of the previously described proximal ends for devices 10, 200, or 201 disclosed herein. The distal tip 334 comprises a leading edge surface for advancing through bone, and a radial or lateral window 304 allowing access to the central channel of the trocar body 302. The window 304 is positioned a short distance proximal to the distal tip 334.

(88) A curveable cannula 322 is positioned in the trocar 302, the curveable cannula 322 having a distal end 324 coupled via linkage 326 to a pivotable arm 310. The proximal end (not shown) of the curveable cannula may comprise a portion or all of any of the previously described proximal ends for devices 10, 200, or 201 disclosed herein. The pivotable arm 310 has a first end pivotable coupled at joint 314 at a location at or near the distal tip 334 of the trocar 334. In a stowed configuration (illustrated in FIG. 19A), the pivotable arm is configured to lay axially in the trocar 302 within slot 306 that runs from pivot 314 proximally to the radial opening or window 304. The proximal (when stowed) end 312 of the arm 310 is coupled to the linkage 326.

(89) As shown in FIG. 19B, the cannula 322 may be advanced laterally outward from window 304 by simply advancing the cannula 322 distally down the trocar 302. The pivotable arm 310 constrains the motion of the curveable end 320 of the cannula to a curved path of specified radius (determined by the length of arm 310. Once the pivotable arm has reached full rotation (shown approximately 90 degrees in FIG. 19B, however such angle may be specified to be any desired amount), the cannula end 320 has created a curved path outward from the trocar toward the desired treatment site. A probe, stylet or similar device (such as curved stylet 60, channeling stylet 90, or probe 100 of FIG. 1) may be positioned at the opening of the distal end 320 to facilitate generating the curved bore without allowing tissue or bone to enter the cannula. The probe, treatment/diagnostic device may then be routed through the cannula end 320 to a region of tissue/bone that is off-axis from the trocar body 302.

(90) It is appreciated that the above systems 201, 300 may be provided as a kit of instruments to treat different regions of the body. For example, the location, orientation and angle of the treatment device with respect to the trocar may be varied by providing a set of instruments at varying increments. This may be achieved by varying the curvature in the curveable cannula (230, 320). The curvature may be varied by varying the radius of curvature, the insertion depth (shaft length and tip length, and/or the final exit angle with respect to the trocar central bore. Thus, the physician may select a different kit for treating a lumber spine segment as opposed to a cervical spine segment, as the anatomy will dictate the path that needs to be channeled.

(91) It is appreciated that each of the instruments in the systems 10, 200, 201, and 300 detailed above may have any length, shape, or diameter desired or required to provide access to the treatment/diagnostic region (e.g. intraosseous nerve trunk) thereby facilitating effective treatment/diagnostic of the target region. For example, the size of the intraosseous nerve to be treated, the size of the passageway in the bone (e.g. pedicle 138) for accessing the intraosseous nerve, and the location of the bone, and thus the intraosseous nerve, are factors that that may assist in determining the desired size and shape of the individual instruments.

(92) The systems 10, 200, 201 and 300 described above may be used with a number of different treatment modalities for therapeutic treatment of the target region. For example, in one embodiment, it is desirable to operate the treatment devices or probes in systems 100, 200, 20 and 300 in a manner that ablates the tissue of the target region (e.g. BVN) to produce heat as described in U.S. Pat. No. 6,699,242, herein incorporated by reference in its entirety.

(93) In another embodiment, the treatment device is configured to deliver therapeutic treatment that is targeted to block nerve conduction without ablating the nerve, i.e. thermal treatment is delivered to the nerve (e.g. via thermal therapy, agent or the like) that results in denervation of the BVN without necrosis of tissue. This may be achieved via delivery of a lesser amount of energy or agent to the tissue site (either in the form of less exposure time, concentration, intensity, etc.) than is required for ablation, but an amount sufficient to achieve some amount of temporary or permanent denervation.

(94) It is further envisioned that the probed described herein may comprise non-therapy devices, such as diagnostic devises (e.g. ultrasound, cameras, or the like) to diagnose a region of tissue independent of or in connection with treatment of the region of tissue.

