Screening for Abdominal Aortic Aneurysm

I am in the process now of building the components of an ideal health check-up that balances the diagnosis of medical problems that when treated or addressed can help us live long healthy, with the ability to avoid unnecessary, needless testing and its attendant costs, logistical nightmares and the associated stress.

One component of a health check-up is screening for abdominal aortic aneurysm.

An aneurysm is an abnormal enlargement of a blood vessel. It is important because it sometimes can rupture and bleed. If not treated immediately, this can lead to instantaneous death. Most aneurysms in the body are typically detected when there are warning signs with microleaks or when scanning or testing is done for some other reason or when they press upon some important structures in the body like nerves, which then lead to symptoms.

It stands to reason therefore that if we can screen for aneurysms in the body on a regular basis and pick them up before they rupture, we can treat them early and avoid catastrophic situations in the future. The problem is that when a vessel, such as the aorta, which is the big artery that carries blood from the heart to all the structures in the body, starts becoming big, it is tough to know when and if it will eventually become an aneurysm and even it does, whether and when it will rupture. Aneurysms are otherwise not common and screening for them in a general population is just a waste of time and money and often leads to the pick-up of incidental findings that only cause stress without helping us to live long, healthy.

The abdominal aorta can easily be looked at with ultrasound (USG), which is a relatively low-cost test (between Rs. 500-Rs. 2000). The USPSTF, which is an agency that we keep coming back to for these issues, advocates one-time screening for abdominal aortic aneurysm in men between 65-75 years of age, who have ever-smoked [1]. The Society of Vascular Surgery (SVS) [2] has argued that many aneurysms may be missed with these guidelines and advocates screening of women smokers between 65-75 years of age, men and women who are first degree relatives of patients with abdominal aneurysm and those > 75 years of age with a history of tobacco use. In the rest of the population, screening for abdominal aortic aneurysms is of no use.

The prevalence in the US used to be 5-6% in this population but is now between 1.2 to 3.3% and is continuously decreasing with the decrease in smoking prevalence. The vast majority of these aneurysms will be asymptomatic, and hence even if screening picks up a borderline aneurysm, whether it needs treatment or not, will still be an issue. In fact, for every one death averted by diagnosing and treating an aneurysm, 4 men will be diagnosed and treated for an aneurysm (overdiagnosis and overtreatment) that may likely have never ruptured [3].

As usual, there are no Indian guidelines or any relevant study. There is just one where screening was performed in patients admitted with heart disease and a prevalence of 4.8% was found in this high-risk population [4].

What does this mean for you and I? If you are not a smoker and have never smoked, and don’t have a first degree relative who has been diagnosed with an abdominal aortic aneurysm, then there is nothing further to be done. If you have smoked or are a smoker, during one annual health check-up, after the age of 65, one ultrasound to check for the size of the abdominal aorta is worth the effort. More importantly, if ultrasound of the abdomen is done for any other reason, do ask the radiologist to mention the size of the aorta.

Footnotes

1. US Preventive Services Task Force. JAMA. 2019 Dec 10;322(22):2211-2218.

2. Carnevale ML et al. J Vasc Surg. 2020 Dec;72(6):1917-1926.

3. Paraskevas KI. The rationale for extending screening guidelines for abdominal aortic aneurysms. J Vasc Surg. 2021 Mar;73(3):1113.

4. Vishwakarma P et al. Screening for Prevalence of Abdominal Aortic Aneurysm During Transthoracic Echocardiography in Patient With Significant Coronary Artery Disease. Cardiol Res. 2021 Oct;12(5):318-323.