Background and purpose: The aim of this study was to analyze the clinical results of Guglielmi detachable bare coil (GDC) embolization of intradural saccular aneurysms (AAs) at a single center and to relate the morphological results at various time points to the clinical situation.
Methods: All intradural saccular AAs treated with GDCs between 1993 and April 2005 were prospectively entered into a database completed by retrospective analysis of charts and images and a long-term clinical outcome questionnaire. In 413 consecutive patients, there were 466 treated AAs, of which 68.7% were ruptured and 31.1% were unruptured.
Results: The periprocedural thromboembolic event rate, retreatment procedures included, was 5.4%, causing permanent neurologic deficits in 2.2% of patients. One patient (0.2%) bled during a mean+/-SD clinical follow-up of 64.3+/-39.9 months (93 AAs were followed up for >8 years and 45 AAs were followed up for >10 years) for a total of 1810 patient-years. The modified Rankin Scale score was 0 in 54.7%, 1 in 21.0%, 2 in 12.1%, 3 in 7.1%, 4 in 2.1%, 5 in 0.3%, and 6 (death from unrelated causes) in 2.7% of patients. If an aneurysm, with or without a remnant, was unchanged for 12 months, then the risk for future morphological loss was 4.8%, whereas if an aneurysm showed a morphological loss during the earlier 12-month interval, the risk for additional late loss was 38.3% (P<0.001, odds ratio=12.4).
Conclusions: Embolization of saccular AAs entails a prolonged management period. A stable angiographic result during a 12-month interval predicts a low risk for morphological deterioration. This regimen, aiming for a stable angiographic result rather than complete aneurysm occlusion, gives a low rebleed rate and excellent clinical long-term results.