We investigated surgical indication and factors relating to risks of rupture in 274 consecutive patients with unruptured cerebral aneurysms. Of the total, 114 (41.6%) patients were surgically treated: 96 were treated with craniotomy, and 18 were treated with coil embolization. The incidence of cases undergoing surgical intervention tended to expand with the increase of their aneurysm size except for cases with large or giant aneurysms. In cases with small aneurysms less than 4 mm, the presence of a familial history of subarachnoid hemorrhage, additional ruptured aneurysms, additional large aneurysms, posterior circulation aneurysms and intractable anxiety of patients were the reasons for surgical intervention.
Nine of 17 (52.9%) cases with additional aneurysms suffering subarachnoid hemorrhage, 32 of 46 (69.6%) patients with a familial history of subarachnoid hemorrhage and 28 of 36 (77.8%) cases whose aneurysm had bleb formation underwent surgical intervention. Complete clipping was achieved in 94 of 96 (97.9%) cases treated with craniotomy, and a sufficient initial embolization rate of over 90% was obtained in all cases treated with coil embolization. Surgical complication affecting patients ADL was observed in only 1 of 119 (0.9%) treated cases, and consequent rupture of aneurysms occurred in 2 older patients during follow-up in 155 conservative cases.
To decide surgical indication for unruptured cerebral aneurysms, it is important to consider factors related to risks of rupture.