The authors experienced 81 cases of AVM during the period from 1963 through 1974, in 57 cases of which surgical removal was performed with one case of operative death. The technical problems were discussed, and it was emphasized that serial magnification stereoangiography is very useful in considering the surgical indication and performing surgery. The remaining 24 cases included 17 cases in which no surgical treatment was indicated because of involvement of the deep structures such as the thalamus and basal ganglia or of extensive area above or below the tentorium. The follow-up study of these non-surgical cases showed that in the 24 cases 19 cases survived and 16 cases of them were leading useful life with no or very little handicap. In 2 cases of these, the AVM was removed afterward because of recurrent hemorrhage. Five cases died in 1-10 years after the onset. The total of mortality and morbidity in this non-surgical group counted about 1/3.
From the study it was concluded that the AVM should be removed totally when the postoperative morbidity could be anticipated to be practically none or only little. The fact that about 2/3 of the lionsurgical cases may survive without considerable disability for a fairly lorg time strongly suggests that the surgical intervention for deep-seated AVM be indicated with greatest care.