(95) It is also appreciated that individual elements of any of the systems 10 200, 201, and 300 detailed above may be used interchangeably where applicable. For example, the curved stylet 60 shown in systems 10 and 200 may be temporarily implemented in place of the probe of systems 201 and 300 to provide additional curving bias to the curveable cannula (230, 320) while the cannula is being driven into the bone. Furthermore, the channeling stylet 90 may be used to further generate a channel beyond the curved path provided by the curveable cannula (230, 320)

(96) As can be seen, therefore, the present invention includes the following inventive embodiments among others:

(97) 1. A system for channeling a path into bone, comprising: a trocar having a proximal end, distal end and a central channel; wherein the central channel is disposed along a central axis of the trocar and extends from the proximal end toward the distal end; wherein the trocar comprises a radial opening at or near the distal end of the trocar, the radial opening being in communication with the central channel; and a curveable cannula sized to be received in said central channel and delivered from the proximal end toward said radial opening; the curveable cannula comprising a curveable distal end configured to be extended laterally outward from the radial opening in a curved path extending away from the trocar; wherein the curveable cannula comprises a central passageway having a diameter configured allow a probe to be delivered through the central passageway to a location beyond the curved path.

(98) 2. A system according to embodiment 1, wherein the trocar further comprises a sharp distal tip configured to pierce through bone to generate a linear path through bone.

(99) 3. A system according to embodiment 2, wherein the curveable cannula comprises a sharpened distal tip configured to pierce through bone to generate a curved path extending from a linear path generated by the trocar.

(100) 4. A system according to embodiment 1, wherein the distal end of the curveable cannula is deformable so as to be delivered in a straight configuration through the trocar and deployed in a curved configuration outward from the radial opening at an angle with respect to the central axis.

(101) 5. A system according to embodiment 4, further comprising: a pull cord coupled to the distal tip of the curveable cannula, the pull cord extending to the proximal end of the trocar; wherein the pull cord is configured to apply a tensile force to the distal end of the curveable cannula to bias the curveable cannula into a curved configuration.

(102) 6. A system according to embodiment 5, wherein the tensile force applied to the distal tip of the curveable cannula may be controlled from the proximal end of the trocar to steer the curveable cannula along a desired path.

(103) 7. A system according to embodiment 4, wherein a distal end of the curveable cannula comprises a plurality of mating links, the links configured to articulate into a curved shape.

(104) 8. A system according to embodiment 4, wherein the central channel of the trocar terminates at a ramp leading to the radial window, said ramp facilitating deployment of said curveable cannula outward from said window.

(105) 9. A system according to embodiment 1, wherein: the curveable cannula comprises a proximal end comprising a proximal body wherein the proximal end of the trocar comprises a housing: said housing having a proximal recess configured to allow reciprocation of the proximal body of the curveable cannula; wherein the proximal recess is in communication with the central channel.

(106) 10. A system according to embodiment 9, wherein a proximal body of the curveable cannula is configured to be releasably restrained with respect to translation within the trocar housing.

(107) 11. A system according to embodiment 10, further comprising a probe sized to fit within the central channel of the cannula; the probe comprising a proximal end configured to be releasably restrained with respect to translation within the cannula proximal body.

(108) 12. A system according to embodiment 11, further comprising a drive nut coupled to the curveable cannula; wherein the drive nut comprises a hardened proximal surface suitable for applying an impact force to advance one or more of the trocar, curveable cannula, or probe through bone.

(109) 13. A system according to embodiment 12, wherein the drive nut comprises a threaded distal recess configured to house the proximal end of the probe.

(110) 14. A system according to embodiment 12, wherein the proximal surface of the drive nut comprises an interchangeable cap; said interchangeable cap configured to provide access to the probe for providing a therapeutic energy.

(111) 15. A method for channeling a path into bone to a treatment location in the body of a patient, comprising: inserting a trocar into a region of bone near the treatment location; the trocar having a having a proximal end, distal end and a central channel disposed therebetween; wherein the trocar comprises a radial opening at or near the distal end of the trocar, the radial opening being in communication with the central channel; delivering a curveable cannula through said central channel and to said radial opening; and deploying the curveable cannula laterally outward from the radial opening in a curved path extending away from the trocar.

