The Effects of Crossing Porcine Renal Artery Ostia with Various Endovascular Stents

Birch, Pattie; Start, R. D.; Whitbread, T.; Palmer, Ian R.; Gaines, Peter A.; Beard, Jonathan

doi:10.1053/ejvs.1998.0672

Cited by 45 publications

(28 citation statements)

References 17 publications

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“…Porcine studies with stents placed across the renal artery ostia report neointima forming on some device struts, and, in a number of cases, filling the area between device struts [20,21]. A rise in serum creatinine levels was also reported.…”

Section: Discussionmentioning

confidence: 95%

Computational Modeling of Shear-Based Hemolysis Caused by Renal Obstruction

Segalova

Rao²,

Zarins

et al. 2012

Journal of Biomechanical Engineering

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As endovascular treatment of abdominal aortic aneurysms (AAAs) gains popularity, it is becoming possible to treat certain challenging aneurysmal anatomies with endografts relying on suprarenal fixation. In such anatomies, the bare struts of the device may be placed across the renal artery ostia, causing partial obstruction to renal artery blood flow. Computational fluid dynamics (CFD) was used to simulate blood flow from the aorta to the renal arteries, utilizing patient-specific boundary conditions, in three patient models and calculate the degree of shear-based blood damage (hemolysis). We used contrast-enhanced computed tomography angiography (CTA) data from three AAA patients who were treated with a novel endograft to build patient-specific models. For each of the three patients, we constructed a baseline model and endoframe model. The baseline model was a direct representation of the patient's 30-day post-operative CTA data. This model was then altered to create the endoframe model, which included a ring of metallic struts across the renal artery ostia. CFD was used to simulate blood flow, utilizing patient-specific boundary conditions. Pressures, flows, shear stresses, and the normalized index of hemolysis (NIH) were quantified for all patients. The overall differences between the baseline and endoframe models for all three patients were minimal, as measured though pressure, volumetric flow, velocity, and shear stress. The average NIH across the three baseline and endoframe models was 0.002 and 0.004, respectively. Results of CFD modeling show that the overall disturbance to flow caused by the presence of the endoframe struts is minimal. The magnitude of the NIH in all models was well below the accepted design and safety threshold for implantable medical devices that interact with blood flow.

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Section: Discussionmentioning

confidence: 95%

Computational Modeling of Shear-Based Hemolysis Caused by Renal Obstruction

Segalova

Rao²,

Zarins

et al. 2012

Journal of Biomechanical Engineering

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“…Appare pertanto giustificata la tendenza a verificare l'effetto nel tempo di queste protesi a livello della funzionalità renale, delle arterie renali e del parenchima renale [13,[16][17][18][19][20].…”

Section: Discussioneunclassified

Endovascular abdominal aortic aneurysm repair and renal complications: a comparison between suprarenal and infrarenal fixation of stent grafts

