LAUSR

BACKGROUND Anterior inferior cerebellar artery (AICA) can present with a myriad of variations. However, the previous studies of AICA anatomy were based on small-scale cadaveric investigation. In this study, we performed an angiographic study of AICA in 500 Chinese with Han nationality based on digital subtraction angiography (DSA). METHODS Patients admitted to our institution between 2015 and 2018 who had underwent DSA were potential candidates for this retrospective evaluation. The exclusion criteria were: a) patients with vascular diseases of the posterior circulation; b) ischemic diseases or moyamoya disease of the anterior circulation. RESULTS Five hundred patients were identified. The patients aged from 6 to 75 years. Two hundred and thirty-seven (62.9%, 237/377) patients have bilateral AICAs at the same level, while 140 (37.1%, 140/377) at different levels. The developing states of AICA were grade 0, grade 1, grade 2, and grade 3 in 31 (3.5%, 31/896), 373 (41.6%, 373/896), 313 (34.9%, 313/896), and 179 (20.0%, 179/896) hemispheres, respectively. Two hundred and twenty-one (22.1%, 221/1000) presented with AICA-PICA common trunks. Thirty-one (3.1%, 31/1000) hemispheres showed no obvious AICA angiographically. AICA arose as a single trunk in 865 (86.5%, 865/1000) hemispheres, as duplicate trunks in 104 (10.4%, 104/1000) hemispheres. Triplicate or more trunks were not noticed. AICA originating from the BA fenestration accounted for 4% (20/500) of the cases. CONCLUSIONS This is the first attempt using DSA data to perform a large-scale investigation of AICA variations. The ever-growing need of endovascular intervention calls for more suitable anatomical explaination of the vascular structures.