Superficial Siderosis With Verrucous Vegetation Around a Dural Defect Confirmed by Intraoperative Ultrasonography.

Superficial siderosis (SS) of the central nervous system (CNS) is a rare disease caused by repeated hemorrhages in the subarachnoid space. We describe surgical treatment of an SS case in which a dural defect with verrucous vegetation in the spinal canal was detected by intraoperative ultrasonography (US). After laminectomy, intraoperative US imaging confirmed verrucous vegetation and epidural fluid collection around the ventral dural defect before incision of the posterior dura mater. As intraoperative US also showed a dural defect at the ventral and right sides of the spinal cord, the posterior dural incision was made in a manner that was slightly more right lateral than standard midline. The ventral dural defect was repaired by direct sutures. After repair, intraoperative US imaging confirmed dural hole closure, removal of vegetation and resolution of the collected fluid. Dural closure was successful and symptoms partially improved despite the patient's long history of SS. Intraoperative US can help surgeons make decisions about precise dural incision before repair. Intraoperative US is useful for detecting the level of dural defect and verrucous vegetation before repair and confirming closure of the dural defect, successful removal of vegetation and resolution of fluid collection after repair.