Systems for radiofrequency neurotomy
Methods and systems for spinal radio frequency neurotomy. Systems include needles capable of applying RF energy to target volumes within a patient. Such target volumes may contain target medial branch nerves along vertebrae or rami proximate the sacrum. Such procedures may be used to ablate or cauterize a portion of the targeted nerve, thus blocking the ability of the nerve to transmit signals to the central nervous system. Disclosed needles may be operable to asymmetrically, relative to a central longitudinal axis of the needle, apply RF energy. Such asymmetry facilitates procedures where a tip of the needle is placed proximate to anatomical structures for location verification. Then RF energy may be applied in a selectable direction relative to the needle tip to ablate volumes that include the targeted medial branch nerves or rami, thus denervating facet joints or the sacroiliac joint, respectively, to relieve pain in a patient.
1 . A radiofrequency neurotomy system comprising:
a radiofrequency probe assembly that comprises;
a radiofrequency probe that comprises a temperature sensor operable to measure temperature at a distal end of the radiofrequency probe; and
a cable; and
a radiofrequency neurotomy needle that comprises:
a first hub;
an elongate member fixedly attached to the first hub, the elongate member comprising a tube that is 16 gauge or smaller and a lumen within the tube, wherein a central longitudinal axis is disposed along a center of the elongate member;
a tip at a distal end of the elongate member shaped to pierce tissue of a patient;
a plurality of filaments movable between a retracted position and a deployed position;
a second hub interconnected to the plurality of filaments; and
an actuator interconnected to the second hub and to the plurality of filaments, wherein rotation of the actuator relative to the first hub in a first direction causes the second hub to move axially to advance the plurality of filaments to the deployed position and rotation of the actuator relative to the first hub in a second direction that is opposite the first direction causes the second hub to move axially to retract the plurality of filaments to the retracted position,
wherein:
the radiofrequency probe is positionable within the lumen of the elongate member;
the plurality of filaments are advanceable to the deployed position without concurrent advancement of the radiofrequency probe relative to the lumen; and
when the radiofrequency probe is positioned within the lumen of the elongate member and is interconnected to a radiofrequency generator via the cable, the radiofrequency probe is configured to transmit radiofrequency energy applied thereto and the plurality of filaments and the tip are configured to conduct and emanate the radiofrequency energy such that the radiofrequency probe, the tip, and the plurality of filaments form a single radiofrequency electrode.
2 . The radiofrequency neurotomy system of claim 1 , wherein the radiofrequency probe is integrated into the needle.
3 . The radiofrequency neurotomy system of claim 2 , wherein the radiofrequency neurotomy needle further comprises an additional tube within which the radiofrequency probe is inserted, wherein the additional tube is conductive, and wherein a portion of the additional tube is housed by the elongate member.
4 . The radiofrequency neurotomy system of claim 3 , wherein the radiofrequency energy is emitted by the radiofrequency probe and is conducted through the additional tube and into and through the plurality of filaments.
5 . The radiofrequency neurotomy system of claim 1 , wherein the radiofrequency neurotomy needle further comprises an additional tube within which the radiofrequency probe is inserted, wherein the additional tube is conductive, and wherein a portion of the additional tube is housed by the elongate member.
6 . The radiofrequency neurotomy system of claim 5 , wherein the radiofrequency energy is emitted by the radiofrequency probe and is conducted through the additional tube and into and through the plurality of filaments.
7 . The radiofrequency neurotomy system of claim 6 , wherein a distal end of the radiofrequency probe is near the tip when the plurality of filaments and the tip conduct and emanate the radiofrequency energy.
8 . The radiofrequency neurotomy system of claim 1 , wherein the radiofrequency probe is configured to be inserted into the lumen of the elongate member during use of the radiofrequency neurotomy needle in the patient, and wherein the radiofrequency probe extends through the first hub when inserted into the lumen of the elongate member.
9 . The radiofrequency neurotomy system of claim 1 , wherein:
the radiofrequency neurotomy system further comprises a projection;
the actuator comprises a helical track sized to accommodate the projection; and
as the actuator is rotated relative to the first hub, the helical track and the projection, in combination, cause the second hub to move axially.
10 . The radiofrequency neurotomy system of claim 9 , wherein rotational motion of the actuator relative to the first hub is not transmitted to the second hub.
11 . The radiofrequency neurotomy system of claim 1 , wherein each filament of the plurality of filaments comprises a distal end that defines a point, and wherein an average of all points of the plurality of filaments is offset from the central longitudinal axis of the elongate member when the plurality of filaments are in the deployed position.
12 . The radiofrequency neurotomy system of claim 1 , wherein the plurality of filaments are at least partially disposed within the elongate member when in the retracted position.
13 . The radiofrequency neurotomy system of claim 12 , wherein distal tips of the plurality of filaments extend distally beyond a distal point of the tip when the plurality of filaments are in the deployed position.
14 . The radiofrequency neurotomy system of claim 1 , wherein a single member runs along at least part of the elongate member and the plurality of filaments are interconnected to the single member.
15 . The radiofrequency neurotomy system of claim 14 , wherein the plurality of filaments are interconnected to the single member at a position proximal to the tip.
16 . The radiofrequency neurotomy system of claim 1 , wherein the plurality of filaments exit from the tip at a common location and form a fan-like arrangement as they are deployed.
17 . The radiofrequency neurotomy system of claim 1 , wherein the plurality of filaments are configured to achieve a lesion having a pyramidal shape when in the deployed position within the patient.
18 . The radiofrequency neurotomy system of claim 1 , wherein the elongate member and the tip are a single unitary structure.
