gms | German Medical Science

Objective: The incidence of recurrent SAH after successful occlusion of an intracranial aneurysm has been reported to be approximately 3%. The incidence of de novo aneurysm formation is most likely higher, but has not been evaluated so far. Our objective is to investigate the incidence of de novo aneurysm formation in patients with SAH and successfully occluded aneurysm on a long-term follow-up basis.

Methods: Between 1981 and 2000 a total number of 379 patients with intracranial aneurysm underwent either microsurgical or endovascular treatment at our institution. The overall mortality in this patient group was 37% (140 patients). Of the remaining 239 patients we were able to contact 218 patients. Those patients were invited for a follow up examination consisting of a review of the medical history since aneurysm treatment, a neurological examination, and MR- or CT-angiography.

Results: So far 58 patients (age: 37 to 83 years, sex: male 19, female 39) with a total of 843 follow-up years (mean follow-up time 14 years) were examined. In this patient group MR- or CT-angiography confirmed six cases of de novo aneurysm formation: one aneurysm in the location of the previously clipped one and five in a distant new location. Out of the six aneurysms five are typical saccular berry aneurysms and one is a fusiform dilation of the basilar tip. No recurrence of SAH in the interim medical history was registered within this patient group. So far the cumulative incidence of de novo aneurysm formation is 6/58 (10,34%).

Conclusions: The incidence of de novo aneurysm formation in patients with successful occlusion of a previous aneurysm is significant. This study is ongoing and will be continued. We expect to include approximately half of the contacted patients. At this point it seems to be reasonable to use long-term MR- or CT-angiographic follow-up to identify patients at risk for de novo aneurysm formation and therefore risk of recurrent SAH.