Comparison of Fluid Dynamics Variations Between Chimney and Fenestrated Endografts for Pararenal Aneurysms Repair: A Patient Specific Computational Study as Motivation for Clinical Decision-Making

Moulakakis, Konstantinos G.; Kakisis, John D.; Gonidaki, Eleni; Lazaris, Andreas; Tsangaris, S.; Geroulakos, George; Manopoulos, Christos

doi:10.1177/1538574419867531

Cited by 6 publications

(3 citation statements)

References 48 publications

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“…Lamooki et al noticed that computer modeling of stent expansion is critical for preventing unrealistic bulging effects and thus should be considered in virtual flow diverter deployment algorithms [ 47 ]. Patient specific AAA blood hemodynamic simulation is a promising tool that may provide important information for understanding hemodynamic factors involved in AAA repair and potentially provide data for clinical decision making [ 48 ]. In our study, as well as in Harrison et al, no comparison between the effects of the different mechanical properties of the patch and of the native artery in terms of disturbed flow [ 49 ].…”

Section: Discussionmentioning

confidence: 99%

Spatial Configuration of Abdominal Aortic Aneurysm Analysis as a Useful Tool for the Estimation of Stent-Graft Migration

et al. 2020

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The aim of this study was to prepare a self-made mathematical algorithm for the estimation of risk of stent-graft migration with the use of data on abdominal aortic aneurysm (AAA) size and geometry of blood flow through aneurysm sac before or after stent-graft implantation. AngioCT data from 20 patients aged 50–60 years, before and after stent-graft placement in the AAA was analyzed. In order to estimate the risk of stent-graft migration for each patient we prepared an opposite spatial configuration of virtually reconstructed stent-graft with long body or short body. Thus, three groups of 3D geometries were analyzed: 20 geometries representing 3D models of aneurysm, 20 geometries representing 3D models of long body stent-grafts, and 20 geometries representing 3D models of short body stent-graft. The proposed self-made algorithm demonstrated its efficiency and usefulness in estimating wall shear stress (WSS) values. Comparison of the long or short type of stent-graft with AAA geometries allowed to analyze the implants’ spatial configuration. Our study indicated that short stent-graft, after placement in the AAA sac, generated lower drug forces compare to the long stent-graft. Each time shape factor was higher for short stent-graft compare to long stent-graft.

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Section: Discussionmentioning

confidence: 99%

Spatial Configuration of Abdominal Aortic Aneurysm Analysis as a Useful Tool for the Estimation of Stent-Graft Migration

et al. 2020

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“…The maximum diameters of the aortic aneurysms were measured from the images, with 55.41 mm for case I and 65.89 mm for case II. To ensure smooth and accurate representations, we applied a previously published smoothing approach 17 . Firstly, a mask was created on the CT scans by selecting an appropriate brightness threshold and properly cropping the region of interest to isolate the pure blood flow aortic and vascular lumens.…”

Section: Methodsmentioning

confidence: 99%

Haemodynamic changes in visceral hybrid repairs of type III and type V thoracoabdominal aortic aneurysms

Ong,

Wee,

Toma

et al. 2023

Sci Rep

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The visceral hybrid procedure combining retrograde visceral bypass grafting and completion endovascular stent grafting is a feasible alternative to conventional open surgical or wholly endovascular repairs of thoracoabdominal aneurysms (TAAA). However, the wide variability in visceral hybrid configurations means that a priori prediction of surgical outcome based on haemodynamic flow profiles such as velocity pattern and wall shear stress post repair remain challenging. We sought to appraise the clinical relevance of computational fluid dynamics (CFD) analyses in the setting of visceral hybrid TAAA repairs. Two patients, one with a type III and the other with a type V TAAA, underwent successful elective and emergency visceral hybrid repairs, respectively. Flow patterns and haemodynamic parameters were analysed using reconstructed pre- and post-operative CT scans. Both type III and type V TAAAs showed highly disturbed flow patterns with varying helicity values preoperatively within their respective aneurysms. Low time-averaged wall shear stress (TAWSS) and high endothelial cell action potential (ECAP) and relative residence time (RRT) associated with thrombogenic susceptibility was observed in the posterior aspect of both TAAAs preoperatively. Despite differing bypass configurations in the elective and emergency repairs, both treatment options appear to improve haemodynamic performance compared to preoperative study. However, we observed reduced TAWSS in the right iliac artery (portending a theoretical risk of future graft and possibly limb thrombosis), after the elective type III visceral hybrid repair, but not the emergency type V repair. We surmise that this difference may be attributed to the higher neo-bifurcation of the aortic stent graft in the type III as compared to the type V repair. Our results demonstrate that CFD can be used in complicated visceral hybrid repair to yield potentially actionable predictive insights with implications on surveillance and enhanced post-operative management, even in patients with complicated geometrical bypass configurations.

