A propensity score-matched study on the short-term outcome of ruptured blood blister-like aneurysm treated by microsurgery or endovascular surgery: a single-center study of 155 cases

Treating blood blister-like aneurysms (BBA) is a major neurosurgical challenge. Whether endovascular repair serves as a better strategy than microsurgery remains controversial. We aim to perform a propensity score-matched (PSM) retrospective study to analyze the short-term outcome in BBA patients who received microsurgery and endovascular treatment. One hundred fifty-five eligible patients with internal carotid artery BBA were retrospectively collected with demographic and angiographic baseline in a single center. Three-month outcome and adverse events were set as outcome endpoints. PSM was used to match the microsurgery and endovascular group. Matching effect was evaluated by distribution variation analysis and love plot. The outcome of neurosurgery and endovascular treatment was then compared before and after PSM. Better WFNS levels (p = .017) and modified Fisher grade (p = .027) were noted in endovascular group before matching. Other baseline including angiographic features were comparable between two groups. Before matching, the 3-month outcome of endovascular repair surgery was more favorable than microsurgery (p < .0001). The occurrence of adverse events was also higher in the microsurgery group (p = .0079). In PSM-adjusted groups, the superior outcome effect of endovascular treatment still existed but with a reduced significance (p = .004). Similar trend was also observed in the adverse event rate (p = .038). Fatality rate was comparable between two adjusted groups regardless of PSM adjustment. Endovascular surgery of BBAs exhibits overall more favorable short-term outcome regardless of PSM matching. Microsurgery does not cause a higher fatality rate, hence it could be considered a salvage plan for those high-grade BBA patients.