Is ligation and division of anterior third of superior sagittal sinus really safe?

Ligation and division of anterior third (AT) of superior sagittal sinus (SSS) is presumed to be safe and is commonly used for approaching anterior skull base tumors and distal anterior cerebral artery aneurysms (DACA). Contrary to this belief we found complications secondary to this procedure more often than described and we have described them along with probable etiology.

A total of 62 patients who underwent bifrontal or extended bifrontal craniotomies with ligation and division of the proximal end of SSS were studied retrospectively. The clinical profiles and postoperative CT scans were studied to look for venous edema and hemorrhages. Venogram (digital subtraction) was done in one of the patients who had developed this complication.

Five patients developed bifrontal venous hemorrhagic infarcts (4 patients with anterior skull base tumors and 1 with DACA aneurysm). These patients had a morbid postoperative hospital stay with memory disturbances and urinary incontinence in the follow up period. Two patients died. The venogram done in one patient revealed complete occlusion of the AT-SSS. The morbidity and mortality that can be attributed to ligation of AT-SSS was 8.06% and 1.6% respectively.

The safety of ligation and division of the AT-SSS is questionable, contrary to traditional teaching. Though only the proximal end of SSS is ligated, the occlusion extends upto the distal craniotomy edge possibly due to reflection of the dural leaf with AT-SSS that causes kinking and thrombosis. It is more often seen in patients with anterior skull base lesions, probably because of already compromised basal venous drainage. A preoperative venogram could possibly predict the safety of this procedure.