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“…However, this study did not investigate the effect of supra‐arch vessels reconstruction. Konstantinos et al 15 performed CFD simulations on two patients with abdominal aortic aneurysms treated with chimney technique and fenestration technique, respectively, and found that compared with the fenestration model, the perfusion of the kidney with the chimney stent was significantly reduced. Asaph Nardi et al 16 studied the preoperative aorta of patients with aortic arch aneurysm, the aorta after aortic arch replacement, chimney technique and hybrid technology, and performed CFD simulations.…”

Section: Introductionmentioning

confidence: 99%

Computational study of fenestration and parallel grafts used in TEVAR of aortic arch aneurysms

Kai

Wang

Sun

et al. 2022

Numer Methods Biomed Eng

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To explore the differences between fenestration technique and parallel grafts technique of thoracic endovascular aortic repair, and evaluate the risk of complications after interventional treatment of aortic arch aneurysms. A three‐dimensional aortic model was established from the follow‐up imaging data of patient who reconstructed the superior arch vessel by the chimney technique, which was called the chimney model. Based on the chimney model, the geometric of the reconstructed vessel was modified by virtual surgery, and the normal model, fenestration model and periscope model were established. The blood flow waveforms measured by 2D phase contrast magnetic resonance imaging were processed as the boundary conditions of the ascending aorta inlet and the superior arch vessels outlets of the normal model. The pressure waveform of descending aorta was obtained using three‐element Windkessel model, and specific pressure boundary conditions were imposed at reconstructed branches for the postoperative models. Through computational fluid dynamics simulations, the hemodynamic parameters of each model were obtained. The reconstructed vessel flow rate of the periscope model and the fenestration model are 33% and 50% of that of the normal model, respectively. The pressure difference between the inner and outer walls of the fenestration stent and periscope stent is 3.15 times and 7.56 times that of the chimney stent. The velocity in the fenestration stent and periscope stent is uneven. The high relative residence time is concentrated in the region around the branch stents, which is prone to thrombosis. The “gutter” part of the chimney model may become larger due to the effect of the stent‐graft DF, increasing the risk of endoleak. For patients with incomplete circle of Willis, the periscope technique to reconstruct the supra‐arch vessels may affect blood perfusion. It is recommended to use balloon‐expandable stent for fenestration stent and periscope stent, and self‐expanding stent for chimney stent. For patients with aortic arch aneurysms, the fenestration technique may be superior to the parallel grafts technique.

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Comparison of Fluid Dynamics Variations Between Chimney and Fenestrated Endografts for Pararenal Aneurysms Repair: A Patient Specific Computational Study as Motivation for Clinical Decision-Making

Cited by 6 publications

References 48 publications

Spatial Configuration of Abdominal Aortic Aneurysm Analysis as a Useful Tool for the Estimation of Stent-Graft Migration

Spatial Configuration of Abdominal Aortic Aneurysm Analysis as a Useful Tool for the Estimation of Stent-Graft Migration

Haemodynamic changes in visceral hybrid repairs of type III and type V thoracoabdominal aortic aneurysms

Computational study of fenestration and parallel grafts used in TEVAR of aortic arch aneurysms

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