A Rabbit Aortic Valve Stenosis Model Induced by Direct Balloon Injury

Summary

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.

Abstract

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.

Introduction

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 manipulation^1,2,3,

Protocol

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 conditions in individual cages. The rabbits were fed either a normal diet or a 0.5% cholesterol-enriched diet supplemented with 50,000 U of vitamin D2....

Results

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.......

Discussion

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,.......

Materials

Name	Company	Catalog Number	Comments
3-0 Silk suture	AILEE	SK312
4% paraformaldehyde(PFA)	Intron	IBS-BP031-2
Alizarin red Solution	Millpore	TMS-008-C
ASAHI SION BLUE	ASAHI		Guide wire
Back Table Cover	Yuhan kimberly	80101-30
Balloon In-deflation Device	Demax Medical	DID30s
Bionet Veterinary monitor	BIONET	BM3 VET
C-Arm	SIEMENS Healthcare GmbH	Cios alpha
Certified Rabbit Diet	Purina	5322	4.7% Hydrogenated Coconut Oil, 0.5% Cholesterol, & 1% Molasse
Curadle Smart Incubator	Autoelex	CS-CV206	Intensive Care Unit (ICU)
Ergocalciferol	Sigma-aldrich	E5750	Vitamin D2
Fechtner conjunctiva forceps titanium	WORLD PRECISSION Instrument	WP1820
Forceps	HEBU	HB203
Gentamicin	Shin Poong
Glycopyrrolate	SamChunDang
Greenflex NS	DAI HAN PHARM		Normal saline 500 mL
Hematoxylin solution	Sigma-aldrich	HT1079-1 SET
Heparin	JW pharmaceutical		25,000 U
Infusion set for single use	SWOON MEDICAL
Iodine	Green pharmaceutical
Iodixanol	GE Healthcare	Visipaque	Inflation solution (contrast agent)
IV catheter 22 G	BD	382423
IV catheter 24 G	BD	382412
Ketoprofen	SamChunDang
Luer-Lok syringe 10 mL	Becton Dickinson Medical
Luer-Lok syringe 3 mL	Becton Dickinson Medical
Microscope	OLYMPUS	SZ61
Microtome	ThermoFisher Scientific	HM 325
MT stain kit	Sigma-aldrich	HT15-1kt
Needel holder	Solco	009-1304
Needle Holder with Lock and Suture	JEUNGDO BIO & PLANT	H-1222-18
Paraffin	LK LABKOREA	H06-660-107
PBS	Gibco	10010-023
Potassium chloride 40	Daihan Pharm		KCl
Prelude Ideal Hydrophilic Sheath	MERIT MEDICAL	PID4F11018SS	Sheath 4F
PTA Balloon Dilatation catheter	Boston Scientific	H749-3903280208-0	Balloon catheter 8.0 mm
Rompun	Elanco		Xylaxine
sterile Gauze	DAE HAN Medical		10 cm x 20 cm
Surgical Gloves	Ansell	Ansell
Surgical Gown	Yuhan kimberly	90002-02
Surgical Scissors	Nopa, Germany	AC020/16
Surgical Tape	3M micopore	1530-1
Syringe 1 mL	Shin Chang Medical
Syringe 10 mL	Shin Chang Medical
Tissue cassette	Scilav korea	Cas3003
Transducer gel	SUNGHEUNG	SH102
Tridol	Yuhan Corp.		Tramadol HCl
Ultrasound system	Philps	Affiniti 50
Von Kossa stain kit	Abcam	ab105689
Zoletil 50	Virbac korea		Tiletamine & zolazepam