Abstract
The purpose of the present study was two-fold.
The first was to determine the clinical factors having a strong bearing upon the bleeding property of cerebral arteriovenous malformations (AVMs). The case records of 160 AVM patients were reviewed as related to sex, the age at onset, initial symptoms, the location of the AVMs, and the size of the AVMs. A proportional hazard model was employed for statistical analysis. Among these five clinical variables, initial symptoms and the location; i. e. deep-seated or not, were revealed to be statistically significant factors. This study showed that the cumulative risk of later hemorrhage was a critical problem in patients with deep-seated AVMs who had experienced bleeding as an initial episode.
The other aim of the study was to detect, from an analysis of the postoperative course, the indication for surgical treatment in patients with deep-seated AVMs. Follow-up study was carried out in ten cases of surgery for deep-seated AVMs in the past several years. In each case, the AVM was small (less than 2cm) and the intraparenchymal hematoma was present close to the AVM. There was no mortality among these ten cases. As to working capability, nine out of the ten cases could finally return to normal social life. However immediate worsening of neurological symptoms was observed following surgery in eight out of the ten cases. Approximately six months were necessary for them to overcome such deficits.
The present results indicate that there are strong indications for surgery in deep-seated AVMs, if the lesion is small and hematoma is present. The period necessary for recovery from postoperative worsening is generally about six months
