Long-term angiographic recurrences after selective endovascular treatment of aneurysms with detachable coils

Background and Purpose - Our aim in this study was to assess the incidence and determining factors of angiographic recurrences after endovascular treatment of aneurysms. Methods - A retrospective analysis of all patients with selective endosaccular coil occlusion of intracranial aneurysms prospectively collected from 1992 to 2002 was performed. There were 501 aneurysms in 466 patients ( mean +/- SD age, 54.20 +/- 12.54 years; 74% female). Aneurysms were acutely ruptured (54.1%) or unruptured (45.9%). Mean +/- SD aneurysm size was 9.67 +/- 5.91 mm with a 4.31 +/- 1.97- mm neck. The most frequent sites were basilar bifurcation (27.7%) and carotid ophthalmic (18.0%) aneurysms. Recurrences were subjectively divided into minor and major ( ideally necessitating re-treatment). The most significant predictors of angiographic recurrence were determined by logistic regression. These results were confirmed by chi(2), t tests, or ANOVAs followed, when appropriate, by Tukey's contrasts. Results - Short-term (less than or equal to1 year) follow-up angiograms were available in 353 aneurysms (70.5%) and long-term ( >1 year) follow-up angiograms, in 277 (55%), for a total of 383 (76.5%) followed up. Recurrences were found in 33.6% of treated aneurysms that were followed up and that appeared at a mean +/- SD time of 12.31 +/- 11.33 months after treatment. Major recurrences presented in 20.7% and appeared at a mean of 16.49 +/- 15.93 months. Three patients (0.8%) bled during a mean clinical follow-up period of 31.32 +/- 24.96 months. Variables determined to be significant predictors ( P < 0.05) of a recurrence included aneurysm size >= 10 mm, treatment during the acute phase of rupture, incomplete initial occlusions, and duration of follow-up. Conclusions - Long-term monitoring of patients treated by endosaccular coiling is mandatory.