This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2020R1A4A3079570), the Ministry of Education (No. 2021R1I1A1A01051425), and the Industrial Strategic Technology Development Program (No. 20014873) funded by the Ministry of Trade, Industry &#38; Energy, Republic of Korea.

All animal research procedures were approved and performed in accordance with the Laboratory Animals Welfare Act, the Guide for the Care and Use of Laboratory Animals, and the Guidelines and Policies for Animal Experiments provided by the Institutional Animal Care and Use Committee (IACUC) at the College of Medicine of The Catholic University of Korea (approval number: CUMC-2021-0176-05). The present study utilized 3 month old male New Zealand white (NZW) rabbits weighing 3.5-4.0 kg, which were maintained under standard ...

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	<li>Aliev, G., Burnstock, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Watanabe+rabbits+with+heritable+hypercholesterolaemia:+A+model+of+atherosclerosis.">Watanabe rabbits with heritable hypercholesterolaemia: A model of atherosclerosis.</a> Histology and Histopathology. 13 (3), 797-817 (1998).</li><li>Cimini, M., Boughner, D. R., Ronald, J. A., Aldington, L., Rogers, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+aortic+valve+sclerosis+in+a+rabbit+model+of+atherosclerosis:+An+immunohistochemical+and+histological+study.">Development of aortic valve sclerosis in a rabbit model of atherosclerosis: An immunohistochemical and histological study.</a> Journal of Heart Valve Disease. 14 (3), 365-375 (2005).</li><li>Drolet, M. C., Couet, J., Arsenault, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+aortic+valve+sclerosis+or+stenosis+in+rabbits:+role+of+cholesterol+and+calcium.">Development of aortic valve sclerosis or stenosis in rabbits: role of cholesterol and calcium.</a> Journal of Heart Valve Disease. 17 (4), 381-387 (2008).</li><li>Sider, K. L., Blaser, M. C., Simmons, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+calcific+aortic+valve+disease.">Animal models of calcific aortic valve disease.</a> International Journal of Inflammation. 2011, 364310 (2011).</li><li>Honda, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+mouse+model+of+aortic+valve+stenosis+induced+by+direct+wire+injury.">A novel mouse model of aortic valve stenosis induced by direct wire injury.</a> Arteriosclerosis, Thrombosis, and Vascular Biology. 34 (2), 270-278 (2014).</li><li>Niepmann, S. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Graded+murine+wire-induced+aortic+valve+stenosis+model+mimics+human+functional+and+morphological+disease+phenotype.">Graded murine wire-induced aortic valve stenosis model mimics human functional and morphological disease phenotype.</a> Clinical Research in Cardiology. 108 (8), 847-856 (2019).</li><li>Robbins, N., Thompson, A., Mann, A., Blomkalns, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+excision+of+murine+aorta;+A+versatile+technique+in+the+study+of+cardiovascular+disease.">Isolation and excision of murine aorta; A versatile technique in the study of cardiovascular disease.</a> Journal of Visualized Experiments. (93), e52172 (2014).</li><li>Wirrig, E. E., Gomez, M. V., Hinton, R. B., Yutzey, K. 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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spectrum+of+calcific+aortic+valve+disease:+Pathogenesis,+disease+progression,+and+treatment+strategies.">Spectrum of calcific aortic valve disease: Pathogenesis, disease progression, and treatment strategies.</a> Circulation. 111 (24), 3316-3326 (2005).</li><li>Lindman, B. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcific+aortic+stenosis.">Calcific aortic stenosis.</a> Nature Reviews Disease Primers. 2, 16006 (2016).</li><li>Cuniberti, L. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+mild+aortic+valve+stenosis+in+a+rabbit+model+of+hypertension.">Development of mild aortic valve stenosis in a rabbit model of hypertension.</a> Journal of the American College of Cardiology. 47 (11), 2303-2309 (2006).</li><li>Marechaux, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+tissue+factor+in+experimental+aortic+valve+sclerosis.">Identification of tissue factor in experimental aortic valve sclerosis.</a> Cardiovascular Pathology. 18 (2), 67-76 (2009).</li><li>Hara, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progression+of+calcific+aortic+valve+sclerosis+in+WHHLMI+rabbits.">Progression of calcific aortic valve sclerosis in WHHLMI rabbits.</a> Atherosclerosis. 273, 8-14 (2018).</li></ol>

The authors have no conflicts of interest to declare with this work.

