Anatomical and clinical factors associated with multiple-stage embolization of brain arteriovenous malformation as a stand alone treatment

Embolization is one of the modalities used to treat brain arteriovenous malformations (bAVMs), which often require a multiple-stage approach. Factors influencing the need for a multiple-stage embolization are poorly defined and not very well understood. The aim of this study was to establish those factors.

We analysed 117 consecutive patients undergoing embolization due to bAVM with intention to treat. Patients undergoing embolization prior to surgery and with history of previous interventions or stereotactic radiosurgery were excluded. We used univariate and multivariate logistic regression analysis to establish possible predictors of the need for a multiple-stage embolization.

In total, 50 patients (42.73%) required more than one embolization procedure, with a mean of 1.67 sessions per patient to achieve complete obliteration. A history of hemorrhage was less frequent among patients requiring staged embolization (29.55% vs. 52.38%; p = 0.019). In this group, arterial supply more commonly originated from the posterior cerebral artery (53.19% vs. 32.31%; p = 0.027) and the anterior choroidal artery (10.64% vs. 0.00%; p = 0.007). Lesions located in the parietal lobe were also more frequently associated with the need for multiple-stage treatment (18.37% vs. 6.25%; p = 0.046). In multivariable logistic regression analysis, nidus size < 3 cm was independently associated with a lower likelihood of requiring multistage embolization (OR 0.06; 95% CI 0.02-0.23; p < 0.001), whereas parietal lobe location remained an independent predictor of staged treatment (OR 8.34; 95% CI 1.34-51.84; p = 0.023).

Multistage embolization was mainly determined by anatomical factors, particularly lesion size and parietal location, rather than clinical presentation. These findings support an individualized, anatomy-based approach to endovascular treatment of brain arteriovenous malformations.