EP4626337A1

EP4626337A1 - Basivertebral nerve access tool, system, and method

Info

Publication number: EP4626337A1
Application number: EP23825240.7A
Authority: EP
Inventors: David John Miller; David Scott Hazlitt; Christopher Kenley SEIGHMAN; Jonathan Bradley Duke; Quinn Jefferson KESSER; Nathan H. White
Original assignee: Medtronic Europe Sarl
Current assignee: Medtronic Europe Sarl
Priority date: 2022-11-30
Filing date: 2023-11-29
Publication date: 2025-10-08
Also published as: WO2024116100A1

Abstract

A surgical access tool (100) includes a split-housing body including a distal portion (108) and a proximal portion (112), the split-housing body movable between a locked state engaged with the distal portion and an unlocked state disengaged from the distal portion, a sheath shaft (116) fixed to the distal portion extends a first length from a first end of the sheath shaft to a second end of the sheath shaft, a channeling tool (120) attached to the proximal portion includes a flexible shaft that is disposed in a lumen of the sheath shaft when the split-housing body is in the locked state and a handle, interconnected to the proximal portion, when rotated in a first direction, is capable of moving the channeling tool from an unbent state into a bent state, and the proximal portion and the channeling tool are separable from the distal portion when the split-housing body is in the unlocked state.

Description

BASIVERTEBRAL NERVE ACCESS TOOL, SYSTEM, AND METHOD

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of and priority to U.S. Provisional Application Serial No. 63/429,077, filed on November 30, 2022, entitled “BASIVERTEBRAL NERVE ACCESS TOOL, SYSTEM, AND METHOD,” the entire disclosure of which is hereby incorporated herein by reference, in its entirety, for all that it teaches and for all purposes.

BACKGROUND

[0002] The present disclosure is generally directed to surgical tools, and relates more particularly to surgical access tools.

[0003] Basivertebral nerve (“BVN”) ablation is a minimally invasive surgical procedure in which an incision is generally made in the back of a subject and access is provided to a site within the spine where the BVN is determined to be a cause of back pain. The access allows a probe to be routed to the site where a portion of the subject’s BVN is subsequently ablated to mitigate or even prevent the generation of future nerve signals that cause pain.

BRIEF SUMMARY

[0004] Example aspects of the present disclosure include:

[0005] A surgical access tool according to at least one embodiment of the present disclosure comprises a split-housing body comprising: a distal body portion; and a proximal body portion, wherein the proximal body portion is configured to selectively attach to the distal body portion and move between a connected state with the distal body portion and a disconnected state from the distal body portion; a sheath shaft connected to the distal body portion and extending a first length from a first end of the sheath shaft to a second end of the sheath shaft, wherein a lumen passes through the sheath shaft from the first end of the sheath shaft to the second end of the sheath shaft; a channeling tool connected to the proximal body portion, the channeling tool comprising; a threaded block; an outer shaft connected to the proximal body portion, the outer shaft extending a second length from a first end of the outer shaft to a second end of the outer shaft, wherein, when the proximal body portion is in the connected state, the outer shaft is disposed at least partially within the lumen of the sheath shaft; and an inner shaft disposed at least partially inside the outer shaft, the inner shaft connected to the threaded block at a first end of the inner shaft, the inner shaft extending a third length from the first end of the inner shaft to a second end of the inner shaft, wherein the inner shaft is fixed to the outer shaft at the second end of the inner shaft and the second end of the outer shaft; and a handle comprising a grip portion and a threaded portion, wherein the handle is rotationally attached to the proximal body portion of the split-housing body such that the grip portion is arranged outside of the proximal body portion and the threaded portion is threadedly engaged with the threaded block, wherein, based on a rotational position of the handle, the first end of the inner shaft is axially movable between a first position relative to the first end of the outer shaft and a second position relative to the first end of the outer shaft, wherein, in the first position relative to the first end of the outer shaft, the inner shaft and outer shaft are unbent along an axial section adjacent the second end of the outer shaft, and wherein, in the second position relative to the first end of the outer shaft, inner shaft and outer shaft are bent along the axial section adjacent the second end of the outer shaft. [0006] Any of the aspects herein, wherein the channeling tool further comprises: a tapered tip arranged at the second end of the inner shaft and the second end of the outer shaft, wherein a steering plane of the channeling tool passes through a longitudinal axis of the outer shaft and the tapered tip, and wherein the steering plane defines a plane in which the inner shaft and outer shaft bends when the first end of the inner shaft moves between the first position relative to the first end of the outer shaft and the second position relative to the first end of the outer shaft.

[0007] Any of the aspects herein, wherein the split-housing body comprises a cross- sectional outer peripheral shape comprising at least one of a pear shape and a triangular shape, and wherein the steering plane passes through an apex of the outer peripheral shape.

[0008] Any of the aspects herein, wherein the apex is disposed along a first portion of the outer peripheral shape having a first radius, and wherein the first radius is less than a second radius disposed on a second portion of the outer peripheral shape adjacent to a point opposite the apex.

[0009] Any of the aspects herein, further comprising a cam lock collar attached to the proximal body portion, the cam lock collar comprising: a body extending a width from a first side of the body to a second side of the body and extending a height from an upper end of the body to a lower end of the body; a first button protruding from the upper end of the body; a second button protruding from the lower end of the body; a split-nut cam aperture disposed through a thickness of the body; and a cam slot disposed in the body of the cam lock collar adjacent the first side of the body.

[0010] Any of the aspects herein, wherein the threaded block comprises: a first split-nut body; a second split-nut body, that is keyed to the first split-nut body; and a pin attached to the first split-nut body, wherein the pin is engaged with the cam slot of the cam lock collar, and wherein the first split-nut body and the second split-nut body are at least partially disposed in the split-nut cam aperture.

[0011] Any of the aspects herein, wherein the cam lock collar is movable relative to the proximal body portion from a locked state to an unlocked state, wherein, in the locked state, the first split-nut body and the second split-nut body are arranged adjacent one another and the distal body portion and the proximal body portion are locked together, and wherein, in the unlocked state, first split-nut body and the second split-nut body are arranged offset a distance from one another and the distal body portion and the proximal body portion are unlocked.

[0012] Any of the aspects herein, wherein, in the unlocked state, the proximal body portion and the channeling tool are separable from the distal body portion and the sheath shaft.

[0013] Any of the aspects herein, wherein, in the locked state, the second button extends through the proximal body portion on a first side of the surgical access tool, and wherein, in the unlocked state, the first button extends through the proximal body portion on a second side of the surgical access tool, the second side of the surgical access tool disposed opposite the first side of the surgical access tool.

[0014] Any of the aspects herein, wherein, in the locked state, an axial position of the second button relative to an aperture of the proximal body portion indicates an amount of bend in at least one of the inner shaft and the outer shaft, wherein a first amount of bend is indicated when the second button is arranged a first distance from the distal body portion, wherein a second amount of bend is indicated when the second button is arranged a second distance from the distal body portion.

[0015] Any of the aspects herein, wherein the second amount of bend is greater than the first amount of bend, and wherein the second distance is greater than the first distance.

[0016] Any of the aspects herein, further comprising a coupling link attached to the cam lock collar, the coupling link comprising a locking protrusion extending substantially perpendicular to an axis of the surgical access tool, and wherein, in the locked state, the locking protrusion engages with a receiving latch contact protrusion arranged in the distal body portion locking the proximal body portion to the distal body portion.

[0017] Any of the aspects herein, further comprising a distal end plug is arranged at the second end of the inner shaft, the distal end plug comprising an outer tapered surface that is arranged coplanar with a tapered end surface of the inner shaft and with a tapered end surface of the outer shaft, wherein the distal end plug comprises a radio-opaque marker arranged inside the inner shaft.

[0018] Any of the aspects herein, wherein the distal end plug comprises stainless steel, wherein the radio-opaque marker comprises tungsten, and wherein the radio-opaque marker identifies at least one of a location, position, and rotational orientation of a distal end tip of the channeling tool.

[0019] Any of the aspects herein, wherein the distal end plug is welded to at least one of the inner shaft and the outer shaft.

[0020] Any of the aspects herein, wherein at least one surface of the handle extends past an outermost peripheral surface of the proximal body portion at a proximal end of the proximal body portion, and wherein an axial clearance runs along an axial length of the split-housing body to the at least one surface.

[0021] Any of the aspects herein, wherein a first plurality of circumferential cuts are arranged axially spaced apart from one another along a length of the outer shaft, and wherein a second plurality of circumferential cuts are arranged axially spaced apart from one another along a length of the inner shaft.

[0022] Any of the aspects herein, wherein the first plurality of circumferential cuts are arranged with first radial openings arranged on a first radial side of the outer shaft, the second plurality of circumferential cuts are arranged with second radial openings arranged on a second radial side of the inner shaft, and wherein the first radial side is arranged 180 degrees from the second radial side.

[0023] Any of the aspects herein, wherein the first radial openings are each arranged adjacent a solid portion of the inner shaft, and wherein the second radial openings are each arranged adjacent a solid portion of the outer shaft.

[0024] A surgical access tool according to at least one embodiment of the present disclosure comprises a split-housing body comprising a distal body portion and a proximal body portion, wherein the proximal body portion is configured to selectively move between a locked state engaged with the distal body portion and an unlocked state disengaged from the distal body portion; a sheath shaft fixed to the distal body portion and extending a first length from a first end of the sheath shaft to a second end of the sheath shaft, wherein a lumen passes through the sheath shaft from the first end of the sheath shaft to the second end of the sheath shaft; a channeling tool comprising a flexible shaft, the channeling tool attached to the proximal body portion at a first end of the channeling tool, wherein the flexible shaft is disposed at least partially within the lumen of the sheath shaft when the split-housing body is in the locked state; and a handle interconnected to the proximal body portion, wherein the handle, when rotated in a first direction, moves the channeling tool from an unbent state into a bent state, and wherein the proximal body portion and the channeling tool are separable from the distal body portion when the splithousing body is in the unlocked state.

