Risk of rebleeding after treatment of acute hydrocephalus in patients with aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE Cerebrospinal fluid drainage is often indicated in patients with acute hydrocephalus after aneurysmal subarachnoid hemorrhage but is believed to increase the risk of rebleeding. We studied the risk of rebleeding in patients with subarachnoid hemorrhage during treatment for acute hydrocephalus. METHODS We included patients with hydrocephalus treated with external ventricular drainage or lumbar punctures within 4 days after the hemorrhage and before aneurysm occlusion. Each treated patient was matched with a control patient with untreated hydrocephalus and a control patient without ventricular enlargement. Patients and controls were matched for interval since subarachnoid hemorrhage, duration of exposure, use of tranexamic acid, clinical condition on admission, and age. We used Cox regression to calculate hazard ratios and we adjusted for rebleeding that had occurred before starting the cerebrospinal fluid drainage. RESULTS In the group treated with external ventricular drainage, rebleeding occurred in seven of 34 patients (21%) with treatment, in seven of 34 controls (21%) with untreated hydrocephalus, and in six of 34 controls (18%) without hydrocephalus. In the group treated with one or more lumbar punctures, rebleeding occurred in one of 21 patients (5%) with treatment, in three of 21 controls (14%) with untreated hydrocephalus, and in none of the 21 controls without hydrocephalus. The hazard ratios for rebleeding were 1.0 (95% CI: 0.4 to 2.7) for external ventricular drainage treatment and 0.7 (95% CI: 0.1 to 6.4) for lumbar puncture treatment. CONCLUSIONS This study does not confirm an importantly increased risk of rebleeding during external ventricular drainage or lumbar punctures for acute hydrocephalus after aneurysmal subarachnoid hemorrhage.