Is annual imaging surveillance necessary following EVAR?

For more than a decade, endovascular aneurysm repair (EVAR) has been the most popular technique to repair abdominal aortic aneurysms, even as questions were raised about its long-term efficacy.

To allay those concerns, the Society of Vascular Surgery recommended patients undergo yearly monitoring with CT scans or ultrasound. By performing surveillance, doctors can assess possible problems such as aortic dilatation, graft slippage or endoleaks.

Some patients, however, may not benefit from the frequent imaging, according to a study published online in JAMA Surgery on July 8.

Matthew W. Mell, MD, MS, and colleagues from Stanford University evaluated nearly 10,000 Medicare patients who underwent EVAR for abdominal aortic aneurysms from Jan. 1, 2002, through Dec. 31, 2005. Most previous studies examining the efficacy of EVAR only followed patients for a year after the procedure. They also typically involved only one institution.

The Stanford study was one of the longest EVAR-related trials ever, according to Mell. Another strength was that it included adults 65 or older, the typical age when people have abdominal aortic aneurysms.

After a mean follow up period of more than five years, patients who did not receive CT scans or ultrasounds on a yearly basis had similar or improved outcomes compared with those who followed the guidelines. Patients who did not receive yearly surveillance had a lower rate of overall mortality and similar rate of aneurysm-related mortality.

Still, Mell made it clear that he’s not recommending to stop using CT scans or ultrasounds. The results were based on retrospective claims data, so the researchers could not adjust for factors that may have led to surveillance issues, including illnesses occurring after the EVAR procedure.

“What I suspect is that some patients will require frequent surveillance and other patients will require less frequent surveillance,” he told Cardiovascular Business. “It would be important to try and determine which patients would fall into which category.”

Mell, who is working on updating the Society of Vascular Surgery guidelines, said future research should also take cost considerations into account. Studies have suggested significant cost savings could be achieved if patients undergo ultrasounds instead of CT scans. Mell said the inconvenience and costs of scanning can increase exponentially over time.

“The medical needs still need to drive our care,” Mell said. “But if we can find opportunities to decrease costs without negatively impacting care, I think that’s an important goal.”