International subarachnoid aneurysm trial of neurosurgical clipping versus endovascular coiling: subgroup analysis of 278 elderly patients.

BACKGROUND AND PURPOSE: It is often thought that elderly patients in particular would benefit from endovascular aneurysm treatment. The aim of this analysis was therefore to compare the efficacy and safety of endovascular coiling (EVT) with neurosurgical clipping (NST) in the subgroup of elderly SAH patients in the International Subarachnoid Aneurysm Trial (ISAT).

METHODS: In the ISAT cohort 278 SAH patients, 65 years or older, were enrolled. The patients were randomly allocated EVT (n=138) or NST (n=140). The primary outcome was the proportion of patients with a modified Rankin scale score of 0 to 2 (independent survival) at 1 year after the SAH. The rates of procedural complications and adverse events were also recorded.

RESULTS: 83 of 138 (60.1%) patients allocated EVT were independent compared to 78 of 140 (56.1%) allocated NST (N.S.). 36 of 50 (72.0%) patients with internal carotid and posterior communicating artery aneurysms allocated EVT were independent compared to 26 of 50 (52.0%) allocated NST (P<0.05). 10 of 22 (45.5%) patients with middle cerebral artery aneurysms allocated EVT were independent compared to 13 of 15 (86.7%) allocated NST (P<0.05). The epilepsy frequency was 0.7% in the EVT group compared to 12.9% in the NST group (P<0.001).

CONCLUSIONS: In good grade elderly SAH patients with small anterior circulation aneurysms, EVT should probably be the favored treatment for ruptured internal carotid and posterior communicating artery aneurysms, whereas elderly patients with ruptured middle cerebral artery aneurysms appear to benefit from NST. EVT resulted in a lower epilepsy frequency than NST.