Endovascular treatment outcomes in patients with residual cerebral aneurysmatic filling after open surgery.

Residual or recurrent aneurysmatic filling may be detected during follow-up after open aneurysm surgery and can necessitate retreatment. In this study, we descriptively report the safety and radiological/clinical outcomes of endovascular treatment (EVT) in patients who previously underwent microsurgical clipping (MSC) or surgical wrapping. We retrospectively reviewed patients treated between 2012 and 2022 at Ankara Numune Training and Research Hospital and Ankara City Hospital. Demographics, timing of initial surgery and EVT, aneurysm location, and EVT modality (flow diverter, stent-assisted coiling, primary coiling) were recorded. Clinical outcomes were assessed using the modified Rankin Scale (mRS). Radiological outcomes were assessed using the O’Kelly–Marotta (OKM) scale for flow diversion and the Modified Raymond–Roy Classification (MRRC) for coiling techniques. Procedure-related complications, mortality, and permanent morbidity were evaluated. A total of 70 aneurysms in 68 patients were treated. Complete occlusion (OKM-D or MRRC-1) was achieved in 64% of aneurysms at follow-up; when near-complete occlusion (OKM-C or MRRC-2) was included, the overall angiographic success rate was 92%. Permanent morbidity was 4.4% and mortality was 1.4%. Functional outcomes improved over follow-up, and clinical results were generally favorable across EVT techniques. EVT appears to be a feasible and effective retreatment option in selected patients with residual or recurrent aneurysmatic filling after prior open aneurysm surgery. Given the retrospective design and limited subgroup sizes, the present findings should be interpreted as descriptive. Larger prospective studies with longer follow-up are warranted to further define optimal retreatment strategies.