Postoperative radiographic findings following acoustic neuroma removal.

This paper assesses the radiographic findings seen on early postoperative CT following acoustic neuroma resection. CT head scans were routinely obtained from 86 patients within 24 hours of tumor resection via a translabyrinthine or retrosigmoid approach. Repeat CT scans were performed in those patients with abnormal clinical symptoms. The abnormalities seen on postoperative CT included cerebellar hematoma (nine patients), cerebral and/or cerebellar infarction (six patients), CSF leak at the incision (two patients), subdural hematoma (two patients), hydrocephalus (one patient), and residual acoustic neuroma (two patients). An unexpected CT finding was ipsilateral temporal lobe lucency, suggesting venous edema, ischemia, and/or infarction in 16% (14/86) of patients. Overall, the clinical complication rate was 8%, and subclinical CT abnormalities were seen in 17% of patients. Temporal lobe venous edema, ischemia, or infarction is a complication of translabyrinthine resection of acoustic neuroma and is thought to be due to obstruction of an inferior temporal lobe draining vein. Some cases may be related to intraoperative interruption of the superior petrosal sinus or petrosal vein, and/or coagulation of the sigmoid sinus dural margins, interruption of an inferior temporal vein, or venous hypotension. Care in dealing with the superior petrosal and sigmoid sinuses at surgery is needed.