[A case of remarkable enlargement of cerebral arteriovenous malformation after operation -special reference to their enlargement- (author's transl)].

Presented case is a 27-year-old male with remarkable enlargement of an arteriovenous malformation (AVM) in the left frontal lobe, four years after subtotal removal operation. First operation was carried out in February, 1973, because of 5 times adversive seizure to the right. Post-operative angiogram disclosed a tiny telangectatic residual AVM. Four years later of first operation, follow-up angiography showed a remarkable enlargement of AVM. The second operation was performed in March, 1979, with angiographically complete disappearance of AVM. A lot of theory for enlargement of AVM have been presented. Author summarized possible factor's, which influence enlargement of the size of AVM, as follows (Table 3). The first of all, histopathological nature of AVM with hemodynamic factor is most important. And, second important factor is a existence of space of adjacent AVM and multiple telangiectasia of the internal and external on nidus of AVM. At last, biological factors, such as a autonomic growth with individual ageing growth, and a size of AVM, should be regarded. It is author's conclusion, the growth of AVM of our case has occurred in the dead-space originated by previous operation, that continuous expansion of residual small vessels (telangiectasia) in vicinity of the operated region. Therefore, authors emphasizes that at the first time, radical removal of AVM should be operated with meticulous care of existent telangiectatic small vessels in surrounding brain tissue of AVM complex.