Anatomical results, rebleeding and factors that affect the degree of occlusion in ruptured cerebral aneurysms after endovascular therapy

Object To present a series of ruptured cerebral aneurysms in consecutive non-selected patients treated with endovascular therapy, analyzing the initial degree of occlusion, its anatomical evolution mid-term and the variables that could statistically affect them. Methods 251 aneurysms were first treated with coiling (embolization). 203 patients were followed up with conventional angiography for 6-8months after the initial treatment and 182 were followed up with three-dimensional time of flight MR angiography at18-24months. Postoperative and mid-term anatomical results were evaluated anonymously and independently using the modified Montreal Scale. Results The initial rate of complete occlusion was 70.9%, with rates of neck remnants and aneurysm remants of 18.3% and 10.7%, respectively. The recurrence rate was 13% after 6months and 2% between 6months and 2years. The rate of retreatment was 11%. Statistically, the variables that were found to be related to the initial degree of occlusion were the use of a remodeling balloon technique (p=0.012), the size of the aneurysm neck (p=0.044) and the size of the aneurysm (p=0.004). The recanalization rate at mid-term depended on the size of the aneurysm. Although aneurysms with partial occlusion initially tended to evolve to a worse degree of closure than those with complete occlusion initially, the relationship was not statistically significant (p=0.110). Conclusions Embolized aneurysms can develop a worse degree of closure even when the initial occlusion is complete. The degree of occlusion depends directly on morphological factors and the use of balloon-assisted techniques. The recanalization rate at mid-term depends on the size of the aneurysm and probably on the density of the packing achieved with the initial treatment.