Animal AVS models are commonly used to study the pathological aspects of AVS, including the initiation and progression of AVS. This protocol introduces a new rabbit AVS model induced by a direct balloon injury to the aortic valve. In this study, the aortic valve injury model showed significant leaflet thickening and calcification. Compared to the mild AVS model induced by dietary supplementation, the aortic valve in the direct balloon injury model was selectively injured, leading to thickened cusps and restricted motion,...

It is increasingly recognized that the use of appropriate animal models can contribute to a better understanding of the pathological mechanisms underlying aortic valve stenosis (AVS) due to the lack of access to reliable sources of diseased human aortic valves associated with the progression of aortic stenosis (AS). Among the various animal models for studying AVS, rabbits are one of the most commonly used large-animal AVS models, and the AVS rabbit model is induced either through cholesterol/vitamin D2 supplementation or genetic manipulation1,2,3,4.
Although rabbit AVS models have provided significant insight into the development and progression of AVS, it still remains challenging to induce AVS consistently and reproducibly, as seen in our preliminary experiments.
In addition to diet-induced and genetically susceptible animal models, a new model of AVS has been established through direct mechanical injury in mice5,6. The mechanical injury model successfully induces aortic stenosis and represents a simple and reproducible AVS model in wild-type mice. To the best of our knowledge, there have been no prior studies examining the effects of a mechanical injury on the aortic valve in rabbit models. Thus, this study provides a new procedure for inducing AVS in male New Zealand white rabbits through a direct balloon injury to the aortic valve, which can accurately mimic the condition of valvular aortic stenosis. This protocol includes step-by-step descriptions of the preparation, the surgical procedure, and the post-operative care, which are useful for inducing reproducible AVS rabbit models.

