RT Journal Article SR Electronic T1 Combined standard bypass and parent artery occlusion for management of giant and complex internal carotid artery aneurysms JF Journal of NeuroInterventional Surgery JO J NeuroIntervent Surg FD BMJ Publishing Group Ltd. SP 593 OP 598 DO 10.1136/neurintsurg-2021-017673 VO 14 IS 6 A1 Dodier, Philippe A1 Wang, Wei-Te A1 Hosmann, Arthur A1 Hirschmann, Dorian A1 Marik, Wolfgang A1 Frischer, Josa M A1 Gruber, Andreas A1 Rössler, Karl A1 Bavinzski, Gerhard YR 2022 UL http://jnis.bmj.com/content/14/6/593.abstract AB Background Complex aneurysms do not have a standard protocol for treatment. In this study, we investigate the safety and efficacy of microsurgical revascularization combined with parent artery occlusion (PAO) in giant and complex internal carotid artery (ICA) aneurysms.Methods Between 1998 and 2017, 41 patients with 47 giant and complex ICA aneurysms were treated by an a priori planned combined treatment strategy. Clinical and radiological outcomes were stratified according to mRS and Raymond classification. Bypass patency was assessed. Median follow-up time was 3.9 years.Results After successful STA–MCA bypass, staged endovascular (n=37) or surgical (n=1) PAO was executed in 38 patients following a negative balloon occlusion test. Intolerance to PAO led to stent/coil treatments in two patients. Perioperative bypass patency was confirmed in 100% of completed STA–MCA bypass procedures. Long-term overall bypass patency rate was 99%. Raymond 1 occlusion and good outcome were achieved in 95% and 97% (mRS 0–2) of cases, respectively. No procedure-related mortality was encountered. Eighty-four percent of patients with preoperative cranial nerve compression syndromes improved during follow-up.Conclusions The combined approach of STA-MCA bypass surgery followed by parent artery occlusion achieves high aneurysm occlusion and low morbidity rates in the management of giant and complex ICA aneurysms. This combined indirect approach represents a viable alternative to flow diversion in patients with cranial nerve compression syndromes or matricidal aneurysms, and may serve as a backup strategy in cases of peri-interventional complications or lack of suitable endovascular access.All data relevant to the study are included in the article or uploaded as supplementary information. Individual de-identified participant data will not be shared due to the general Data Protection regulation which came into effect on May 25 2018 in Austria. The study protocol in the German language will be available on request.