Stent-Assisted Coiling vs. Flow Diversion in Unruptured Anterior Circulation Aneurysms: A Single-Center Cohort Study

Stent-assisted coiling (SAC) achieves immediate aneurysm occlusion, while flow diversion (FD) promotes progressive remodeling. Comparative data in unruptured anterior circulation aneurysms remain limited.

A retrospective review of our institutional database was conducted between 2021 and 2024. A total of 129 aneurysms treated with SAC (n = 33) or FD (n = 96) were identified and included in the analysis. Outcomes included angiographic occlusion, retreatment, complications, and the modified Rankin Scale (mRS). A 1:1 propensity score matching (PSM) was performed on sex, age, aneurysm size, and location (caliper 0.2, exact sex matching).

A total of 130 patients (89 women, 41 men) were included in the study, with a mean age of 59.8 years (range 22-81). In the full cohort, SAC achieved higher immediate complete occlusion (62.5% vs. 8.3%, p < 0.001), while FD demonstrated superior long-term stability (71.9% vs. 60.6%). Retreatment occurred in 18.2% of SAC cases and none with FD (p < 0.001). Complication rates were comparable overall: intraoperative (15.2% SAC vs. 10.4% FD, p = 0.37), periprocedural ≤72 h (15.2% vs. 8.3%, p = 0.34), and delayed ≥12 months (9.1% vs. 10.4%, p = 0.85). In patients aged 70-80 years, periprocedural complications were more frequent with SAC (37.5% vs. 5.9%, p = 0.08). Functional independence (mRS 0-2) at last follow-up was 87.9% for SAC and 89.6% for FD (p = ns). In the matched cohort, SAC preserved higher immediate occlusion (60% vs. 10%, p < 0.001), whereas FD provided greater long-term occlusion (65% vs. 55%, p = 0.33) and required no retreatments versus 15% in SAC (p < 0.001). Subgroup analysis showed that SAC-related complications were largely confined to complex Y/T-stent reconstructions for MCA bifurcation and AComA aneurysms, while single-stent SAC demonstrated a safety profile comparable to FD.

SAC offers rapid angiographic exclusion but at the cost of higher retreatment. FD ensures durable occlusion and absence of retreatment, with a consistent safety profile. After stratification by technical complexity, excess morbidity associated with SAC originated from anatomically demanding multistent constructs, whereas single-stent SAC showed safety comparable to FD. Age may influence periprocedural risk, particularly with SAC. These findings reinforce a tailored strategy: "Close fast with SAC, close forever with FD."