Intraoperative contrast-enhanced ultrasound for intramedullary spinal neoplasms: patient series

BACKGROUND: Primary intramedullary spinal tumors cause significant morbidity and death. Intraoperative ultrasound as an adjunct for localization and monitoring the extent of resection has not been systematically evaluated in these patients; the effectiveness of intraoperative contrast-enhanced ultrasound (CEUS) remains almost completely unexplored. OBSERVATIONS: A retrospective case series of patients at a single institution who had consented to the off-label use of intraoperative CEUS was identified. Seven patients with a mean age of 52.8 ± 15.8 years underwent resection of intramedullary tumors assisted by CEUS performed by a single attending neurosurgeon. Histopathological evaluation revealed 3 cases of hemangioblastoma, 1 case of pilocytic astrocytoma, 2 cases of ependymoma, and 1 case of subependymoma. Contrast enhancement correlated with gadolinium enhancement on preoperative magnetic resonance imaging. Intraoperative CEUS facilitated precise lesion localization and myelotomy planning. Dynamic CEUS studies were useful in demonstrating the blood supply to lesions with a dominant vascular pedicle. Regardless of contrast uptake, the differential enhancement between spinal cord tissue and neoplasm assisted in determining interface boundaries. LESSONS: Intraoperative CEUS constitutes a useful adjunct for the intraoperative delineation of contrast-enhancing intramedullary tumors and in vivo confirmation of gross-total resection. Systematic investigation is needed to establish the role of CEUS for resection of intramedullary spinal tumors of various pathologies.