[0025] A method according to at least one embodiment of the present disclosure comprises inserting a first access tool through a portion of a subject to a first point in proximity to a treatment site, the first access tool comprising an access shaft extending from the first point to a point outside of a body of the subject; providing a surgical access tool, comprising: a split-housing body comprising a distal body portion and a proximal body portion, wherein the proximal body portion is configured to selectively move between a locked state engaged with the distal body portion and an unlocked state disengaged from the distal body portion; a sheath shaft fixed to the distal body portion and extending a first length from a first end of the sheath shaft to a second end of the sheath shaft, wherein a lumen passes through the sheath shaft from the first end of the sheath shaft to the second end of the sheath shaft; a channeling tool comprising a flexible shaft, the channeling tool attached to the proximal body portion at a first end of the channeling tool, wherein the flexible shaft is disposed at least partially within the lumen of the sheath shaft when the split-housing body is in the locked state; and a handle interconnected to the proximal body portion, wherein the handle, when rotated in a first direction, moves the channeling tool from an unbent state into a bent state, and wherein the proximal body portion and the channeling tool are separable from the distal body portion when the splithousing body is in the unlocked state; inserting the sheath shaft and the flexible shaft of the surgical access tool into the access shaft of the first access tool while the surgical access tool is in the locked state; creating a channel to the treatment site by advancing a distal tip of the channeling tool in a direction toward the treatment site; moving the splithousing body of the surgical access tool into the unlocked state; separating the proximal body portion and the channeling tool from the distal body portion and the sheath shaft while the sheath shaft remains in position in the subject; inserting an ablation probe into the sheath shaft from the first end of the sheath shaft such that a distal end of the ablation probe is arranged adjacent the treatment site; and ablating, by the ablation probe, a nerve at the treatment site.

[0026] Any of the aspects herein, further comprising removing the ablation probe from the sheath shaft; and removing the distal body portion and the sheath shaft from the subject.

[0027] Any of the aspects herein, wherein prior to removing the distal body portion and the sheath shaft from the subject, the method further comprises: moving the split-housing body of the surgical access tool into the locked state by attaching the proximal body portion to the distal body portion; and tapping a portion of the handle in an extraction direction away from the treatment site.

[0028] Any of the aspects herein, wherein the access tool is a transpedicular access tool, and wherein the portion of the subject is a pedicle of a spine of the subject to a first point in proximity to a treatment site.

[0029] Any of the aspects herein, wherein the nerve is a basivertebral nerve (“BVN”), and wherein the ablation probe is a radiofrequency ablation probe.

[0030] Any aspect in combination with any one or more other aspects.

[0031] Any one or more of the features disclosed herein.

[0032] Any one or more of the features as substantially disclosed herein.

[0033] Any one or more of the features as substantially disclosed herein in combination with any one or more other features as substantially disclosed herein.

[0034] Any one of the aspects/features/embodiments in combination with any one or more other aspects/features/embodiments.

[0035] Use of any one or more of the aspects or features as disclosed herein.

[0036] It is to be appreciated that any feature described herein can be claimed in combination with any other feature(s) as described herein, regardless of whether the features come from the same described embodiment.

[0037] The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims.

[0038] The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. When each one of A, B, and C in the above expressions refers to an element, such as X, Y, and Z, or class of elements, such as Xi-Xn, Yi-Ym, and Zi-Z₀, the phrase is intended to refer to a single element selected from X, Y, and Z, a combination of elements selected from the same class (e.g., Xi and X2) as well as a combination of elements selected from two or more classes (e.g., Yi and Z_o).

[0039] The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably.

[0040] The preceding is a simplified summary of the disclosure to provide an understanding of some aspects of the disclosure. This summary is neither an extensive nor exhaustive overview of the disclosure and its various aspects, embodiments, and configurations. It is intended neither to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure but to present selected concepts of the disclosure in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other aspects, embodiments, and configurations of the disclosure are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.

[0041] Numerous additional features and advantages of the present disclosure will become apparent to those skilled in the art upon consideration of the embodiment descriptions provided hereinbelow.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0042] The accompanying drawings are incorporated into and form a part of the specification to illustrate several examples of the present disclosure. These drawings, together with the description, explain the principles of the disclosure. The drawings simply illustrate preferred and alternative examples of how the disclosure can be made and used and are not to be construed as limiting the disclosure to only the illustrated and described examples. Further features and advantages will become apparent from the following, more detailed, description of the various aspects, embodiments, and configurations of the disclosure, as illustrated by the drawings referenced below. [0043] FIG. 1 A is a distal perspective view of a basivertebral nerve (“BVN”) access tool according to at least one embodiment of the present disclosure;

[0044] FIG. IB is a proximal perspective view of the BVN access tool shown in FIG.

1A;

[0045] FIG. 1C is an exploded distal perspective view of the BVN access tool shown in FIG. 1A;

[0046] FIG. ID is a distal elevation view of the BVN access tool shown in FIG. 1 A; [0047] FIG. IE is a schematic cross-section view of an outer peripheral shape of the BVN access tool according to at least one embodiment of the present disclosure;

[0048] FIG. 2A is a perspective view of a cam lock subassembly of the BVN access tool according to at least one embodiment of the present disclosure;

[0049] FIG. 2B is an exploded perspective view of the cam lock subassembly shown in FIG. 2A;

[0050] FIG. 2C is a schematic distal elevation cross-section view of the cam lock subassembly in a locked state;

[0051] FIG. 2D is a schematic distal elevation cross-section view of the cam lock subassembly in an unlocked state;

[0052] FIG. 2E is a side elevation cross-section view of the BVN access tool with the cam lock subassembly in a locked state;

[0053] FIG. 2F is a side elevation cross-section view of the BVN access tool with the cam lock subassembly in an unlocked state;

[0054] FIG. 2G is a side elevation cross-section view of the BVN access tool in an unlocked state with the proximal body portion separated from the distal body portion of the BVN access tool;

[0055] FIG. 3 A is a side elevation view of the sheath and tool subassembly of the BVN access tool according to at least one embodiment of the present disclosure;

[0056] FIG. 3B is an exploded side elevation view of the sheath and tool subassembly of the BVN access tool shown in FIG. 3 A;

[0057] FIG. 3C is a schematic side elevation view of the sheath and tool subassembly of the BVN access tool in a first articulated state according to at least one embodiment of the present disclosure;

[0058] FIG. 3D is a schematic side elevation view of the sheath and tool subassembly of the BVN access tool in a second articulated state according to at least one embodiment of the present disclosure; [0059] FIG. 3E is a partial side elevation cross-section view of the distal end of the channeling tool outer and inner shaft of the BVN access tool according to at least one embodiment of the present disclosure;

[0060] FIG. 3F is a partial section view of the channeling tool outer and inner shaft taken from area 3F shown in FIG. 3E;

[0061] FIG. 3G is a detail section view of the distal tip of the channeling tool taken from circle 3G shown in FIG. 3E;

[0062] FIG. 4 is a schematic cross-section view of a vertebral section of a subject used according to at least one embodiment of the present disclosure;

[0063] FIG. 5 is a side elevation view of an introducer and access system used according to at least one embodiment of the present disclosure;

[0064] FIG. 6A is a schematic diagram of a first transpedicular access procedure according to at least one embodiment of the present disclosure;

[0065] FIG. 6B is a schematic diagram of a second transpedicular access procedure according to at least one embodiment of the present disclosure;

[0066] FIG. 6C is a schematic diagram of routing a BVN access tool inside the shaft of an introducer and access system according to at least one embodiment of the present disclosure;

[0067] FIG. 6D is a schematic diagram of creating an access channel inside the vertebral body area using the BVN access tool according to at least one embodiment of the present disclosure;

[0068] FIG. 6E is a schematic diagram of creating a further access channel inside the vertebral body area using the BVN access tool to reach a treatment site according to at least one embodiment of the present disclosure;

[0069] FIG. 6F is a schematic diagram of unlocking the proximal body portion from a connected state with the distal body portion of the BVN access tool according to at least one embodiment of the present disclosure;

[0070] FIG. 6G is a schematic diagram of separating the proximal body portion from the distal body portion of the BVN access tool and removing the channeling tool portion thereof according to at least one embodiment of the present disclosure;

[0071] FIG. 6H is a schematic diagram of routing an ablation probe into the sheath shaft of the distal body portion left in place and forming a portion of the access path to the treatment site according to at least one embodiment of the present disclosure; [0072] FIG. 7A is a partial perspective cross-section view of the distal end of the ablation probe according to at least one embodiment of the present disclosure;

[0073] FIG. 7B is a detail perspective breakaway section view of the distal end of the ablation probe according to at least one embodiment of the present disclosure; and [0074] FIG. 8 is a flowchart of a method of treating a BVN according to at least one embodiment of the present disclosure.

DETAILED DESCRIPTION

[0075] It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example or embodiment, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, and/or may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the disclosed techniques according to different embodiments of the present disclosure). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a computing device and/or a medical device.

[0076] Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Further, the present disclosure may use examples to illustrate one or more aspects thereof. Unless explicitly stated otherwise, the use or listing of one or more examples (which may be denoted by “for example,” “by way of example,” “e.g.,” “such as,” or similar language) is not intended to and does not limit the scope of the present disclosure.

[0077] The terms proximal and distal are used in this disclosure with their conventional medical meanings, proximal being closer to the operator or user of the system, and further from the region of surgical interest in or on the patient/subject, and distal being closer to the region of surgical interest in or on the patient/subject, and further from the operator or user of the system.

[0078] Described herein are devices, tools, and methods of unilateral off-axis BVN access and radio frequency ablation. The devices of the present disclosure are capable of channeling through high density, low density, and/or combinations thereof bone pockets and other biological material. In at least one embodiment of the present disclosure, a BVN access tool is described including a channeling tool and access sheath shaft. The channeling tool may include a multiple shaft assembly including an inner shaft disposed within an outer shaft. The inner shaft may be locked to the outer shaft at a distal tip thereof. At least one of the inner shaft and the outer shaft may include a plurality of circumferential cuts disposed at least partially around a circumference thereof. These circumferential cuts may be configured as slots or notches that allow the inner shaft and the outer shaft of the channeling tool to flex, or bend, along an axial length of the inner and outer shaft having the circumferential cuts. In some embodiments, the circumferential cuts may be disposed spaced apart from one another along the axial length of the inner shaft and/or outer shaft. The spacing may vary depending on the desired flexibility of the inner and outer shaft. For instance, the circumferential cuts may be spaced apart from one another by a first distance along a distal tip section of the channeling tool and a second distance along a proximal section of the channeling tool. The closer the distance of the spacing between adjacent cuts, the greater the flexibility of the section will become.

