Intraoperative ultrasound using a linear (minimally invasive) transducer during anterior cervical surgery

Wednesday, February 21, 2024

Presenting Author(s)

Michael E. Tawil, BS

Medical Student
University of California San Francisco
San Francisco, CA, US

Co-Author(s)

VA

Vardhaan S. Ambati, MS

Medical Student
University of California San Francisco
San Jose, CA, US
Timothy Chryssikos, MD, PhD

Attending Physician
University of Maryland Medical Center
Baltimore, Maryland, United States
MM

Mohamed Macki, MD, MPH

Neurosurgeon
Cleveland Clinic
San Francisco, CA, US
Praveen V. Mummaneni, MD, MBA

Joan O'Reilly Endowed Professor and Vice Chair of Neurosurgery
Department of Neurological Surgery, University of California, San Francisco
San Francisco, CA, US
LT

Lee Tan, MD

Attending Surgeon
UCSF
Indianapolis, Indiana, United States

Introduction: Intraoperative ultrasound (IOUS) has been utilized during posterior cervical surgery, but its use has not been described during anterior cervical surgery. We hypothesized that a small linear transducer (designed for transsphenoidal surgery) can visualize the spinal cord, nerve roots, and surrounding structures during anterior cervical surgery.

Methods: IOUS was performed with the bkActive system (range 2-20 MHz) (BK Medical, Burlington, MA) using the “minimally invasive” transducer (N20P6/9007). Eleven patients underwent anterior cervical surgery (16 levels total) and 1 patient that underwent one-level corpectomy (7 males, 5 females). IOUS was used to judge central decompression after discectomy and resection of the PLL and neural foraminal decompression after foraminotomy or uncinectomy. If indicated by IOUS, additional decompression was completed. Visualization of subarachnoid space surrounding the spinal cord and CSF pulsatility within the nerve root sleeve served as the criteria for adequate spinal cord and nerve root decompression, respectively.

Results: IOUS influenced surgical management in 6/16 levels (37.5%). IOUS identified persistent nerve root compression in 3 cases, including after foraminotomy (1 case) and after uncinectomy (2 cases). Two planned uncinectomies were aborted after IOUS showed adequate CSF pulsatility within the nerve root sleeve. Additional central decompression behind the cranial-most vertebral body was performed after corpectomy in one patient after IOUS demonstrated persistent compression cranial to the corpectomy bed. Incidentally, IOUS visualized the position of the vertebral artery on standard brightness and doppler modes. In addition to this abstract, figures and operative video with surgical and real-time IOUS footage are available to demonstrate the technique and results.

Conclusion : The neural elements and their relationships to normal and pathological structures can be visualized with IOUS using a minimally invasive transducer during anterior cervical spine surgery and can facilitate judgment of the adequacy of spinal cord and nerve root decompression.