Long-term follow-up of intra-aneurysmal coil embolization for unruptured paraclinoid aneurysms

Abstract

Objectives: The selection of therapeutic modalities, including endovascular coil embolization and surgical clipping, for management of unruptured paraclinoid aneurysms, remains controversial. Detailed long-term outcome data for endovascular coil embolization of unruptured paraclinoid aneurysms are still lacking. Thus, we evaluated the safety and efficacy of coil embolization of unruptured paraclinoid aneurysms.Methods: From January 1998 to July 2010, 138 patients underwent endovascular coiling for 140 unruptured paraclinoid aneurysms. Their medical records and radiologic images were reviewed retrospectively.Results: Complications occurred in 5·7% of 140 procedures and the morbidity rate was 0·7%. Of the 140 unruptured paraclinoid aneurysms, a total of 111 aneurysms underwent follow-up imaging evaluation at 2 years or more, or showing reopening on imaging studies within 2 years (65·6±37·2 months). Multivariate analysis revealed two predictors for reopening of the aneurysms: a maximum diameter of aneurysms and a dome/neck ratio of aneurysms (P<0·05). Reopening rates of aneurysms with maximum sizes of <8, 8–10, and >10 mm were 1%, 25%, and 75%, respectively. Reopening rates were significantly different among the three groups (P<0·05). In aneurysms with a maximum diameter of 8–10 mm, there was a significant difference of dome/neck ratios between the presence and absence of reopened aneurysms (P<0·05).Discussion: The results indicate that endovascular coil embolization is a safe and effective treatment modality in selected patients with unruptured paraclinoid aneurysms. Consideration of the aneurysm size and the dome/neck ratio could assist in the selection of therapeutic modalities for these aneurysms.