[0079] Embodiments of the present disclosure provide technical solutions to one or more of the problems of (1) repeatedly removing and replacing different tools along an access path to a pain site of a subject during surgery, (2) requiring multiple tools to channel through various bone densities in a subject, (3) not knowing the position, location, rotational orientation (e.g., plane of steering, etc.) of a distal end of a channeling tool when in use during surgery, (4) not knowing an amount of curvature produced by a channeling tool, or that is available, during surgery, (5) a lack of axial stiffness in an access tool and potential buckling of the channeling tool during surgery, (6) a lack of features that allow retraction of an access tool from being embedded in a bone portion of a subject, and (7) the associated increased operation times, greater chances of injury or infection to the subject, increased risks of misalignment, and/or the like, associated with conventional tools. [0080] FIGS. 1 A-1D show various views of a BVN access tool 100 and/or one or more components, features, and aspects of the BVN access tool 100 in accordance with embodiments of the present disclosure.

[0081] Features of the BVN access tool 100 may be described in conjunction with a coordinate system 102. The coordinate system 102, as shown in the figures, includes three-dimensions comprising an X-axis, a Y-axis, and a Z-axis. Additionally or alternatively, the coordinate system 102 may be used to define planes (e.g., the XY-plane, the XZ-plane, and the YZ-plane) of the BVN access tool 100. These planes may be disposed orthogonal, or at 90 degrees, to one another. While the origin of the coordinate system 102 may be placed at any point on or near the components of the BVN access tool 100, for the purposes of description, the axes of the coordinate system 102 are always disposed along the same directions from figure to figure. In some examples, reference may be made to dimensions, angles, directions, relative positions, and/or movements associated with one or more components of the BVN access tool 100 with respect to the coordinate system 102. For example, the width of the BVN access tool 100 may be defined as a dimension along the X-axis of the coordinate system 102, the height of the BVN access tool 100 may be defined as dimension along the Y-axis of the coordinate system 102, and the length of the BVN access tool 100 may be defined as a dimension along the Z-axis of the coordinate system 102. Additionally or alternatively, the width of the housing body 104 may be defined as a dimension along the X-axis of the coordinate system 102, the height of the housing body 104 may be defined as dimension along the Z-axis of the coordinate system 102, and the length of the housing body 104 may be defined as a dimension along the Y-axis of the coordinate system 102.

[0082] The BVN access tool 100 may include a housing body 104, which may be referred to herein as a split-housing body, comprising a distal body portion 108 and a proximal body portion 112. In some embodiments, the proximal body portion 112 may be selectively locked to, and separated from, the distal body portion 108. For instance, the proximal body portion 112 may be completely separated from the distal body portion 108 upon unlocking the proximal body portion 112 from the distal body portion 108 and moving the proximal body portion 112 away from the distal body portion 108. In addition to being separated by the distal body portion 108 and the proximal body portion 112, the housing body 104 may be split into an upper housing portion 104 A and a lower housing portion 104B. As shown in FIG. IB, the upper housing portion 104A may contact the lower housing portion 104B along a housing split line 115. The housing split line 115 may be arranged along a plane that is parallel to the XY-plane of the coordinate system 102. The distal body portion 108 may include a upper distal body portion 108 A and a lower distal body portion 108B. The proximal body portion 112 may include an upper proximal body portion 112A and a lower proximal body portion 112B, as illustrated in FIG. 1C. In some embodiments, the upper distal body portion 108 A may be attached to the lower distal body portion 108B via one or more fasteners, clips, tabs, and/or the like. Similarly, if not identically, the upper proximal body portion 112A may be attached to the lower proximal body portion 112B via one or more fasteners, clips, tabs, and/or the like. In one embodiment, the upper distal body portion 108 A may be ultrasonically welded to, fused with, adhered to, and/or otherwise formed with the lower distal body portion 108B. Additionally or alternatively, the upper proximal body portion 112A may be ultrasonically welded to, fused with, adhered to, and/or otherwise formed with the lower proximal body portion 112B.

[0083] The distal body portion 108 may include the sheath shaft 116. The sheath shaft 116 may be attached to the distal body portion 108 such that the sheath shaft 116 does not rotate about the tool axis 106 or move axially along the tool axis 106 independently from the distal body portion 108. Stated another way, the sheath shaft 116 and the distal body portion 108 may be joined or fixed together. The sheath shaft 116 may provide an access path, or lumen, extending from a first end of the sheath shaft 116 disposed at a proximal end of the distal body portion 108, through the distal body portion 108, to a second end of the sheath shaft 116 disposed adjacent a distal end 140 of the BVN access tool 100.

[0084] The distal body portion 108 may include a handle recess 137 or area where a user (e.g., surgeon, operator, technician, etc.) may grasp the BVN access tool 100 during surgery. The handle recess 137 may extend along an axial length of the distal body portion 108 from a handle ridge 138 to a proximal portion of the distal body portion 108. The handle ridge 138 may extend radially outside of an outermost periphery of the handle recess 137. The handle ridge 138 may provide a ledge or surface that a user can contact while manipulating the distal body portion 108 and/or the BVN access tool 100. As can be appreciated, the handle ridge 138 may provide a contact surface that prevents the distal body portion 108 of the BVN access tool 100 from slipping out of a user’s hand, especially while moving the distal body portion 108 in a direction along the Y-axis running from the proximal end 130 toward the distal end 140.

[0085] When the distal body portion 108 and the proximal body portion 112 are connected to one another (e.g., in a locked state, etc.) at least one surface of the distal body portion 108 may contact the proximal body portion 112 along the interconnection line 114. The interconnection line 114 may be used as a reference to indicate where the proximal body portion 112 can be separated from the distal body portion 108.

[0086] The proximal body portion 112 may at least partially house and/or interconnect with a cam lock subassembly 110, a handle 124, a coupling link 132, a channeling tool outer shaft 120, a channeling tool inner shaft 126, and/or other component of the BVN access tool 100. In some embodiments, the proximal body portion 112 may be referred to as the channeling tool of the BVN access tool 100.

[0087] Referring to FIG. 1C, an exploded distal perspective view of the BVN access tool 100 is shown in accordance with embodiments of the present disclosure. As illustrated in FIG. 1C, the handle 124 may be rotationally attached to the proximal body portion 112 via a radial bearing 121 (e.g., ball bearing, etc.). In some embodiments, the radial bearing 121 may be arranged in a corresponding groove, slot, or recess disposed in the lower proximal body portion 112B. The radial bearing 121 may allow the handle 124 to rotate about the tool axis 106. The handle 124, when rotated, may be used to articulate the channeling tool outer shaft 120 and/or a portion of the sheath shaft 116. Additionally or alternatively, a user may advance the entire BVN access tool 100 to a treatment site of a subject (e.g., patient, etc.) by tapping a proximal end 130 of the handle 124 with a mallet. For example, when a user taps the proximal end 130 of the handle 124 (e.g., using a mallet, etc.), the force may be transmitted to an outer flange 127 (shown in FIG. 1 C) of the handle 124 that contacts the housing end surface 136 (shown in FIG. IB) of the proximal body portion 112. This force may be used to index, or advance, the BVN access tool 100 distally along the tool axis 106.

[0088] The channeling tool outer shaft 120 may include a grip portion disposed adjacent the proximal end 130 and a threaded end 123 disposed opposite the grip portion. The threaded end 123 may correspond to a lead screw, ball screw, acme screw, helical thread, or other threaded protrusion extending into the proximal body portion 112. As the handle 124 is rotated, the threaded end 123, which is engaged with at least one threaded nut of the cam lock subassembly 110, may rotate in place and the cam lock collar 122 may be caused to axially travel relative to the proximal body portion 112.

[0089] The proximal body portion 112 may include a first button aperture 128 and a second button aperture 134 that are configured to receive at least a portion, or protrusion, of the cam lock collar 122 of the BVN access tool 100. The first button aperture 128 is shown disposed surrounding an apex of the upper, or top, portion of the proximal body portion 112 and the second button aperture 134 is shown disposed on a lower, or bottom, portion of the proximal body portion 112. More specifically, the first button aperture 128 is shown disposed in the upper proximal body portion 112A and the second button aperture 134 is shown disposed in the lower proximal body portion 112B.

[0090] When the distal body portion 108 and the proximal body portion 112 are attached to one another (e.g., in a locked, or connected, state), the sheath shaft 116, the channeling tool outer shaft 120, and the channeling tool inner shaft 126 may form the sheath and tool subassembly 111. Although referred to herein as a subassembly, it should be appreciated that the sheath shaft 116 is attached to the distal body portion 108 while the channeling tool outer shaft 120 and the channeling tool inner shaft 126 are interconnected to the proximal body portion 112. Accordingly, as the proximal body portion 112 is separated from the distal body portion 108 (e.g., in an unlocked, or disconnected, state) the channeling tool outer shaft 120 and channeling tool inner shaft 126 are removed from the sheath shaft 116 (e.g., from the lumen of the sheath shaft 116).

[0091] FIG. ID is an elevation view of the BVN access tool 100 taken from the distal end 140 of the BVN access tool 100. In some embodiments, the handle 124 may extend beyond an outermost peripheral surface of the proximal body portion 112 at a proximal end 130 of the proximal body portion 112. This extension may provide an axial clearance that runs along an axial length of the housing body 104 to the at least one surface of the handle 124. As illustrated in FIG. ID, the handle 124 may be rotationally positioned (e.g., in a handle rotation direction 142 about the tool axis 106, etc.) such that a first mallet strike zone 125A extends a first extension distance 144 from the upper proximal body portion 112A. In this rotational position, the handle provides a second mallet strike zone 125B that extends a second extension distance 146 from the lower proximal body portion 112B. In some embodiments, a user may use one or more of the mallet strike zones 125 A, 125B to retract or extract the BVN access tool 100 from a subject anatomy (e.g., spine, bone, etc.). For instance, if the sheath shaft 116 and/or the channeling tool outer shaft 120 is jammed or stuck in a bone or body of the subject, the user may tap one or more of the mallet strike zones 125A, 125B to apply a retraction force in a direction from the distal end 140 to the proximal end 130 of the BVN access tool 100.

[0092] FIG. IE is a schematic cross-section view of an outer peripheral shape 150 of the BVN access tool 100 according to at least one embodiment of the present disclosure. The outer peripheral shape 150 may correspond to a cross-sectional shape taken along a length of the BVN access tool 100 at the distal body portion 108, the proximal body portion 112, the handle recess 137, and/or the handle ridge 138. In some embodiments, the outer peripheral shape 150 may be generally pear-shaped. As illustrated in FIG. IE, the outer peripheral shape 150 may include a height, H, and a width, W. The height, H, of the outer peripheral shape 150 may be measured from the rear point 148 (e.g., at the lower housing portion 104B of the BVN access tool 100) to the apex 152 (e.g., at the upper housing portion 104A of the BVN access tool 100). In some embodiments, the height, H, may correspond to a greatest distance between points on opposing surfaces of the BVN access tool 100 taken along the vertical centerline 156 (e.g., that is coincident with a plane parallel to the YZ-plane of the coordinate system 102). The width, W, of the outer peripheral shape 150 may be measured from one side of the BVN access tool 100 to the other side of the BVN access tool 100. In some embodiments, the width, W, may correspond to a greatest distance between points on opposing surfaces of the BVN access tool 100 taken along horizontal centerline 155 (e.g., that is coincident with a plane parallel to the XY-plane of the coordinate system 102). In some embodiments, the horizontal centerline 155 may correspond to the housing split line 115 described above.

