Abstract
The present study retrospectively analyzes cases of large arteriovenous malformation (AVM) that were treated surgically between 1975 and 1995. Our principle operative strategy for AVM is total removal under a one-stage operation without intravascular intervention procedures. Blood pressure is controlled during surgery and the post-operative course.
Fourteen out of 84 surgical cases of AVM during that period presented with AVM larger than 6cm in maximum diameter. The patients consisted of 3 females and 11 males, aged from 18 to 53 years (mean 36.8 yrs). Initial symptoms consisted of bleeding attacks in 7 cases, epilepsy in 5 cases and headaches in 2 cases. The patients were divided into two groups according to the presence of complicating hemorrhage; Group A consisted of 8 patients who showed no complication and Group B consisted of 6 patients with complications. Complicating hemorrhage can be manifested by an arterial component such as occlusion of high shunt flow (normal perfusion pressure breakthrough: NPPB) or by a venous mechanism such as occlusion hyperemia. Group B patients showed no posterior fossa AVM. All cases had more than 2 large feeding arteries and prominent draining veins. Stagnating arteries were detected in the post-operative angiography of 4 cases in Group A and in all cases in Group B. The outcome at the time of discharge was as follows: in Group A (ADL-1: 6 cases, ADL-2: 1 case, ADL-3: 1 case), in Group B (ADL-1: 3 cases, ADL-3: 2 cases, death: 1 case). There were no characteristic pre-operative findings in Group-B. The causes of poor clinical outcome in Group B included embolic complications associated with the intravascular procedure and hemorrhage due to NPPB. However, the recent development of staged surgical procedures, intravascular embolization and arterial pressure control may allow effective surgical treatment of large AVM.
