Blood Flow after Endovascular Repair in the Aortic Arch: A Computational Analysis.

Hector De Beaufort,Santi Trimarchi,Francesco Secchi,Ferdinando Auricchio,Michele Conti,Massimiliano Marrocco-Trischitta,Frans Moll,Rodrigo Romarowski,Simone Morganti,Theodorus Van Bakel,Joost Van Herwaarden

doi:10.1055/s-0039-1683771

Abstract

Background The benefits of thoracic endovascular aortic repair (TEVAR) have encouraged stent graft deployment more proximally in the aortic arch. This study quantifies the hemodynamic impact of TEVAR in proximal landing zone 2 on the thoracic aorta and the proximal supra-aortic branches. Methods Patients treated with TEVAR in proximal landing zone 2 having available preoperative and 30-day postoperative computer tomography angiography and phase-contrast magnetic resonance imaging data were retrospectively selected. Blood flow was studied using patient-specific computational fluid dynamics simulations. Results Four patients were included. Following TEVAR in proximal landing zone 2, the mean flow in the left common carotid artery (LCCA) increased almost threefold, from 0.21 (0.12–0.41) L/min to 0.61 (0.24–1.08) L/min (+294%). The surface area of the LCCA had not yet increased commensurately and therefore maximum flow velocity in the LCCA increased from 44.9 (27.0–89.3) cm/s to 72.6 (40.8–135.0) cm/s (+62%). One of the patients presented with Type Ib endoleak at 1-year follow-up. The displacement force in this patient measured 32.1 N and was directed dorsocranial, perpendicular to the distal sealing zone. There was a linear correlation between the surface area of the stent graft and the resulting displacement force ( p = 0.04). Conclusion TEVAR in proximal landing zone 2 alters blood flow in the supra-aortic branches, resulting in increased flow with high flow velocities in the LCCA. High displacement forces were calculated and related to stent graft migration and Type I endoleak during 1-year follow-up.

Highlights

Thoracic endovascular aortic repair (TEVAR) has decreased perioperative mortality and morbidity in treatment of diseases of the descending thoracic aorta.[1,2] The benefits of endovascular treatment have encouraged most vascular surgeons to deploy stent grafts more proximally into the aortic arch
There was a linear correlation between the surface area of the stent graft and the resulting displacement force (p 1⁄4 0.04)
On in the adoption of TEVAR as first-line treatment, a classification for preoperative planning of TEVAR in the aortic arch was proposed, identifying four proximal landing zones in the ascending aorta and aortic arch: zone 0 to 3.4 Stent graft deployment in zones 0, 1, and 2 determines the coverage of one or more proximal supra-aortic branches, which is generally managed by creating an extra-anatomical bypass, redirecting blood flow

Summary

Introduction

Thoracic endovascular aortic repair (TEVAR) has decreased perioperative mortality and morbidity in treatment of diseases of the descending thoracic aorta.[1,2] The benefits of endovascular treatment have encouraged most vascular surgeons to deploy stent grafts more proximally into the aortic arch. On in the adoption of TEVAR as first-line treatment, a classification for preoperative planning of TEVAR in the aortic arch was proposed, identifying four proximal landing zones in the ascending aorta and aortic arch: zone 0 to 3.4 Stent graft deployment in zones 0, 1, and 2 determines the coverage of one or more proximal supra-aortic branches, which is generally managed by creating an extra-anatomical bypass, redirecting blood flow. The benefits of thoracic endovascular aortic repair (TEVAR) have encouraged stent graft deployment more proximally in the aortic arch. This study quantifies the hemodynamic impact of TEVAR in proximal landing zone 2 on the thoracic aorta and the proximal supra-aortic branches

Objectives

Methods

Results

Conclusion