System and methods for performing surgical procedures and assessments

• US 8,005,535 B2
• Filed: 04/14/2009
• Issued: 08/23/2011
• Est. Priority Date: 09/25/2001
• Status: Expired due to Term

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Martinelli, Scot, Finley, Eric, Elbanna, Jamil, Kaula, Norbert F., Gharib, James, Blewett, Jeffrey J., Farquhar, Allen
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): Foreman; Jonathan M
• Application Number:
  US12/423,559
• Publication Number:
  US 20090192403A1
• Time in Patent Office: 861 Days
• Field of Search: 600/546, 600/554, 606/32, 606/41, 607/115, 607/116, 607/117, 623/17.11
• 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 method of inserting a spinal implant through a trans-psoas operative corridor to an intervertebral disc, comprising:

mounting a plurality of EMG electrodes proximate to selected leg muscles;

activating a control unit operable to provide a stimulation signal and including a graphical user interface to receive user input and to display neuromuscular response information in response to signals from the EMG electrodes;

inserting an initial dilator cannula in a trans-psoas path through bodily tissue toward a lateral aspect of a spine while an elongate stimulation instrument is disposed within an inner lumen of the initial dilator cannula;

activating the elongate stimulation instrument to deliver the stimulation signal proximate to a distal end of the initial dilator cannula when the initial dilator cannula is inserted into the trans-psoas path toward the spine;

monitoring the neuromuscular response information displayed by the control unit in response to delivery of the stimulation signal when the initial dilator cannula is inserted into the trans-psoas path toward the spine;

advancing two or more sequential dilator cannulas of increasing diameter in the trans-psoas path toward the spine;

advancing a working corridor instrument over the two or more sequential dilator cannulas in the trans-psoas path toward the spine;

establishing a trans-psoas operative corridor to an intervertebral disc of the spine using the working corridor instrument; and

delivering a spinal fusion implant through the trans-psoas operative corridor toward the spine.

2. The method of claim 1, wherein the elongate stimulation instrument is equipped with a stimulation electrode proximate to a distal tip of the elongate stimulation instrument.

3. The method of claim 1, further comprising removing the two or more sequential dilator cannulas from the working corridor instrument when establishing the trans-psoas operative corridor to the intervertebral disc of the spine.

4. The method of claim 3, wherein the step of advancing the two or more sequential dilator cannulas comprises delivering dilator cannulas in a sequence such that each subsequent dilator cannula has an increased diameter and a decreased length as compared to a previously delivered dilator cannula.

5. The method of claim 1, wherein at least one of the initial dilator cannula, the two or more sequential dilator cannulas, and the working corridor instrument is equipped with a stimulation electrode operable to deliver the stimulation signal.

6. The method of claim 1, wherein the elongate stimulation instrument comprises a K-wire instrument insertable into the initial dilator cannula.

7. The method of claim 1, wherein the working corridor instrument comprises a working cannula that defines an inner lumen.

8. The method of claim 1, wherein the neuromuscular response information displayed by the control unit is indicative of at least one of nerve proximity and direction relative to the elongate stimulation instrument.

9. The method of claim 8, wherein the step of activating the control unit comprises activating a neurophysiology monitoring unit that is configured to:

measure the response of nerves innervated by the stimulation signal, determine a relationship between the elongate stimulation instrument and a nerve based on the measured response, and communicate the relationship via a display device.

10. The method of claim 8, wherein the stimulation signal delivered by the elongate stimulation instrument comprises stimulation current pulses, and the neuromuscular response information displayed by the control unit comprises a numeric stimulation threshold current level.

11. The method of claim 10, wherein the numeric stimulation threshold current level displayed by the control unit indicates an amplitude of the stimulation current pulses that evokes an EMG response having an amplitude value greater than a predetermined voltage value.

12. The method of claim 10, wherein the stimulation current pulses of the signal delivered by the elongate stimulation instrument comprises rectangular monophasic current pulses output from the elongate stimulation instrument when the initial dilator cannula and the elongate stimulation instrument are inserted into the trans-psoas path toward the spine.