Dural sinus thrombosis and pseudotumor cerebri: unexpected complications of suboccipital craniotomy and translabyrinthine craniectomy

Object. The goal of this study was to document the hazards associated with pseudotumor cerebri resulting from transverse sinus thrombosis after tumor resection. Dural sinus thrombosis is a rare and potentially serious complication of suboccipital craniotomy and translabyrinthine craniectomy. Pseudotumor cerebri may occur when venous hypertension develops secondary to outflow obstruction. Previous research indicates that occlusion of a single transverse sinus is well tolerated when the contralateral sinus remains patent. Methods. The authors report the results in five of a total of 107 patients who underwent suboccipital craniotomy or translabyrinthine craniectomy for resection of a tumor. Postoperatively, these patients developed headache, visual obscuration, and florid papilledema as a result of increased intracranial pressure (ICP). In each patient, the transverse sinus on the treated side was thrombosed; patency of the contralateral sinus was confirmed on magnetic resonance (MR) imaging. Four patients required lumboperitoneal or ventriculoperitoneal shunts and one required medical treatment for increased ICP. All five patients regained their baseline neurological function after treatment. Techniques used to avoid thrombosis during surgery are discussed. Conclusions. First, the status of the transverse and sigmoid sinuses should be documented using MR venography before patients undergo posterior fossa surgery. Second, thrombosis of a transverse or sigmoid sinus may not be tolerated even if the sinus is nondominant; vision-threatening pseudotumor cerebri may result. Third, MR venography is a reliable, noninvasive means of evaluating the venous sinuses. Fourth, if the diagnosis is made shortly after thrombosis, then direct endovascular thrombolysis with urokinase may be a therapeutic option. If the presentation is delayed, then ophthalmological complications of pseudotumor cerebri can be avoided by administration of a combination of acetazolamide, dexamethasone, lumbar puncture, and possibly lumboperitoneal shunt placement.