Umbrella review and meta-analysis of reconstructed individual patient data of mortality following conventional endovascular and open surgical repair of infrarenal abdominal aortic aneurysm

Abstract

Objectives: This umbrella review aims to quality assess published meta-analyses, conduct a de-novo meta-analysis of the available randomized control trials (RCTs), and test the hypothesis that there is a long-term difference in mortality between OSR and EVAR.

Methods: A systematic search was conducted in MEDLINE and EMBASE's bibliographic databases (June 2022). Data were extracted using standardized extraction forms. The methodological quality of publications was assessed using the ROBIS tool. Data were analyzed with 'one-stage' and 'two-stage' approaches.

Results: According to two-stage analysis, EVAR has significantly favorable mortality for up to four years (increasing evidence). Subsequently, until the longest available time period, there is no difference between EVAR and OSR; all the results are statistically non-significant.In one stage analysis, the Cox model demonstrated a non-significant (weak evidence) hazard ratio of 1.03 (95% confidence interval [CI]: 0.94-1.12) in favor of OSR. The best-fitting parametric model (generalized gamma), leads to an hazard ratio of 0.97 (95% CI: 0.93-1.01) in favor of EVAR, with the results approaching significance (weak evidence).

Conclusion: The results of this umbrella systematic review and meta-analysis failed to demonstrate any difference in long-term mortality following planned EVAR, compared with OSR of infrarenal AAA.

Keywords: Abdominal aortic aneurysm; EVAR; IPD meta-analysis; Umbrella systematic literature review; mortality.