The analysis of long-term follow-up screening in patients with surgically treated intracranial aneurysms.

Aim: To understand the late anatomical results of surgically treated intracranial aneurysms (IA's) and to investigate the incidence of recurrent, de novo aneurysms, the natural history of residual aneurysms, and the morphological changes in temporarily clipped vascular segments.

Material And Methods: A total of 117 patients underwent screening with digital subtraction angiography (DSA) or computed tomographic angiography (CTA) in a range of 3 - 13 years. Late angiographies were evaluated in terms of recurrence, change in known residua, the presence of de novo aneurysms and the morphological changes in temporarily clipped vessels. We also analysed the cumulative data including previously published results.

Results: In the long-term DSA, three residual aneurysms were observed to be enlarged while four remnants showed no morphological change. In one patient, spontaneous obliteration was seen. No recurrent aneurysm was detected. One de novo aneurysm was observed. We did not find any morphological change in 71 temporarily clipped vascular segments.

Conclusion: Our data demonstrates that completely occluded aneurysms could remain stable even years later. Most of the small neck residues appeared to remain unchanged or even be thrombosed but they should be carefully followed. The incidence of de novo aneurysms might be expected to be lower.