Endovascular outcomes for anterior choroidal artery aneurysms: systematic review and meta-analysis

Background: Anterior choroidal artery (AchoA) aneurysms are relatively rare compared to other types of aneurysms. However, the occurrence of transient or permanent occlusion of the choroidal artery during endovascular or surgical treatment is an uncommon but potentially serious complication. In this study, we aim to investigate the safety and efficacy profile of endovascular treatment (EVT) for AchoA aneurysms.

Methods: The primary outcome of interest was angiographic and clinical outcomes. Secondary outcome variables transient and permanent ischemic complications, symptomatic choroidal artery occlusion and retreatment rates. A random-effects model was used to calculate prevalence rates and their corresponding 95 % confidence intervals (CI), and subgroup analyses were performed to assess the complication rates for Type 1(arterial type, directly arising from ICA) and Type 2(neck type, arising from AchoA branch)) AchoA aneurysms, ruptured vs non-ruptured and for flow diverter (FD) treatment versus coiling.

Results: Our study included 10 studies with 416 patients with 430 AchoA aneurysms. The overall good clinical outcome rate (mRS score 0-2) is 94.5 % with a retreatment rate of 2.0 %. A subgroup analysis showed no statistical difference between coiling(75.3 %) and flow diverter(80.9 %) treatment in terms of complete occlusion(p-value:0.62). Overall permanent complication rate is 1.4 % (p-value:0.54) and transient ischemic complications rate is 4.2 %(p-value:0.61). Symptomatic choroidal artery occlusion rate is 0.8 %(p-value:0.51)Type 2 AchoA aneurysms had a significantly higher complication rate of 9.8 % (p-value<0.05) compared to Type 1 aneurysms. Unruptured aneurysms have significantly better clinical outcomes than ruptured aneurysms(OR: 0.11; [0.02;0.5], p-value:<0.05) CONCLUSION: Endovascular treatment of AchoA aneurysms demonstrated positive clinical results, with low rates of retreatment and complications. Coiling and flow diverters proved similar outcomes in achieving aneurysm occlusion. Ruptured aneurysms have lower good clinical outcomes comparing to unruptured aneurysms. Type 2 AchoA aneurysms had a higher risk of complications compared to Type 1.