Background: Most studies evaluating long-term efficacy after coil embolisation of intracranial aneurysms have
not differentiated between ruptured and unruptured aneurysms.
Objectives: The aim of this study was to analyse factors that influence recanalisation in ruptured and unruptured
Methods: We performed a retrospective analysis of 182 (98 ruptured, 84 unruptured) aneurysms, treated with coil
embolisation alone that received follow-up with digital substraction angiography (DSA).
Results: At 6 months 26% of the aneurysms showed recanalisation. Multivariate variance analysis revealed that different
factors influenced recanalisation in ruptured and unruptured aneurysms. In ruptured aneurysms patient age was a
determinant, with younger patients recanalising more frequently than older ones (p = 0.016). Also, low initial packing
density led to higher recanalisation rates (p = 0.015) than higher packing. In the unruptured aneurysm group these factors
were not significant. Here, only a larger aneurysm volume led to higher recanalisation rates (p = 0.027).
Conclusions: Our data suggest that in ruptured aneurysms, high packing density is a key factor to prevent recanalisation,
while in unruptured aneurysms, aneurysm volume is the main predictor for recanalisation.