Method of stabilizing an endoscopic assembly
Methods and apparatus for direct visual rhizotomy using an elongated tubular sheath. The sheath includes: a proximal end configured to removably receive a cannula; a distal end; a horizontal shaft having a longitudinal axis extending between the proximal end and the distal end; a first cut-away generally defining a first plane at the distal end, the first cut-away characterized by a first angle relative to a vertical plane; and a second cut-away generally defining a second plane at the distal end, the second cut-away characterized by a second angle relative to a horizontal plane. The sheath further includes an endoscope camera disposed at the distal end, the camera having a line of sight substantially orthogonal to the first plane.
1. A method of stabilizing an endoscopic assembly on an internal anatomical surface during surgery, comprising:
providing a tubular sheath having an axis and a distal end, the distal end including a first surface defining an aperture and a second surface defining a docking land, the first and second surfaces each inclined relative to the axis at respective angles in the range of about 45 to 75 degrees;
inserting the distal end of the sheath into a patient;
inserting an endoscope into the sheath and disposing an endoscope camera proximate the aperture;
displaying a signal received from the camera on a screen; and
using the displayed signal to maneuver the docking land onto the anatomical surface.
2. The method of claim 1 , further comprising:
equipping the endoscopic assembly with an actuator; and
while the docking land is disposed on the anatomical surface, manipulating the actuator to move the camera a predetermined distance from a retracted position to an extended position.
3. The method of claim 2 , wherein the actuator comprises a spring, and further wherein manipulating the actuator comprises squeezing a trigger to compress the spring.
4. The method of claim 2 , wherein moving the camera to the extended position causes the displayed signal to provide a close-up view of the anatomical surface.
5. The method of claim 2 , wherein the predetermined distance is in the range of about 2 to 3 millimeters.
6. The method of claim 2 , further comprising:
inserting a cutter into the endoscopic assembly; and
using the cutter to sever tissue on the anatomical surface while the docking land rests on the anatomical surface.
7. The method of claim 6 , wherein the cutter comprises an electrode, the anatomical surface comprises a transverse process of a vertebral body, and the tissue comprises a medial branch of a spinal nerve root.
8. The method of claim 7 , wherein severing the tissue comprises extending the electrode beyond the distal end of the sheath to thereby cauterize the medial branch.
9. The method of claim 6 , further comprising:
after severing the tissue, removing the endoscope from the sheath; and
after removing the endo scope from the sheath, removing the sheath from the patient.
10. The method of claim 1 , further comprising:
inserting a cannula into the sheath while the distal end of the sheath is inside the patient;
wherein inserting the endoscope into the sheath comprises inserting the endoscope into an endoscopic channel of the cannula.
11. The method of claim 10 , wherein the cannula further comprises a fluid ingress channel and a fluid egress channel, the method further comprising:
pumping fluid into the ingress channel to thereby maintain an expanded fluid bubble in the tissue proximate the camera.
12. The method of claim 1 , wherein the docking land comprises a substantially flat surface.
13. The method of claim 1 , wherein at least a portion of the docking land comprises a substantially concave surface.
14. A method of facilitating a direct visualized rhizotomy (DVR) surgical procedure on a human patient, comprising:
providing an endoscopic assembly including a sheath, a camera, and a cutter, wherein the distal end of the sheath comprises: i) a docking land cut at a first angle with respect to a longitudinal axis of the sheath; and ii) an oppositely disposed aperture cut at a second angle with respect to the longitudinal axis such that a line of sight associated with the camera is inclined away from the docking land;
inserting the distal end of the endoscopic assembly into the patient;
displaying a visual feed from the camera;
using the visual feed to stabilize the docking land on a transverse process proximate a twig; and
severing the twig using the cutter.
15. The method of claim 14 , wherein the first angle is in the range of 45° to 75°.
16. The method of claim 14 , further comprising:
providing the endoscopic assembly with a toggle mechanism; and
manually actuating the toggle mechanism to move the camera back and forth along the longitudinal axis to thereby extend and retract the camera.
17. The method of claim 16 , wherein the toggle mechanism comprises a spring loaded trigger.
18. The method of claim 14 , further comprising:
providing the endoscopic assembly with at least one fluid channel; and
pumping fluid through the at least one fluid channel to thereby maintain a fluid bubble in the vicinity of the twig.
19. The method of claim 14 , wherein the sheath comprises an inner wall, and the endoscopic assembly further comprises a cannula having a first lobe and a second lobe defining a fluid channel therebetween and partially bounded by the inner wall.
20. A method of stabilizing an endoscopic assembly on an internal anatomical surface during surgery, comprising:
providing a tubular sheath having a sheath axis and a distal end including a docking land inclined relative to the sheath axis at an angle in the range of about 45 to 75 degrees;
inserting the distal end of the sheath into a patient;
stabilize the docking land on a transverse process proximate a twig;
inserting a tool through the sheath; and
severing the twig with the tool.