Vasospasm after cranial base tumor resection: pathogenesis, diagnosis, and therapy.

OBJECTIVE: Cerebral vasospasm is well known to occur after various cerebral neurosurgical events that cause subarachnoid hemorrhage. However, cerebral vasospasm can occur after cranial base tumor resection. We present a series of nine patients with angiographically evident vasospasm that was clinically symptomatic in eight of them.
METHODS: A total of 470 consecutive patients with cranial base tumors were operated in our institution between April 1993 and December 1996. Nine had evidence of cerebral vasospasm postoperatively (1.9% of the total population), of whom eight were asymptomatic. There were seven males and two females with an age range of 33 to 65 years (average 48.5 years). There were seven meningiomas, one chordoma, and one trigeminal schwannoma.
RESULTS: Vasospasm manifested clinically 1 to 30 days postoperatively in eight patients. Most patients were symptomatic within 7 days. In the ninth case, surgery was delayed when asymptomatic vasospasm was noted on an angiogram before second stage surgery. Symptoms included altered mental status in four patients, hemiparesis in three patients (one patient had both hemiparesis and altered mental status), and monoparesis in two patients. Factors that were found to correlate with a higher incidence of vasospasm were tumor size, total operative time, vessel encasement, vessel narrowing, and preoperative embolization. All eight patients with symptomatic vasospasm were treated with hypertensive, hypervolemic, hemodilutional (HHH) therapy. Five patients also underwent intraluminal angioplasty, in conjunction with papaverine in one case. One patient received intraarterial papaverine alone. Angiographic results were good in all patients. Significant clinical improvement was seen in six of the eight symptomatic cases.
CONCLUSION: Delayed neurological deterioration in a patient who has undergone cranial base tumor surgery not explained by an intracranial mass lesion should be promptly investigated with angiography. If vasospasm is diagnosed, it should be treated aggressively with hypertensive, hypervolemic, hemodilutional therapy and early angioplasty.