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			<td>3-0 Silk suture</td>
			<td>AILEE</td>
			<td>SK312</td>
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			<td>4% paraformaldehyde(PFA)</td>
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			<td>IBS-BP031-2</td>
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			<td>Alizarin red Solution</td>
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			<td>ASAHI SION BLUE&#160;</td>
			<td>ASAHI</td>
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			<td>80101-30</td>
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			<td>DID30s</td>
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			<td>Bionet Veterinary monitor</td>
			<td>BIONET</td>
			<td>BM3 VET</td>
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			<td>C-Arm</td>
			<td>SIEMENS Healthcare GmbH</td>
			<td>Cios alpha</td>
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			<td>Certified Rabbit Diet</td>
			<td>Purina</td>
			<td>5322</td>
			<td>4.7% Hydrogenated Coconut Oil, 0.5% Cholesterol, &#38; 1% Molasse</td>
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			<td>Curadle Smart Incubator</td>
			<td>Autoelex</td>
			<td>CS-CV206</td>
			<td>Intensive Care Unit (ICU)</td>
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			<td>Ergocalciferol</td>
			<td>Sigma-aldrich&#160;</td>
			<td>E5750</td>
			<td>Vitamin D2</td>
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			<td>Fechtner conjunctiva forceps titanium</td>
			<td>WORLD PRECISSION Instrument</td>
			<td>WP1820</td>
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			<td>Forceps</td>
			<td>HEBU</td>
			<td>HB203</td>
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			<td>Gentamicin</td>
			<td>Shin Poong</td>
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			<td>Glycopyrrolate&#160;</td>
			<td>SamChunDang</td>
			<td></td>
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			<td>Greenflex NS</td>
			<td>DAI HAN PHARM</td>
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			<td>Normal saline 500 mL</td>
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			<td>Hematoxylin solution</td>
			<td>Sigma-aldrich&#160;</td>
			<td>HT1079-1 SET</td>
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			<td>Heparin</td>
			<td>JW pharmaceutical</td>
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			<td>25,000 U</td>
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			<td>Infusion set for single use</td>
			<td>SWOON MEDICAL</td>
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			<td>Iodine</td>
			<td>Green pharmaceutical</td>
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			<td>Iodixanol</td>
			<td>GE Healthcare</td>
			<td>Visipaque</td>
			<td>Inflation solution (contrast agent)</td>
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			<td>IV catheter 22 G</td>
			<td>BD&#160;</td>
			<td>382423</td>
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			<td>IV catheter 24 G</td>
			<td>BD</td>
			<td>382412</td>
			<td></td>
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			<td>Ketoprofen</td>
			<td>SamChunDang</td>
			<td></td>
			<td></td>
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			<td>Luer-Lok syringe 10 mL</td>
			<td>Becton Dickinson Medical</td>
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			<td>Luer-Lok syringe 3 mL</td>
			<td>Becton Dickinson Medical</td>
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			<td>Microscope</td>
			<td>OLYMPUS</td>
			<td>SZ61</td>
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			<td>Microtome</td>
			<td>ThermoFisher Scientific</td>
			<td>HM 325</td>
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			<td>MT stain kit</td>
			<td>Sigma-aldrich</td>
			<td>HT15-1kt</td>
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			<td>Needel holder</td>
			<td>Solco</td>
			<td>009-1304</td>
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			<td>Needle Holder with Lock and Suture</td>
			<td>JEUNGDO BIO &#38; PLANT</td>
			<td>H-1222-18</td>
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			<td>Paraffin</td>
			<td>LK LABKOREA</td>
			<td>H06-660-107</td>
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			<td>PBS</td>
			<td>Gibco</td>
			<td>10010-023</td>
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			<td>Potassium chloride 40</td>
			<td>Daihan Pharm</td>
			<td></td>
			<td>KCl</td>
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			<td>Prelude Ideal Hydrophilic Sheath</td>
			<td>MERIT MEDICAL</td>
			<td>PID4F11018SS</td>
			<td>Sheath 4F</td>
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			<td>PTA Balloon Dilatation catheter</td>
			<td>Boston Scientific</td>
			<td>H749-3903280208-0</td>
			<td>Balloon catheter 8.0 mm</td>
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			<td>Rompun</td>
			<td>Elanco</td>
			<td></td>
			<td>Xylaxine</td>
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			<td>sterile Gauze</td>
			<td>DAE HAN Medical</td>
			<td></td>
			<td>10 cm x 20 cm&#160;</td>
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			<td>Surgical Gloves</td>
			<td>Ansell</td>
			<td>Ansell</td>
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			<td>Surgical Gown</td>
			<td>Yuhan kimberly</td>
			<td>90002-02</td>
			<td></td>
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			<td>Surgical Scissors</td>
			<td>Nopa, Germany</td>
			<td>AC020/16</td>
			<td></td>
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			<td>Surgical Tape</td>
			<td>3M micopore</td>
			<td>1530-1</td>
			<td></td>
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			<td>Syringe 1 mL</td>
			<td>Shin Chang Medical</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe 10 mL</td>
			<td>Shin Chang Medical</td>
			<td></td>
			<td></td>
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			<td>Tissue cassette</td>
			<td>Scilav korea</td>
			<td>Cas3003</td>
			<td></td>
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			<td>Transducer gel&#160;</td>
			<td>SUNGHEUNG</td>
			<td>SH102</td>
			<td></td>
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			<td>Tridol</td>
			<td>Yuhan Corp.</td>
			<td></td>
			<td>Tramadol HCl</td>
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			<td>Ultrasound system</td>
			<td>Philps</td>
			<td>Affiniti 50</td>
			<td></td>
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		<tr>
			<td>Von Kossa stain kit</td>
			<td>Abcam</td>
			<td>ab105689</td>
			<td></td>
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			<td>Zoletil 50</td>
			<td>Virbac korea</td>
			<td></td>
			<td>Tiletamine &#38; zolazepam</td>
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a rabbit aortic valve stenosis model induced by direct balloon injury

