0000000000454994
AUTHOR
Giuseppe D'ancona
Computational analysis to predict false-lumen perfusion and outcome of type B aortic dissection.
We have attempted to identify potential predictors foracute and late aortic events starting from admission computed tomographic images.
Early distal remodeling after elephant trunk repair of thoraco-abdominal aortic aneurysms
Hemodynamic alterations occur when the elephant trunk (ET) technique is adopted to treat extensive aortic aneurysms. In planning the 2nd stage operation to complete ET repair, surgeons must weigh an adequate recovery time after initial surgery against the risk of postoperative ET-related complications. The purpose of this study was to understand the mechanistic link between the flow alteration caused by the ET graft and the development of premature aortic rupture before the 2nd stage operation. Specifically, fluid-structure interaction (FSI) analysis was performed using the CT imaging data of aorta at different stages of ET repair, and then computational variables were compared to those obs…
Haemodynamic predictors of a penetrating atherosclerotic ulcer rupture using fluid-structure interaction analysis
We present preliminary data on the flow-induced haemodynamic and structural loads exerted on a penetrating atherosclerotic aortic ulcer (PAU). Specifically, one-way fluid-structure interaction analysis was performed on the aortic model reconstructed from a 66-year-old male patient with a PAU that evolved into an intramural haematoma and rupture of the thoracic aorta. The results show that elevated blood pressure (117 mmHg) and low flow velocity at the aortic wall (0.15 m/s(2)) occurred in the region of the PAU. We also found a low value of time-averaged wall shear stress (1.24 N/m(2)) and a high value of the temporal oscillation in the wall shear stress (oscillatory shear index = 0.13) in t…
Computational fluid dynamics simulation to evaluate aortic coarctation gradient with contrast-enhanced CT
Coarctation of aorta (CoA) is a narrowing of the aorta leading to a pressure gradient (Delta P) across the coarctation, increased afterload and reduced peripheral perfusion pressures. Indication to invasive treatment is based on values of maximal (systolic) trans-coarctation Delta P. A computational fluid dynamic (CFD) approach is herein presented for the non-invasive haemodynamic assessment of Delta P across CoA. Patient-specific CFD simulations were created from contrast-enhanced computed tomography (CT) and appropriate flow boundary conditions. Computed Delta P was validated with invasive intravascular trans-CoA pressure measurements. Haemodynamic indices, including pressure loss coeffic…
An In Vitro Phantom Study on the Role of the Bird-Beak Configuration in Endograft Infolding in the Aortic Arch.
Purpose: To assess endograft infolding for excessive bird-beak configurations in the aortic arch in relation to hemodynamic variables by quantifying device displacement and rotation of oversized stent-grafts deployed in a phantom model. Methods: A patient-specific, compliant, phantom pulsatile flow model was reconstructed from a patient who presented with collapse of a Gore TAG thoracic endoprosthesis. Device infolding was measured under different flow and pressure conditions for 3 protrusion extensions (13, 19, and 24 mm) of the bird-beak configuration resulting from 2 TAG endografts with oversizing of 11% and 45%, respectively. Results: The bird-beak configuration with the greatest protr…
Predicting Outcome of Aortic Dissection with Patent False Lumen by Computational Flow Analysis
Although Type B aortic dissection (AoD) has better in-hospital survival than Type A AoD, the short- and long term outcome for patients remains challenging, with 50–80% deaths at 5-years. Dissection-related complications include rapid aortic expansion, impending rupture, and malperfusion syndromes. We aimed to assess hemodynamic implications of patients with patent false lumen (FL) of dissected aorta. Computational fluid dynamic analyses were performed on patient-specific aortic geometries reconstructed from computed tomography scans of 25 patients with AoDs, who were admitted in our hospital from 2007 to 2013. We used the development of acute complications and chronic aneurysmal evolution a…