犬左室乳头肌的导管超声消融

背景：近年来的研究表明左室乳头肌在室性心律失常的发生中起到了重要的作用。目的：在经胸超声图像监控下，观察自制的超声消融导管消融动物左室乳头肌的可行性和安全性。方法：普通杂种犬9只，随机分为2组：对照组3只，消融组6只。3％戊巴比妥钠麻醉后于无菌条件下分离其颈动脉并置入8F动脉鞘管，行机械通气并记录体表心电图，导管在经胸超声的引导下达到左心室腔，通过经胸超声图像调整导管与乳头肌的贴靠关系，保持导管与乳头肌贴靠良好，随后以声强50W／cm2、时间60s消融左室乳头肌。结果与结论：所有动物在观察期内均正常存活，乳头肌等解剖结构经胸超声图像显示清楚，并能通过经胸超声图像明确导管与乳头肌的相对位置及贴靠情况，切开动物心肌后，大体可见乳头肌内消融灶与周围正常心肌组织界限清晰，中央区呈白色，绕以淡红色的周边区。光镜下见消融灶与周边组织界线分明，灶内心肌细胞坏死，细胞间隙增宽，大量红细胞浸润。无附壁血栓、心肌灼伤及穿孔和心脏破裂等手术相关并发症。可见在经胸超声的实时监控下，能够实现导管对乳头肌深部组织安全有效的消融。

Left ventricular papillary muscle ablation in canines by ultrasound ablation catheter

BACKGROUND： Studies in recent years have found that the left ventricular papUlary muscle plays an important role in ventricular arrhythmia. OBJECTIVE： To observe the feasibility and safety of homemade ultrasound ablation catheter in animal left ventricular papillary muscle ablation with transthoracic echocardiography.METHODS： Nine ordinary mongrel dogs were collected and divided into two groups： control group （n=3） and ablation group （n=6）. The carotid artery was separated with 3% pentobarbital sodium under sterile conditions, and implanted into the 8F arterial sheath was into to perform the mechanical ventilation, then the surface electrocardiogram was recorded. The abutting relationship between the catheter and papillary muscle was adjusted with transthoracic echocardiography image in order to keep the excellent contact between the catheter and papillary muscle. Then, 50 W/cm2 acoustic intensity was applied to ablate the papillary muscle for 60 seconds. RESULTS AND CONCLUSION： All the animals were normally survived during the observation period, the anatomical structure of papillary muscle was clearly displayed on the transthoracic echocardiography image, and the relative position and abutting relationship between catheter and papillary muscle could be confirmed with the transthoracic echocardiography image. After cutting the animal myocardium, the ablation lesions in the papillary muscle could be seen, which was white in central and light red around and a clear boundary with the surrounding normal myocardium. The clear boundary between ablation lesions and the surrounding tissues could be seen under light microscope, and many necrotic cardiomyocytes were observed in the ablation lesion which space was increased and infiltrated with red blood cells. No associated complications of ablation （such as thromboembolism, myocardial burned or perforation and cardiac rupture） were detected. The catheter could achieve the ablation of deep papillary muscle effectively and safely by transthoracic echocardiography real-time monitoring.