Background: Abdominal aortic aneurysm (AAA) refers to localized dilation of abdominal
aorta. AAA is largely asymptomatic, but aneurysmal rupture results in a high mortality rate. AAA
with a diameter greater than 55 mm carries a high risk of rupture. There are currently no known medical
treatments effective in limiting the growth of small AAA.
Objective: To review the current status of and challenges faced in limiting AAA growth.
Methods: Data from human investigations and animal model studies were summarized. In particular,
the ClinicalTrials.gov website was searched for details of ongoing or completed studies related to
AAA growth. We searched the key words ‘abdominal aortic aneurysm’ and ‘drugs’ to identify potential
target drugs for slowing or stopping AAA growth.
Results: These clinical trials involve a number of challenges, including demonstrating the design of
the trial, minimizing the participant dropout rate, and developing accurate outcome assessments during
the trials. A number of clinical trials have concentrated on pharmaceutical intervention (such as angiotensin-
converting enzyme inhibitors, beta-blockers, statins, and antibiotics) that could be effective for
AAA patients in delaying or reversing aneurysm expansion and postponing the endpoint for elective
Conclusions: Further randomized, controlled, clinical trials are required to develop effective nonsurgical
therapies for AAA.