Morita K, Kurosawa H, Nomura K, Ko Y, Hanai M, Kawada N, Matsumura Y, Inoue T
Department of Cardiovascular Surgery, Jikei University School of Medicine, 3-25-8 Nishi-Shinbashi, Minato-ku, Tokyo 102-8461, Japan.
Jpn J Thorac Cardiovasc Surg. 2001 Apr;49(4):207-15. doi: 10.1007/BF02913517.
We conducted an acute experimental study to test the feasibility of dynamic cardiomyoplasty in a setting of modified Fontan procedure for univentricular heart with pulmonary hypertension to obtain a possible proxy for high-risk Fontan candidates.
After electrical preconditioning of the left latissimuss dorsi for 6 weeks in 8 dogs, the right ventricular cavity was totally obliterated with concomittent closure of the tricuspid valve and right pulmonary artery. Modified Fontan circulation was established with the aortic homograft anastomosed between the right atrium and pulmonary trunk, incorporated with a pericardial pouch as a compression chamber (neoright ventricle) fixed onto the epicardial surface of the ventricle. After cardiopulmonary bypass termination, a latissimus dorsi was applied to wrap the pericardial pouch and ventricle clockwise and stimulated with a trained-pulse (25 Hz) at 1:1 synchronization ratio with cardiac beats.
Profound right heart failure was noted during Fontan circulation in increased pulmonary vascular resistance (11 +/- 3.2 Wood units), whereas graft pacing showed significant augmentation of systolic pulmonary pressure by 54 +/- 12%, the mean pulmonary flow by 68 +/- 23%, and aortic pressure by 23 +/- 5% at a physiological range of central venous pressure (13.2 +/- 0.7 mmHg). Right heart function curve analysis confirmed marked augmentation of right heart performance, restoring almost normal pulmonary circulation. These functional benefits were sustained up to 4 hours in 4 animals until experiments were terminated.
Dynamic cardiomyoplasty in a modified Fontan procedure is a viable surgical option for univentricular heart, not a Fontan candidate.
我们进行了一项急性实验研究，以测试在伴有肺动脉高压的单心室心脏改良Fontan手术中动态心肌成形术的可行性，从而为高危Fontan手术候选者找到一种可能的替代方法。
对8只犬的左背阔肌进行6周的电预处理后，完全闭塞右心室腔，同时关闭三尖瓣和右肺动脉。通过将主动脉同种异体移植物吻合在右心房和肺动脉干之间建立改良Fontan循环，并结合一个心包袋作为压缩腔（新右心室），固定在心室的心外膜表面。体外循环结束后，应用背阔肌顺时针包裹心包袋和心室，并以1:1的同步比与心跳同步，用训练脉冲（25Hz）刺激。
在Fontan循环期间，肺动脉血管阻力增加（11±3.2伍德单位），出现严重的右心衰竭，而在中心静脉压的生理范围内（13.2±0.7mmHg），移植物起搏显示收缩期肺动脉压显著增加54±12%，平均肺血流量增加68±23%，主动脉压增加23±5%。右心功能曲线分析证实右心功能显著增强，恢复了几乎正常的肺循环。这些功能益处持续了4小时，在4只动物中直至实验结束。
改良Fontan手术中的动态心肌成形术对于单心室心脏、非Fontan手术候选者是一种可行的手术选择。