[0093] The first radius, Rl, arranged at the apex 152 of the outer peripheral shape 150 may have a first dimension that is smaller than the second radius, R2, and/or the third radius, R3. In some embodiments, the first radius, Rl, may be referred to as a “sharp” edge of the BVN access tool 100. The first radius, Rl, may be arranged to coincide with, or surround, the vertical centerline 156. The vertical centerline 156 may define a steering plane of the channeling tool (e.g., a plane in which the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126 bends, or flexes). Having a smaller radius at the first radius, Rl, allows a user to quickly and easily determine or identify a steering plane of the BVN access tool 100 while in use (e.g., by feel, etc.). Stated another way, while a user is manipulating the BVN access tool 100 (e.g., during surgery, etc.), the user may feel, or even look at, the first radius, Rl, of the outer peripheral shape 150 to determine a steering plane and/or a direction in which the channeling tool will articulate. In some embodiments, the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126 may be caused to articulate or bend in a direction from the tool axis 106 shown in FIG. IE toward the apex 152 (e.g., along the vertical centerline 156). The second radius, R2, and the third radius, R3, may be any dimension larger than the first radius, Rl. Although the second radius, R2, and the third radius, R3, may have different dimensions from one another, in some embodiments, the second radius, R2 and the third radius, R3, may have the same dimension. In some embodiments, the outer peripheral shape 150 may include a plurality of radiused surfaces surrounding the BVN access tool 100 and may include a flat transition surface extending from the second radius, R2, and/or the third radius, R3, to the first radius, Rl, and/or the apex 152.

[0094] The BVN access tool 100 may be used, for example, to carry out one or more aspects of the methods 800 described herein. The BVN access tool 100 or similar systems may also be used for other purposes than those described herein.

[0095] Referring now to FIGS. 2A-2B, perspective views of the cam lock subassembly 110 of the BVN access tool are shown according to at least one embodiment of the present disclosure. The cam lock subassembly 110 may include a cam lock collar 122, a first splitnut body 236, a second split-nut body 240, and one or more dowel pins 260. The cam lock collar 122 of the cam lock subassembly 110 may be configured to translate or move along the Z-axis between an unlocked and a locked state or position. As shown in FIG. 2A, the cam lock collar 122 is in an unlocked state where the first split-nut body 236 and the second split-nut body 240 are separated and offset from one another along the X-axis direction.

[0096] The cam lock collar 122 may comprise a cam body 204 extending a width along the X-axis, a height along the Z-axis, and a thickness along the Y-axis. A split-nut cam aperture 228 may be disposed through the thickness of the cam body 204 providing one or more interior surfaces that are configured to capture and/or guide the first split-nut body 236 and/or the second split-nut body 240. First and second cam slots 232A, 232B may be arranged on opposing width sides of the cam body 204. The first and second cam slots 232A, 232B may extend from a first position and distance from a center of the cam body 204 to a second position and distance from the center of the cam body 204. The first position and distance may correspond to a location for the dowel pins 260 when the cam lock subassembly 110 is in the unlocked state and the second position and distance may correspond to a location for the dowel pins 260 when the cam lock subassembly 110 is in the locked state. The cam lock collar 122 may include a first button 208 protruding from the cam body 204 in a first direction and a second button 212 protruding from the cam body 204 in a second direction opposite the first direction. In some embodiments, the second button 212 may correspond to an unlock contact button and the first button 208 may correspond to a lock contact button. Stated another way, to unlock the proximal body portion 112 from the distal body portion 108, the second button 212 may be moved in the positive Z-axis direction of the coordinate system 102. To lock the proximal body portion 112 to the distal body portion 108, when the distal body portion 108 and the proximal body portion 112 are brought into contact at the interconnection line 114, the first button 208 may be moved in the negative Z-axis direction of the coordinate system 102. The cam body 204 may include at least one link receiving groove 220 and link contact protrusion 224 disposed on one or more sides of the cam lock collar 122. The link receiving groove 220 may receive the coupling link 132 and the link contact protrusion 224 may hold or retain the coupling link 132 against the cam lock collar 122. In some embodiments, the cam lock collar 122 and/or features thereof, may be centerline symmetrical through a plane parallel to the YZ-plane of the coordinate system 102 running through a width center (e.g., along the X-axis) of the cam body 204.

[0097] Together, the first split-nut body 236 and second split-nut body 240 may correspond to a threaded nut that is capable of engaging with the threaded end 123 of the handle 124. For instance, each of the first split-nut body 236 and the second split-nut body 240 may include one or more threaded portions 244 disposed on a respective inner recessed surface of the first split-nut body 236 and the second split-nut body 240. These threaded portions 244 may threadedly engage with the threads of the threaded end 123 of the handle 124 when the first split-nut body 236 and the second split-nut body 240 are arranged adjacent and in contact with one another. The first split-nut body 236 may be disposed inside the split-nut cam aperture 228 such that the cam-and-pin contact zone 256 thereof includes a thickness of the cam body 204. When in this position, the first split-nut body 236 may receive a dowel pin 260 inserted into a pin receiving aperture 258 of the first split-nut body 236 and that passes through the first cam slot 232A. The second splitnut body 240 may be disposed inside the split-nut cam aperture 228 such that the cam-and- pin contact zone 256 thereof includes a thickness of the cam body 204. When in this position, the second split-nut body 240 may receive a dowel pin 260 inserted into a pin receiving aperture 258 of the second split-nut body 240 and that passes through the second cam slot 232B. The first split-nut body 236 may be keyed to the second split-nut body 240 and/or vice versa. For instance, the second split-nut body 240 may include a key 248 and the first split-nut body 236 may include a keyway 252. The key 248 may engage with the key way 252 maintaining the first split-nut body 236 and the second split-nut body 240 in a slidable arrangement along the X-axis (e.g., movable along the X-axis relative to one another).

[0098] FIGS. 2C and 2D show schematic distal elevation cross-section views of the cam lock subassembly 110 in a locked state and an unlocked state, respectively. As shown in FIG. 2C, the cam lock collar 122 is shown in a locked state where the first split-nut body 236 and the second split-nut body 240 are in contact with one another, or close to one another, at the vertical centerline 156. In this position, the threaded portions 244 of the first split-nut body 236 and/or the second split-nut body 240 are threadedly engaged with the threaded end 123 of the handle 124. In this locked and engaged position, as the handle 124 is rotated in a first rotational direction, the first split-nut body 236, the second split-nut body 240, and the cam lock collar 122 may move (e.g., together) toward the distal end 140 of the BVN access tool 100. Additionally or alternatively, while in the locked and engaged position shown in FIG. 2C, as the handle 124 is rotated in a second rotational direction (e.g., opposite the first rotational direction), the first split-nut body 236, the second splitnut body 240, and the cam lock collar 122 may move (e.g., together) toward the proximal end 130 of the BVN access tool 100. As described herein, the rotation of the handle 124 may alter a bend, or degree of bend, associated with the channeling tool (e.g., the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126). In the locked state shown in FIG. 2C, the bodies of the first split-nut body 236 and the second split-nut body 240 are captured in an upper portion of the split-nut cam aperture 228 and the dowel pins 260 are arranged in an upper portion of the first and second cam slots 232A, 232B. [0099] In FIG. 2D, an unlocking force 268 is applied to the second button 212 (e.g., the unlock button), moving the cam lock collar 122 upwardly, in the positive Z-axis direction of the coordinate system 102. As the cam lock collar 122 moves upwardly the first and second cam slots 232A, 232B cause the first split-nut body 236 and the second split-nut body 240 to separate from one another an offset distance along the X-axis of the coordinate system 102. For instance, the dowel pin 260 of the first split-nut body 236 is moved along a first separation direction 270A away from the center of the threaded end 123 of the handle 124 and the second split-nut body 240 is moved along a second separation direction 270B (opposite the first separation direction 270A) away from the center of the threaded end 123 of the handle 124. In this unlocked and disengaged position, the threaded portions 244 of the first split-nut body 236 and/or the second splitnut body 240 are disengaged (e.g., threadedly disengaged) from the threaded end 123 of the handle 124. While in this position, any rotation of the handle 124 would not result in any axial translation or movement of the first split-nut body 236, the second split-nut body 240, and the cam lock collar 122. Rather, the handle 124 may be allowed to freely rotate about the tool axis 106. Moreover, while in this unlocked and disengaged position, the proximal body portion 112 may be separated from the distal body portion 108 of the BVN access tool 100. For example, the movement of the first split-nut body 236 and the second split-nut body 240 away from one another along the X-axis may create a gap 264 between the first split-nut body 236 and the second split-nut body 240 and the threaded end 123 of the handle 124.

[0100] FIGS. 2E and 2F show side elevation cross-section views of the BVN access tool 100 with the cam lock subassembly 122 in a locked state and in an unlocked state, respectively. The side elevation cross-section view of FIG. 2E may correspond to the position of the cam lock collar 122 shown in FIG. 2C while the side elevation crosssection view of FIG. 2F may correspond to the position of the cam lock collar 122 shown in FIG. 2D.

[0101] In FIG. 2E, while the proximal body portion 112 is in a locked state relative to the distal body portion 108, the coupling link 132 is shown engaged with a latch contact protrusion 274 of the distal body portion 108. In some embodiments, the coupling link 132 may comprise a locking protrusion extending substantially perpendicular to an axis of the surgical access tool (e.g., along the Z-axis, plus or minus 30 degrees). The latch contact protrusion 274 may correspond to a receiving latch contact protrusion arranged in the distal body portion 108 such as a hook, recessed slot, and/or the like. When in the locked state, the distal body portion 108 and the proximal body portion 112 may form a unitary housing body 104.

