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 complic ation of suboccipital craniotomy and translabyrinthine craniectomy. Pseudot umor cerebri may occur when venous hypertension develops secondary to outfl ow obstruction. Previous research indicates that occlusion of a single tran sverse 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, v isual obscuration, and florid papilledema as a result of increased intracra nial pressure (ICP). In each patient, the transverse sinus on the treated s ide was thrombosed; patency of the contralateral sinus was confirmed on mag netic resonance (MR) imaging. Four patients required lumboperitoneal or ven triculoperitoneal shunts and one required medical treatment for increased I CP. All five patients regained their baseline neurological function after t reatment. 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 tol erated even if the sinus is nondominant; vision-threatening pseudotumor cer ebri may result. Third, MR venography is a reliable, noninvasive means of e valuating the venous sinuses. Fourth, if the diagnosis is made shortly afte r 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.