Patient-specific analysis of displacement forces acting on fenestrated stent grafts for endovascular aneurysm repair

Kandail, Harkamaljot S.; Hamady, Mohammad; Xu, Xiao Yun

doi:10.1016/j.jbiomech.2014.08.011

Cited by 39 publications

(56 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These estimates could point out possible SG kink, gap between SG and arterial wall or collateral artery coverage, and thus potential risk of thrombosis, endoleak or artery occlusion. Additionally, a computer fluid dynamics (CFD) simulation (Kandail et al, 2014), or even a fluid structure interaction (FSI) simulation (Prasad et al, 2013), could be performed after simulating SG deployment to obtain a finer assessment of these complication risks.…”

Section: Discussionmentioning

confidence: 99%

Patient-specific simulation of endovascular repair surgery with tortuous aneurysms requiring flexible stent-grafts

Perrin

Badel

Orgéas

et al. 2016

Journal of the Mechanical Behavior of Biomedical Materials

View full text Add to dashboard Cite

The rate of post-operative complications is the main drawback of endovascular repair, a technique used to treat abdominal aortic aneurysms. Complex anatomies, featuring short aortic necks and high vessel tortuosity for instance, have been proved likely prone to these complications. In this context, practitioners could benefit, at the preoperative planning stage, from a tool able to predict the post-operative position of the stent-graft, to validate their stent-graft sizing and anticipate potential complications. In consequence, the aim of this work is to prove the ability of a numerical simulation methodology to reproduce accurately the shapes of stent-grafts, with a challenging design, deployed inside tortuous aortic aneurysms. Stent-graft module samples were scanned by X-ray microtomography and subjected to mechanical tests to generate finite-element models. Two EVAR clinical cases were numerically reproduced by simulating stent-graft models deployment inside the tortuous arterial model generated from patient pre-operative scan. In the same manner, an in vitro stent-graft deployment in a rigid polymer phantom, generated by extracting the arterial geometry from the preoperative scan of a patient, was simulated to assess the influence of biomechanical environment unknowns in the in vivo case. Results were validated by comparing stent positions on simulations and post-operative scans. In all cases, simulation predicted stents deployed locations and shapes with an accuracy of a few millimetres. The good results obtained in the in vitro case validated the ability of the methodology to simulate stent-graft deployment in very tortuous arteries and led to think proper modelling of biomechanical environment could reduce the few local discrepancies found in the in vivo case. In conclusion, this study proved that our methodology can achieve accurate simulation of stent-graft deployed shape even in tortuous patient specific aortic aneurysms and may be potentially helpful to help practitioners plan their intervention.

show abstract

Section: Discussionmentioning

confidence: 99%

Patient-specific simulation of endovascular repair surgery with tortuous aneurysms requiring flexible stent-grafts

Perrin

Badel

Orgéas

et al. 2016

Journal of the Mechanical Behavior of Biomedical Materials

View full text Add to dashboard Cite

show abstract

“…LGA -left gastric artery; SMA -superior mesenteric artery; RRA -right renal artery; LRA -left renal artery; IMA -inferior mesenteric artery; CS -cadaveric study; US -ultrasound; MRA -magnetic resonance angiography; SS -surgical study; CTA -computerised tomographic angiography; F -fasting; P -postprandial; M -men; W -women; I -intraabdominal; T -transabdominal; Ty -typical; V -variation Renal arteries evaluation is important for a number of diseases and procedures, including renovascular hypertension and renal transplantation. Detailed knowledge of renal arteries diameter is necessary for stent design for treatment of renal artery aneurysm [14] or stenosis [27] and even more for personalised fenestrated or chimney-stent grafts for endovascular aneurysm repair of aneurysms of supra-renal aorta [38,40,62]. Morphometry of accessory renal arteries is of special importance because, especially lower poles, vascularise the kidney segmentally alongside with upper ureters and thus should be preserved and anastomosed in case of renal transplantation.…”

