Ruptured pseudoaneurysm of the basilar artery confirmed by repeat digital subtraction angiography: a case report

Abstract

Initial digital subtraction angiography (DSA) occasionally fails to identify hemorrhagic lesions in patients with subarachnoid hemorrhage (SAH). Therefore, repeat DSA is considered useful for detecting the etiology of SAH. Here, we report a case of SAH in which DSA identified the bleeding source 40 days from onset. A 48-year-old man presented with sudden headache, and computed tomography revealed thick SAH in the basal cisterns and hydrocephalus. Although DSA was repeated four times within 14 days from onset, the bleeding source could not be identified. At 40 days from onset, DSA confirmed a pseudoaneurysm near the distal end of the basilar artery. Though trapping and bypass are typically effective for treating pseudoaneurysms, it was difficult to perform due to the site of the aneurysm. Therefore, we treated the patient by implanting a single LVIS Jr. Stent (Terumo, Tokyo, Japan) in order to promote flow diversion, and the pseudoaneurysm disappeared within 3 months after the operation. No consensus has been reached regarding the appropriate length of time to perform DSA for SAH of unknown etiology, which is known to have a better prognosis. However, the use of DSA should be considered in the chronic setting of diffuse or thick SAH of unknown etiology.