[0102] In FIG. 2F, an unlocking force 268 is applied to the second button 212 of the cam lock collar 122 moving the cam lock collar 122 upward (e.g., along the positive Z-axis direction). As the cam lock collar 122 moves upward, the coupling link 132, disposed in the link receiving groove 220 and retained by the link contact protrusion 224, moves upward such that the locking protrusion of the coupling link 132 disengages from the latch contact protrusion 274. When moved into the unlocked state, as shown in FIG. 2F, the proximal body portion 112 and/or channeling tool (e.g., the channeling tool outer shaft 120 and the channeling tool inner shaft 126) may be completely separated from the distal body portion 108 and the sheath shaft 116, as illustrated in FIG. 2G. In some embodiments, the distal body portion 108 and sheath shaft 116 may remain in a subject while the proximal body portion 112 and the channeling tool is removed. Among other things, removal of the proximal body portion 112 and the channeling tool may provide access to a treatment site via a lumen 275 passing through the sheath shaft 116 and the channel created in the bone of the patient (e.g., by the channeling tool) to the treatment site. At least one benefit of splitting and separating the BVN access tool 100, as described herein, includes allowing a user to quickly insert an ablation probe, or other tool, in the sheath shaft 116 without requiring removal of the sheath shaft 116 and insertion of a different tool. Additionally or alternatively, by routing an ablation probe into the sheath shaft 116 after the channel has been created by the channeling tool allows for precise alignment with the channel and faster operation times.

[0103] FIGS. 3A and 3B show side elevation views of the sheath and tool subassembly 111 of the BVN access tool 100 according to at least one embodiment of the present disclosure. As previously provided, the channeling tool may include the channeling tool outer shaft 120 and the channeling tool inner shaft 126 while the distal body portion 108 of the BVN access tool 100 may include the sheath shaft 116. In some embodiments, the channeling tool including the proximal body portion 112 may be unlocked, disengaged, and separated from the distal body portion 108 of the BVN access tool 100. As the proximal body portion 112 is separated from the distal body portion 108, the channeling tool outer shaft 120 and the channeling tool inner shaft 126 are removed and separated from disposition inside the sheath shaft 116. FIGS. 3A and 3B show the sheath and tool subassembly 111 when the BVN access tool 100 is in the locked state.

[0104] The sheath and tool subassembly 111 comprises the channeling tool portion, for example, including the channeling tool outer shaft 120 and the channeling tool inner shaft 126. When the distal body portion 108 and the proximal body portion 112 are in a locked state (e.g., engaged with one another) the channeling tool portion is disposed inside the sheath shaft 116. In some embodiments, the channeling tool outer shaft 120 and the channeling tool inner shaft 126 may be joined together (e.g., welded, pinned, crimped, and/or otherwise locked to one another) at the distal end 140. For instance, the channeling tool outer shaft 120 and the channeling tool inner shaft 126 may be joined together at an inner-outer shaft lock point 320.

[0105] The sheath shaft 116 may include a sheath shaft block 304 disposed at a proximal end of the sheath shaft 116. The sheath shaft block 304 may be configured to fit inside a portion of the distal body portion 108 of the BVN access tool 100 (e.g., adjacent a proximal end of the distal body portion 108, etc.). In one embodiment, the sheath shaft block 304 may be substantially rectangular or square in cross-sectional shape (e.g., when viewed in the XZ-plane). In some embodiments, the sheath shaft block 304 may be received in a similarly shaped receptacle or recess in the distal body portion 108 (e.g., in the upper distal body portion 108 A and/or the lower distal body portion 108B). At least one advantage of using a rectangular cross-sectional shape includes preventing independent rotation of the sheath shaft 116 about the tool axis 106 relative to the BVN access tool 100.

[0106] The channeling tool outer shaft 120 may include an outer shaft block 308 disposed at a proximal end of the channeling tool outer shaft 120. The outer shaft block 308 may be configured to fit inside a portion of the proximal body portion 112 of the BVN access tool 100 (e.g., adjacent a distal end of the proximal body portion 112, etc.). In one embodiment, the outer shaft block 308 may be substantially rectangular or square in cross- sectional shape (e.g., when viewed in the XZ-plane). In some embodiments, the outer shaft block 308 may be received in a similarly shaped receptacle or recess in the proximal body portion 112 (e.g., in the upper proximal body portion 112A and/or the lower proximal body portion 112B). Similar to the advantage described above, the rectangular cross- sectional shape may prevent independent rotation of the channeling tool outer shaft 120 about the tool axis 106 relative to the BVN access tool 100.

[0107] The channeling tool inner shaft 126 may include an inner shaft block 312 disposed at a proximal end of the channeling tool inner shaft 126. The inner shaft block 312 may be configured to fit inside a portion of the cam lock subassembly 110 of the BVN access tool 100. For instance, the inner shaft block 312 may be interconnected to the first split-nut body 236 and/or the second split-nut body 240. In one embodiment, the inner shaft block 312 may be substantially rectangular or square in cross-sectional shape (e.g., when viewed in the XZ-plane). In some embodiments, the inner shaft block 312 may be received in a similarly shaped receptacle or recess in the first split-nut body 236 and/or the second split-nut body 240. This receptacle or recess may be disposed proximal the key 248 of the second split-nut body 240. The rectangular cross-sectional shape of the inner shaft block 312 may prevent independent rotation of the channeling tool inner shaft 126 about the tool axis 106 relative to the BVN access tool 100. Stated another way, each of the sheath shaft 116, channeling tool outer shaft 120, and the channeling tool inner shaft 126 may be prevented from rotating about the tool axis 106 without rotating the BVN access tool 100. In this arrangement, the sheath shaft 116, channeling tool outer shaft 120, and the channeling tool inner shaft 126 can be considered to be rotationally fixed relative to the housing body 104 and/or other portion of the BVN access tool 100.

[0108] Although the sheath shaft 116, channeling tool outer shaft 120, and the channeling tool inner shaft 126 may be rotationally fixed to the BVN access tool 100, the channeling tool inner shaft 126 is allowed to move along the Y-axis direction relative to the channeling tool outer shaft 120 and/or the sheath shaft 116. For example, the outer shaft block 308 is axially fixed to the proximal body portion 112 such that the outer shaft block 308 is prevented from axial translation along the Y-axis direction. However, the inner shaft block 312 interconnected with the first split-nut body 236 and/or the second split-nut body 240 of the cam lock subassembly 110 is capable of moving in a proximal direction (e.g., toward the proximal end 130) and/or in a distal direction (e.g., toward the distal end 140) along the Y-axis based on a particular handle rotation direction 142 of the handle 124. In one example, a clockwise rotation of the handle 124 may cause the inner shaft block 312 and the channeling tool inner shaft 126 to translate, or displace, along the Y-axis toward the proximal end 130 of the BVN access tool 100. Continuing this example, a counterclockwise rotation of the handle 124 may cause the inner shaft block 312 and the channeling tool inner shaft 126 to translate, or displace, along the Y-axis toward the distal end 140 of the BVN access tool 100. As the inner shaft block 312 and the channeling tool inner shaft 126 is caused to translate, the variable articulation distance 318 (e.g., the distance between the fixed outer shaft block 308 and the movable inner shaft block 312) may increase or decrease.

[0109] As illustrated in FIG. 3B, the channeling tool inner shaft 126 may include a plurality of inner shaft cuts 310A arranged along a length of the channeling tool inner shaft 126 defining an inner shaft flexible region 328A. The inner shaft cuts 310A may correspond to a number of circumferential cuts through a radial side of the channeling tool inner shaft 126. The inner shaft cuts 310A may be arranged axially spaced apart from one another along a length of the channeling tool inner shaft 126. The inner shaft cuts 310A may be evenly spaced apart from one another in the inner shaft flexible region 328A. In some embodiments, the spacing between the inner shaft cuts 310A may vary along the length of the channeling tool inner shaft 126. For instance, a closer spacing may be defined in a center section of the inner shaft flexible region 328A where increased flexibility is desired. In this case, the spacing between the inner shaft cuts 310A outside of the center section may be separated by a greater separation distance than in the center section. The channeling tool inner shaft 126 may include at least one inner shaft lock point 320A disposed adjacent the inner shaft distal tip 324A.

[0110] The channeling tool outer shaft 120 may include a plurality of outer shaft cuts 310B arranged along a length of the channeling tool outer shaft 120 defining an outer shaft flexible region 328B. The outer shaft cuts 310B may correspond to a number of circumferential cuts through a radial side of the channeling tool outer shaft 120. The outer shaft cuts 310B may be arranged axially spaced apart from one another along a length of the channeling tool outer shaft 120. The outer shaft cuts 310B may be evenly spaced apart from one another in the outer shaft flexible region 328B. In some embodiments, the spacing between the outer shaft cuts 310B may vary along the length of the channeling tool outer shaft 120. For instance, a closer spacing may be defined in a center section of the outer shaft flexible region 328B where increased flexibility is desired. In this case, the spacing between the outer shaft cuts 310B outside of the center section may be separated by a greater separation distance than in the center section. The channeling tool outer shaft 120 may include at least one outer shaft lock point 320B disposed adjacent the outer shaft distal tip 324B. In some embodiments, the inner shaft lock point 320A of the channeling tool inner shaft 126 and the outer shaft lock point 320B of the channeling tool outer shaft 120 may align with one another. The shaft lock points 320A, 320B may correspond to holes or apertures (e.g., that are configured to receive a locking pin, weld, etc.).

[OHl] The sheath shaft 116 may include a plurality of sheath cuts 310C arranged along a length of the sheath shaft 116 defining a sheath shaft flexible region 328C. The sheath cuts 310C may correspond to a number of circumferential cuts through a radial side of the sheath shaft 116. The sheath cuts 310C may be arranged axially spaced apart from one another along a length of the sheath shaft 116. The sheath cuts 310C may be evenly spaced apart from one another in the sheath shaft flexible region 328C. In some embodiments, the spacing between the sheath cuts 310C may vary along the length of the sheath shaft 116. For instance, a closer spacing may be defined in a center section of the sheath shaft flexible region 328C where increased flexibility may be desired. In this case, the spacing between the sheath cuts 310C outside of the center section may be separated by a greater separation distance than in the center section. The sheath shaft 116 includes a lumen that passes from the proximal end of the sheath shaft 116 adjacent the sheath shaft block 304 to the sheath shaft distal tip 324C.

