Retreatment rate and strategies for recurrent and residual aneurysms after Woven EndoBridge (WEB) treatment: a comprehensive systematic review and meta-analysis.

Woven Endo Bridge (WEB) is a flow diverter device used to treat wide-necked intracranial aneurysms. We conducted a systematic review and meta-analysis to determine the retreatment rate and strategies following aneurysmal recurrence after WEB treatment. A systematic literature search was conducted through four electronic databases. The Cochrane risk of bias tool for non-randomized trials (ROBINS-I) was used for risk of bias assessment. A meta-analysis and meta-regression were performed on relevant variables. A total of 29 studies with 2067 patients were included. Initially treated aneurysms had an adequate occlusion rate of 84.7% (20 studies, 980/1156, 95%CI: 79%-89%) at the last follow-up. The overall retreatment rate was 8.6% (24 studies, 251/2893, 95%CI: 6.5%-10.9%). Following retreatment, the immediate complete occlusion rate post retreatment and complete occlusion rate at last follow-up were 52% (six studies, 95%CI, 11%-91%) and 65% (six studies, 77/120, 95%CI: 56%-73%) respectively. Stent-assisted coiling achieved a 100% (95%CI: 57%-100%, P-value < 0.01) immediate adequate occlusion rate and 74% complete occlusion rate (95%CI: 16%-100%, P-value = 0.63) at last follow-up, which was higher than clipping, coiling, and flow diversion. On meta-regression, aneurysm height and neck width significantly associated with higher retreatment rate. The current meta-analysis showed a 9% retreatment rate after initial aneurysms treatment with WEB and overall adequate retreatment occlusion was high. Although stent-assisted coiling showed a higher adequate occlusion rate post-operatively, there was no significant difference between retreatment strategies in long-term radiological outcomes.