# Intraoperative Ultrasound in the Management of Rare Lesions Involving the Intradural Extramedullary Spinal Compartment: A Quick, but Effective Helping Hand to Define the Optimal Surgical Strategy

## TL;DR

Intraoperative ultrasound helps surgeons safely manage rare spinal cord lesions by providing real-time imaging during surgery.

## Contribution

The paper introduces specific ultrasound patterns for rare spinal lesions and their surgical implications.

## Key findings

- IOUS depicts rare spinal lesions with distinct ultrasound features like anechoic cysts and vascular patterns.
- IOUS improves surgical planning by guiding bone and dural openings and assessing residual disease.
- IOUS is a safe, cost-effective tool for managing rare intradural spinal pathologies.

## Abstract

Rare lesions inside the coverings of the spinal cord are hard to spot and remove safely. Scans performed before surgery do not always show exact edges or nearby vessels, so surgeons must decide how wide to open the bone and the dura, and when removal is complete. We evaluate intraoperative ultrasound as a real-time guide at the operating table. We describe how these lesions appear on ultrasound, how blood flow can be mapped during surgery, and how changes in tissue stiffness can confirm release in the tethered cord. Our goal is to give clear, practical cues that help surgeons find the lesion, plan the approach, and check for residual disease while limiting manipulation of the cord. Sharing these patterns may speed adoption, improve safety, and create a common language for future studies.

Intraoperative ultrasound (IOUS) is an increasingly adopted adjunctive intraoperative visualization method in spinal tumor surgery, offering real-time imaging that improves lesion localization, exposure planning, and resection control. This paper focuses on IOUS findings in rare intradural entities (neuroenteric/respiratory cysts, chronic spinal subdural hematoma, tethered cord/scarring, intradural extramedullary hemangioblastomas, and arachnoid cysts) where evidence remains limited. Across these lesions, IOUS typically depicts cysts as anechoic or hypoechoic cavities with definable walls and occasional septations; CSSDH is also delimited by hypoechoic subdural collections bounded by echogenic membranes; hemangioblastomas, as well as circumscribed, homogeneous nodules often with cystic components; and arachnoid webs/cysts with their boundaries and subtle subarachnoid communications. Doppler and micro-Doppler can delineate feeding and draining vessels in highly vascular tumors, while shear wave elastography provides quantitative stiffness changes that support effective detethering. IOUS complements preoperative MRI, shortens exposure, helps tailor bone and dural openings, and allows immediate assessment of residual disease. Taken together, current data and our experience support IOUS as a safe, cost-effective, and versatile intraoperative tool for rare intradural spinal pathology, while underscoring the need for prospective studies to refine sonographic criteria and validate outcome benefits.