Preliminary Outcome of a Novel Edge-to-Edge Closure Device to Manage Mitral Regurgitation in Dogs.

Bo Liu,Liujun Jia,Stacey B Leach,Wenzhi Pan,Xueying Zhou,Fangyu Zheng,Jing Li

doi:10.3389/fvets.2020.597879

Abstract

Background: Veterinary management of mitral valve regurgitation due to mxyomatous valve disease in dogs is limited to medical treatments, which only postpones the onset of congestive heart failure or alleviates clinical symptoms. Most surgical procedures to manage this condition in humans require cardiopulmonary bypass and have a high risk of complications.Animals: Eight dogs with naturally occurring mitral valve regurgitation.Methods: Prospective observational study. All dogs were treated with a novel edge-to-edge transcatheter device named ValveClamp. The total surgical procedural time and total catheterization time were recorded. Echocardiographic variables measured pre- and post-procedure were compared using Wilcoxin-signed rank test with a P < 0.05 considered significant. Data were expressed as median and interquartile range and absolute numbers and percentages.Results: The procedural success rate was 100% and all the dogs survived without complications. The median (interquartile range) total surgical procedural time was 86.5 (76–96.2) minutes and catheterization time was 23.5 (22–33.8) minutes. Echocardiography revealed a significant reduction in mitral regurgitation severity in all dogs following the procedure based on both a reduced mitral regurgitant maximum jet area (P = 0.012) and a reduced mitral regurgitant maximum jet area to left atrial area (P = 0.018).Conclusion: The ValveClamp device is effective at reducing the severity of mitral regurgitation in dogs with naturally occurring myxomatous valve disease.

Highlights

Myxomatous mitral valve disease (MMVD) is the most common cardiac disease in dogs, primarily affecting small breeds [1]
Dogs were selected for the study based on the presence of a left apical systolic heart murmur heard on auscultation and mitral regurgitation confirmed by echocardiography
Semiquantification of mitral regurgitation severity was performed at baseline and post-operatively using color-flow Doppler to determine the ratio of the mitral regurgitant maximum jet area (MRA) to left atrial area (LAA), with regurgitation considered trace if the MRA/LAA was 5% and 20% and 50%

Summary

Introduction

Myxomatous mitral valve disease (MMVD) is the most common cardiac disease in dogs, primarily affecting small breeds [1]. The standard care for this disease is primarily medical therapy, while surgical treatment is performed in a minority of dogs [2]. Medical therapy postpones the onset of congestive heart failure (CHF), and increases the survival time once CHF develops. One of the standard treatments for MMVD is surgical mitral valve repair via thoracic surgery. Given the risk associated with surgical repair and cardiopulmonary bypass, novel less invasive catheterization techniques are emerging [9,10,11]. Veterinary management of mitral valve regurgitation due to mxyomatous valve disease in dogs is limited to medical treatments, which only postpones the onset of congestive heart failure or alleviates clinical symptoms. Most surgical procedures to manage this condition in humans require cardiopulmonary bypass and have a high risk of complications.

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