The Impact of Diabetes Mellitus and Metformin Use on Outcomes After Endovascular Aneurysm Repair.

: To study the influence of diabetes mellitus (DM) and metformin treatment on aneurysm sac remodeling after endovascular aneurysm repair (EVAR). : A retrospective single-center cohort analysis was conducted on consecutive patients who underwent elective EVAR for an infrarenal abdominal aortic aneurysm (AAA) between January 2011 and December 2021. Differences between study groups were analyzed and Kaplan-Meier analysis were employed to describe overall and reintervention-free survival. Cox regression analysis was performed to identify predictors of sac shrinkage. : A total of 529 patients were included: 74 (14.0%) had DM and metformin treatment, 26 (4.9%) had DM without metformin treatment, and 429 (81.1%) did not have DM. At one-year follow-up, diabetic patients showed significantly less sac shrinkage compared to non-diabetic patients (40.0% vs. 52.0%; = 0.038), with a trend toward more stable sac behavior in diabetic patients (52% vs. 42%; = 0.055). At last follow-up, sac shrinkage was significantly less in diabetic patients on metformin treatment compared to non-diabetics (48.6% vs. 59.9%; = 0.047). No differences in sac shrinkage were observed between diabetics with and without metformin treatment. The presence of endoleak was significantly higher in groups showing stable sac behavior and growth. Through nine-year follow-up, overall survival was significantly less in diabetic patients compared to non-diabetic ones (23.5% vs. 37.5%; < 0.001). : This study showed a negative impact of diabetes mellitus and metformin treatment on sac shrinkage following EVAR. The presence of any type of endoleak was associated with reduced sac shrinkage at both time points. Overall survival was significantly lower in diabetic patients compared to non-diabetic patients.