Ultrasound screening for abdominal aortic aneurysms Evidence from randomized controlled trials

Background. Abdominal aortic aneurysm (AAA) rupture is associated with a high mortality rate. The only preventive therapy is early diagnosis and elective surgery of ruptureprone AAAs. AAAs can be detected very reliably at an early stage using B-mode sonography. Population-based ultrasound screening might therefore lower the risk of AAA ruptures. Materials and methods. An analysis of the literature (up to June 2014) was performed in the databases of MEDLINE, PubMed, and SCOPUS, including all randomized controlled trials (RCTs), systematic reviews, meta-analyses, health technology assessments (HTA reports), and medical guidelines on AAA screening. The following keywords were used: abdominal aortic aneurysm, ultra-sound screening, evidence, guidelines. Clinically relevant endpoints were the following: AAA-associated mortality, overall mortality, number of elective AAA operations, number of ruptured AAAs, and emergency surgery for different follow-up intervals. Results. In four RCTs, men aged between 65 and 83 years had either a single or no ultrasound examination of the abdominal aorta. Older women were only analyzed in one RCT. A meta-analysis of the RCT results shows that ultrasound screening led to a significant decrease in AAA-associated mortality, the number of ruptured AAAs, and the number of emergency AAA operations, whereas the number of elective AAA operations significantly increased. Overall mortality was only moderately decreased by AAA screening. Conclusion. Evidence was provided in population-based RCTs and meta-analyses for the efficiency of ultrasound-based AAA screening in men older than 65 years. The German Federal Joint Committee (G-BA) and the Institute for Quality and Efficiency in Health Care (IQWIG) are currently evaluating a national ultrasound-based AAA screening program for Germany. However, additional clinical trials are necessary to assess risk groups underrepresented in previous studies, especially men under 65 years of age and women with nicotine abuse and/or cardiovascular diseases.