NEW YORK (Reuters Health) – Compared with open repair of abdominal aortic aneurysm (AAA), endovascular repair has some early benefits — but overall mortality rates converge within a few years, new research shows.
Not only does the early benefit of endovascular repair disappear in the long term, but associated complications and reinterventions end up making this approach the more costly one, according to The United Kingdom EVAR Trial Investigators.
The findings of the randomized EVAR 1 trial were published online April 12 in The New England Journal of Medicine. A companion paper reports results of the UK EVAR 2 trial, which asked the question: Is EVAR better than no intervention in patients ineligible for open repair?
Three randomized controlled trials have shown a marked benefit of endovascular aneurysm repair with respect to 30-day operative mortality, but careful long-term follow-up of endovascular repair is lacking, the researchers note.
In the EVAR 1 study, they compared the long-term results of EVAR with open repair in 1252 patients with abdominal aortic aneurysms at least 5.5 cm in diameter. Patients were equally and randomly split between EVAR and open repair (626 patients in each group) and followed for a median of 6 years (maximum, 10 years). Everyone in the study was at least 60 years old.
Only 1216 patients actually had their aneurysms repaired. The 30-day operative mortality rate was 1.8% in the EVAR group (11 of 614 patients) versus 4.3% in the open-repair group (26 of 602); the adjusted odds ratio was 0.39 with EVAR as compared with open repair (p = 0.02).
The EVAR group had an early benefit with respect to aneurysm-related mortality. Within 6 months after randomization, 14 patients in the EVAR group died of an aneurysm-related cause compared with 30 in the open-repair group; the rates per 100 person-years were 4.6 and 10.0, respectively (adjusted HR, 0.47).
But the benefit in terms of aneurysm-related mortality was completely lost in the longer term, according to the study team. Beyond 6 months, the EVAR group had another 22 aneurysm-related deaths (12 between 6 months and 4 years, and 10 in patients who were more than 4 years out) – while the open surgery group only had another 10.
Beyond 4 years, rates of death from aneurysm-related complications, per 100 person-years, were 0.8 and 0.2 in the EVAR and open repair groups, respectively. Survivors in the EVAR group had an adjusted hazard ratio of 4.85 for aneurysm-related death compared to survivors in the open surgery group.
At the end of the study, however, there was no significant difference in total mortality between the two study arms.
“Secondary rupture after aneurysm repair was reported only after endovascular repair and appeared to explain the long-term increase in aneurysm-related mortality,” the investigators report. Altogether, 25 secondary aneurysm ruptures occurred, including 18 (72%) that were fatal.
“Open repair does relatively better in the late stages because of a small number of EVAR (endovascular aneurysm repair) ruptures,” principal investigator Dr. Roger M. Greenhalgh of the Imperial College Vascular Surgery Research Group in London told Reuters Health by email.
He and his colleagues pointed out, “The overall rates of graft-related complications and reinterventions were higher by a factor of three to four in the endovascular-repair group than in the open-repair group.” Furthermore, “new complications occurred up to 8 years after randomization, contributing to higher overall costs.”
Including all the follow-up complications and readmissions, the endovascular approach ended up costing an average of GB