Acute hydrocephalus and chronic hydrocephalus with the need of postoperative shunting after aneurysmal subarachnoid hemorrhage.

During a 6-year period, 168 consecutive patients who presented with subarachnoid hemorrhage (SAH) and underwent surgical clipping of aneurysms were reviewed at a follow-up examination from 6 to 77 months (mean 38 months) after the ictus. Acute hydrocephalus was defined when the bicaudate index was greater than the 95th percentile for age on a computed tomographic scan within 72 hours of the hemorrhage. Forty (24%) patients developed acute hydrocephalus. The Hunt and Hess grades and Fisher's SAH grades at the time of admission, the presence of intraventricular hemorrhage and symptomatic cerebral vasospasm, and cerebrospinal fluid (CSF) diversion were found to be significantly associated with acute hydrocephalus. The overall mortality in this study was 16%. Of the 141 surviving patients, 20 (14%) patients underwent ventriculoperitoneal (VP) shunt replacement secondary to chronic hydrocephalus. In the present study, we found that the following factors were significantly related to the need of VP shunting: increasing age, the presence of acute hydrocephalus, preoperative CSF diversion, low admission Hunt and Hess grades, and poor Fisher's SAH grades. No patient was readmitted for shunt replacement at our hospital later than 117 days after hemorrhage. Acute hydrocephalus was combined with high mortality (28%) at our follow-up review. Ten of 29 (34%) patients with acute hydrocephalus required definite shunt replacement. However, less than 10% of patients without acute hydrocephalus needed shunting postoperatively. We recommend that patients with aneurysmal SAH should be followed up at least 6 months after the hemorrhage, especially in those patients with high risks of developing chronic hydrocephalus.