Surgical access system and related methods

• US 8,192,357 B2
• Filed: 12/30/2009
• Issued: 06/05/2012
• Est. Priority Date: 10/08/2002
• Status: Active Grant

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Miles, Patrick, Martinelli, Scot, Finley, Eric, Gharib, James, Farquhar, Allen, Kaula, Norbert, Blewett, Jeffrey
• Primary Examiner(s): Nguyen, Victor
• Application Number:
  US12/650,271
• Publication Number:
  US 20100174146A1
• Time in Patent Office: 888 Days
• Field of Search: 600/202, 600/214, 600/546, 600/554, 600/219, 607/2, 606/90, 606/99
• 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 17/0218 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 17/0293 with ring member to support retractor elements
• CPC Class Codes: A61B 17/3421 Cannulas
• CPC Class Codes: A61B 2017/00261 Discectomy
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61B 2017/0262 with a provision for protecting nerves
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/395 Details of stimulation, e.g. nerve stimulation to elicit EMG response
• CPC Class Codes: A61B 90/37 Surgical systems with images on a monitor during operation
• CPC Class Codes: A61M 29/02 Dilators made of swellable material balloon catheters for angioplasty A61M25/104

Abstract

A system for accessing a surgical target site and related methods, involving an initial distraction system for creating an initial distraction corridor, and an assembly capable of distracting from the initial distraction corridor to a secondary distraction corridor and thereafter sequentially receiving a plurality of retractor blades for retracting from the secondary distraction corridor to thereby create an operative corridor to the surgical target site, 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 spinal disc of a lumbar spine through an operative corridor, comprising:

an initial dilating cannula configured to create a tissue distraction corridor to a lumbar spine, wherein said initial dilating cannula is deliverable to a spinal disc along a lateral, trans-psoas path to the lumbar spine, the distal tip region of the initial dilating cannula including a stimulation electrode exposed along a tapered outer surface that is angled relative to a longitudinal axis of said initial dilating cannula such that the stimulation electrode delivers electrical stimulation away from the distal tip region for nerve monitoring when the initial dilating cannula is positioned in the lateral, trans-psoas path,

a secondary distraction assembly comprising a plurality of dilators of sequentially larger width deliverable to the spinal disc along the lateral, trans-psoas path; and

a refraction assembly comprising a mounting structure and four refractor blades releasably attachable to said mounting structure, wherein said retraction assembly is configured to maintain an operative corridor along the lateral, trans-psoas path to the lumbar spine that is enlarged from the tissue distraction corridor along the lateral, trans-psoas path to the lumbar spine, wherein, when the four retractor blades are positioned along the lateral, trans-psoas path, a first of the four retractor blades is a posterior-most retractor blade, a second of the four retractor blades is an anterior-most retractor blade, a third of the four retractor blades is a caudal-most retractor blade, and a fourth of the four retractor blades is a cephalad-most retractor blade, wherein said posterior-most retractor blade is spaced apart from said anterior-most retractor blade when said four retractor blades maintain the operative corridor along the lateral, trans-psoas path to the lumbar spine,

wherein 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 said posterior-most retractor blade is movable towards and away from said anterior-most retractor blade.

3. The system of claim 1, wherein said anterior-most retractor blade is movable towards and away from said posterior-most retractor blade.

4. The system of claim 1, wherein said caudal-most retractor blade is movable towards and away from said cephalad-most retractor blade.

5. The system of claim 1, wherein said cephalad-most retractor blade is movable towards and away from said caudal-most retractor blade.

6. The system of claim 1, wherein said posterior-most retractor blade and said anterior-most retractor blade are slidably movable in the posterior-anterior direction.

7. The system of claim 1, wherein said cephalad-most retractor blade and said caudal-most retractor blade are slidably movable in the cephalad-caudal direction.

8. The system of claim 1, wherein said caudal-most refractor blade is spaced apart from said cephalad-most retractor blade when said four retractor blades maintain the operative corridor along the lateral, trans-psoas path to the lumbar spine.

9. The system of claim 1, wherein each of the plurality of dilators of the secondary distraction assembly comprises a stimulation electrode that delivers electrical stimulation for nerve monitoring.

10. The system of claim 1, wherein each of the four retractor blades comprises a stimulation electrode that delivers electrical stimulation for nerve monitoring.

11. The system of claim 1, wherein the angular orientation of said posterior-most retractor blade and said anterior-most retractor blade is independently adjustable relative to said mounting structure such that the distal ends of said posterior-most refractor blade and said anterior-most retractor blade are capable of being angled toward each other.

12. The system of claim 1, wherein the angular orientation of said posterior-most retractor blade and said anterior-most retractor blade is independently a adjustable relative to said mounting structure such that the distal ends of said posterior-most refractor blade and said anterior-most retractor blade are capable of being angled away from each other.

13. The system of claim 1, further comprising a monitoring system that delivers an electrical stimulation signal to the stimulation electrode of the initial dilating cannula, monitors electromyographic activity detected by a set of sensor electrodes in muscle myotomes associated with nerves in the vicinity of the spinal disc, and displays, to a user, data indicating a stimulation threshold required to obtain the electromyographic activity in at least one of said muscle myotomes.