Animal models are emerging as an important tool to understand the pathologic mechanisms underlying aortic valve stenosis (AVS) because of the lack of access to reliable sources of diseased human aortic valves. Among the various animal models, AVS rabbit models are one of the most commonly used in large animal studies. However, traditional AVS rabbit models require a long-term period of dietary supplementation and genetic manipulation to induce significant stenosis in the aortic valve, limiting their use in experimental studies. To address these limitations, a new AVS rabbit model is proposed, in which stenosis is induced by a direct balloon injury to the aortic valve. The present protocol describes a successful technique for inducing AVS in New Zealand white (NZW) rabbits, with step-by-step procedures for the preparation, the surgical procedure, and the post-operative care. This simple and reproducible model offers a promising approach for studying the initiation and progression of AVS and provides a valuable tool for investigating the underlying pathological mechanisms of the disease.

Rabbit AVS model induced by aortic valve injury 
To induce the rabbit AVS model, male NZW rabbits weighing 3.5-4.0 kg were used for this study. According to the surgical procedures described in step 2 (Figure 2), the AVS model was established by aortic valve injury, which resulted in mechanical aortic valve degeneration and calcification. The control group included rabbits fed with a 0.5% cholesterol-enriched diet (high-cholesterol, HC) and 50,000 U of vitamin D2 (VitD2...

Watch this Scientific Journal Video about A Rabbit Aortic Valve Stenosis Model Induced by Direct Balloon Injury at JoVE.com

A Rabbit Aortic Valve Stenosis Model Induced by Direct Balloon Injury

An appropriate animal model is needed to understand the pathologic mechanisms underlying aortic valve stenosis (AVS) and to evaluate the efficacy of therapeutic interventions. The present protocol describes a new procedure for developing the AVS rabbit model via a direct balloon injury in vivo.

Animal models are emerging as an important tool to understand the pathologic mechanisms underlying aortic valve stenosis (AVS) because of the lack of ...

