Aortic Biomechanics and Surgical Outcomes: Multidisciplinary Perspectives
Authors:   , Mandigers Tim Johannes 
Published: October 2024

The aim of this thesis is to provide multidisciplinary perspectives on aortic biomechanics, anatomy, and open surgical or endovascular treatment of the aorta and its side branches. In light of contemporary advancements in terms of available technologies, medical devices, and expanding indications for surgery (more frequent use of endovascular repair), these aspects and their interaction deserved further exploration. Thereby, this thesis ultimately aims to contribute to the improvement of clinical outcomes of patients with aortic disease.

Part I continues with Chapter 2, a systematic review that assessed the available literature on changes in cardiovascular haemodynamics after endovascular repair of blunt thoracic aortic injury (BTAI).

In part II, we present three experimental studies that utilize a mock cardiovascular circulatory flow loop to perform porcine ex vivo analyses on aortic biomechanics including blood flow dynamics, more specifically, on changes in aortic stiffness with different arch geometries and after aortic surgery, as quantified by aortic pulse wave velocity (PWV). Chapter 3 investigates the role of arch angulation in defining aortic PWV and blood pressures. Chapter 4 investigates aortic PWV and blood pressures before and after open surgical descending aortic interposition grafting and compares this with TEVAR-induced aortic stiffening. Chapter 5 investigates potential intergenerational differences in TEVAR-induced aortic stiffening.

Part III of this thesis starts with two studies on in silico computational (numerical) tools to virtually simulate endovascular repair of the thoracic aorta, potentially useful for predicting technical and clinical TEVAR outcomes. Chapter 6 is a scoping review that explores the currently available TEVAR procedure and stent-graft modelling options. Chapter 7 presents the application of a novel high-fidelity numerical TEVAR simulation methodology to a clinical case. Then, Part III continues with two imaging-based studies of the proximal thoracic and abdominal aorta. Chapter 8 is a morphometric analysis of the ascending aorta and arch based on electrocardiogram-gated computed tomography scans. Chapter 9 is a meta-analysis assessing the most reproducible method of ultrasound caliper placement to measure abdominal aortic diameters.

Part IV of this thesis consists of five clinical studies based on the data from international collaborative registries and single-center experiences. Chapter 10 presents the long-term sex-related outcomes of thoracic endovascular aortic repair for any disease, and then performed stratified subgroup analyses for each aortic disease. Chapter 11 investigates the impact of annual surgeon TEVAR volume on the outcomes of TEVAR for blunt thoracic aortic injury. Chapter 12 reports long-term patency rates of surgical left subclavian artery revascularization in the setting of TEVAR with zone 2 proximal seal. Chapter 13 is a comparative analysis of in-hospital complications and mortality in patients undergoing zone 2 TEVAR with left subclavian artery revascularization, stratified by revascularization type. Finally, Chapter 14 evaluates the role of the International Registry of Acute Aortic Dissection (IRAD) in promoting the understanding and management of acute aortic dissection over its first 25 years of existence.

In Part V, we discuss the findings of the different chapters of this thesis in Chapter 15 and conclude with a summary and discussion in Dutch in Chapter 16.