Opportunistic Ultrasound Screening for Abdominal Aortic Aneurysm.

Objective: In patients with abdominal aortic aneurysm (AAA), early detection and optimal elective treatment before rupture are desirable. In the absence of an established public screening system, opportunistic screening during ultrasound examination for another purpose might be efficacious. The aim of this study was to evaluate the efficacy of opportunistic screening for AAA. Methods: This prospective multicenter observational study enrolled patients who were scheduled to undergo ultrasound for reasons other than AAA. After the ultrasound for the original purpose, evaluation of the abdominal aorta was added. If the abdominal aorta was clear enough for measurement, its diameter and shape were recorded. Furthermore, information on comorbidities was collected for each patient. Results: A total of 10325 patients (echocardiography: 6150; abdominal ultrasound: 4162) from 16 institutions were enrolled. The abdominal aorta was well visualized in 92.9% of patients who underwent echocardiography. Among 9791 patients, AAA was diagnosed in 122 (1.3%) (107 fusiform and 15 saccular), with a diameter range of 30-63 mm. The diagnostic rate increased with age. On multivariate analysis, older age, male sex, coronary artery disease, peripheral arterial disease, and smoking habituation were the risk factors for AAA. Conclusion: Opportunistic screening for AAA was efficacious.