Arteriovenous malformations of the brain: risk of first bleeding, rebleeding and related risk factors in 168 untreated patients

Abstract

A long-term follow-up study of 168 patients with untreated arteriovenous malformations (AVMs) who were admitted to the neurosurgical departments of Verona and Padua was conducted to evaluate the risk of bleeding and rebleeding of the cerebral AVMs. Two different prospective (historical) trials were performed in two groups of patients. The risk of first bleeding was evaluated in a first group of 71 patients who had never bled before: mean bleeding risk was 2.8% per year. The risk of rebleeding was evaluated in a second group of 107 patients who had had one previous haemorrhage: the risk of bleeding was 3.5% per year. In 41 patients who had survived a second haemorrhage, a 7.7% mean risk of a third haemorrhage was observed. The risk of death was 1.3%, 1.6% and 3%, respectively, in the three groups.