Effect of cisternal drainage after early operation for ruptured intracranial aneurysms.

The effect of postoperative cisternal drainage was assessed in 132 patients who underwent early surgery for ruptured aneurysms. Although the incidence of both cerebral vasospasm and mortality was low in the patients who had cisternal drainage, the incidence of hydrocephalus was significantly higher in these patients. Drainage has been recommended as a useful procedure because it has been shown to improve the prognosis through prophylaxis and relief of vasospasm and removal of blood-contaminated cerebrospinal fluid. However, the results of this study indicate that extensive cerebrospinal fluid drainage may lead to hydrocephalus, which can be controlled by regulation of the drainage outflow and pressure.