Annual models are emerging as an important tool to understand the pathologic mechanisms underlying aortic valve stenosis because of the lack of access to reliable sources of diseased human aortic valves. Traditional aortic valve stenosis rabbit models require long-term dietary supplementation and genetic manipulation to induce significant stenosis in the aortic valve, limiting their use in experimental studies. This technique describes a new procedure for inducing aortic valve stenosis in rabbits through a direct ballon injury to the aortic valve, which can accurately mimic the condition of a human with aortic stenosis.Demonstrating the procedure will be Eun-Hye Park, Jin-Moo Kim, and Eunmi Lee, research specialists from my regulatory. Begin preparing the dilation balloon catheter set by connecting the in deflation device filled with the one-to-one mixture of saline and commercially available contrast medium to the Luer lock part of the balloon catheter. After filling the balloon with an inflation solution, remove the air from the balloon catheter.Begin the surgery procedure by inserting a 24 gauge intravenous or IV catheter into the marginal auricular vein of the anesthetized rabbit. Connect an infusion set with 100 units per kilogram of heparin heparinized saline. Next, connect the rabbit with a multi-parameter veterinary monitor to continuously monitor the vital signs such as the oxygen saturation signal or SpO2 temperature and blood pressure.After placing the rabbit in a supine position on an operating table equipped with a C-arm fluoroscopy, remove the hair from the ventral neck area using animal hair clippers. Sterilize the incision area with iodine and cover the rabbit with surgical towels. To position the rabbit's heart, turn on the C-arm and select the fluoroscopic mode for cardiac imaging.Adjust the rabbit's position to ensure the heart is at the center of the imaging field. Once the position is adjusted, make a longitudinal incision of approximately three centimeter in the skin of the neck and use surgical scissors to cut the fascia and fat tissue. Then carefully separate the muscles until approximately 3 to 3.5 centimeters of the left common carotid artery, or LCCA, is exposed.Ligate the LCCA with a 3-0 silk suture at the top and end of the exposed LCCA to stop the blood flow. Insert a 22 gauge IV catheter into the LCCA. Then introduce a 0.016 inch guide wire into the left ventricle through the IV catheter, ensuring that the tip of the catheter is properly positioned in the imaging field of the C-arm.Next, withdraw the IV catheter, leaving the guide wire before placing a 4 French sheath over the guide wire into the LCCA to introduce the balloon catheter. Carefully insert the eight millimeter balloon catheter over the guide wire into the aortic valve under C-arm fluoroscopic guidance. Place the balloon catheter tip approximately one to two centimeters distal to the aortic valve and inflate the balloon by purging the inflation solution with a pressure inflator at six atmospheres.Next, advance the balloon into the left ventricle or LV apex and pull it back into the LV outlet. Repeat this procedure five times before deflating the balloon. Withdraw the balloon catheter and guide wire, then slowly remove the sheath from the LCCA and immediately tie the LCCA with the suture on the way down to the aortic valve.Clean the incision area with saline to remove the blood clots. Inspect the punctured site for arterial bleeding before closing the muscle and skin with a 3-0 non-absorbable suture. Once done, sterilize the wound using iodine.After the surgery, remove the monitoring patches and clips and keep the rabbit in an intensive care incubator. After eight weeks of the balloon injury, place the anesthetized rabbit on an echo table in the supine position. Apply ultrasound transducer gel to the chest after shaving the chest area.Adjust the transducer to obtain the peristernal long-axis view and the peristernal short-axis view of the aortic valve. Use mode imaging to record images of the aortic valve and save the images for later analysis. The structural change assessment in the aortic valve revealed that eight weeks after the aortic valve injury, the cusps were thickened and the motion was restricted in the injured rabbits fed with the high cholesterol and vitamin D2 diet compared to the control or wild type rabbits, and the rabbits fed the high cholesterol and vitamin D2 diet without valve injury.The rabbits were sacrificed and the hearts were excised eight weeks after the injury for histological analysis of the aortic valve. The aortic valve stained with Masson's trichrome showed increased thickness of the aortic valve cusps in the injured group compared to the control in high cholesterol and vitamin-D2-diet-induced groups. Alizarin Red staining and Von Kossa staining were performed to compare the degree of valvular calcium deposits indicated negligible calcium deposits in the valvular leaflets in the high cholesterol and vitamin-D2-diet induced group.In contrast, significant calcific deposits were observed in the balloon injured group. Successful technique for inducing arctic valve stenosis, in the rabbit model is demonstrated here with a step-by-step explanation of a direct balloon injury to the aortic valve. This simple and reproducible model offers a promising approach for studying the initiation and progression of aortic valve stenosis, and provides a valuable tool for investigating the underlying pathological mechanisms of aortic valve stenosis.

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842 Görüntüleme.  The Catholic University of Korea. Yıllık modeller, hastalıklı insan aort kapaklarının güvenilir kaynaklarına erişim eksikliği nedeniyle aort kapak darlığının altında yatan patolojik mekanizmaları anlamak için önemli bir araç olarak ortaya çıkmaktadır. Geleneksel aort kapak darlığı tavşan modelleri, aort kapağında önemli darlıkları indüklemek için uzun süreli diyet takviyesi ve genetik manipülasyon gerektirir ve bu da deneysel çalışmalarda kullanımlarını sınırlar. Bu teknik, aort darl...