Morphological predictors of intraprocedural rupture during coil embolization of ruptured cerebral aneurysms: do small basal outpouchings carry higher risk?

Abstract

Object This study aimed to investigate morphological predictors of intraprocedural rupture (IPR) during coil embolization of ruptured cerebral aneurysms. Methods A retrospective analysis was conducted in 322 consecutive patients with ruptured cerebral aneurysms who were treated with coil embolization over an 8-year period from January 2005 to December 2012. The authors analyzed all available data with emphasis on morphological characteristics of the aneurysm as shown on baseline angiography in relation to IPR. Regarding aneurysm morphology, the authors classified patients according to multilobulation, presence of a daughter sac, and presence of a small basal outpouching (SBO). Results The incidence of IPR was 4.8% (16 of 332). In terms of aneurysm configuration, the presence of multilobulation (100.0% [16 of 16] in the IPR group vs 89.2% [282 of 316] in the non-IPR group, p = 0.388) and daughter sac (75.0% [12 of 16] in the IPR group vs 59.2% [187 of 316] in the non-IPR group, p = 0.208) were not significantly associated with IPR. However, SBO, found in 9% (30 of 332) of the study population, was significantly associated with IPR (56.3% [9 of 16] in the IPR group vs 6.7% [21 of 316] in the non-IPR group, OR 18.06, p < 0.0001). Conclusions Based on the authors' data, the more general groups of multilobulation and daughter sac were not significantly associated with IPR, although the more specific subgroup with an SBO was. More confirmation studies on these results are required, but they point to the possibility that SBO (with its possible connection to basal rupture) is an important morphological risk factor for IPR during coiling. In addition, future comparison of coiling and clipping treatment for ruptured aneurysms associated with an SBO seems necessary.