Windkessel Preserving Aortic Stent Graft Attenuates Left Ventricular Remodelling after Thoracic Endovascular Aortic Repair in a Porcine Model.

Abstract

Thoracic endovascular aortic repair (TEVAR) has largely replaced open surgery for aortic pathologies and trauma due to its minimally invasive nature and reduced peri-operative risk. However, conventional stent grafts are significantly stiffer than the native aorta and may impair Windkessel function, promoting adverse cardiac remodelling, particularly in younger trauma patients with longer life expectancies. This study aimed to evaluate the impact of conventional stiff vs. compliant Windkessel preserving stent grafts on aortic biomechanics and left ventricular (LV) remodelling in a swine model of TEVAR. Twenty juvenile swine were divided into three groups: seven sham operated controls, eight animals implanted with conventional stiff stent grafts (CS-SG), and five animals implanted with novel compliant nanofibrous stent grafts (NF-SG). Longitudinal cardiac gated computed tomography angiography was used to quantify aortic volumes, diameter pulsatility, and LV mass over 4.3 months. CS-SG implantation resulted in a 93% reduction in aortic pulsatility in the descending thoracic aorta and accelerated LV mass gain (4.83 ± 2.34 g/month), approximately 70% faster than controls. In contrast, NF-SG preserved local aortic compliance and maintained Windkessel function, with systolic to diastolic volume and diameter ratios in the stented segment similar to baseline. LV growth in the NF-SG group (2.80 ± 1.84 g/month) was comparable with controls (2.83 ± 2.46 g/month), indicating attenuation of adverse remodelling. CS-SG impair Windkessel function and promote LV hypertrophy, while compliant stent grafts preserve aortic biomechanics and mitigate cardiac remodelling. These findings highlight the importance of compliance matched endografts in TEVAR patients and support further development of Windkessel preserving technologies.