New Model for the Assessment of Transcatheter Aortic Valve Replacement Devices in Sheep

Carney, John P.; Faustich, Jill Schappa; Lahti, Matthew T.; Ashworth, Paul; Dalmasso, Agustin P.; Moklyak, Yuriy; Bianco, Richard W.

doi:10.1080/08941939.2020.1864796

Cited by 9 publications

(8 citation statements)

References 25 publications

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“…All remaining prostheses were fully functional in echocardiographic evaluation, with no thrombosis, calcifications, or perivalvular leaks. The overall mortality is significantly lower when compared with that of previous preclinical models of THV implantation and long-term evaluation with total mortality at follow-up of 36% versus 57% as described by others 4 , 5 , 7 ( Table 1 ). As the learning curve progresses, we have shown even lower procedure-related mortality.…”

Section: Discussionmentioning

confidence: 69%

“…The only available models of THV implantation in the native annulus or in descending aorta with creation of aortic valve insufficiency were associated with high procedural and follow-up mortality rates. 4 , 5 , 6 Although anchoring was achieved in the most recent model by Carney et al, 7 this model requires cardiopulmonary bypass and long creation times, and mortality remains significant. The summary of currently available models of preclinical models and methods of THV evaluation is presented in Table 1 .…”

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confidence: 99%

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6-Month Evaluation of a Transcatheter Aortic Valve (Myval) in a Novel Ovine, Supra-Aortic Banding Model

Buszman

Kachel

Ceballos

et al. 2022

JACC: Basic to Translational Science

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Section: Discussionmentioning

confidence: 69%

mentioning

confidence: 99%

6-Month Evaluation of a Transcatheter Aortic Valve (Myval) in a Novel Ovine, Supra-Aortic Banding Model

Buszman

Kachel

Ceballos

et al. 2022

JACC: Basic to Translational Science

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“…CPB was initiated and when adequate return to the venous reservoir was established, the animal was cooled to approximately 28 °C a standard practice common in heart valve replacement surgeries in large animals. 1 , 6 , 10 A small stab incision was made through the center of a previously placed purse string in the left ventricular apex and an appropriately sized venous cannula was positioned within the left ventricle. Venting was established immediately at low flow.…”

Section: Methodsmentioning

confidence: 99%

Establishing Background Pathologic Changes of Valve Replacement Surgery in Sheep

Faustich

Carney

Lahti

et al. 2021

Cardiovasc Eng Tech

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Purpose Sheep are the standard preclinical model for assessing safety of novel replacement heart valves, yet the anatomic and pathologic effects of invasive surgery, including those involving cardiopulmonary bypass (CPB), are unknown. Thus, we aimed to determine the gross, hematologic and biochemical effects of sham mitral and aortic replacement valve procedures in sheep to establish a useful control for evaluation of novel replacement valves. Methods Six control sheep were examined without any surgical intervention. Six sham mitral valve replacements (MVR) and six sham aortic valve replacements (AVR) were performed on 12 sheep. Complete blood counts and serum biochemistry were performed throughout the study. Sheep were sacrificed with a necropsy performed at 90 days. Results Renal infarcts (RIs) were the most frequently observed lesion, averaging 4.7 in control sheep, 2.5 with MVR and 5.8 with AVR. The number of infarcts strongly correlated with total estimated area of infarcted kidney (r = .84, p < .01). Additional cardiac interventions were significantly correlated with increased numbers of RIs (r = .85, p < .01). There was no correlation between number of RIs and time on CPB, or between AVR and MVR procedures. Conclusion The sheep model for AVR and MVR requires invasive surgery and CPB, which are associated with background anatomic and pathologic changes, especially in cases with additional surgical cardiac interventions. These findings serve as a critical control for future evaluation and development of novel replacement valves in order to distinguish device-related safety issues from expected outcomes of the surgical procedure and normal background changes in sheep.

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“…Use of the sheep model in evaluating novel cardiac devices and their translation to the clinical setting has been widely reported in published literature, especially in evaluating long-term hemodynamic performance and durability, thromboembolic complications, and biocompatibility 16 – 24 . As a result, the sheep has become the standard large animal model for in vivo testing and evaluation of novel cardiac valve replacement devices prior to human use 21 .…”

Section: Introductionmentioning

confidence: 99%

Multimodal preoperative imaging for transcatheter mitral valve replacement in the domestic sheep model

Carney,

Bianco

2024

Sci Rep

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Preclinical in vivo evaluation is an essential step in the progression of new cardiac devices into patient use, with studies predominantly performed in the domestic sheep model. A growing area of interest in cardiac device development is transcatheter mitral valve replacement (TMVR). Clinically, multimodal imaging, or computed tomography (CT) and echocardiography (echo) are used extensively to preoperatively determine mitral valve morphology prior to an intervention, but there is no description on how these modalities can be implemented to support preclinical studies. The purpose of this study is to apply clinically relevant CT and echo acquisition and assessment techniques to a large group of naive research sheep in order to analyze and report modality-related effects on mitral valve dimensional reference intervals in the sheep model. To this end, fifty-five adult domestic sheep underwent preoperative CT and echo exams and resultant images were analyzed using a landmark-based multiplanar measurement protocol and compiled into a master dataset for statistical analysis. We found moderate agreement between CT and echo-derived measurements of the mitral valve in sheep and propose the first clinically-relevant dimensional indices for the sheep’s naive mitral valve which can be used to guide future studies evaluating novel TMVR devices. This study is the first of its kind in proposing a reproducible method for detailed examination of the mitral valve in the sheep model using clinically-relevant multimodal imaging. As in patients, CT and echo can reveal accurate native mitral valve dimensions in the sheep prior to preclinical TMVR studies.

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New Model for the Assessment of Transcatheter Aortic Valve Replacement Devices in Sheep

Cited by 9 publications

References 25 publications

6-Month Evaluation of a Transcatheter Aortic Valve (Myval) in a Novel Ovine, Supra-Aortic Banding Model

6-Month Evaluation of a Transcatheter Aortic Valve (Myval) in a Novel Ovine, Supra-Aortic Banding Model

Establishing Background Pathologic Changes of Valve Replacement Surgery in Sheep

Multimodal preoperative imaging for transcatheter mitral valve replacement in the domestic sheep model

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