Iezzi

Giancristofaro

et al. 2007

Radiol med

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Purpose. This study was performed to compare the rate of morphological (renal infarction and/or ischaemic lesions) and functional renal complications after the suprarenal and infrarenal fixation of aortic stent-grafts for endovascular abdominal aortic aneurysm repair (EVAR). Materials and methods. We retrospectively reviewed all followup computed tomography (CT) angiograms (obtained at 1, 6 and 12 months and yearly thereafter) and laboratory data pertaining to 102 patients who underwent suprarenal (60 patients, group A) or infrarenal (42 patients, group B) placement of aortic stent-grafts. The groups were compared in terms of complications affecting kidney function (creatinine clearance) and morphology (renal artery steno-occlusions, morphological and structural parenchymal changes), and pre-and postprocedural arterial pressure (AP). Results. Analysis of patient demographics revealed no statistically significant difference between the two groups. The proximal neck was shorter in group A (2.14 cm±0.84 cm) than in group B (3.41 cm±1.21 cm). Creatinine clearance (CrCl) decreased in both groups (group A: from 64.24 ml/min to 60.66 ml/min; group B: from 72.41 ml/min to 68.73 ml/min) without any significant difference in terms of changes in renal function (CrCl variation: -8.75% vs. -6.4%) or morphology (post-EVAR stenosis: 2.6% vs. 0%; progression of existing steno-occlusive lesions: 1% vs. 0%; ischaemic lesions: 3.2% vs. 0%), or in AP. Conclusions. In our experience, the use of abdominal endografts with suprarenal fixation did not lead to any significant increase in morphological and/or functional renal complications compared with those with infrarenal fixation. RiassuntoObiettivo. Confrontare il tasso di complicanze renali morfologiche (infarto e/o lesioni ischemiche renali) e funzionali dopo posizionamento di endoprotesi aortiche ad aggancio sopra e sottorenale per il trattamento endovascolare dell'aneurisma dell'aorta addominale (EVAR). Materiali e metodi. Sono stati analizzati retrospettivamente tutti gli esami angio-TC di controllo (follow-up a 1, 6, 12 mesi e quindi 1/anno) e i test di laboratorio eseguiti su 102 pazienti sottoposti a posizionamento di endoprotesi ad aggancio soprarenale (60 pazienti, gruppo A) o sottorenale (42 pazienti, gruppo B). I due gruppi di pazienti sono stati confrontati in termini di complicanze renali funzionali (valutazione della funzionalità renale mediante clearance della creatinina) e morfologiche (steno-ostruzioni delle arterie renali; alterazioni morfo-strutturali del parenchima renale) e di pressione arteriosa pre-e post-procedurale. Risultati. I due gruppi di pazienti sono risultati omogenei da un punto di vista epidemiologico. La lunghezza del colletto prossimale è risultata inferiore nel gruppo A (2,14 cm±0,84 cm) rispetto al gruppo B (3,41 cm±1,21 cm). In entrambi i gruppi di pazienti si è registrato un decremento della ClCr (gruppo A: da 64,24 ml/min a 60,66 ml/min; gruppo B: da 72,41 ml/min a 68,73 ml/min), in assenza di differenze statisticamente significative in termin...

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“…Although clinical and experimental studies have suggested that the impact on the renal ostia or renal blood flow depends mainly on the type of stent-graft used, [25][26][27][28][29][30] gradual accumulation of cellular material on the wire may affect renal blood flow. Liffman et al 24 demonstrated in a recent experimental study that larger deposits on 2 wires across a renal artery model decreased the flow by 41%.…”

Section: Discussionmentioning

confidence: 99%

Diagnostic Value of CT Virtual Intravascular Endoscopy in Aortic Stent-Grafting

Sun¹,

Winder²,

Kelly

et al. 2004

J Endovasc Ther

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VIE was not found to play a role in most preoperative situations compared to axial CT images. However, VIE provided additional postgrafting information on the 3D relationship of the suprarenal stent struts to the aortic branch ostia (in particular the renal and superior mesenteric arteries). VIE findings might aid clinicians in accurately assessing the effect of suprarenal stent-grafting on the renal arteries.

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The Effects of Crossing Porcine Renal Artery Ostia with Various Endovascular Stents

Abstract: Covering renal arteries with the Wallstent appears to be safe in the short-term. Placement of stents with larger struts across renal arteries will require imaging methods, such as intravascular ultrasound (IVUS) to ensure that the ostia are not obstructed.

Cited by 45 publications

References 17 publications

Computational Modeling of Shear-Based Hemolysis Caused by Renal Obstruction

Computational Modeling of Shear-Based Hemolysis Caused by Renal Obstruction

Endovascular abdominal aortic aneurysm repair and renal complications: a comparison between suprarenal and infrarenal fixation of stent grafts

Diagnostic Value of CT Virtual Intravascular Endoscopy in Aortic Stent-Grafting

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