Predictors of complete obliteration and favourable outcome after single-modality treatment for low-grade...

Patient and arteriovenous malformation (AVM) characteristics that portend success after treatment for low-grade brain AVMs remain unknown.

We utilised the MISTA multicentre registry to identify patients with Spetzler-Martin (SM) grade I or II AVMs treated with stand-alone curative-intent intervention (resection, stereotactic radiosurgery [SRS] or endovascular embolisation). Bivariate and multivariable analyses were performed to identify patient and AVM characteristics predictive of complete obliteration or favourable outcome (complete obliteration without new permanent deficit or post-treatment haemorrhage).

A total of 522 patients were included (292 microsurgery, 152 SRS, 78 embolisation). Complete obliteration rates differed between microsurgery (95.9%), SRS (75.0%) and embolisation (71.8%) (P < .001); among patients classified as cured, digital subtraction angiography (DSA) confirmed obliteration in 96.1%, 75.9% and 52.4%, respectively. Favourable outcome was achieved in 89.4%, 64.5% and 67.9% (P < .001). In adjusted models for obliteration, elderly age (odds ratio [OR] 0.49, P = .022), larger nidus (OR 0.64, P = .005) and compacted morphology (OR 1.93, P = .019) were independent predictors overall; paediatric age predicted incomplete obliteration after microsurgery (OR 0.05, P = .045), and elderly age (OR 0.19, P = .001) and larger nidus (OR 0.59, P = .015) after SRS. For favourable outcome, SM grade II overall (adjusted OR [aOR] 0.58, P = .031) and elderly age after SRS (aOR 0.31, P = .019) were independent negative predictors.

Low-grade AVMs showed high rates of complete obliteration, though DSA-confirmed rates were substantially lower after embolisation, underscoring the importance of angiographic confirmation.

The predictors identified in this study may help guide management when 2 or 3 of the primary treatment options carry clinical equipoise.