Less frequent post-EVAR monitoring may be safe in some patient groups
The results of the retrospective multicentre ODYSSEUS study conducted in the Netherlands suggest that less frequent monitoring after endovascular aneurysm repair (EVAR) may be warranted. However, authors Anna CM Geraedts (University Medical Centers Amsterdam, Amsterdam, The Netherlands) and colleagues point out that future studies are needed to determine the patient groups in which this would be safe.
The study, recently published in the European Journal of Vascular and Endovascular Surgery (EJVES), highlighted the fact that discontinuation of post-EVAR imaging surveillance is common in the Netherlands. It also shows that discontinuing annual follow-up in patients with initial postoperative computed tomography (CTA) angiography without abnormalities is not associated with poor outcomes.
“EVAR has become the predominant modality for the treatment of infrarenal abdominal aortic aneurysms (AAAs) in the Netherlands,” the authors write, adding that lifelong monitoring is recommended after the procedure. However, they also note that there are concerns about the long-term durability of EVAR, lifelong follow-up routines, and adherence to monitoring programs. This study therefore aimed to examine the association between adherence to postoperative monitoring and survival and secondary interventions in patients with an initial postoperative CTA without abnormalities.
Between 2007 and 2012, all consecutive patients undergoing EVAR for intact AAA at 16 hospitals were retrospectively identified, the authors write, noting that the patients were followed through December 2018.
Geraedts et al specify that patients were included if the initial postoperative CTA showed no type I-III endoleak, kink, infection or limb occlusion. The primary outcomes were aneurysm-related mortality and secondary interventions, and the secondary outcome was all-cause mortality.
Of the 1,596 patients included in the study, the authors report that the cumulative aneurysm-related, overall, intervention-free survival was 99.4/94.8/96.1%, 98.5/72.9 /85.9% and 96.3/45.4/71.1% at one, five and ten years respectively. They note that the American Society of Anesthesiologists (ASA) classification (ASA IV risk ratio [HR], 3.810; 95% confidence interval [CI], 1.296-11.198), increase in AAA diameter (HR, 3.299; 95% CI, 1.408-7.729) and continued follow-up (HR, 3.611; 95% CI, 1.780-7.323) were independently associated with aneurysm-related mortality. The same variables and age (HR, 1.063 per year; 95% CI, 1.052-1.074) were significantly associated with all-cause mortality, the authors add.
In terms of secondary interventions, Geraedts and colleagues report that no difference was observed between patients with continuous and interrupted follow-up (89/552; 15% versus 136/1044; 13%; p=0.091) .
write in EJVES, the authors acknowledge various limitations of their study, including its retrospective observational study design. This carries a risk of information bias, they state, noting for example that “it was unclear if patients were lost to follow-up, if imaging studies were discontinued after uncomplicated monitoring or if of patients had been monitored by imaging elsewhere”.
Additionally, they acknowledge that including patients only up to 2012 limits the ability to draw conclusions from newer devices, there were no clear protocols as to when a patient might be discharged. further follow-up, information on the cause of death was missing. , as well as the fact that the reasons why the patients were no longer under surveillance were not noted.
Despite these limitations, Geraedts et al also point to some notable research strengths, such as the use of population-based data with long-term follow-up and the accuracy of death verification through the National Death Registry. Additionally, they note that the survey includes all imaging studies performed as a result of EVAR, and thus “provides a comprehensive overview of national practice and adherence to ESVS.” [European Society for Vascular Surgery] guidelines”.
Geraedts and colleagues conclude that “discontinuation of follow-up is not associated with poor outcomes”, however noting that “future prospective studies are indicated to determine in which patient groups follow-up can be safely reduced”.