Patterns of brain arteriovenous malformation treatment: prospective, population-based study.

BACKGROUND AND PURPOSE: The extent of variation in the interventional treatment of brain arteriovenous malformations (AVMs) is unknown, so we explored patterns of treatment at 4 neuroscience centers in one European country.

METHODS: We included every participant with an AVM in a prospective, population-based cohort study of adults aged >or=16 years residing in Scotland at the time of AVM diagnosis in 1999 to 2003.

RESULTS: Only 11 (5%) of the 229 adults were not managed at a neuroscience center. Adults who received interventional treatment were younger (median, 43 versus 54 years), more likely to have presented with hemorrhage (OR, 2.8; 95% CI, 1.6 to 4.9), and had smaller AVMs (median nidus diameter, 2 cm versus 3 cm; P=0.003) than those who did not. Adults seen at the 4 centers only differed in AVM Spetzler-Martin grade (P=0.04). The 4 centers did not differ in the proportion of adults with AVMs who received interventional treatment (P=0.16), but they differed in the Spetzler-Martin grade of the AVMs they treated (Grades III to IV, P=0.01) and the interventional treatments used (P=0.004). The 2 largest centers differed from each other in the likelihood of surgical resection (OR, 0.2; 95% CI, 0.1 to 0.6) and stereotactic radiosurgery (OR, 2.8; 95% CI, 1.3 to 6.1), and the choice of modality varied within some Spetzler-Martin grades.

CONCLUSIONS: Patient characteristics and patterns of AVM interventional treatment differ between neuroscience centers in the same population necessitating careful consideration of these factors when comparing one hospital's outcome with another.