System and methods for performing surgical procedures and assessments

• US 7,522,953 B2
• Filed: 03/25/2004
• Issued: 04/21/2009
• Est. Priority Date: 09/25/2001
• Status: Expired due to Term

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Kaula, Norbert F., Gharib, James, Blewett, Jeffrey J., Farquhar, Allen, Medeiros, legal representative
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): Foreman; Jonathan M
• Application Number:
  US10/809,280
• Publication Number:
  US 20050075578A1
• Time in Patent Office: 1,853 Days
• Field of Search: 600/546,547,554 607/2 606/32,41
• US Class Current: 600/546
• 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 17/3417 Details of tips or shafts, e.g. grooves, expandable, bendable; Multiple coaxial sliding cannulas, e.g. for dilating syringe needles A61M5/32; dilators A61M29/00
• CPC Class Codes: A61B 17/3421 Cannulas
• CPC Class Codes: A61B 17/3423 Access ports, e.g. toroid shape introducers for instruments or hands access sites for liquids A61M39/0247
• CPC Class Codes: A61B 2017/00039 Electric or electromagnetic phenomena other than conductivity, e.g. capacity, inductivity, Hall effect
• CPC Class Codes: A61B 2017/00199 with a console, e.g. a control panel with a display
• CPC Class Codes: A61B 2017/0262 with a provision for protecting nerves
• CPC Class Codes: A61B 2034/2053 Tracking an applied voltage gradient
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 34/25 User interfaces for surgical systems
• CPC Class Codes: A61B 5/296 for electromyography [EMG]
• CPC Class Codes: A61B 5/388 Nerve conduction study, e.g. detecting action potential of peripheral nerves
• CPC Class Codes: A61B 5/4893 Nerves
• CPC Class Codes: A61B 5/6828 Leg
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: A61B 90/36 Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: A61B 90/37 Surgical systems with images on a monitor during operation
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/4611 : of spinal prostheses
• CPC Class Codes: A61F 2002/4635 : using minimally invasive surgery
• CPC Class Codes: A61N 1/0551 : Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/0553 : Paddle shaped electrodes, e.g. for laminotomy
• CPC Class Codes: A61N 1/36142 : for improving safety
• CPC Class Codes: A61N 1/37247 : User interfaces, e.g. input or presentation means

Abstract

The present invention involves systems and related methods for performing surgical procedures and assessments, including the use of neurophysiology-based monitoring to: (a) determine nerve proximity and nerve direction to surgical instruments employed in accessing a surgical target site; (b) assess the pathology (health or status) of a nerve or nerve root before, during, or after a surgical procedure; and/or (c) assess pedicle integrity before, during or after pedicle screw placement, all in an automated, easy to use, and easy to interpret fashion so as to provide a surgeon-driven system.

Claims

1. A system for performing surgical procedures and assessments, comprising:

a surgical accessory having at least one stimulation electrode; and

a processing system having at least one of computer programming software, firmware and hardware pre-programmed to incorporate at least two pre-selected threshold ranges, and capable of stimulating said at least one stimulation electrode on a surgical accessory with an electrical stimulation signal, measuring the response of nerves depolarized by said stimulation signal, automatically determining a stimulation threshold of said nerves by automatically adjusting said stimulation signal by variable increments, and communicating to a user which range of said at least two pre-selected ranges that said stimulation threshold lies to indicate at least one of nerve proximity, and pedicle integrity.

2. The system set forth in claim 1 and further, wherein the response of said depolarized nerves is measured by monitoring the EMG waveforms of myotomes associated with said depolarized nerves.

3. The system set forth in claim 2 and further, wherein said surgical accessory comprises a system for establishing an operative corridor to a surgical target site.

4. The system set forth in claim 3 and further, wherein said system for establishing an operative corridor to a surgical site includes a series of sequential dilator cannulae, each having at least one stimulation electrode near a distal end.

5. The system of claim 3 and further, wherein said surgical target site is a spinal target site.

6. The system of claim 5 and further, wherein said operative corridor may be established via a lateral, trans-psoas approach.

7. The system set forth in claim 1 and further, wherein said surgical accessory comprises a pedicle testing device including a handle and a pedicle probe.

8. The system set forth in claim 7 and further wherein said pedicle testing device is capable of testing at least one of the interior of a hole formed in a pedicle and a pedicle screw after insertion into said hole.

9. The system set forth in claim 8 and further, wherein said handle includes at least one button for initiating the transmission of said stimulation signal from said processing system to said pedicle probe.

10. The system set forth in claim 1 and further, wherein said system includes a display for communicating said at least one of nerve proximity and pedicle integrity.

11. The system set forth in claim 10 and further, wherein said display is configured to show at least one of alpha-numeric and graphic indicia related to said at least one of said nerve proximity and pedicle integrity.

12. The system set forth in claim 11 and further, wherein said display shows a color indicative of at least one of said nerve proximity and pedicle integrity.

13. The system set forth in claim 1 and further, wherein said system is configured to audibly communicate said at least one of nerve proximity and pedicle integrity.

14. The system set forth in claim 1 and further, wherein said at least two pre-selected threshold ranges comprise a safe range and an unsafe range.

15. The system set forth in claim 14 and further, wherein said system comprises three pre-selected threshold ranges.

16. The system set forth in claim 15 and further, comprising a cautionary range in-between said unsafe and safe ranges.

17. The system set forth in claim 16 and further, wherein one of the colors red, yellow, and green, are highlighted on a display to communicate the appropriate range of said determined stimulation threshold.

18. The system set forth in claim 17 and further, wherein the color red indicates said unsafe range, the color yellow indicates said cautionary range, and the color green indicates said safe range.

19. The system set forth in claim 1 and further, wherein automatically adjusting said stimulation signal by variable increments comprises doubling the amplitude of successive stimulation signals until a corresponding nerve response measures at least a preselected intensity level.

20. The system set forth in claim 19 and further, wherein automatically adjusting said stimulation signal by variable increments further comprises decreasing the amplitude of subsequent stimulation signals until a corresponding nerve response measures below said preselected intensity level.

21. The system set forth in claim 19 and further, wherein the amplitude of said first stimulation signal to evoke said corresponding nerve response of at least a preselected intensity level and the immediately preceding stimulation signal comprise an initial bracket.

22. The system set forth in claim 21 and further, wherein said initial bracket is bisected to a pre-selected width.

23. The system set forth in claim 1 and further, wherein said system is configured to automatically adjust said stimulation signal according to at least one of a bracketing method and a bisection method.

24. The system set forth in claim 23 and further, wherein said system is configured to first determine a bracket within which said stimulation threshold must lie and thereafter to bisect said bracket until said stimulation threshold is known to a specified accuracy.

25. The system set forth in claim 24 and further, wherein said system may determine whether said stimulation threshold has changed by stimulating said at least one stimulation electrode at a stimulation current just below said previously determined stimulation threshold and at least one of at and just above said previously determined stimulation threshold.