Management strategies for unruptured cerebral aneurysms

We discussed management strategies for unruptured aneurysms by an analysis of 62 treated and 48 untreated cases. The treated cases were divided into the following two groups; Group A consisted of 38 patients with 46 aneurysms treated during our initial 13 years (7 males, 31 females, 54 +/- 9 years old), and Group B of 24 patients with 32 aneurysms (8 males, females 16, 57 +/- 9 years old) during the last 3 years. In Group A, 36 patients were treated with neck clipping, except for two patients, who had giant aneurysms treated with internal carotid ligation and bypass surgery. All the patients in Group B were treated with either clipping or endovascular coil embolization. Our indications for coil embolization include patients with aneurysms located in paraclinoid internal carotid or basilar arteries, or with multiple aneurysms requiring more than one operation, or with a systemic risky disease for general anesthesia. In group A, 2.6% of cases resulted in death during operation and 10.3% of cases resulted in morbidity, while in group B, there was neither mortality nor morbidity caused by clipping, except for a patient with mild hemiparesis who had been treated with clipping for SAH caused by a procedure of coil embolization. The 50 aneurysms of 48 untreated patients have been observed without any neurosurgical treatment during periods of 6 months to 10 years with a mean of 2 years 7 months. Eventually, four aneurysms resulted in SAH, which cases were treated with emergency clipping or coil embolization. The high rupture rate (3.1% per year) in the natural history may suggest that some aneurysms are more likely to rupture than generally considered. We also reviewed operative findings of all entry clipping cases; more than 80 percent of aneurysms, including those measuring less than 5 mm in diameter, had red colored, thin wall domes with or without bleb. Our conclusion is that surgical indications are for a complementary use of clipping and coil embolization.