Lower Short-Term, Higher Long-term Mortality Seen With Endovascular Aortic Aneurysm Repair

By Rob Goodier

November 24, 2021

NEW YORK (Reuters Health) - Patients undergoing endovascular repair of an intact abdominal aortic aneurysm have a lower risk of death in the short term than do those undergoing open surgery, according to new findings.

But the picture changes over time, with more deaths and aortic interventions starting to be seen with the minimally invasive approach, researchers report.

"The advice to physicians should be, when considering the patient in front of you, ask yourself which is more important: A short-term survival benefit in the 30 days following surgery or long-term durability (prevention of death)?" senior author Dr. Ramon Varcoe of Prince of Wales Hospital, University of New South Wales, in Sydney, Australia, told Reuters Health by email.

"Elderly comorbid patients are likely to benefit from EVAR and perhaps not require the long-term benefits of open surgery. For the young, fit patient the converse may be true," he said.

For their study, published in Annals of Surgery, Dr. Varcoe and colleagues mined data from a clinical registry linked to three administrative hospital and mortality datasets for New South Wales over a 9.5-year period starting in 2010. The study included 3,460 patients who underwent endovascular aneurism repair patients and 427 who had open surgery.

After inverse probability of treatment-weighted survival analysis, the two weighted cohorts of patients were similar across all characteristics. During follow-up, 28% of those getting open surgery died versus 30% of those getting endovascular surgery (hazard ratio, 1.14; 95% confidence interval, 1.04 to 1.24).

Within the first 30 days of surgery, however, endovascular repair patients had a much lower risk of death (HR, 0.24; 95% CI, 0.15 to 0.36).

The mortality risk was roughly the same among both groups from 30 days to one year after surgery. But one to four years after surgery, endovascular-repair patients had a 31% higher mortality risk (HR, 1.31; 95% CI, 1.14 to 1.51).

After four years, the mortality risk among the endovascular-repair patients was 45% higher than that of open-surgery patients (HR, 1.45; 95% CI, 1.25 to 1.67).

Cardiovascular mortality followed a similar pattern. Cardiovascular conditions were the most common cause of mortality among both groups, at 36%-40% percent of deaths. The numbers were similar within the 9.5-year follow-up period, but they varied significantly over time, roughly lining up with the all-cause mortality risk.

Rates of secondary interventions were similar at roughly 10% in both groups, but the types of interventions were different. Incisional hernia was most common among open-surgery patients and accounted for 59% of interventions, while endovascular interventions were most common after endovascular repair, accounting for 36% of the total.

Secondary aortic interventions were performed in 4.2% of patients after open surgery and in 9.8% after endovascular repair (HR, 2.45; 95% CI, 2.01 to 2.99). Subsequent aneurysm repair was nearly three times as likely after endovascular repair (HR: 2.94; 95% CI, 2.13 to 4.06).

The higher rates of secondary aortic interventions and aneurysm repair after endovascular procedures may be a clue to the cause of increased late mortality, Dr. Varcoe said.

"This suggests that suture-less stent-grafts may provide a less durable exclusion of the aortic aneurysm as a synthetic surgical graft sewn into place. Particularly when devices are used in vascular anatomy which falls outside of instructions for use. This may lead to endoleak, treatment failure and late aneurysm rupture. This is the most likely cause in my view," he said.

The study adds data to previously reported risks of complications and mortality following both procedures and confirms the recent shift from open surgery to endovascular repair, said Dr. Jason Chuen, director of Vascular Surgery at Austin Health in Heidelberg, a suburb of Melbourne, Australia, who was not involved in the research.

Dr. Chuen was not involved in the study but sits on the executive committee of the ANZ Society for Vascular Surgery, which administers the prospective clinical registry used in this research, the Australasian Vascular Audit.

"This study confirms our understanding that patients who are offered (endovascular aneurism repair) are less likely to die of a heart attack or lung disease during or shortly after surgery than with open repair, but because they tend to be sicker they still suffer from higher rates of fatal heart and lung disease in the following years," Dr. Chuen told Reuters Health by email.

SOURCE: https://bit.ly/3FxMLii Annals of Surgery, online October 20, 2021.