[0112] Each of the shaft cuts 310A, 310B, 310C allow for controlled flexibility and rigidity along the length of the respective shafts 126, 120, 116. For example, the arrangement of the shaft cuts 310A, 310B, 310C may provide substantial rigidity and/or resistance to buckling along the Y-axis, while being capable of providing flexibility in the YZ-plane of the coordinate system 102. Stated another way, the shaft cuts 310A, 310B, 310C may provide axial stiffness of the shafts 126, 120, 116 when in compression along the Y-axis. However, as the inner shaft block 312 and the channeling tool inner shaft 126 are moved proximally toward the proximal end 130 (e.g., via handle 124 rotation and movement of the cam lock collar 122, first split-nut body 236, and second split-nut body 240, etc.) relative to the fixed outer shaft block 308, the channeling tool inner shaft 126, which is joined at the distal end 140 to the channeling tool outer shaft 120, may cause the channeling tool shafts 120, 126 to articulate, or bend, along the shaft cuts 310A, 310B (e.g., in the YZ-plane).

[0113] FIG. 3C shows a schematic side elevation view of the sheath and tool subassembly 111 of the BVN access tool 100 in a first articulated state according to at least one embodiment of the present disclosure. In FIG. 3C, the inner shaft block 312 has been moved (e.g., by rotation of the handle 124, etc.) along the Y-axis in a direction toward the proximal end 130 of the BVN access tool 100 providing a first articulation distance 318A between the inner shaft block 312 and the outer shaft block 308. The tension on the channeling tool inner shaft 126 joined to the channeling tool outer shaft 120 at the inner-outer shaft lock point 320 causes the distal end 140 of the channeling tool to bend at a first articulation angle, Al, in the YZ-plane (e.g., in the positive Z-axis direction). In one embodiment, the first articulation angle, Al, may correspond to any angle in a range of 0.5° to 30°, or more.

[0114] FIG. 3D shows a schematic side elevation view of the sheath and tool subassembly 111 of the BVN access tool 100 in a second articulated state according to at least one embodiment of the present disclosure. In FIG. 3D, the inner shaft block 312 has been moved (e.g., by rotation of the handle 124, etc.) along the Y-axis a further distance in a direction toward the proximal end 130 of the BVN access tool 100 providing a second articulation distance 318B between the inner shaft block 312 and the outer shaft block 308. The tension on the channeling tool inner shaft 126 joined to the channeling tool outer shaft 120 at the inner-outer shaft lock point 320 causes the distal end 140 of the channeling tool to bend at a second articulation angle, A2, in the YZ-plane (e.g., in the positive Z-axis direction). In one embodiment, the second articulation angle, A2, may correspond to any angle in a range of 30° to 90°, or more.

[0115] In FIGS. 3C and 3D, the distal end 140 of the channeling tool (e.g., the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126, etc.) is caused to bend out of alignment with the Y-axis and out of the XY-plane.

[0116] FIGS. 3E-3G show various details of the channeling tool shafts 120, 126 in accordance with embodiments of the present disclosure.

[0117] FIG. 3E is a partial side elevation cross-section view of the distal end of the channeling tool outer and inner shafts 120, 126 of the BVN access tool 100 according to at least one embodiment of the present disclosure. As described above, the channeling tool may be arranged to provide a controlled flexibility along the length of the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126. In FIG. 3F, a partial schematic section view of the channeling tool outer shaft 120 and the channeling tool inner shaft 126 is taken from area 3F of FIG. 3E. The channeling tool inner shaft 126 may be arranged inside the channeling tool outer shaft 120 such that the inner shaft cuts 310A and the outer shaft cuts 31 OB are arranged 108 degrees from one another. For example, the channeling tool outer shaft 120 may be arranged such that the outer shaft cuts 310B are facing a first radial side of the channeling tool. In this arrangement, the outer shaft cuts 310B may provide flexibility for the channeling tool outer shaft 120 in a direction from the tool axis 106 to the periphery of the channeling tool outer shaft 120 on this side. To control the flexibility of this side, the channeling tool inner shaft 126 may be arranged such that an uncut, or rigid solid, section of the channeling tool outer shaft 120 is facing the outer shaft cuts 310B on the first radial side. The combination of the flexibility provided by the outer shaft cuts 310B and the rigidity from the solid section of the channeling tool inner shaft 126 on this side provide a first rigid-flexible region 330A. Continuing this example, the channeling tool inner shaft 126 may be arranged such that the inner shaft cuts 310A are facing a second (e.g., opposite) radial side of the channeling tool. On this second radial side, the channeling tool inner shaft 126 may be arranged such that the inner shaft cuts 310A are facing an uncut, or rigid solid, section of the channeling tool outer shaft 120. The combination of the flexibility provided by the inner shaft cuts 310A and the rigidity from the solid section of the channeling tool outer shaft 120 on this side provide a second rigid- flexible region 330B. While the combination of the first rigid-flexible region 330A and the second rigid-flexible region 330B provide compressive rigidity, and resistance to buckling of the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126 along the Y-axis, the arrangement allows for controlled bending in the YZ-plane.

[0118] FIG. 3G is a detail section view of the distal tip 324 of the channeling tool taken from circle 3G shown in FIG. 3E. More specifically, FIG. 3G shows a cross-section detail view of the channeling tool outer shaft 120 and the channeling tool inner shaft 126. As described above, the channeling tool inner shaft 126 may be fixedly attached to the channeling tool outer shaft 120 at one or more inner-outer shaft lock points 320. The inner-outer shaft lock point 320 may include a pinned, welded, or crimped interconnection. In some embodiments, a distal end plug 334 may be arranged in an end of the channeling tool inner shaft 126 and/or the channeling tool outer shaft 120. The channeling tool outer shaft 120, the channeling tool inner shaft 126, and the distal end plug 334 may be made from stainless steel and welded at the distal end 140 to form a solid end of the channeling tool. In some embodiments, the channeling tool distal tip 324 may be tapered at a distal tip taper angle, A3, from a proximal portion to a distal-most portion ending at a point. The distal tip taper angle, A3, may correspond to an angle of approximately 30°, plus or minus 15°.

[0119] In some embodiments, the channeling tool distal tip 324 may include one or more markers that are capable of identifying a position of the channeling tool distal tip 324 under X-ray or other surgical imaging system. In one embodiment, the distal end plug 334 may include a recess disposed in an interior of the channeling tool inner shaft 126. The recess in the distal end plug 334 may be configured to receive a radio-opaque marker 336. The radio-opaque marker 336 may be made from any radio-opaque material and may include, but is in no way limited to, tungsten, platinum, iridium, and/or combinations thereof. In some embodiments, the distal end plug 334 may be press-fit into an interior of the channeling tool inner shaft 126, welded to the channeling tool inner shaft 126 and/or the channeling tool outer shaft 120, and then ground or otherwise machined to form the tapered tip having the distal tip taper angle, A3.

[0120] FIG. 4 is a schematic cross-section view of a vertebral section 400 of a subject used according to at least one embodiment of the present disclosure. Use of the BVN access tool 100 may be described in conjunction with one or more surgical access and/or channeling procedures. For the sake of example, a BVN treatment is described herein to highlight the benefits of the BVN access tool 100. Accordingly, reference may be made to one or more features of a vertebral section 400 of a subject (e.g., patient). The vertebral section 400 may include at least one pedicle 404, a vertebral foramen 408, a spinous process 412, a transverse process 416, a BVN 420, and a vertebral body area 424.

[0121] FIG. 5 is a side elevation view of an introducer and access system 500 used according to at least one embodiment of the present disclosure. The introducer and access system 500 may correspond to a Kyphon® Osteo Introducer System or equivalent transpedicular tool, manufactured by Medtronic, Inc. of Minneapolis, MN. The introducer and access system 500 may include an access introduction handle 504, an access shaft 508, a stylet 512, and an introducer handle 516. In some embodiments, the stylet 512 may correspond to a trocar that is interconnected with the introducer handle 516. The introducer handle 516 may be threadedly engaged with the access introduction handle 504. To remove the stylet 512, the introducer handle 516 may be unscrewed from the access introduction handle 504 and the stylet 512 can be retracted from the access shaft 508, moving the introducer handle 516 and the stylet 512 proximally (e.g., in a direction from the distal end 540 to the proximal end 530 of the introducer and access system 500). [0122] FIGS. 6A-6H show schematic diagrams of a treatment method using the BVN access tool 100 according to at least one embodiment of the present disclosure. In some embodiments, FIGS. 6A-6H may correspond to one or more steps of the method 800 described in conjunction with FIG. 8, or vice versa. The sequence shown in FIGS. 6A-6H illustrate an example BVN treatment method using the BVN access tool 100 and is not intended to be considered a limiting use of the BVN access tool 100. The BVN treatment may be used to alleviate or eliminate back pain in a patient that emanates from a treatment site 602 (e.g., a pain site, etc.).

[0123] In FIG. 6A, transpedicular access is provided to the vertebral body area 424 of the vertebral section 400 via traversing the pedicle 404. In some embodiments, an incision may be made in a subject and the distal end 540 of the introducer and access system 500 is routed to a point outside of the pedicle 404 (e.g., between the spinous process 412 and the transverse process 416). The introducer and access system 500 may be caused to pass through the pedicle 404 into the vertebral body area 424. Once in position in the vertebral body area 424, the introducer handle 516 and stylet 512 may be removed from the introducer and access system 500 (shown in FIG. 6B), leaving the access shaft 508 and the access introduction handle 504 in place. In this position, a shaft access lumen 604 is provided running from the access introduction handle 504 to the distal end 540 of the introducer and access system 500.

[0124] While the access shaft 508 of the introducer and access system 500 remains in place (e.g., in contact with the vertebral section 400 of the subject), the channeling tool and sheath shaft 116 of the BVN access tool 100 may be inserted into the shaft access lumen 604 and the channeling tool outer shaft 120 may be moved into the vertebral body area 424, as shown in FIG. 6C. In some embodiments, a mallet may be used to apply a tool advancement force 608 to the handle 124 at the proximal end 130 to advance the BVN access tool 100 into the bone of the vertebral body area 424 (e.g., in a direction of the distal end 140 of the BVN access tool 100). In initiating the creation of the channel, the handle 124 may be rotated in a handle rotation direction 142 to begin to bend the channeling tool outer shaft 120 in a direction toward a treatment site 602.

[0125] In FIG. 6D, the BVN access tool 100 is manipulated by a user using a mallet to continue to advance the channeling tool outer shaft 120 into the vertebral body area 424 and rotation of handle 124 to move the channeling tool outer shaft 120 in a direction of the treatment site 602. As described above, rotation of the handle 124 may cause an articulation of the channeling tool outer shaft 120, the channeling tool inner shaft 126, and/or the sheath shaft 116.

[0126] The BVN access tool 100 may be repeatedly manipulated (e.g., via advancement and/or handle rotation, etc.) to complete the channel to the target treatment site 602 as shown in FIG. 6E. The position, location, and/or rotational orientation of the channeling tool distal tip 324 (see, e.g., FIG. 3A) may be determined by monitoring a radio-opaque marker 336 under a surgical imaging system (e.g., X-ray, etc.) of the vertebral section 400 of the subject.

