Impact of smoking on occlusion rates following stereotactic radiosurgery for Spetzler Martin grade I-III brain arteriovenous malformations - A propensity score matched analysis of the MISTA consortium

Background and Objective: The authors compare occlusion rates in grade I-III AVMs in smokers and non-smokers, using propensity score matching (PSM). Methods: The authors performed a subgroup analysis of the MISTA consortium, a multicenter registry that includes patients aged 1 to 89 years with AVMs treated between January 2010 and December 2023. Only grade I-III AVMs were included. PSM was used to control confounders. Primary endpoints included angiographic obliteration. Results: A total of 353 patients with bAVMs, with a median age of 37, were included in this study: 236 were never smokers, and 117 were current or previous smokers. After 1:1 PSM of smokers and non-smokers, 33 matched pairs were obtained. The smokers were more likely to display complete obliteration at last imaging follow-up compared to non-smokers (57.6 % vs. 27.3 %; p < 0.01). The median time to last clinical (p = 0.45) and angiographic (p = 0.33) follow up was not statistically different between the two groups. There were no statistically significant differences between the two matched groups in the incidence of post-SRS edema (p = 0.23), post-treatment rupture (0 %), overall mortality (p = 0.31), and functional status at the last follow-up (p = 0.69). Conclusion: Individuals with a positive history of smoking are more likely to achieve complete obliteration of grades I-III bAVMs following SRS treatment. However, smokers do not differ from non-smokers in terms of the incidence of post-treatment rupture, overall mortality, or functional status at the last follow-up.