Long-Term Outcomes of Surgical Clipping of Woven EndoBridge-Eligible Middle Cerebral Artery Bifurcation Aneurysms.

Abstract

Background and objectives: Endosaccular flow disruption with the Woven EndoBridge (WEB) embolization device emerged as an alternative treatment for wide-necked bifurcation aneurysms (WNBAs). Previous studies used pooled aneurysm locations to conclude the efficacy of the WEB device, failing to account for locational differences in outcomes, most notably at the middle cerebral artery (MCA). Thus, we analyzed characteristics and outcomes among a cohort of WEB-eligible MCA bifurcation aneurysms treated surgically.

Methods: We retrospectively reviewed a prospectively maintained aneurysm database at UT Southwestern between 2002 and 2022. WEB-eligible aneurysms met the criteria of a dome-to-neck ratio ≥1, a neck diameter >4.0 mm or a dome-to-neck ratio of ≤2, and an aneurysm diameter of 3.0-11.0 mm. Both unruptured and ruptured aneurysms were included. The end points assessed were functional status changes (modified Rankin scale [mRS]), complication rates, aneurysm recurrence, residual, morbidity, and mortality.

Results: One hundred two patients met radiographic inclusion criteria as WEB-eligible WNBA who underwent microsurgical clipping. Eighty-five (83.3%) aneurysms were unruptured. Patients with ruptured aneurysms presented with a worse mRS and experienced more significant improvements in functional status at the final follow-up. Regardless of rupture status, outcomes with open surgery were excellent, with a 99% treatment success rate, 4.9% morbidity rate, and 0% mortality rate. Among unruptured MCA WNBAs, functional outcomes showed a final mRS ≤2 in 94.1% of patients and an improved or stable functional status in 91.8%. Microsurgical treatment of unruptured MCA WNBA carried a 5.9% thromboembolic complication rate.

Conclusion: Outcomes of WEB-eligible MCA WNBAs are comparable with the high success rates in large, heterogeneous series of MCA aneurysms and superior to those in WEB cohorts. Functional outcomes remain excellent regardless of treatment strategy; however, surgical treatment may offer higher complete occlusion rates, lower retreatment rates, and lower complication rates than endovascular treatment with WEB.