Introduction: Brain arteriovenous malformation (AVM) is an uncommon vascular abnormality that can cause significant morbidity and mortality. Stereotactic radiosurgery (SRS) has been reported to be safe and effective treatment modality for brain AVMs, resulting in complete obliteration in 60-80% of cases. While it has been proposed that certain AVM flow-related characteristics can play a role in obliteration after SRS, very few studies have focused on AVM angioarchitectural features that correlate with flow. Our objective was to investigate the association between AVM angioarchitectural features and obliteration rates after SRS treatment.
Methods: A retrospective review of 150 patients who underwent SRS treatment for AVM obliteration between 2009-2017 was performed. All patients who were missing pre-treatment angiograms or had less than 36 months follow-up without complete obliteration of the AVM were excluded. Comprehensive clinical data collection and detailed investigation of AVM angioarchitectural features (arterial feeders, presence of arterial enlargement, patterns of venous drainage, presence of venous obstruction/ectasia/rerouting/pseudophlebitis, nidus morphology, and presence of flow-related/intranidal aneurysms) was completed. Parametric and non-parametric univariate analysis was performed as appropriate to investigate associations of AVM characteristics and obliteration.
Results: Among 68 patients included in the analysis, 50 patients (73.5%) underwent SRS and 18 patients (26.5%) received SRS in conjunction with embolization and/or surgery. 42 patients (55.3%) achieved complete AVM obliteration. Among all AVM angioarchitectural features, arterial enlargement was found to be negatively associated with obliteration after SRS (P=0.0145). In addition, AVM location in the areas amenable to less constrained SRS planning (non-eloquent cortex (P=0.0104), right side(P=0.0073), frontal lobe (P=0.0371)), absence of focal deficit (P=0.0071) and presence of hemorrhage (P=0.0076) on presentation, and black race (P=0.0117) were positively correlated with AVM obliteration.
Conclusions: AVM angioarchitectural features reflective of high flow as well as certain clinical factors influence AVM obliteration rates after SRS treatment, which has important implications in AVM treatment planning and prognostication.
Patient Care: Our findings alert clinicians to the relationship between AVM angioarchitecture and responsiveness to Gamma Knife radiosurgery.
Learning Objectives: By the conclusion of this session, participants should be able to:
- Discuss AVM epidemiology, presentation, available treatment modalities, and the use of stereotactic radiosurgery for AVM obliteration
- Appreciate the relationship between certain angioarchitectural features and complex AVM flow dynamics
- Recognize angioarchitectural features and clinical characteristics that are associated with AVM obliteration after SRS treatment
References: 1. Starke RM, Yen CP, Ding D, et al. A practical grading scale for predicting outcome after radiosurgery for arteriovenous malformations: analysis of 1012 treated patients. J Neurosurg. 2013;119:981–987.
2. Starke RM, Kano H, Ding D, Lee JY, Mathieu D, Whitesell J, et al. Stereotactic radiosurgery for cerebral arteriovenous malformations: evaluation of long-term outcomes in a multicenter cohort. J Neurosurg. 2017;126:36–44.
3. Taeshineetanakul P, Krings T, Geibprasert S, Menezes R, Agid R, Terbrugge KG, Schwartz ML. Angioarchitecture determines obliteration rate after radiosurgery in brain arteriovenous malformations. Neurosurgery. 2012;71:1071–1078; discussion 1079.