Surgical access system and related methods

• US 8,303,498 B2
• Filed: 02/18/2011
• Issued: 11/06/2012
• Est. Priority Date: 02/27/2003
• Status: Active Grant

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Miles, Patrick, Martinelli, Scot, Finley, Eric, Gharib, James, Farquhar, Allen, Blewett, Jeffrey J., Kaula, Norbert F.
• Primary Examiner(s): Hammond, Ellen C
• Application Number:
  US13/030,798
• Publication Number:
  US 20110144439A1
• Time in Patent Office: 627 Days
• Field of Search: 600/201, 600/202, 600/204, 600/206, 600/208, 600/210, 600/214, 600/215, 600/219, 600/224, 600/233, 600/235
• US Class Current: 600/224
• 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 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 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.

Claims

1. A system for accessing a lateral aspect of 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 portion of the elongate member penetrates into an annulus of the spinal disc;

a dilator system to advance along the lateral, trans-psoas path to the lumbar spine to create a distraction corridor, the dilator system comprising at least one dilator tool that is configured to slidably engage with an exterior of the elongate member during advancement to the spinal disc along the lateral, trans-psoas path to the lumbar spine, wherein at least one of the elongate member and the dilator tool includes a stimulation electrode that outputs electrical stimulation for nerve monitoring when at least one of the elongate member and the dilator tool is positioned in the lateral, trans-psoas path;

a three-bladed retractor assembly to slidably engage with an exterior of the dilator system while the three-bladed refractor assembly is advanced toward the spinal disc along the lateral, trans-psoas path, the three-bladed retractor assembly including a posterior-most retractor blade, a caudal-most refractor blade, and a cephalad-most retractor blade that extend generally perpendicularly relative to arm members of a handle assembly, wherein the caudal-most retractor blade and the cephalad-most retractor blade are movable relative to the posterior-most retractor blade in response to two of the arm members pivoting about a pivot axis, wherein handle assembly comprises a locking shaft extending between said two of the arm members and having exterior threads, the locking shaft being positioned further away from said retractor blades than said pivot axis, wherein the three-bladed retractor assembly is slidably advanceable over the exterior of the dilator system when in a first position in which the retractor blades are generally adjacent to one another, and wherein the handle assembly is configured to adjust the three-bladed retractor assembly to a second 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.

2. The system of claim 1, wherein the exterior threads of the locking shaft mates with a locking nut coupled to one of said two of the arm members.

3. The system of claim 2, wherein the locking shaft and the locking nut operate as a locking mechanism configured to selectively lock said two of the arm members relative to one another when said two of the arm members are pivoted to move the caudal-most retractor blade and the cephalad-most retractor blade away from the posterior-most retractor blade.

4. The system of claim 1, wherein the pivot axis is positioned between the locking shaft and said retractor blades.

5. The system of claim 1, further comprising a posterior shim element that is releasably engageable with grooves along an inner face 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.

6. The system of claim 1, wherein the handle assembly is configured to adjust the three-bladed retractor assembly to the second position by squeezing proximal gripper portions of the handle assembly so that the caudal-most refractor blade and the cephalad-most retractor blade are simultaneously moved away from one another.

7. The system of claim 6, wherein the handle assembly is configured to simultaneously move the caudal-most retractor blade and the cephalad-most retractor blade away from one another while the posterior-most retractor blade is maintained in a generally fixed position relative to the lumbar spine.

8. The system of claim 1, wherein said two of the arm members of the handle assembly comprise:

a first pivotable arm member arranged between a first proximal gripper portion and the caudal-most retractor blade, and a second pivotable arm member arranged between a second proximal gripper portion and the cephalad-most retractor blade.

9. The system of claim 8, wherein the handle assembly further comprises a translating arm member coupled to the posterior-most retractor blade.

10. The system of claim 1, wherein the elongate member is deliverable to the spinal disc together with the at least one dilator tool.

11. The system of claim 1, wherein when the three-bladed retractor assembly is adjusted to the second position, the posterior-most retractor blade, the caudal-most retractor blade, and the cephalad-most retractor blade are spaced apart and configured to be maintained generally parallel to one another.

12. The system of claim 1, wherein when the three-bladed retractor assembly is in the first position, the posterior-most retractor blade, the caudal-most retractor blade, and the cephalad-most retractor blade generally abut with one another.

13. The system of claim 1, wherein the dilator system comprises a plurality of dilator tools that are sequentially deliverable along the lateral, trans-psoas path to the lumbar spine.

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

15. The system of claim 1, further comprising a nerve monitoring system to deliver an electrical stimulation signal to the stimulation electrode of at least one of the elongate member and the dilator tool when at least one of the elongate member and the dilator tool is positioned in the lateral, trans-psoas path, the nerve monitoring system being configured to detect electromyographic activity via a set of sensor electrodes in leg muscle myotomes associated with nerves in the vicinity of the spinal disc, and the nerve monitoring system comprising a video display device that displays information regarding electromyographic activity in at least one of said leg muscle myotomes.

16. The system of claim 15, wherein the nerve monitoring system comprises a control unit having the 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.

17. The method of claim 16, 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.