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Resectability of Spetzler-Martin grade IV and V cerebral arteriovenous malformations

This study retrospectively analysed treatment modalities and outcomes in 63 cases of high grade cerebral arteriovenous malformations (Spetzler-Martin's classification grade IV 51, V 12) who were admitted to this institute between January 1986 and April 1998. Twenty-seven of 37 cases with haemorrhagic onset received surgical resection with or without pre-operative embolisation. Total extirpation was achieved in 23 cases, and small residual nidus was treated by postoperative radiosurgery in two of four subtotally resected cases. Another 6 of 37 haemorrhagic cases received radiosurgery with or without preradiosurgical embolisation. Four cases with haemorrhagic onset received partial embolisation. Finally, 29 of 37 haemorrhagic cases obtained complete disappearance of nidus. On the other hand, 4 of 26 non-haemorrhagic cases received surgical total resection, 5 radiosurgery, 9 partial embolisation and 8 observation without treatment. Microsurgical morbidity was 9% and mortality was 0%. Post-treatment haemorrhage was seen in 11 cases (1 after subtotal resection, 4 after radiosurgery, 6 after partial embolisation) and was fatal in 3 cases. Surgical resection can be achieved with acceptable morbidity, and complete obliteration of nidus should be accomplished in any treatment modality to avoid post-treatment haemorrhage.