SURGICAL ACCESS SYSTEM AND RELATED METHODS

• US 20100130827A1
• Filed: 12/11/2009
• Published: 05/27/2010
• Est. Priority Date: 09/25/2003
• Status: Active Grant

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Martinelli, Scot, Finley, Eric, Miles, Patrick, Pimenta, Luiz
• Granted Patent: US 8,303,515 B2
• Time in Patent Office: Days
• US Class Current: 600/223
• CPC Class Codes: A61B 1/32 Devices for opening or enlarging the visual field, e.g. of a tube of the body dilators A61M29/00
• CPC Class Codes: A61B 17/02 for holding wounds open; Tractors specula A61B1/32 ; drainage appliances for wounds A61M27/00
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof

Abstract

A surgical access system including a tissue distraction assembly and a tissue retraction assembly, both of which may be equipped with one or more electrodes for use in detecting the existence of (and optionally the distance and/or direction to) neural structures before, during, and after the establishment of an operative corridor to a surgical target site. Some embodiments of the surgical access system may be particularly suited for establishing an operative corridor to a surgical target site in the spine. Such an operative corridor may be established through the retroperitoneal space and the psoas muscle during a direct lateral, retroperitoneal approach to the spine.

Claims

1. A method of forming and using an operative corridor through a retroperitoneal space and a psoas muscle during a substantially lateral, retroperitoneal approach to a lumbar spine, the method comprising:

while a user'"'"'s finger is inserted through a skin incision, moving a tip portion of the user'"'"'s finger through bodily tissue that is generally lateral from a lumbar spine for blunt finger dissection of the bodily tissue proximate to a retroperitoneal space;

advancing the tip portion of the user'"'"'s finger into the retroperitoneal space so as to palpate to a psoas muscle;

advancing an elongate stimulation instrument along a lateral, trans-psoas path through the retroperitoneal space, through the psoas muscle, and to the lumbar spine such that a distal tip portion of the elongate stimulation instrument penetrates into an annulus of a spinal disc of the lumbar spine, the distal tip portion of the elongate stimulation instrument including a stimulation electrode that outputs electrical stimulation for nerve monitoring during advancement of the elongate stimulation instrument through the psoas muscle;

advancing a dilator system along the lateral, trans-psoas path to the lumbar spine to create a distraction corridor, the dilator system comprising at least one dilator that slidably engages an exterior of the elongate stimulation instrument, the at least one dilator being advanced to the spinal disc along the lateral, trans-psoas path to the lumbar spine;

slidably advancing a three-bladed retractor assembly over the dilator system toward the spinal disc along the lateral, trans-psoas path, the three-bladed retractor assembly including a posterior-most retractor blade, a caudal-most retractor blade, and a cephalad-most retractor blade that extend generally perpendicularly relative to arm members of a handle assembly, wherein the three-bladed retractor assembly is slidably advanced over the dilator system when in a closed position in which the posterior-most retractor blade, the caudal-most retractor blade, and the cephalad-most retractor blade are generally adjacent to one another;

actuating the handle assembly to adjust the three-bladed retractor assembly to an opened position in which the caudal-most retractor blade and the cephalad-most retractor blade are moved away from the posterior-most retractor blade to enlarge the distraction corridor and form an operative corridor along the lateral, trans-psoas path to the lumbar spine;

inserting an implant that is releasably secured to an inserter tool through the operative corridor formed by the three-bladed retractor assembly along the lateral, trans-psoas path to the lumbar spine;

releasing the implant from the inserter tool when the implant is positioned in a disc space of the lumbar spine.

2. The method of claim 1, wherein the step of actuating the handle assembly comprises squeezing handle portions of the handle assembly toward one another so that the caudal-most retractor blade and the cephalad-most retractor blade move away from the posterior-most retractor blade.

3. The method of claim 2, further comprising releasably engaging a posterior shim element with grooves along an inner facing of the posterior-most retractor blade so that at least a portion of the posterior shim element extends distally from the posterior-most retractor blade and anchors into the spinal disc.

