Delayed aneurysm rupture following treatment with the WEB embolization device.

Delayed rupture of an aneurysm following WEB embolization has not yet been reported. We present a case of a multiply ruptured anterior communicating artery aneurysm treated via WEB embolization. A post-treatment CT scan confirmed no evidence of rebleeding during treatment. Four hours after treatment, the patient developed an acute, significant increase in intracranial pressure with bloody ventriculostomy output, with CT scan demonstrating new parenchymal and intraventricular hemorrhage. The aneurysm was subsequently treated via microsurgical clipping that did not identify an "uncovered" bleb or rupture source.