Long-term follow-up study of endovascularly treated intracranial aneurysms.

Long-term follow-up studies after endovascular treatment for intracranial aneurysm are still rare and inconclusive. The aim of this study was to assess the long-term clinical and angiographic outcome of patients with endovascularly treated aneurysms. The clinical outcome of all 185 patients with endovascularly treated aneurysms were analyzed and 77 out of 122 surviving patients were examined with MRI and MRA nine to 16 years (mean 11 years) after the initial endovascular treatment. Sixty-three patients were deceased at the time of follow-up. The cause of death was aneurysm-related in 34 (54%) patients. The annual rebleeding rate from the treated aneurysms was 1.3% in the ruptured group and 0.1% in the unruptured group. In long-term follow-up MRA 18 aneurysms (53%) were graded as complete, 11 aneurysms (32%) had neck remnants and five aneurysms (15%) were incompletely occluded in the ruptured group. The occlusion grade was lower in the unruptured group with 20 aneurysms (41%) graded as complete, 11 (22%) had neck remnants and 18 (37%) were incomplete. However, only three aneurysms were unstable during the follow-up period and needed retreatment. Endovascular treatment of unruptured aneurysms showed incomplete angiographic outcome in 37% of cases. However, the annual bleeding rate was as low as 0.1%. Endovascular treatment of ruptured aneurysms showed incomplete angiographic outcome in 15% of cases and the annual rebleeding rate was 1,3%.