SURGICAL ACCESS SYSTEM AND RELATED METHODS

• US 20110196210A1
• Filed: 01/04/2011
• Published: 08/11/2011
• Est. Priority Date: 01/16/2003
• Status: Active Grant

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Martinelli, Scot, Finley, Eric, Miles, Patrick, Blewett, Jeffrey, Kaula, Norbert, Gharib, James, Farquhar, Allen, Medeiros, Goretti
• Granted Patent: US 8,439,832 B2
• Time in Patent Office: Days
• 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 17/0206 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:

a dilator system to create a distraction corridor along a lateral, trans-psoas path to a lumbar spine, the dilator system comprising;

an initial dilator to advance laterally through the psoas muscle toward a targeted spinal disc, and a plurality of sequential dilators to sequentially advance along the lateral, trans-psoas path over the initial dilator, wherein the initial dilator comprises a central lumen configured to receive an elongate inner member, and wherein at least the initial dilator includes a stimulation electrode that outputs electrical stimulation for nerve monitoring during advancement of the initial dilator laterally through the psoas muscle;

a three-bladed retractor tool slidable over an exterior of an outermost sequential dilator of the dilator system toward the targeted spinal disc along the lateral, trans-psoas path, the three-bladed retractor assembly including;

an external blade-holder assembly,

a posterior-most retractor blade, a cephalad-most retractor blade, and a caudal-most retractor blade that extend from the external blade-holder assembly, wherein the posterior-most, cephalad-most, and caudal-most retractor blades are slidably advanced over the exterior of the outermost sequential dilator while in a closed position in which the posterior-most, cephalad-most, and caudal-most retractor blades are generally adjacent to one another, wherein the external blade-holder assembly is adjustable to move the posterior-most, cephalad-most, and caudal-most retractor blades to an opened position in which the cephalad-most and caudal-most retractor blades are moved away from the posterior-most retractor blade, and

a fixation element to releasably engage with one of said retractor blades so that at least a portion of the fixation element extends distally into the lumbar spine; and

wherein three-bladed retractor tool is configured to define an operative corridor along the lateral, trans-psoas path to the lumbar spine in which a space extending to the targeted spinal disc between the posterior-most, cephalad-most, and caudal-most refractor blades 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 the external blade-holder assembly is adjustable to move the cephalad-most and caudal-most retractor blades away from the posterior-most retractor blade while the posterior-most retractor blade remains in a generally stationary position relative to the targeted spinal disc.

3. The system of claim 1, wherein the elongate inner member is advanced along the lateral, trans-psoas path to the targeted spinal discs such that a distal tip portion of the elongate stimulation instrument penetrates into an annulus of the targeted spinal disc.

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

5. The system of claim 1, wherein the initial dilator is advanced to the targeted spinal disc together with the elongate inner member received within the central lumen of the initial dilator.

6. The system of claim 1, wherein when the three-bladed retractor tool defines the operative corridor, the posterior-most, cephalad-most, and caudal-most retractor blades are spaced apart and maintained generally parallel to one another.

7. The system of claim 1, wherein when the three-bladed retractor tool is in the closed position, each of the posterior-most, cephalad-most, and caudal-most retractor blades at least partially with edges of the other two of the posterior-most, cephalad-most, and caudal-most retractor blades.

8. The system of claim 1, wherein further comprising a light emitting device to direct light through the operative corridor toward the targeted spinal disc.

9. The system of claim 1, further comprising a fourth retractor blade that couples with the external blade-holder assembly only after the external blade-holder assembly moves the posterior-most, cephalad-most, and caudal-most retractor blades to the opened position.

10. 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.

11. The system of claim 1, further comprising a monitoring system that delivers an electrical stimulation signal to the stimulation electrode of the initial dilator, monitors electromyographic activity detected by a set of sensor electrodes in leg muscle myotomes associated with nerves in the vicinity of the targeted spinal disc, and displays information on a display screen in response to the detection of said electromyographic activity via said set of sensor electrodes in said leg muscle myotomes.

12. A method for accessing a spinal disc of a lumbar spine of a patient, comprising:

sequentially inserting a plurality of sequentially larger diameter dilators into said patient along a lateral, trans-psoas path to create a distraction corridor along said lateral, trans-psoas path toward a targeted spinal disc, wherein at least an initial dilator of said plurality of sequentially larger diameter dilators comprises a stimulation electrode and is inserted under conditions wherein an electrical stimulation is delivered to said stimulation electrode of said initial dilator for nerve monitoring during insertion of said initial dilator along said lateral, trans-psoas path, wherein the initial dilator comprises a central lumen configured to receive an elongate inner member that anchors into the targeted spinal disc;

simultaneously advancing a posterior-most retractor blade, a cephalad-most retractor blade, and a caudal-most retractor blade of a three-bladed retractor tool along said lateral, trans-psoas path and over an exterior of an outermost dilator of said plurality of sequentially larger diameter dilators, said three-bladed retractor tool comprising an external retractor blade holder and said posterior-most, cephalad-most, and caudal-most retractor blades attached to said external retractor blade holder;

removing said plurality of sequentially larger diameter dilators from said patient after said posterior-most, cephalad-most, and caudal-most retractor blades are advanced through the psoas muscle, wherein an operative corridor along the lateral, trans-psoas path to the targeted spinal disc is at least partially defined by said posterior-most, cephalad-most, and caudal-most retractor blades; and

maintaining said operative corridor along said lateral, trans-psoas path using said three-bladed retractor tool while delivering a spinal implant to a disc space of the targeted spinal disc.

13. The method of claim 12, further comprising adjusting said external retractor blade holder of said three-bladed retractor tool so as to move said cephalad-most and caudal-most retractor blades away from said posterior-most retractor blade to create said operative corridor along said lateral, trans-psoas path to said targeted spinal disc, wherein said operative corridor is dimensioned so as to pass a spinal implant through said operative corridor along said lateral, trans-psoas path to said targeted spinal disc.

14. The method of claim 13, wherein said external retractor blade holder is adjustable to move the cephalad-most and caudal-most retractor blades away from the posterior-most retractor blade while the posterior-most retractor blade remains in a generally stationary position relative to the targeted spinal disc.

15. The method of claim 13, wherein said plurality of sequentially larger diameter dilators are removed from said patient after said step of adjusting said external retractor blade holder of said three-bladed retractor tool so as to move said cephalad-most and caudal-most retractor blades away from said posterior-most retractor blade.

16. The method of claim 12, further comprising activating a light emitting device to direct light through said operative corridor toward the targeted spinal disc, the light emitting device being coupled to one of the posterior-most, cephalad-most, and caudal-most retractor blades.

17. The method of claim 12, further comprising advancing said elongate inner member along said lateral, trans-psoas path and into the disc space.

18. The method of claim 12, wherein said elongate inner member comprises a stimulation electrode.

19. The method of claim 12, wherein each of said plurality of sequentially larger diameter dilators comprises a distal end on which a respective stimulation electrode is situated, said distal end being angled relative to a longitudinal axis of said dilator such that said stimulation electrode is angled relative to said longitudinal axis.

20. The method of claim 12, further comprising:

activating a nerve monitoring system that delivers an electrical stimulation signal to the stimulation electrode of the initial dilator during delivery of the initial dilator along the lateral, trans-psoas path to the lumbar spine, the nerve monitoring system detecting neuromuscular responses via a set of sensors in leg muscle myotomes associated with nerves in the vicinity of the spinal disc; and

during advancement of the initial dilator through the psoas muscle, viewing a video display device of the nerve monitoring system that displays information in response to the detection of said neuromuscular responses via said set of sensor in said leg muscle myotomes.