Impact of ARUBA on Management Decision and Outcome of Unruptured Brain Arteriovenous Malformation(bavms) in Adult Patients

Introduction: Despite being criticized for study design and short follow-up duration, the ARUBA trial has impacted the decision making of bAVMs. Recent publications using National Inpatient Sample analysis have shown that overall intervention for bAVMs has decreased, but adverse outcomes have increased. However, population databases have its limitations. In this study we aim to clarify management decision and outcome of adult unruptured bAVM patients using an institutional database.

Methods: All adult, unruptured bAVM patients were queried from our institutional bAVM database. Patients were grouped into pre-ARUBA and post-ARUBA era (cutoff date is August, 2014). Patient characteristics, bAVM features, and management outcomes were compared. Percentage of treated patients was presented. Of note, many in the treated category were salvage treatment given failed conservative management. Outcome was defined as risk of subsequent hemorrhage in untreated interval. Multivariable Poisson regression was utilized to determine association of ARUBA with likelihood of follow-up hemorrhages.

Results: A total of 477 adult unruptured bAVM patients were included, among which 350(73.4%) were pre-ARUBA. In pre-ARUBA group, 76.6% patients were treated, compared to 59.2% in post-ARUBA group(p < 0.001), despite with more low-grade bAVMs in post-ARUBA group(39.1% vs. 51.0%, p=0.039). In pre-ARUBA group, a total of 31 hemorrhages occurred in 1598.7511 patient-years, translating to 1.9% per year risk. In post-ARUBA group, 8 hemorrhages occurred in 225.78 patient-years, translating to 3.5% per year. In multivariable analysis, post-ARUBA(p=0.0468), eventual treatment(p=0.001), and increasing age(p=0.018) were associated with increased risk of subsequent hemorrhages. Those with subsequent rupture has 8.6% mortality attributable to bAVMs, compared to 1.6% in those without subsequent rupture.

Conclusion : We observed a trend of increasing conservative management in post-ARUBA era, despite having more low-grade patients compared to pre-ARUBA. However, this might have resulted in higher rate of subsequent hemorrhages, and more patients with mortality attributed to bAVM rupture.