19 . The radiofrequency neurotomy system of claim 1 , wherein the radiofrequency probe, the plurality of filaments, and the tip form a monopolar electrode.
20 . The radiofrequency neurotomy system of claim 1 , wherein the plurality of filaments comprise a shape memory alloy, and wherein a pre-set bias is present in the plurality of filaments such that the plurality of filaments are curved when in the deployed position.
21 . The radiofrequency neurotomy system of claim 1 , wherein the temperature sensor of the radiofrequency probe assembly comprises a thermocouple.
22 . The radiofrequency neurotomy system of claim 1 , wherein the radiofrequency probe is insertable into the lumen of the elongate member after the plurality of filaments have been advanced to the deployed position.
23 . The radiofrequency neurotomy system of claim 1 ,
wherein:
the radiofrequency probe extends through the first hub when the radiofrequency probe is inserted into the lumen of the elongate member;
the radiofrequency neurotomy needle further comprises a projection and the actuator comprises a helical track sized to accommodate the projection;
as the actuator is rotated relative to the first hub, the helical track and the projection, in combination, cause the second hub to move axially;
rotational motion of the actuator relative to the first hub is not transmitted to the second hub;
each filament of the plurality of filaments comprises a distal end that defines a point, and an average of all points of the plurality of filaments is offset from the central longitudinal axis of the elongate member when the plurality of filaments are in the deployed position;
the plurality of filaments are at least partially disposed within the elongate member when in the retracted position;
the plurality of filaments are configured to achieve a lesion having a pyramidal shape when in the deployed position within the patient;
the plurality of filaments comprise a shape memory alloy; and
a pre-set bias is present in the plurality of filaments such that the plurality of filaments are curved when in the deployed position.
24 . The radiofrequency neurotomy system of claim 23 , wherein a distal end of the radiofrequency probe is near the tip when the plurality of filaments and the tip conduct and emanate the radiofrequency energy.
25 . The radiofrequency neurotomy system of claim 24 , wherein distal tips of the plurality of filaments extend distally beyond a distal point of the tip when the plurality of filaments are in the deployed position, and wherein when the radiofrequency neurotomy needle is placed generally perpendicular to a surface of a bone of the patient and the deployed filaments are proximate to the surface, the radiofrequency neurotomy needle is configured to achieve a lesion width along the surface that is wider than what the radiofrequency neurotomy needle would create if the plurality of filaments were not deployed.
26 . The radiofrequency neurotomy system of claim 25 , wherein:
the elongate member is 18 gauge;
the radiofrequency neurotomy needle further comprises an additional tube within which the radiofrequency probe is inserted;
the additional tube is conductive;
a portion of the additional tube is housed by the elongate member; and
the radiofrequency energy is emitted by the radiofrequency probe and is conducted through the additional tube and into and through the plurality of filaments.
27 . The radiofrequency neurotomy system of claim 25 , wherein a single member runs along at least part of the elongate member and the plurality of filaments are interconnected to the single member at a position proximal to the tip.
28 . The radiofrequency neurotomy system of claim 7 , wherein the plurality of filaments exit from the tip at a common location and form a fan-like arrangement as they are deployed.
29 . The radiofrequency neurotomy system of claim 25 , wherein the radiofrequency probe, the plurality of filaments, and the tip form a monopolar electrode.
30 . The radiofrequency neurotomy system of claim 25 , wherein the radiofrequency probe is integrated into the needle.
31 . The radiofrequency neurotomy system of claim 25 , wherein the radiofrequency probe is insertable into the lumen of the elongate member after the plurality of filaments have been advanced to the deployed position within the patient.
32 . The radiofrequency neurotomy system of claim 1 , wherein the elongate member is 18 gauge.
33 . The radiofrequency neurotomy system of claim 1 , wherein the radiofrequency neurotomy needle is sized for use in spinal radiofrequency neurotomy.
34 . The radiofrequency neurotomy system of claim 1 , wherein when the radiofrequency neurotomy needle is placed generally perpendicular to a surface of a bone of the patient and the deployed filaments are proximate to the surface, the radiofrequency neurotomy needle is configured to achieve a lesion width along the surface that is wider than what the radiofrequency neurotomy needle would create if the plurality of filaments were not deployed.
35 . The radiofrequency neurotomy system of claim 13 , wherein when the radiofrequency neurotomy needle is placed generally perpendicular to a surface of a bone of the patient and the deployed filaments are proximate to the surface, the radiofrequency neurotomy needle is configured to achieve a lesion width along the surface that is wider than what the radiofrequency neurotomy needle would create if the plurality of filaments were not deployed.
36 . The radiofrequency neurotomy system of claim 1 , wherein the number of filaments is three.
37 . The radiofrequency neurotomy system of claim 36 , wherein tips of the three filaments form a polygon that has a centroid when the three filaments are in the deployed position, and wherein the centroid is offset from the central longitudinal axis such that the three filaments are configured to produce a lesion that is offset from the central longitudinal axis.
38 . The radiofrequency neurotomy system of claim 1 , wherein adjacent filaments are positioned about 120 degrees apart from each other about the central longitudinal axis.
39 . The radiofrequency neurotomy system of claim 1 , wherein each of the plurality of filaments is curved away from the central longitudinal axis when in the deployed position.
40 . The radiofrequency neurotomy system of claim 6 , wherein the additional tube comprises an additional lumen that is configured to transport fluid from a fluid source and is configured to subsequently accept the radiofrequency probe therein.
41 . The radiofrequency neurotomy system of claim 40 , where a maximum cross-dimension of the additional lumen is less than about 0.85 millimeters.