Bleeding from cerebral arteriovenous malformations as part of their natural history

TLDR

The authors reviewed 191 cerebral AVM patient records, analyzing factors such as age, sex, lesion size, location, initial hemorrhage type, and patient condition, with mean follow‑up of 4.8 years for unruptured and 2 years for ruptured lesions. Among the cohort, 102 patients had a single hemorrhage, 32 had recurrent bleeding, and 57 never bled; larger AVMs were associated with higher first‑hemorrhage risk, with an annual risk of 2–3 %, most common in ages 11–35, and rebleeding risk rose with age, reaching 6 % in the first year and about 2 % per year thereafter up to 20 years.

Abstract

The case records of 191 patients with a cerebral arteriovenous malformation (AVM) were reviewed to determine bleeding characteristics of these lesions. Possible influences of age, sex, the location and size of the AVM, type of initial hemorrhage, and condition of the patients were analyzed. Of these 191 patients, 102 had a single hemorrhage, 32 had a recurrent hemorrhage, and 57 never bled. The follow-up period for patients with an unruptured AVM was a mean of 4.8 years and a maximum of 31 years; for those with a ruptured AVM, the mean was 2 years, and the maximum 37 years. Size of the AVM was significantly related to the risk of first hemorrhage. The average yearly risk for first hemorrhage was between 2% and 3%. Bleeding occurred most frequently in the 11- to 35-year-old age group. The risk of rebleeding increased with advancing age. Among 93 patients followed after their AVM had ruptured, the risk of rebleeding was 6% in 1 year. After the first year, the average rebleeding rate was about 2% per year up to 20 years.