The optimal temporary occlusion time for the treatment of internal carotid artery aneurysms

Post-operative silent DWI hyperintensities are potential risk factors for cognitive dysfunction. Microsurgical clipping offers high occlusion rates and low recurrence, and temporary occlusion is often essential to safely dissect aneurysms. However, addressing these DWI changes is crucial for improving outcomes and minimizing complications. This study aimed to determine the optimal temporary occlusion time for ICA aneurysm treatment. A retrospective analysis was performed on 267 cases of ICA aneurysms. Clinical outcomes and factors associated with post-operative DWI hyperintensities were analyzed. The post-operative DWI hyperintensities were classified as either perforating artery infarction or 'other' infarction. Of 267 cases, post-operative DWI hyperintensity signals were observed in 38 cases (14.2%), including two symptomatic cases. Temporary occlusion was performed in 239 cases (89.5%), and retrograde suction and decompression (RSD) in 65 cases (24.3%). Multi-variate analysis revealed a significant association between maximum temporary occlusion duration (per 1-min increment) and perforator infarction (OR: 1.29, 95% CI [1.07-1.54]). Temporary occlusion under 5 min presented the lowest risk of DWI changes, while risks significantly increased beyond 12.5 min. Poor outcomes (mRS ≥ 2) were noted in 6 patients (2.2%). Adjunct techniques such as temporary occlusion or RSD used in microsurgical clipping, allow for safer manipulation of ICA aneurysms and dissection of surrounding structures, enabling complete aneurysmal neck clipping. However, post-operative DWI hyperintensities particularly in the perforator infarction may be observed in cases with prolonged temporary occlusion. This study highlights the safety of temporary occlusion when performed for less than 5 min intervals for the treatment of ICA aneurysms.