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Background-Aim: Limited data exist concerning the fluid dynamic changes induced by endovascular aortic repair with fenestrated and chimney graft modalities in pararenal aneurysms. We aimed to investigate and compare the wall shear stress (WSS) and flow dynamics for the branch vessels before and after endovascular aortic repair with fenestrated and chimney techniques., Methods: Modeling was done for patient specific pararenal aortic aneurysms employing fenestrated and chimney grafts (Materialise Mimics 10.0) before and after the endovascular procedure, using computed tomography scans of patients. Surface and spatial grids were created using the ANSYS CFD meshing software 2019 R2. Assessment of blood flow, streamlines, and WSS before and after aneurysm repair was performed., Results: The endovascular repair with chimney grafts leaded to a 43% to 53% reduction in perfusion in renal arteries. In fenestrated reconstruction, we observed a 15% reduced perfusion in both renal arteries. In both cases, we observed a decrease in the recirculation phenomena of the aorta after endovascular repair. Concerning the grafts of the renal arteries, we observed in both the transverse and longitudinal axes low WSS regions with simultaneous recirculation of the flow 1 cm distal to the ostium sites in both aortic graft models. High WSS regions appeared in the sites of ostium., Conclusions: We observed reduced renal perfusion in chimney grafts compared to fenestrated grafts, probably caused by the long and kinked characteristics of these devices.

Background: An occluded lower limb arterial bypass is associated with poor prognosis for the limb. Currently, no risk assessment method to estimate the risk of early graft failure exists. Aim of this study was to investigate the effect of various potential factors on early graft failure of infrainguinal bypass surgery and to develop a risk-scoring model to predict it., Methods: A prospective observational clinical study was performed. One hundred infrainguinal bypass procedures (60 autologous and 40 synthetic grafts), throughout a 3-year period were included. Nearly, 84 patients suffered by chronic limb ischemia, whereas 16 by acute limb ischemia or popliteal aneurysm disease. Various possible factors including demographic data, atherosclerosis predisposing factors, and technical details of the procedure were examined as possible causes of early graft failure. Using a combination of univariable and multivariable analysis techniques, the most significant factors were extracted, and a simple predicting risk-scoring system of early graft failure was calculated., Results: The overall early graft failure rate was 14%. The factors related to it at a statistically significant level, 0.05, were the female gender, a bypass performed after a previous ipsilateral lower limb angioplasty, a redo procedure on the same limb, and a distal anastomosis at an inframalleolar level (pedal bypass). After internal validation, the FARP 2 -predicting scoring system was formed as following: Female gender 1 point (F), bypass after a previous Angioplasty 1 point (A), Redo bypass 1 point (R), and Pedal bypass 2 points (P 2 ). An overall score equal or greater than 2, provided an early graft failure prediction with sensitivity of 100%, specificity 86%, positive predictive value 54%, and negative predictive value of 100% (area under the receiver operator characteristic curve: 0.959)., Conclusions: FARP 2 is a simple scoring system for predicting early graft failure after an infrainguinal bypass procedure. Further external validation in larger populations is needed., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The multilayer stents are occasionally used for the treatment of complicated aortic aneurysms, including thoracoabdominal aneurysms. No aneurysm-related mortality among patients treated with this technique has been described in the literature to date. We describe a case of rupture of an aortic aneurysm previously treated with a multilayer stent., (Copyright © 2012 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)