Combined Outcomes of Endovascular or Surgical Treatment of Unruptured Anterior Communicating Artery Aneurysms: Is a More Aggressive Management Strategy Warranted?

Abstract

Updated natural history studies that suggest anterior communicating artery aneurysms have a higher risk of rupture than formerly appreciated. As endovascular and open techniques advance, morbidity may fall to levels that suggest the feasibility of intervention even for small aneurysms. This study was conducted to assess the risk associated with treating smaller, unruptured anterior communicating artery aneurysms. A cross-sectional study of 149 patients with unruptured anterior communicating aneurysms treated over a 6-year period was performed. Treatment was based on an estimate of the highest efficacy/lowest risk for each patient. Outcomes were recorded at 3 months and 1 year after treatment. The primary outcome measure was a modified Rankin scale score of >2 at 1 year, or persistent cognitive impairment confirmed by a neurologist. The average patient age was 61 years (range, 34-84 years), and the median aneurysm size was 5.5 mm (interquartile range, 4-7 mm). Clipping was performed in 98 patients (65.8%). Poor outcome was observed in 12 patients (8%). Neither aneurysm size nor treatment method was predictive of poor outcome. Both a history of coronary artery disease/myocardial infarction and age were most significantly associated with poor outcome (coronary artery disease/myocardial infarction: odds ratio [OR], 8.11; 95% confidence interval [CI], 2.20-29.86; P= 0.002; age: OR, 1.09; 95% CI, 1.019-1.17; P= 0.013). Dichotomized for age >65 years, the odds of poor outcome increased nearly 11-fold (OR, 10.93; 95% CI, 2.29-52.03; P= 0.003). The risk associated with treating unruptured anterior communicating artery aneurysms in patients age <65 years is low. Comparing risk with natural history studies, these patients can be expected to outperform natural history within 5 years. Recognizing the risk of smaller anterior communicating artery aneurysms, these findings suggest that treatment of even small lesions may be beneficial.