French WINDOW Trial Investigators Evaluate Cost-Effectiveness of Fenestrated/Branched EVAR for Complex Aortic Aneurysms
January 16, 2018—Two-year results from a study of the cost-effectiveness of fenestrated/branched endovascular aneurysm repair (f/b EVAR) compared with open surgical repair (OSR) for patients with thoracoabdominal aortic aneurysms (TAAAs) or complex abdominal aortic aneurysms (AAAs) were published online in European Journal of Vascular and Endovascular Surgery (EJVES) by Morgane Michel, MD, et al on behalf of the WINDOW trial participants.
As summarized in EJVES, two matched cohorts of patients with TAAAs or complex AAAs were compared after a follow-up of 2 years. Patients included in the French WINDOW multicenter prospective registry were treated by f/b EVAR and compared with patients who underwent OSR and were extracted from the French national hospital discharge database.
The investigators assessed all-cause mortality along with readmissions and hospital costs. They studied the association between treatment and 2-year mortality by univariate/multivariate Cox regression analyses using pre- and postoperative characteristics. The incremental cost-effectiveness ratio (ICER) was estimated for pararenal/juxtarenal AAAs and infra- and supradiaphragmatic TAAAs.
A total of 268 high-risk patients were treated by f/b EVAR and 1,678 average-risk or low-risk patients were treated with OSR during the same period. Mortality did not significantly differ between the groups (14.9% vs 11.8%; P = .15) and multivariate Cox regressions did not find an association between 2-year mortality and treatment. Similar proportions of patients were readmitted at least once (69.7% with f/b EVAR vs 64.2% with OSR; P = .096), but f/b EVAR patients had more readmissions on average (2.2 vs 1.7; P = .001). Two-year hospital costs were higher in the f/b EVAR group (€46,039 vs €22,779; P < .001).
At 2 years, f/b EVAR was dominated (more expensive and less effective), except in the supradiaphragmatic TAAA subgroup with an ICER of €42,195,800 per death averted. In comments to Endovascular Today, Dr. Michel explained that this means that in treating the patients with supradiaphragmatic TAAAs using f/b EVAR, an approximate average of an additional €42 million must be spent to save an extra life compared to OSR; the uncertainty surrounding the result is high because of the small number of patients in that group.
The investigators concluded that f/b EVAR in high-risk patients offers similar 2-year mortality to OSR performed in lower-risk patients but at a higher cost. The cost is mainly driven by the cost of the stent graft, which is not compensated for by lower health care resource consumption. Further studies are necessary to evaluate the cost-effectiveness in low-risk f/b EVAR patients who may experience fewer complications, advised the WINDOW investigators in EJVES.
Dr. Michel commented to Endovascular Today, "The results are quite positive for f/b EVAR in terms of effectiveness as we compared a group of high-risk patients (f/b EVAR) to a group of low-risk/moderate-risk patients (OSR). The fact that there is no significant difference in terms of mortality at 2 years between the two groups is therefore very encouraging. We can hypothesize that if we had included low-risk/moderate-risk patients in the f/b EVAR group, their survival would have been better than with OSR. In terms of costs and cost-effectiveness, however, it seems unlikely that a lower-risk population in the f/b EVAR group would have much impact on the results due to the very high cost of the stent graft."
In August 2015, the initial WINDOW registry findings were published by Dr. Michel et al in EJVES (2015;50:189–196).