[0127] Once, the channeling tool distal tip 324 is arranged adjacent to the treatment site 602, the user may apply an unlocking force 268, by pressing the second button 212 of the cam lock collar 122 into the unlock state such that the first button 208 moves out of the first button aperture 128 in the upper proximal body portion 112 A, as shown in FIG. 6F. In this state, the proximal body portion 112 and the channeling tool are unlocked from the distal body portion 108. The unlocked, or unconnected, state of the BVN access tool 100 shown in FIG. 6F may correspond to the states shown at least in FIGS. 2D and 2F.

[0128] In FIG. 6G, the proximal body portion 112, including the channeling tool outer shaft 120 and the channeling tool inner shaft 126, is separated from the distal body portion 108. The distal body portion 108 may remain, in place, in the vertebral section 400 including the sheath shaft 116 formed in a bent state and a channeled volume 616 (e.g., a void of displaced material, bone, etc.) disposed between the sheath shaft 116 and the treatment site 602. The proximal body portion 112 may then be completely separated from the distal body portion 108 providing a path from the proximal end of the sheath shaft 116 to the treatment site 602.

[0129] FIG. 6H shows a schematic diagram of routing an ablation probe 630 into the sheath shaft 116 of the distal body portion 108 left in place and forming a portion of the access path to the treatment site 602 according to at least one embodiment of the present disclosure. Since the distal body portion 108 and the sheath shaft 116 are allowed to remain in place from the channeling operation performed by the BVN access tool 100, the accuracy of the path from the proximal end of the sheath shaft 116 to the treatment site 602 can be guaranteed. Moreover, by not requiring removal of the sheath shaft 116 and replacement with a different sheath, the operation time can be significantly reduced when using the BVN access tool 100 compared to conventional treatments. After inserting the ablation probe 630 into proximity with the treatment site 602, the ablation probe 630 may be activated ablating a portion of the BVN and eliminating the future nerve signals generated from the treatment site 602 that may be responsible for causing pain in the subject.

[0130] Referring now to FIGS. 7A and 7B, various views of the distal end of the ablation probe 630 are shown according to at least one embodiment of the present disclosure. In some embodiments, the ablation probe 630 may comprise a probe distal tip 700 including a domed distal end 708, an insulator 704, and a probe proximal shaft 702. The ablation probe 630 may include at least one electrical interconnection 712 running from the proximal end of the ablation probe 630 to the domed distal end 708. The ablation probe 630 may be configured with similar circumferential cuts to the shaft cuts 310A- 310C that provide flexibility along a length of the ablation probe 630. For instance, the ablation probe 630 may include a plurality of inner shaft cuts 710A and plurality of outer shaft cuts 710B disposed in one or more bodies of the ablation probe 630.

[0131] In some embodiments, the end of the electrical interconnection 712 may be captured in the domed distal end 708 by a ring and a crimped portion of the inner shaft of the ablation probe 630. The crimped portion may comprise four arms 714 extending from an end of the inner shaft to the domed distal end 708 of the ablation probe 630. In some embodiments, the four arms 714 may be welded to the domed distal end 708. Although described as including four arms 714, it should be appreciated that more or fewer arms may be employed to contain and hold the ring and end of the electrical interconnection 712.

[0132] FIG. 8 is a flowchart of a method 800 that may be used, for example, in treating pain by ablating a portion of a BVN according to at least one embodiment of the present disclosure.

[0133] The method 800 comprises providing an access path to an area of the BVN where pain may be originating for a subject using a transpedicular tool (step 804). In some embodiments, this step may correspond to providing access to the vertebral body area 424 using the introducer and access system 500 illustrated in FIG. 6A and associated description. A user may insert and advance the introducer and access system 500 through the pedicle 404 of a vertebral section 400 and into the vertebral body area 424.

[0134] The method 800 also comprises removing the stylet 512 from the access shaft 508 of the introducer and access system 500 (e.g., a transpedicular tool), which provides an access lumen to a general area where the BVN is located (step 808). In some embodiments, the introducer handle 516 of the introducer and access system 500 may be unscrewed from the access introduction handle 504 allowing the stylet 512 to be extracted from the access shaft 508.

[0135] The method 800 also comprises inserting a portion (e.g., distal end) of the sheath and tool subassembly 111 into the access lumen of the introducer and access system 500 (step 812). In this step, the BVN access tool 100 is in an engaged and locked state, where the proximal body portion 112 and the distal body portion 108 are joined together. The user may insert the channeling tool outer shaft 120, or the channeling tool distal tip 324, into the access lumen, and then advance the BVN access tool 100 in a direction toward the vertebral section 400.

[0136] The method 800 also comprises determining a position of the channeling tool distal tip 324 relative to the treatment site 602 (step 816). In some embodiments, this determination may be made by monitoring the radio-opaque marker 336 of the channeling tool distal tip 324 under a surgical imaging system. Additionally or alternatively, a user may rely upon the first radius, Rl, arranged at the apex 152 of the outer peripheral shape 150 of the BVN access tool 100 to know a bend or steering plane of the BVN access tool 100. As the BVN access tool 100 is moved relative to the treatment site 602, the radioopaque marker 336 may be used to indicate the position of the channeling tool distal tip 324 relative to the treatment site 602.

[0137] The method 800 also comprises creating a channel to the treatment site 602 by advancing the BVN access tool 100 and articulating (e.g., bending) the channeling tool outer shaft 120 and/or channeling tool inner shaft 126 (step 820). The BVN access tool 100 may be advanced toward the vertebral body area 424 by tapping the handle 124 with a mallet in a direction from the proximal end 130 toward the distal end 140. In some embodiments, the BVN access tool 100 may be retracted from the vertebral body area 424 by tapping at least one mallet strike zone 125 A, 125B of the handle 124 in a direction from the distal end 140 to the proximal end 130. Since the sheath shaft 116 may not be arranged to provide a direct line to the treatment site 602, the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126 may be articulated (e.g., bent) by rotating the handle 124 about the tool axis 106. This rotation may move the cam lock collar 122 and adjust the variable articulation distance 318 between the inner shaft block 312 and the outer shaft block 308, as described above. A user may alternate between advancement and articulation, as needed, to create a channel from the distal end 140 of the sheath shaft 116 to the treatment site 602. [0138] As a user articulates the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126, an amount of articulation, or bend, may be determined based on a position of the second button 212 inside the second button aperture 134. For example, the closer the second button 212 is to the distal end 140 (e.g., or the distal body portion 108), the greater the amount of articulation remains available to the user (e.g., the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126 may be considered to have a low, or no, bend). Continuing this example, the closer the second button 212 is to the proximal end 130 of the BVN access tool 100, the lesser the amount of articulation remains available to the user (e.g., the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126 may be considered to have a high, or maximum allowable, bend). The position of the second button 212 in the second button aperture 134 may be measured as a distance from an outer peripheral edge of the second button 212 to an edge of the second button aperture 134 along the Y-axis of the coordinate system 102.

[0139] The method 800 also comprises releasing tension on the channeling tool and then unlocking the proximal body portion 112 relative to the distal body portion 108 (step 824). In this step, the user may apply an unlocking force 268 to the second button 212 of the cam lock collar 122. As the cam lock collar 122 moves inside the proximal body portion 112, the coupling link 132 disengages from a latch contact protrusion 274 of the distal body portion 108. At the same time, the first split-nut body 236 and the second split-nut body 240 separate from one another thereby disengaging the threaded connection between the threaded end 123 of the handle 124 and the threaded portions 244 of the split-nut bodies 236, 240.

[0140] The method 800 also comprises separating the proximal body portion 112 from the distal body portion 108 and removing the channeling tool outer shaft 120 and/or the channeling tool inner shaft 126 from the sheath shaft 116 (step 828). While the BVN access tool 100 is in the unlocked state, the proximal body portion 112 may be moved proximally away from the distal body portion 108. The distal body portion 108 and the sheath shaft 116 are allowed to remain in the subject and in contact with the vertebral body area 424 of the subject.

[0141] The method 800 also comprises inserting the ablation probe 630 into the sheath shaft 116 of the distal body portion 108 left in place, in contact with the subject (step 832). The ablation probe 630 may be inserted in a lumen of the sheath shaft 116 running from a proximal end of the distal body portion 108 to the distal end 140 of the sheath shaft 116. Since the sheath shaft 116 and the distal body portion 108 have not been removed from the patient, the access path and channel created for the ablation probe 630 is held in alignment with the sheath shaft 116. The domed distal end 708 of the ablation probe 630 may be moved into position in the vertebral body area 424 and the channeled volume 616 adjacent the treatment site 602.

[0142] The method 800 also comprises treating the BVN with the ablation probe 630 (step 836). Treatment may include applying a radiofrequency ablation from the domed distal end 708 of the ablation probe 630. This ablation may eliminate, remove, and/or cauterize a portion of the BVN located at the treatment site 602. The ablation causes the BVN to cease generating pain signals at the treatment site 602.

[0143] The method 800 also comprises removing the ablation probe 630 from the sheath shaft 116 and the distal body portion 108 (step 840). After ablation, or treatment, the user may extract the ablation probe 630 by pulling the ablation probe 630 from the sheath shaft 116 in the proximal direction.

[0144] In some embodiments, the method 800 also comprises reattaching the proximal body portion 112 to the distal body portion 108 (step 844). Once the proximal body portion 112 is reattached to the distal body portion 108, the proximal body portion 112 may be locked to the distal body portion 108 and the proximal body portion 112 and the distal body portion 108 form an attached housing body 104. By reattaching the proximal body portion 112, the user may leverage the mallet strike zones 125 A, 125B of the handle 124 in subsequent removal of the sheath shaft 116 from the vertebral section 400.

[0145] The method 800 also comprises removing the distal body portion 108 and the sheath shaft 116 from the vertebral section 400 and the subject (step 848). As provided above, the proximal body portion 112 may be reattached and locked to the distal body portion 108 to aid in extracting the sheath shaft 116 from the vertebral section 400. In any event, the distal body portion 108 and the sheath shaft 116 may be pulled in a direction away from the vertebral section 400 such that the sheath shaft 116 is removed from the body of the subject.

[0146] The present disclosure encompasses embodiments of the method 800 that comprise more or fewer steps than those described above, and/or one or more steps that are different than the steps described above.

