Intracranial aneurysm perforation during endosaccular coiling: impact on clinical outcome, initial occlusion, and recanalization rates.

Objective: The aim of this study was to evaluate the acute and follow-up outcomes of cerebral aneurysms that perforated during endovascular treatment.

Methods: Nine hundred ten patients harboring 1056 intracranial aneurysms received 1164 endovascular treatments over 11 years at our institution. Intraprocedural aneurysm perforation occurred in 20 cases (1.7%). Thirteen cases (mean size, 6.2 mm) demonstrated contrast leakage, whereas the other 7 cases (mean size, 5.3 mm) showed only nonleak coil extrusion from the aneurysms. Results of follow-up magnetic resonance angiography or catheter angiography at least 6 months after embolization were available in 11 contrast leak and 6 nonleak cases. Acute and follow-up results were reviewed.

Results: New neurological deficits directly associated with aneurysm perforation were identified at discharge in only 4 contrast leak patients (20%). Their respective modified Rankin Scale scores were 1, 2, 3, and 5. Respective acute results in the contrast leak and nonleak groups were as follows: complete occlusion in 7 (54%) and 3 (43%), neck remnant in 3 (23%) and 4 (57%), and incomplete occlusion in 3 (23%) and 0. Respective follow-up results were as follows: major recanalization in 3 (27%) and 1 (17%), minor recanalization in 3 (27%) and 1 (17%), and stable occlusion in 5 (46%) and 4 (67%).

Conclusion: Intraprocedural aneurysm perforation with leakage of contrast appears to be associated with relatively high rates of incomplete acute results and major recanalizations during follow-up, although perforation frequently occurs in small aneurysms. Nonleak perforation may also lead to major recanalization through the potentially weak point of initial coil extrusion.