Decreases in diameters of treated abdominal aortic aneurysms and reduction in rupture rate

Objective: To determine whether the diameters of treated abdominal aortic aneurysms (AAAs) have changed during the last 10 years. Design, Setting, and Patients: A retrospective record review was completed on all patients undergoing any AAA repair from January 1, 2000, through December 31, 2009, at a single high-volume institution. All cases of repaired AAAs that had computed tomographic scanswithin 3 months of surgery were included. The mean and median maximal diameters of AAAs were noted. Correlation and regression analyses were used. Main Outcome Measures: The mean and median maximal diameters of AAAs. Results: Of 360 patients with treated AAAs, 339 met the inclusion criteria. The mean (SD) diameter of repaired AAAs decreased from 6.49 (1.46) cm (median, 6.40 cm) in 2000 to 5.83 (1.23) cm (median, 5.60 cm) in 2009. Correlation analysis confirmed a decrease in diameter across years (Pearson R=-0.141; P=.01). A fitted regression line also showed a decreasing trend (slope=-0.059 cm per year; P=.01). Conclusions: The diameters of repaired AAAs at our hospital have decreased progressively during the last decade. This observation is consistent with a reduction in the expansion rates of AAAs and may account for the progressive decreases in the aneurysm rupture rate in the United States.