4. The method of claim 3, wherein the step of releasably engaging the posterior shim element is performed prior to the step of actuating the handle assembly to adjust the three-bladed retractor assembly to the opened position.

5. The method of claim 3, further comprising releasably engaging a first retractor blade extender with grooves along an inner facing of the caudal-most retractor blade so that at least a portion of the first retractor blade extender protrudes from the caudal-most retractor blade, and releasably engaging a second retractor blade extender with grooves along an inner facing of the cephalad-most retractor blade so that at least a portion of the second retractor blade extender protrudes from the cephalad-most retractor blade.

6. The method of claim 5, wherein the first and second retractor blade extenders inhibit ingress of tissue into the operative corridor after the three-bladed retractor assembly is adjusted to the opened position.

7. The method of claim 1, wherein the step of moving the tip portion of the user'"'"'s finger through the bodily tissue separates fatty tissue before the elongate stimulation instrument is advanced into the retroperitoneal space.

8. The method of claim 1, further comprising activating a plurality of light emitting devices to direct light through the operative corridor toward the spinal disc, the plurality of light emitting devices including a first light emitting device coupled to the cephalad-most retractor blade and a second light emitting device coupled to the caudal-most retractor blade.

9. The method of claim 8, further comprising inserting at least one preparation tool through the operative corridor formed by the three-bladed retractor assembly along the lateral, trans-psoas path to the lumbar spine so as to remove a portion of the spinal disc from the disc space.

10. The method of claim 9, further comprising inserting a sizer instrument into the disc space of the lumbar spine before the implant is inserted into the disc space.

11. The method of claim 1, wherein the step of actuating the handle assembly comprises:

pivoting two of the arm members of the handle assembly so as to move the caudal-most retractor blade and the cephalad-most retractor blade away from the posterior-most retractor blade, and rotating a knob element on the handle assembly so as to linearly move the posterior-most retractor blade relative to the caudal-most retractor blade and the cephalad-most retractor blade.

12. The method of claim 11, wherein the two arm members of the handle assembly are pivoted in response to squeezing proximal gripper portions of the handle assembly so that the caudal-most retractor blade and the cephalad-most retractor blade are simultaneously moved away from one another.

13. The method of claim 12, wherein the caudal-most retractor blade and the cephalad-most retractor blade are simultaneously moved away from one another while the posterior-most retractor blade is maintained in generally fixed position relative to the lumbar spine.

14. The method of claim 1, wherein the step of advancing the elongate stimulation instrument comprises delivering the elongate stimulation instrument together with the at least one dilator cannula along the lateral, trans-psoas path to the lumbar spine.

15. The method of claim 1, wherein when the three-bladed retractor assembly is adjusted to the opened position, the posterior-most refractor blade, the caudal-most retractor blade, and the cephalad-most retractor blade are spaced apart and maintained generally parallel to one another.

16. The method of claim 1, wherein when the three-bladed retractor assembly is in the closed position, the posterior-most retractor blade, the caudal-most retractor blade, and the cephalad-most retractor blade are in generally abutting relation with one another.

17. The method of claim 1, wherein the step of advancing the dilator system comprises sequentially advancing a plurality of supplemental dilators along the lateral, trans-psoas path to the lumbar spine.

18. The method of claim 1, wherein the elongate stimulation instrument comprises a K-wire.

19. The method of claim 1, further comprising:

activating a nerve monitoring system that delivers an electrical stimulation signal to the stimulation electrode of the elongate member during delivery of the elongate member along the lateral, trans-psoas path to the lumbar spine, the nerve monitoring system detecting electromyographic activity via a set of sensor electrodes in leg muscle myotomes associated with nerves in the vicinity of the spinal disc; and

viewing a video display device of the nerve monitoring system that contemporaneously displays;

a numeric stimulation threshold required to obtain the electromyographic activity in at least one of said leg muscle myotomes, and myotomes levels being monitored.

20. The method of claim 1, wherein the skin incision through which the user'"'"'s finger is inserted is different from a skin penetration point of the elongate stimulation instrument.