Abstract
The purpose of this AVM study is to investigate the relation between Spetzler's grade and operative result, and examine the application of appropriate surgical treatment, especially for high grade (over grade III) AVMs.
Overall, operations were performed on 60 of 73 cases of AVM. Fifty-three patients (88%) had good prognosis, and 7 (12%) had poor. Patients with poor prognosis had not always been classified high grade, but commonly the AVM was located in the eloquent area.
Therefore, we classified Spetzler's grade more minutely according to a combination of factors. Then we re-examined the relation between the eloquence of the adjacent brain and the prognosis.
As a result, AVMs in the non-eloquent area were found to be closely related to their grade and prognosis, but this was not always found to be true in the eloquent area and, on the contrary, some low grade patients had poor prognosis.
As Spetzler's paper shows, it is important, in cases of AVMs in the eloquent area, to estimate the circulation and metabolism of the adjacent brain. For instance, in excising a small AVM in the eloquent area, if the circulation and metabolism of the surrounding normal brain are preserved, it is important to do least possible operative injury to the surrounding brain. But large AVMs have more or less stolen from the surrounding normal brain, so the eloquence may vary from normal, therefore, operative injury has less influence on the operative result. So appropriate treatment of post operative circulation change has great influence on the operative result.
Spetzler's grade, with preoperative assessment of circulation and metabolism of surrounding brain, may suggest the appropriate management of high grade AVMs, especially in the eloquent area.
