Yield of Repeat 3D Angiography in Patients with Aneurysmal-Type Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE: Aneurysmal-type subarachnoid hemorrhage is a serious disease with high morbidity and mortality. When no aneurysm is found, the patient remains at risk for rebleeding. Negative findings for SAH on angiography range from 2% to 24%. Most previous studies were based on conventional 2D imaging. 3D rotational angiography depicts more aneurysms than 2D angiography. The purpose of this study was to evaluate the yield of repeat 3D rotational angiography in patients with aneurysmal-type SAH with negative initial 3D rotational angiography findings and to classify the initial occult aneurysms. MATERIALS AND METHODS: Between March 2013 and January 2016, 292 patients with SAH and an aneurysmal bleeding pattern were admitted. Of these 292 patients, 30 (10.3%; 95% CI, 7.3%-14.3%) had initial negative 3D rotational angiography findings within 24 hours. These patients underwent a second 3D rotational angiography after 7-10 days. RESULTS: In 8 of 30 patients (26.7%; 95% CI, 14.0%-44.7%) with initial negative 3D rotational angiography findings, a ruptured aneurysm was found on repeat 3D rotational angiography. Three of 8 initial occult aneurysms were very small (1-2 mm), 2 were supraclinoid carotid artery dissecting aneurysms (2 and 8 mm), 2 were small (1 and 3 mm) basilar perforator aneurysms, and 1 was a 3-mm vertebral artery dissecting aneurysm. CONCLUSIONS: In 10% of patients with aneurysmal-type SAH, initial 3D rotational angiography findings were negative, and in 1 in 4, repeat 3D rotational angiography demonstrated a ruptured aneurysm. Initial occult aneurysms were dissecting aneurysms of perforators or main arteries or were very small (1-2 mm) or both. Our results indicate that repeat 3D rotational angiography is mandatory in patients with initial 3D rotational angiography findings negative for aneurysmal-type SAH.