Abdominal aortic aneurysm pathology and progress towards a medical therapy

Abdominal aortic aneurysm (AAA) is an important cause of mortality in older adults due to aortic rupture. Surgical repair (either by endovascular or open surgery) is the only treatment for AAA. However, large randomized controlled trials have demonstrated that elective repair of small (<55 mm) AAAs does not reduce all-cause mortality. Most AAAs detected through screening programs or incidental imaging are too small to warrant immediate surgical repair. Such patients are managed conservatively with repeated imaging to monitor AAA diameter. Nonetheless, 60–70% of AAAs managed in this way eventually grow to a size warranting elective surgery. Discovery of a drug therapy which effectively slows the growth of small AAAs has significant potential to improve patient welfare and reduce the number of individuals requiring elective surgery. This chapter reviews the current understanding of AAA pathogenesis gained through assessment of animal models and clinical samples. Previous AAA drug trials are also discussed. Finally, the challenges in developing AAA drugs are outlined