New initiative boosts surveillance imaging, cuts mortality after aortic aneurysm repair

Through a statewide partnership, hospitals in Michigan drastically increased the number of patients who receive follow up imaging after undergoing aortic aneurysm repair, according to a recent study.

The rate of imaging in the year following endovascular aneurysm repair, or EVAR, improved from nearly 28% in 2017 to just below 80% in 2023.

Patients who participated in surveillance imaging had a nearly 60% decrease in the likelihood of dying within one year of surgery, after controlling for other comorbidities.

The results are published in Circulation: Population Health and Outcomes.

"EVAR is now more common that open surgery, yet as many as 57% of patients were missing essential follow up imaging," said first author Frank M. Davis, M.D., assistant professor of surgery at University of Michigan Medical School and vascular surgeon at the U-M Health Frankel Cardiovascular Center.

"Through this partnership, we saw sweeping improvements in surveillance imaging that will allow clinicians to detect early problems that can lead to device failure or future, threatening complications such as aortic rupture."

Current guidelines from the Society for Vascular Surgeons recommend annual lifelong surveillance after EVAR with CT scanning or ultrasound.

More than 30 hospitals participated in the improvement initiative that offered financial insurance reimbursement for encouraging surveillance imaging in the year following endovascular repair of abdominal aortic aneurysm.

The initiative formed through the Blue Cross Blue Shield of Michigan Cardiovascular Consortium, or BMC2, registry.

The consortium, housed at Michigan Medicine, is comprised of hospitals across the state of Michigan that use data they collect to inform quality projects, and improve care and patient outcomes.

Before the study, the rate of EVAR surveillance imaging just one year after the operation varied in Michigan from 3.7% at smaller hospitals to 62.5% at larger facilities.

The effort led to improvement across Michigan hospitals and was not driven by high-performing health care systems.

By 2023, 95% of participating hospitals had EVAR surveillance rates above 60%.

The long term success of a surveillance program like this depends on identifying processes at each participating hospital that can be built into routine practice, making them easier for health care teams to sustain."

Nicholas Osborne, M.D., M.S., senior author, Ramon Bergeur M.D., Ph.D., Research Professor of Vascular Surgery at U-M Medical School and director of BMC2

Each year, around 200,000 Americans are affected by abdominal aortic aneurysm.

Around 14% of patients who have EVAR require a second procedure within four to five years and less than 2% experience late aortic rupture as a complication.

Patients who received surveillance imaging during the study period had a higher number of repeat interventions than those who did not get imaging.

Their mortality rate, however, was significantly lower.

Past studies have mixed results as to whether follow up imaging is associated with reduced risk of death after endovascular repair.

Researchers say future studies using BMC2 data will assess mortality risk after five and 10 years of surveillance.

"This study demonstrates the importance of BMC2, as implementation of quality programs across the state of Michigan care lead to substantial improvement in care for patients including those who have aortic surgery," Davis said.