Treatment Length and External Iliac Artery Extension Are Associated with Increased Aortic Stiffness After Endovascular Aortic Repair: A Prospective, Monocentric, Single-Arm Study

<b>Background/Objectives</b>: Aortic stiffness is a strong independent factor in cardiovascular outcomes. The method of choice for evaluating aortic stiffness is the measurement of aortic pulse wave velocity (PWV). Endovascular aortic repair (EVAR) increases aortic rigidity and thus aortic stiffness. The aim of this study is to investigate the correlation between endograft length and post-operative increases in PWV in patients with abdominal aortic aneurysms (AAAs) subjected to EVAR. <b>Methods</b>: A prospective observational study enrolling 107 patients from February to December 2025 was conducted. Patient demographics and comorbidities were recorded. The length of the endografts was calculated by studying computed tomography angiograms (CTAs) and digital subtraction angiographies (DSAs) of the patients. PWV was measured pre-operatively and post-operatively during the first 24 h after EVAR, and the difference in PWV (dPWV) was calculated. <b>Results</b>: The mean age of the patients was 72 ± 7.5 years, and 93.5% of them were males. The mean transverse AAA diameter was 5.7 ± 1.1 mm, and the mean endograft length was 169.7 ± 26.9 mm. An extension to the external iliac artery was deployed in 10 patients (9.3%). A strong positive correlation was observed between dPWV and endograft length, indicating that each additional 1 mm in graft length corresponded to a 0.541% increase in dPWV. Patients with an extension to external iliac arteries exhibited a significantly higher mean dPWV (9.95 ± 2.08% vs. 27.12% ± 12.15%, t = -4.463, <i>p</i> = 0.002). No statistically significant differences in dPWV between the different endograft types were found (<i>p</i> = 0.74). <b>Conclusions</b>: Endograft length is strongly related to PWV elevation during the immediate post-operative time after EVAR, especially when the endograft is extended to the external iliac arteries.