One normal angiogram is not always diagnostic after subarachnoid hemorrhage: case report and review of the literature.

How many angiograms should be obtained after subarachnoid hemorrhage if the first one fails to identify an aneurysm? We recently encountered this common clinical problem: a patient with subarachnoid hemorrhage confirmed by computed tomography required three angiograms to identify an aneurysm at the posterior communicating artery. Review of the literature reveals conflicting recommendations as to proper management of this common and sometimes perplexing problem. Decision-making must be applied on a case-by-case basis, but persistence is probably warranted when the index of suspicion is high.