Section: Discussionmentioning

confidence: 99%

“…Stent grafts design and placement for endovascular repair of AA and branches aneurysms [38,40], chemoembolisation for haemorrhage or chemotherapy [5], visceral aneurysm diagnosis and treatment [8] and transplantation [36,87] are based on precise calculation of AA branches' diameters. Diagnosis, staging and treatment of many relative common diseases including chronic mesenteric ischaemia or other occlusive diseases of AA branches [25] and chronic renal insufficiency [3] utilise such measurements.…”

Section: Introductionmentioning

confidence: 99%

A study concerning morphometry of abdominal aorta branches and abdominal viscera: relations and correlation

et al. 2016

View full text Add to dashboard Cite

show abstract

“…A number of CFD studies have been done on FSGs to evaluate their efficacy for FEVAR. For example, Avrahami et al, 10 Georgakarakos et al, 11 , 12 Kandail et al, 13 , 14 Sun et al, 15 and Sutalo et al, 16 among others, performed CFD simulations on either patient-specific or ideal models of FSGs to shed light on hemodynamic conditions within the fenestrated endoprostheses. With the exception of Sun et al, 15 most of these studies, however, neglected the effect of a flared renal stent.…”

Section: Introductionmentioning

confidence: 99%

Effect of a Flared Renal Stent on the Performance of Fenestrated Stent-Grafts at Rest and Exercise Conditions

Kandail

Hamady

2016

J Endovasc Ther

Self Cite

View full text Add to dashboard Cite

Purpose: To quantify the hemodynamic impact of a flared renal stent on the performance of fenestrated stent-grafts (FSGs) by analyzing flow patterns and wall shear stress–derived parameters in flared and nonflared FSGs in different physiologic scenarios. Methods: Hypothetical models of FSGs were created with and without flaring of the proximal portion of the renal stent. Flared FSGs with different dilation angles and protrusion lengths were examined, as well as a nonplanar flared FSG to account for lumbar curvature. Laminar and pulsatile blood flow was simulated by numerically solving Navier-Stokes equations. A physiologically realistic flow rate waveform was prescribed at the inlet, while downstream vasculature was modeled using a lumped parameter 3-element windkessel model. No slip boundary conditions were imposed at the FSG walls, which were assumed to be rigid. While resting simulations were performed on all the FSGs, exercise simulations were also performed on a flared FSG to quantify the effect of flaring in different physiologic scenarios. Results: For cycle-averaged inflow of 2.94 L/min (rest) and 4.63 L/min (exercise), 27% of blood flow was channeled into each renal branch at rest and 21% under exercise for all the flared FSGs examined. Although the renal flow waveform was not affected by flaring, flow within the flared FSGs was disturbed. This flow disturbance led to high endothelial cell activation potential (ECAP) values at the renal ostia for all the flared geometries. Reducing the dilation angle or protrusion length and exercise lowered the ECAP values for flared FSGs. Conclusion: Flaring of renal stents has a negligible effect on the time dependence of renal flow rate waveforms and can maintain sufficient renal perfusion at rest and exercise. Local flow patterns are, however, strongly dependent on renal flaring, which creates a local flow disturbance and may increase the thrombogenicity at the renal ostia. Smaller dilation angles, shorter protrusion lengths, and moderate lower limb exercise are likely to reduce the risk of thrombosis in flared geometries.

show abstract

Patient-specific analysis of displacement forces acting on fenestrated stent grafts for endovascular aneurysm repair

Cited by 39 publications

References 20 publications

Patient-specific simulation of endovascular repair surgery with tortuous aneurysms requiring flexible stent-grafts

Patient-specific simulation of endovascular repair surgery with tortuous aneurysms requiring flexible stent-grafts

A study concerning morphometry of abdominal aorta branches and abdominal viscera: relations and correlation

Effect of a Flared Renal Stent on the Performance of Fenestrated Stent-Grafts at Rest and Exercise Conditions

Contact Info

Product

Resources

About