To summarize the experience gained from the use of intraoperative ultrasound (IOUS) in thoracic intramedullary spinal tumor surgery.

Clinical data of 11 patients with thoracic intramedullary tumor who treated by IOUS guided micro-surgery in our hospital from January 2020 to May 2021 were retrospectively analyzed, including gender, age, tumor segment, pathology, intraoperative IOUS image, and the amount of tumor resection. The clinical characteristics and surgical effects were summarized.

Among the 11 patients, 6 were male and 5 were female, the range of age was 18-63 years, the course of disease was from 0.5 to 24 months. The tumors were located in the upper thoracic region (T1-4) in 3 cases, in the middle thoracic region (T5-8) in 3 cases, and in the lower thoracic region (T9-12) in 5 cases. Intramedullary tumor resection was performed under IOUS guidance and neuroelectrophysiological monitoring. Intraoperative use of IOUS could detect the location of lesions and peripheral nerve and vascular structures in all cases. In 3 cases, IOUS showed inadequate lamina exposure, so the lamina bone window was further expanded before dural opening. In 11 cases of intramedullary tumors, IOUS was used to probe again and adjust the incision range accurately before myelotomy. Total resection was performed in 9 cases (81.8%) and subtotal resection in 2 cases (18.2%). Postoperative pathology showed ependymoma in 5 cases, hemangioma in 3 cases, glioma in 2 cases and cyst in 1 case. 6 patients were followed up for more than 1 year, and no tumor recurrence was found during the follow-up period.

IOUS is an important tool of thoracic intramedullary spinal tumor surgery, which can show the lesion before dural opening. This modality helps the surgeon to limit the laminectomy, duratomy and myelotomy, to minimize the intraoperative damage of spinal stability and spinal cord funciton, improving the safety and efficacy of surgery.