SURGICAL ACCESS SYSTEM AND RELATED METHODS

• US 20100160738A1
• Filed: 12/14/2009
• Published: 06/24/2010
• Est. Priority Date: 01/16/2003
• Status: Active Grant

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Finley, Eric, Martinelli, Scot, Miles, Patrick, Kaula, Norbert, Gharib, James, Blewett, Jeffrey J., Farquhar, Allen, Medeiros, Goretti
• Granted Patent: US 8,403,841 B2
• Time in Patent Office: Days
• US Class Current: 600/202
• 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 17/0206 with antagonistic arms as supports for retractor elements
• CPC Class Codes: A61B 17/0218 for minimally invasive surgery A61B17/0281, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 2017/00473 Distal part, e.g. tip or head A61B2017/00464 takes precedence
• CPC Class Codes: A61B 2017/0262 with a provision for protecting nerves
• CPC Class Codes: A61B 5/4893 Nerves

Abstract

A surgical access system including a tissue distraction assembly and a tissue refraction 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.

Claims

1. A system for forming an operating corridor to a lumbar spine, comprising:

an elongate member deliverable to a spinal disc along a lateral, trans-psoas path to the lumbar spine such that a distal tip region of the elongate member penetrates into an annulus of the spinal disc, the distal tip region of the elongate member including a stimulation electrode that delivers electrical stimulation for nerve monitoring during advancement of the elongate member along the lateral, trans-psoas path to the lumbar spine;

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

a three-bladed retractor assembly slidable over the dilator system toward the spinal disc along the lateral, trans-psoas path, the three-bladed retractor assembly including;

a handle assembly and first, second, and third retractor blades that extend generally perpendicularly relative to arm portions of the handle assembly,

wherein the three-bladed retractor assembly is adjustable from a closed position in which the first, second, and third retractor blades are adjacent to one another and slidable over the dilator system to an opened position in which the second and third retractor blades are moved away from the first retractor blade to enlarge the distraction corridor and thereby form an operative corridor along the lateral, trans-psoas path to the lumbar spine, and

wherein the second and third retractor blades are movable relative to the first blade in response to pivoting movement of two of the arm portions of the handle assembly,

a posterior shim element to releasably engage with a posterior-most retractor blade of the first, second, and third retractor blades so that at least a portion of the posterior shim element extends distally from the posterior-most retractor blade to anchor into the spinal disc; and

wherein when the three-bladed retractor assembly is adjusted to the opened position to form the operative corridor along the lateral, trans-psoas path to the lumbar spine, the first retractor blade is the posterior-most retractor blade of the first, second, and third retractor blades and the operative corridor is dimensioned so as to pass an implant through the operative corridor along the lateral, trans-psoas path to the lumbar spine.

2. The system of claim 1, wherein when the three-bladed retractor assembly is adjusted to the opened position to form the operative corridor, the first retractor blade is the posterior-most retractor blade, the second blade is a cephalad-most retractor blade, and the third blade is a caudal-most retractor blade.

3. The system of claim 2, wherein when the three-bladed retractor assembly is adjusted to the opened position to form the operative corridor, the cephalad-most retractor blade and the caudal-most retractor blade are moved away from one another and the posterior shim element is releasably engaged with the posterior-most retractor blade.

4. The system of claim 2, wherein when the three-bladed retractor assembly is adjusted to the opened position to form the operative corridor, the cephalad-most retractor blade and the caudal-most retractor blade are moved away from one another and a fourth retractor blade is positioned anterior to the cephalad-most retractor blade and the caudal-most retractor blade.

9. The system of claim 1, wherein when the three-bladed retractor assembly is adjusted to the opened position to form the operative corridor along the lateral, trans-psoas path, a distal portion of the posterior shim element is configured to anchor in the spinal disc to secure the posterior-most retractor blade in fixed relation relative the lumbar spine.

10. The system of claim 1, further comprising a fourth retractor blade that couples with the handle assembly of the three-bladed retractor assembly.

11. The system of claim 10, wherein the fourth retractor blade releasably couples with the handle assembly so that the fourth retractor blade is an anterior-most retractor blade.

12. The system of claim 1, wherein the elongated member is advanced together with the at least one dilator cannula along the lateral, trans-psoas path to the lumbar spine.

13. The system of claim 1, wherein when the three-bladed retractor assembly is opened to create the operative corridor, the first, second, and third retractor blades are spaced apart and maintained generally parallel to one another.

14. The system of claim 1, wherein when the three-bladed retractor assembly is in the closed position, each of the first, second, and third retractor blades are in generally abutting relation with the other two of the first, second, and third retractor blades.

15. The system of claim 1, wherein the dilator system comprises a plurality of supplemental dilators for sequential insertion along the lateral, trans-psoas path to the lumbar spine.

16. The system of claim 15, wherein each of the plurality of supplemental dilators comprises a stimulation electrode that delivers electrical stimulation for nerve monitoring.

17. The system of claim 1, wherein the elongate member comprises a K-wire.

18. The system of claim 1, further comprising a monitoring system that delivers an electrical stimulation signal to the stimulation electrode of the elongate member, monitors electromyographic activity detected by a set of sensor electrodes in leg muscle myotomes associated with nerves in the vicinity of the spinal disc, and displays to a user:

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

19. The system of claim 18, wherein the monitoring system comprises a control unit having a video display device, a patient module connected to the control unit via a data cable, an EMG sensor harness having the set of sensor electrodes connected to the patient module.

20. The method of claim 19, wherein the control unit receives signals from the patient module and processes EMG responses output from the sensor electrodes to extract characteristic information for each of said leg muscle myotomes.

5. The system of clam 1, wherein the posterior shim element is slidable along an engagement slot defined along an inner-facing of the posterior-most retractor blade.

6. The system of claim 5, wherein the posterior shim element comprises at least one rearward protrusion to engage with the engagement slot along the inner facing of the posterior-most retractor blade.

7. The system of claim 6, wherein the posterior shim element comprises a distal portion to penetrate into the spinal disc, the distal portion of the posterior shim element having a width that is less than a proximal portion of the posterior shim element, and the posterior shim element comprises at least one rear tab to engage with the engagement slot along the inner facing of the posterior-most retractor blade.

8. The system of claim 7, wherein the distal portion of posterior shim element has a smallest width at a rounded distal tip.