Rupture in Small Abdominal Aortic Aneurysms: Beyond the Rates…

Abstract

Rupture of an abdominal aortic aneurysm (AAA) is unpredictable, rarely foreshowed by warning symptoms but lethal in 90%. There is now compelling evidence that the risk of rupture in small aneurysms is much lower than what was previously thought. The systematic review of Powell et al. in this issue of European Journal of Vascular and Endovascular Surgery (EJVES) adds substantially to the published data on the rupture rate of small aneurysms. However, the available heterogeneous data did not allow the authors to provide strong suggestions, one of the major issues complicating the understanding of rupture in small AAAs being the dissimilar reporting of rates and diameter ranges over various follow-up lengths on an event rate that changes (and probably not constantly) over time. After retrievingmore than ten thousands of articles, only 14 were eligible for the final analysis; but only seven selected studies (including 5934 AAAs) reported on conditional followupdatawhereaneurysmsizewasknownat the timeof rupture. The authors calculated that the risk of rupture in aneurysms between 3.5 and 5.5 cm in diameter is extraordinarily low and ranges from 0 to 1.61 ruptures per 100 person-years. Of note, six out of the seven studies reported rates below 0.5 per 100 person-years; the only one showing higher rate analysed exclusively 5.0e5.4-cm aneurysms.