Grading System and Outcome of Surgical Treatment of Arteriovenous Malformations

Arterovenous malformations(AVVMs) represent the most commonly encountered symptomatic vascular malformations in the field of vascular neurosurgery. Surgically accessible AVMs that present with hemorrhage should be removed to reduce the risk of subsequent hemorrhage. The advance of surgery is based on the size, location and pattern of venous drainage and these anatomic features influence the treatment risk. The author studied the above features for predictor of the surgical resection of AVMs.

Nineteen patients(8 male and 11 female patients) with intracranial AVMs were treated at the Ewha Womans Medical Center between March 1989 and Dec. 1996. The mean age, and sexual ratio, of the pts as will as symptoms, location, feeding arteries, pattern of venous drainage and size of the nidus were studied. AVMs were graded according to the Spetzler and martin grade system. Overall outcome and postoperative results in eighteen patients were evaluated according to Glasgow Outcome SCale(GOS).

The average age at the time of treatment was 30.8 years old(range 4-55 years old). The hemorrhage was the most common symptom, occurring in 15(80%) patients, and 2(10%) patients presented with headache, 195%) patient with seizure, 1(5%) patient with neurological deficit. The feeding arteries were as the followings ; middle cerebral artery 8(42%), anterior cerebral artery 2(10%), posterior cerebral artery 1(5%), The pattern of draining veins were described into superficial and deep ; superficial 9(47%), deep 10(53%), The size of the nidus were as the followings ; small(<3cm) 9(47.5%), medium(3-6cm) 9(47.5%), large(>6cm) 1(5%), The Spetzler-Martin's grade and the outcome according to the grade were as follows ; grade I;3(17%) resulted GOS-5 3 patients, grade II ;5(26%) did GOS-5 6 patients, grade III; 5(26%) did GOS-5 4 patients and GOS-4 1 patient, grade IV;4(21%) did GOS-5 3 patients and GOS-4 1 patient, grade V;1(5%0 did GOS-1 1 patient. Overall, there were no death in surgical treatment, patients, the morbidity value was 2(10%) patients, the remainder were completely cured.

The Spetzler-Martin grade I-IV AVMs were associated with low rates of surgical morbidity and mortality, Therefore, surgery is the best treatment in the these grades.