Intraoperative ultrasound in spinal surgery for surgical tailoring and control - A single center case series

Intraoperative ultrasound (IOUS) has gained recognition as a valuable imaging modality for enhancing surgical precision in neurosurgical procedures. However, its routine clinical integration in spine surgery remains limited.

This study aims to elucidate role of intraoperative ultrasound (IOUS) in spinal surgery and to propose the Spinal Cord Pulsatility Index (SCPI) as a novel, ultrasound-based parameter for evaluating spinal cord decompression.

This retrospective single-center case series included all consecutive patients who underwent spinal surgery with IOUS guidance between June 2024 and January 2025. In a subset of patients undergoing posterior decompression, the SCPI - defined as the ratio between the spinal cord pulsation and the corresponding heart rate - was calculated.

Overall, IOUS was performed in 28 patients, and 3 main IOUS applications were determined: (1) anatomic localization, (2) augmentive use, and (3) spinal cord decompression assessment. Importantly, IOUS was fast and technically feasible in all cases, across regions of the spine and regardless of the surgical approach. In a subset of n = 8 cases, we noted a significant SCPI increase at the time-point of final decompression (*p < 0.05).

IOUS in spinal surgery serves as a simple, safe, cost-effective, and non-invasive imaging modality for real-time localization of intradural and intramedullary pathologies and supplementary neurovascular structures. Based on the principle of communicating fluid dynamics, the spinal cord pulsation index may serve as a novel parameter for indirect assessment of sufficient spinal cord decompression beyond the levels of surgical exposure.