New research suggests that surveillance for small abdominal aortic aneurysms (AAA) may not always provide meaningful benefit in older patients, particularly those with significant comorbidities. The data was presented during Plenary Session 5 by Sowmya Mangipudi, MD, MSc.
The study examined whether there may be a point at which continued AAA surveillance is unlikely to change outcomes because patients are far more likely to die from other causes before the aneurysm progresses to a size requiring intervention.
“The question of this paper is really getting at when to end AAA surveillance, if ever,” said Mangipudi, first author on the study and a resident physician at the University of California San Fransico. “There aren’t really great guidelines around which patients it makes sense to stop surveillance for. The goal of this paper was to try to generate high-quality evidence that might be able to help us inform guidelines going forward.”
The analysis drew data from Kaiser Permanente’s Northern California Regional Thoracic Aortic Aneurysm Surveillance Program, which has tracked arterial aneurysms since 2007 across 19 medical centers serving roughly five million patients. Investigators evaluated over 10,600 patients aged 65 years and older with AAA or ectatic aorta.
Using a validated large language model from a previous study, the researchers extracted maximal aneurysm diameters from radiology reports and analyzed patient outcomes over time. Primary outcomes included death, aneurysm progression to an operable size and aneurysm repair. Predictive modeling was then used to determine which patients had a greater than 90% likelihood of dying before their aneurysm progressed or required surgery.
The data showed women older than 85 with aneurysms smaller than 3.5 cm and men over 80 with aneurysms smaller than 3.5 cm had a 90% or greater chance that their first event was death. In patients with higher comorbidity burdens, there was a 90% or greater chance of death prior to reaching operative size at 75 years of age or older for men with AAA 2.7 to 3.4 cm, 85 years or older for men with AAA under 4 cm and 85 years or older for women with AAA 2.7 to 3.4 cm.
“While we calculated this for the 20th and the 80th percentile, you could hypothetically calculate this for any percentile comorbidity in the cohort,” said Mangipudi. “The idea is that you could look at these tables and say, ‘I have an 85-year-old patient and they have a low comorbidity burden and their starting AAA scan size is 3.2 cm. Do I need to continue to recommend professional imaging every three years?’”
Mangipudi said the findings are not intended to establish rigid stopping rules, but rather to support individualized decisions between physicians and patients. “We’re hoping this will be a shared decision-making tool between surgeons and patients to be able to really look at these scales and say, ‘What level of risk are we both comfortable with?’ If you’re anxious and you feel like you need to continue to advance, that is absolutely fine.”
The study also raises questions about the broader burden of imaging in elderly patients who are unlikely to ever require intervention. Mangipudi said the findings could help reduce unnecessary testing, referrals and patient anxiety while allowing clinicians to better tailor surveillance strategies based on overall health status rather than aneurysm size alone.
“Whoever your patient is, there may be a safe point at which you can stop surveillance for their AAA,” said Mangipudi. “Based on how sick they are and the intuition that surgeons already use to make some of these decisions, we hope that this will be an evidence-based method to have that conversation with patients. A lot of people are already doing it, so hopefully this will just give them more confidence.”