[0147] As noted above, the present disclosure encompasses methods with fewer than all of the steps identified in FIG. 8 (and the corresponding description of the method 800), as well as methods that include additional steps beyond that identified in FIG. 8 (and the corresponding description of the method 800). The present disclosure also encompasses methods that comprise one or more steps from one method described herein, and one or more steps from another method described herein.

[0148] The foregoing is not intended to limit the disclosure to the form or forms disclosed herein. In the foregoing Detailed Description, for example, various features of the disclosure are grouped together in one or more aspects, embodiments, and/or configurations for the purpose of streamlining the disclosure. The features of the aspects, embodiments, and/or configurations of the disclosure may be combined in alternate aspects, embodiments, and/or configurations other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed aspect, embodiment, and/or configuration. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the disclosure.

[0149] Moreover, though the foregoing has included description of one or more aspects, embodiments, and/or configurations and certain variations and modifications, other variations, combinations, and modifications are within the scope of the disclosure, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative aspects, embodiments, and/or configurations to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.

Claims

CLAIMS What is claimed is:

1. A surgical access tool, comprising: a split-housing body comprising: a distal body portion; and a proximal body portion, wherein the proximal body portion is configured to selectively attach to the distal body portion and move between a connected state with the distal body portion and a disconnected state from the distal body portion; a sheath shaft connected to the distal body portion and extending a first length from a first end of the sheath shaft to a second end of the sheath shaft, wherein a lumen passes through the sheath shaft from the first end of the sheath shaft to the second end of the sheath shaft; a channeling tool connected to the proximal body portion, the channeling tool comprising; a threaded block; an outer shaft connected to the proximal body portion, the outer shaft extending a second length from a first end of the outer shaft to a second end of the outer shaft, wherein, when the proximal body portion is in the connected state, the outer shaft is disposed at least partially within the lumen of the sheath shaft; and an inner shaft disposed at least partially inside the outer shaft, the inner shaft connected to the threaded block at a first end of the inner shaft, the inner shaft extending a third length from the first end of the inner shaft to a second end of the inner shaft, wherein the inner shaft is fixed to the outer shaft at the second end of the inner shaft and the second end of the outer shaft; and a handle comprising a grip portion and a threaded portion, wherein the handle is rotationally attached to the proximal body portion of the split-housing body such that the grip portion is arranged outside of the proximal body portion and the threaded portion is threadedly engaged with the threaded block, wherein, based on a rotational position of the handle, the first end of the inner shaft is axially movable between a first position relative to the first end of the outer shaft and a second position relative to the first end of the outer shaft, wherein, in the first position relative to the first end of the outer shaft, the inner shaft and outer shaft are unbent along an axial section adjacent the second end of the outer shaft, and wherein, in the second position relative to the first end of the outer shaft, inner shaft and outer shaft are bent along the axial section adjacent the second end of the outer shaft.

2. The surgical access tool of claim 1, wherein the channeling tool further comprises: a tapered tip arranged at the second end of the inner shaft and the second end of the outer shaft, wherein a steering plane of the channeling tool passes through a longitudinal axis of the outer shaft and the tapered tip, and wherein the steering plane defines a plane in which the inner shaft and outer shaft bends when the first end of the inner shaft moves between the first position relative to the first end of the outer shaft and the second position relative to the first end of the outer shaft.

3. The surgical access tool of claim 2, wherein the split-housing body comprises a cross-sectional outer peripheral shape comprising at least one of a pear shape and a triangular shape, and wherein the steering plane passes through an apex of the outer peripheral shape.

4. The surgical access tool of claim 3, wherein the apex is disposed along a first portion of the outer peripheral shape having a first radius, and wherein the first radius is less than a second radius disposed on a second portion of the outer peripheral shape adjacent to a point opposite the apex.

5. The surgical access tool of claim 1, further comprising: a cam lock collar attached to the proximal body portion, the cam lock collar comprising: a body extending a width from a first side of the body to a second side of the body and extending a height from an upper end of the body to a lower end of the body; a first button protruding from the upper end of the body; a second button protruding from the lower end of the body; a split-nut cam aperture disposed through a thickness of the body; and a cam slot disposed in the body of the cam lock collar adjacent the first side of the body.

6. The surgical access tool of claim 5, wherein the threaded block comprises: a first split-nut body; a second split-nut body, that is keyed to the first split-nut body; and a pin attached to the first split-nut body, wherein the pin is engaged with the cam slot of the cam lock collar, and wherein the first split-nut body and the second split-nut body are at least partially disposed in the split-nut cam aperture.

7. The surgical access tool of claim 6, wherein the cam lock collar is movable relative to the proximal body portion from a locked state to an unlocked state, wherein, in the locked state, the first split-nut body and the second split-nut body are arranged adjacent one another and the distal body portion and the proximal body portion are locked together, and wherein, in the unlocked state, first split-nut body and the second split-nut body are arranged offset a distance from one another and the distal body portion and the proximal body portion are unlocked.

8. The surgical access tool of claim 7, wherein, in the unlocked state, the proximal body portion and the channeling tool are separable from the distal body portion and the sheath shaft.

9. The surgical access tool of claim 7, wherein, in the locked state, the second button extends through the proximal body portion on a first side of the surgical access tool, and wherein, in the unlocked state, the first button extends through the proximal body portion on a second side of the surgical access tool, the second side of the surgical access tool disposed opposite the first side of the surgical access tool.

10. The surgical access tool of claim 9, wherein, in the locked state, an axial position of the second button relative to an aperture of the proximal body portion indicates an amount of bend in at least one of the inner shaft and the outer shaft, wherein a first amount of bend is indicated when the second button is arranged a first distance from the distal body portion, wherein a second amount of bend is indicated when the second button is arranged a second distance from the distal body portion, wherein the second amount of bend is greater than the first amount of bend, and wherein the second distance is greater than the first distance.

11. The surgical access tool of claim 10, further comprising: a coupling link attached to the cam lock collar, the coupling link comprising a locking protrusion extending substantially perpendicular to an axis of the surgical access tool, and wherein, in the locked state, the locking protrusion engages with a receiving latch contact protrusion arranged in the distal body portion locking the proximal body portion to the distal body portion.

12. The surgical access tool of claim 1, further comprising: a distal end plug is arranged at the second end of the inner shaft, the distal end plug comprising an outer tapered surface that is arranged coplanar with a tapered end surface of the inner shaft and with a tapered end surface of the outer shaft, wherein the distal end plug comprises a radio-opaque marker arranged inside the inner shaft.

13. The surgical access tool of claim 12, wherein the distal end plug comprises stainless steel, wherein the radio-opaque marker comprises tungsten, and wherein the radio-opaque marker identifies at least one of a location, position, and rotational orientation of a distal end tip of the channeling tool.

14. The surgical access tool of claim 1, wherein at least one surface of the handle extends past an outermost peripheral surface of the proximal body portion at a proximal end of the proximal body portion, and wherein an axial clearance runs along an axial length of the split-housing body to the at least one surface.

15. The surgical access tool of claim 1, wherein a first plurality of circumferential cuts are arranged axially spaced apart from one another along a length of the outer shaft, and wherein a second plurality of circumferential cuts are arranged axially spaced apart from one another along a length of the inner shaft.

16. The surgical access tool of claim 15, wherein the first plurality of circumferential cuts are arranged with first radial openings arranged on a first radial side of the outer shaft, the second plurality of circumferential cuts are arranged with second radial openings arranged on a second radial side of the inner shaft, and wherein the first radial side is arranged 180 degrees from the second radial side.

17. The surgical access tool of claim 16, wherein the first radial openings are each arranged adjacent a solid portion of the inner shaft, and wherein the second radial openings are each arranged adjacent a solid portion of the outer shaft.

18. A surgical access tool, comprising: a split-housing body comprising a distal body portion and a proximal body portion, wherein the proximal body portion is configured to selectively move between a locked state engaged with the distal body portion and an unlocked state disengaged from the distal body portion; a sheath shaft fixed to the distal body portion and extending a first length from a first end of the sheath shaft to a second end of the sheath shaft, wherein a lumen passes through the sheath shaft from the first end of the sheath shaft to the second end of the sheath shaft; a channeling tool comprising a flexible shaft, the channeling tool attached to the proximal body portion at a first end of the channeling tool, wherein the flexible shaft is disposed at least partially within the lumen of the sheath shaft when the split-housing body is in the locked state; and a handle interconnected to the proximal body portion, wherein the handle, when rotated in a first direction, moves the channeling tool from an unbent state into a bent state, and wherein the proximal body portion and the channeling tool are separable from the distal body portion when the split-housing body is in the unlocked state.

19. A method, comprising: inserting a first access tool through a portion of a subject to a first point in proximity to a treatment site, the first access tool comprising an access shaft extending from the first point to a point outside of a body of the subject; providing a surgical access tool, comprising: a split-housing body comprising a distal body portion and a proximal body portion, wherein the proximal body portion is configured to selectively move between a locked state engaged with the distal body portion and an unlocked state disengaged from the distal body portion; a sheath shaft fixed to the distal body portion and extending a first length from a first end of the sheath shaft to a second end of the sheath shaft, wherein a lumen passes through the sheath shaft from the first end of the sheath shaft to the second end of the sheath shaft; a channeling tool comprising a flexible shaft, the channeling tool attached to the proximal body portion at a first end of the channeling tool, wherein the flexible shaft is disposed at least partially within the lumen of the sheath shaft when the split-housing body is in the locked state; and a handle interconnected to the proximal body portion, wherein the handle, when rotated in a first direction, moves the channeling tool from an unbent state into a bent state, and wherein the proximal body portion and the channeling tool are separable from the distal body portion when the split-housing body is in the unlocked state; inserting the sheath shaft and the flexible shaft of the surgical access tool into the access shaft of the first access tool while the surgical access tool is in the locked state; creating a channel to the treatment site by advancing a distal tip of the channeling tool in a direction toward the treatment site; moving the split-housing body of the surgical access tool into the unlocked state; separating the proximal body portion and the channeling tool from the distal body portion and the sheath shaft while the sheath shaft remains in position in the subject; inserting an ablation probe into the sheath shaft from the first end of the sheath shaft such that a distal end of the ablation probe is arranged adjacent the treatment site; and ablating, by the ablation probe, a nerve at the treatment site.

20. The method of claim 19, further comprising: removing the ablation probe from the sheath shaft; moving the split-housing body of the surgical access tool into the locked state by attaching the proximal body portion to the distal body portion; tapping a portion of the handle in an extraction direction away from the treatment site; and removing the distal body portion and the sheath shaft from the subject.