Abstract

Background and Importance: Intraoperative ultrasound is a widely available and powerful tool in a spine surgeon’s armamentarium. Particularly when pre-operative imaging or intraoperative visualization is limited, ultrasound can help characterize lesions, confirm adequate decompression, and more. We present a case in which intraoperative ultrasound helped to differentiate whether a mass lesion was extradural versus intradural in a patient unable to undergo pre-operative MR imaging.
Clinical Presentation: An 81-year-old female with a history of a suspected calcified, extradural, ventral lesion at the T2-3 disc space treated with T1-T5 posterior fusion and partial T3 corpectomy presented to clinic three years later with progressive difficulty ambulating. She was weak in hip flexion and had lower extremity hyperreflexia. Due to prior placement of an MRI-incompatible pacemaker, she underwent CT myelogram that demonstrated persistent lesion ventral to the spinal cord at T2. Due to its increase in size, there were concerns for an intradural mass rather than extradural calcified disk. She was taken to the operating where intraoperative ultrasound confirmed a large, intradural lesion causing posterior displacement of the spinal cord with severe compression. The dura was opened proximal and distal to the lesion, arachnoid and dentate ligaments separated, T3 nerve root coagulated, and the lesion was debulked and separated from the dura. Final pathology confirmed meningioma. Post-operatively, the patient was neurologically intact.
Conclusion: Intraoperative ultrasound can be used during spine surgery in patients unable to obtain pre-operative MRI to aid in identifying extradural versus intradural lesions to provide correctly indicated surgical intervention.

Keywords: calcified disk, intradural lesion, intraoperative ultrasound, CT myelogram, MRI incompatible.