From structural repair to biomechanical compatibility: Aortic stiffness after open and endovascular aortic repair

Evaluation of aortic repair has traditionally prioritised perioperative safety, exclusion of the diseased segment and durability. As endovascular treatment expands to younger patients, attention is turning towards the biomechanical compatibility of prosthetic grafts with the native aorta. Native aortic compliance supports Windkessel function, whereas grafts create a compliance transition that may accelerate pulse-wave transmission, alter wave reflection and increase left-ventricular load. This narrative review distinguishes established evidence from emerging concepts after open surgical repair, endovascular aneurysm repair and thoracic endovascular aortic repair. Carotid-femoral pulse-wave velocity (cfPWV) is the accepted reference non-invasive measure of regional aortic stiffness; cardiovascular magnetic resonance (CMR)-derived segmental pulse-wave velocity and distensibility provide complementary information. Brachial-ankle pulse-wave velocity, the cardio-ankle vascular index, and augmentation index assess different territories or haemodynamic properties and are not interchangeable with cfPWV. Left-ventricular strain and mass are downstream cardiac outcomes. Clinical evidence generally reports increases in measured arterial-stiffness indices after endovascular repair, whereas findings after open repair are heterogeneous. Treatment length, landing-zone location, oversizing, anatomy and baseline vascular phenotype may be as important as graft fabric or stent-frame category. Conflicting comparisons of polyester and expanded polytetrafluoroethylene arise from small, non-randomised studies using non-equivalent endpoints and do not support a reliable ranking of commercial devices. Emerging 4D-flow CMR, simulation and compliant graft materials illustrate a shift from structural exclusion alone towards compliance-aware repair, but evidence of improved outcomes remains insufficient. Future studies should use standardised longitudinal stiffness, blood-pressure and cardiac assessments and relate biomechanical changes to hypertension, ventricular remodelling and cardiovascular outcomes.