Introduction

Symptomatic mitral regurgitation (MR) is associated with high morbidity and mortality which can be ameliorated by surgical valve replacement or repair. Despite this, many patients are excluded from surgery. Transcatheter mitral repair and replacement has emerged as a promising therapeutic option for the treatment of severe MR. The majority of these procedures rely on high definition three dimensional (3D) transesophageal echocardiographic (TEE) real time imaging. The sheep model is the model of choice for preclinical studies of transcatheter mitral valve (MV) replacement and repair. However due to the thoracic conformation TEE studies in those animals are suboptimal.

Methods and Results

In this study we tested and compared the feasibility of conventional TEE and newly described transpericardial 3D echocardiography (TPE) for assessment of the MV as a tool to plan and possibly guide transcatheter/transapical procedures in the sheep model. The conventional TEE was challenging and produced incomplete data in all of the animals. In contrast, the TPE method clearly depicted the left atria and ventricle, MV apparatus, LVOT, aortic valve and proximal ascending aorta facilitating high resolution 3D rendering in all of the animals.

Conclusion

The value of TEE in the sheep model is limited and could not be reliable for complete assessment of the LV and mitral valve apparatus. Whereas, TPE produce reliable and similar imaging to TEE in the human patients which could allow animal testing of devices designed to be delivered in humans.

中文翻译：

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绵羊模型中的经心包 3D 超声心动图，促进实时解剖评估以规划和指导经导管二尖瓣置换和修复

介绍

有症状的二尖瓣关闭不全 (MR) 与高发病率和死亡率相关，可以通过手术瓣膜置换或修复来改善。尽管如此，仍有许多患者被排除在手术之外。经导管二尖瓣修复和置换已成为治疗严重 MR 的一种有前景的治疗选择。大多数这些程序依赖于高清三维 (3D) 经食道超声心动图 (TEE) 实时成像。绵羊模型是经导管二尖瓣 (MV) 置换和修复临床前研究的首选模型。然而，由于这些动物的胸部构象 TEE 研究并不理想。

方法和结果

在这项研究中，我们测试并比较了传统 TEE 和新描述的经心包 3D 超声心动图 (TPE) 评估 MV 作为规划和可能指导绵羊模型中经导管/经心尖手术的工具的可行性。传统的 TEE 具有挑战性，并且在所有动物中产生的数据不完整。相比之下，TPE 方法清楚地描绘了左心房和心室、MV 装置、LVOT、主动脉瓣和近端升主动脉，促进了所有动物的高分辨率 3D 渲染。

结论

绵羊模型中 TEE 的值是有限的，对于 LV 和二尖瓣装置的完整评估是不可靠的。然而，TPE 在人类患者中产生与 TEE 相似的可靠成像，这可以允许对设计用于人体的设备进行动物测试。