Endovascular Treatment of Spontaneous Intracranial Fusiform and Dissecting Aneurysms: Outcomes Related to Imaging Classification of 309 Cases.

Abstract

To propose a modified classification system for spontaneous intracranial dissecting aneurysms (IDAs) that can guide treatment decisions. Between January 2010 and December 2015, 3183 consecutive patients were referred to our department for endovascular treatment of a cerebral aneurysm. Among this group, 309 patients harboring a total of 323 spontaneous IDAs were identified. Based on a modified imaging classification system, spontaneous IDAs were classified into 4 subtypes: classic dissecting aneurysm, segmental ectasia, dolichoectatic dissecting aneurysm, and large mural bleeding ectasia. A logistic regression analysis was conducted to identify predictors of clinical outcomes. Of the 323 IDAs, 216 (66.87%) were treated with stent-assisted coiling, 47 (14.55%) with internal trapping, and 60 (18.58%) with sole stenting. Of the 309 patients, 8 (2.59%) suffered intraoperative complications, 40 (12.94%) experienced postoperative complications, 9 died (2.79%), and 1 (0.32%) had severe disability. The mean duration of clinical follow-up of the 309 patients was 10.40 months (range, 3-72 months). Imaging follow-up was available for 262 patients (274 IDAs), with a mean duration of 7.10 months (range, 3-60 months), and 24 aneurysm recurrences (9.16%) were noted. Aneurysm type was the sole independent predictor of different outcomes on logistic regression analysis (P = 0.004). There was a strong relationship between the subtypes of spontaneous IDAs and clinical course. Our classification system is confirmed to be helpful in assessing patients' prognosis and guiding their treatment.