14. The system of claim 13, 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, and an EMG sensor harness having the set of sensor electrodes connected to the patient module.

15. The system of claim 14, wherein the control unit receives signals from the patient module and processes EMG response output from the sensor electrodes to extract characteristic information for each of said muscle myotomes.

16. The system of claim 14, wherein the initial dilating cannula is connected to said monitoring system via a removable connector that establishes electrical communication between the monitoring system and the stimulation electrode at the distal tip region of the initial dilating cannula.

17. A system for accessing a spinal disc of a lumbar spine through an operative corridor, comprising:

an initial dilating cannula configured to create a tissue distraction corridor to a lumbar spine, wherein said initial dilating cannula is deliverable to a spinal disc along a lateral, trans-psoas path to the lumbar spine, the distal tip region of the initial dilating cannula including a stimulation electrode exposed along a tapered outer surface that is angled relative to a longitudinal axis of said initial dilating cannula such that the stimulation electrode is configured to deliver electrical stimulation away from the distal tip region for nerve monitoring when the initial dilating cannula is positioned in the lateral, trans-psoas path,

a secondary distraction assembly comprising a plurality of dilators of sequentially larger diameter deliverable to the spinal disc along the lateral, trans-psoas path; and

a retraction assembly comprising a blade holder apparatus and a plurality of retractor blades releasably attachable to said blade holder apparatus, wherein said retraction assembly is configured to maintain an operative corridor along the lateral, trans-psoas path to the lumbar spine that is enlarged from the tissue distraction corridor along the lateral, trans-psoas path to the lumbar spine, wherein the retraction assembly further comprises a fixation element that is releasably attachable to a first refractor blade of the plurality of retractor blades such that a distal portion of said fixation element extends distally of a distal end of the said first retractor blade and is configured to penetrate into the lumbar spine for affixing the first retractor blade to the lumbar spine, said fixation element including a proximal portion having a width that is greater than a maximum width of said distal portion of said fixation element, wherein a second retractor blade of the plurality of retractor blades is movable away from the first retractor blade for establishing said operative corridor to the lumbar spine between said first and second retractor blades,

wherein 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.

18. The system of claim 17, wherein said fixation element of the retraction assembly is slidably engageable with said first retractor blade.

19. The system of claim 18, wherein said distal portion of said fixation element is configured to penetrate into the lumbar spine so as to affix said first retractor blade in said fixed relative position.

20. The system of claim 17, further comprising a monitoring system that delivers an electrical stimulation signal to the stimulation electrode of the initial dilating cannula, monitors electromyographic activity detected by a set of sensor electrodes in muscle myotomes associated with nerves in the vicinity of the spinal disc, and displays numeric data indicating a stimulation threshold required to obtain the electromyographic activity in at least one of said muscle myotomes.

21. The system of claim 20, 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, and an EMG sensor harness having the set of sensor electrodes connected to the patient module.

22. The system of claim 21, wherein the control unit receives signals from the patient module and processes EMG response output from the sensor electrodes to extract characteristic information for each of said muscle myotomes.

23. The system of claim 21, wherein the initial dilating cannula is connected to said monitoring system via a removable connector that establishes electrical communication between the monitoring system and the stimulation electrode at the distal tip region of the initial dilating cannula.

24. The system of claim 20, wherein the monitoring system displays said numeric data comprises a value of milliAmps indicative of the stimulation threshold required to obtain the electromyographic activity.

25. The system of claim 17, wherein at least one of the plurality of dilators of the secondary distraction assembly comprises a stimulation electrode that delivers electrical stimulation for nerve monitoring.

26. The system of claim 17, wherein each of the plurality of retractor blades comprises a stimulation electrode that delivers electrical stimulation for nerve monitoring.

27. The system of claim 17, wherein an angular orientation of said first retractor blade and said second retractor blade is independently adjustable relative to said blade holder apparatus.

28. The system of claim 27, wherein the angular orientation of said first retractor blade and said second retractor blade is independently adjustable such that the distal ends of said first retractor blade and said second retractor blade are capable of being angled toward each other.

29. The system of claim 27, wherein the angular orientation of said first retractor blade and said second retractor blade is independently adjustable such that the distal ends of said first retractor blade and said second retractor blade are capable of being angled away from each other.

30. The system of claim 17, wherein said first retractor blade is configured to be delivered along the lateral, trans-psoas path before said second retractor blade is delivered along the lateral, trans-psoas path.

31. The system of claim 17, wherein said second retractor blade is movable away from said first refractor blade under force from said plurality of dilators of sequentially larger diameter.

32. The system of claim 17, wherein said plurality of retractor blades comprises four retractor blades.

33. The system of claim 32, wherein when the four retractor blades are delivered along the lateral, trans-psoas path, the first retractor blade of the four retractor blades is a posterior-most retractor blade, the second retractor blade of the four retractor blades is an anterior-most retractor blade, a third retractor blade of the four retractor blades is a caudal-most retractor blade, and a fourth retractor blade of the four refractor blades is a cephalad-most retractor blade.