(112) 16. A method according to embodiment 15, further comprising: delivering a treatment device through a central passageway in the curveable cannula to a treatment location beyond the curved path.

(113) 17. A method according to embodiment 16, further comprising: delivering a therapeutic amount of thermal energy to the treatment location.

(114) 18. A method according to embodiment 17, wherein inserting a trocar into a region of bone comprises: deploying the trocar through a cortical bone region and into a cancellous bone region of a vertebral body; wherein the curved path is generated though at least a portion of the cancellous bone region of the vertebral body.

(115) 19. A method according to embodiment 16, further comprising: steering the curveable cannula via a pull cord coupled to the distal tip of the curveable cannula to bias the curveable cannula in the curved path.

(116) 20. A method according to embodiment 18, wherein the treatment location comprises a BVN associated with the vertebral body, the method further comprising: delivering the thermal energy to the treatment location to denervate at least a portion of the BVN.

(117) 21. A spine therapy system, comprising: a trocar having a proximal end, distal end and a central channel; wherein the central channel is disposed along a central axis of the trocar and extends from the proximal end toward the distal end; wherein the trocar comprises a radial opening at or near the distal end of the trocar, the radial opening being in communication with the central channel; wherein the trocar is configured to be deployed through a cortical bone region and into a cancellous bone region of a vertebral body; a curveable cannula sized to be received in said central channel and delivered from the proximal end toward said radial opening; the curveable cannula comprising a central passageway and curveable distal end configured to be extended laterally outward from the radial opening in a curved path extending away from the trocar; wherein the curved path is generated though at least a portion of the cancellous bone region of the vertebral body; and a treatment probe configured to be delivered through the central passageway to a location beyond the curved path.

(118) 22. A system according to embodiment 21, wherein the trocar further comprises a sharp distal tip configured to pierce through bone to generate a linear path through bone.

(119) 23. A system according to embodiment 22, wherein the curveable cannula comprises a sharpened distal tip configured to pierce through bone to generate a curved path extending from a linear path generated by the trocar.

(120) 24. A system according to embodiment 21, wherein the distal end of the curveable cannula is deformable so as to be delivered in a straight configuration through the trocar and deployed in a curved configuration outward from the radial opening at an angle with respect to the central axis.

(121) 25. A system according to embodiment 24, further comprising: a pull cord coupled to the distal tip of the curveable cannula, the pull cord extending to the proximal end of the trocar; wherein the pull cord is configured to apply a tensile force to the distal end of the curveable cannula to bias the curveable cannula into a curved configuration.

(122) 26. A system according to embodiment 24, wherein a distal end of the curveable cannula comprises a plurality of mating links, the links configured to articulate into a curved shape.

(123) 27. A system according to embodiment 21, wherein: the curveable cannula comprises a proximal end comprising a proximal body wherein the proximal end of the trocar comprises a housing: said housing having a proximal recess configured to allow reciprocation of the proximal body of the curveable cannula; and wherein the proximal recess is in communication with the central channel.

(124) 28. A system according to embodiment 27, wherein a proximal body of the curveable cannula is configured to be releasably restrained with respect to translation within the trocar housing.

(125) 29. A system according to embodiment 28, wherein the probe comprises a proximal end configured to be releasably restrained with respect to translation within the cannula proximal body.

(126) 30. A system according to embodiment 29, further comprising: a drive nut coupled to the curveable cannula; wherein the drive nut comprises a hardened proximal surface suitable for applying an impact force to advance one or more of the trocar, curveable cannula, or probe through bone; wherein the drive nut comprises a threaded distal recess configured to house the proximal end of the probe; wherein the probe comprises mating threads with the distal recess so as to allow controlled translation of the probe with respect to the drive nut.

(127) 31. A system according to embodiment 30, wherein the proximal surface of the drive nut comprises an interchangeable cap; said interchangeable cap configured to provide access to the probe for providing a therapeutic energy.

(128) Although the description above contains many details, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.”