Elefteriades John, Lovoulos Costantinos, Edwards Randolph, Tittle Shawn, Riley Timothy, Tang Paul, Rocco Edward, Kopf Gary
Section of Cardiothoracic Surgery, Yale University School of Medicine, New Haven, CT 06510, USA.
J Thorac Cardiovasc Surg. 2003 Jun;125(6):1283-90. doi: 10.1016/s0022-5223(02)73617-9.
Our prior laboratory work has permitted adding a whole donor heart to a preserved recipient right heart, producing a heart-and-a-half preparation able to cope with pulmonary hypertension in the recipient. The experiments in the present study explore the feasibility of the converse operation: adding an isolated donor right heart to an entire preserved heart.
Eight adult mongrel dogs (4 donors and 4 recipients) were used in 4 transplant operations performed through a right thoracotomy without cardiopulmonary bypass (using side-biting control of recipient vessels). The donor heart underwent resection of the left atrium and left ventricle, leaving an isolated donor right heart. Blood supply to the donor right ventricle was preserved from the donor ascending aorta. Through a right thoracotomy, the donor right heart was transplanted in parallel to the native right heart of the recipient by using the following anastomoses: (1) donor superior vena cava to recipient superior vena cava (end-to-side anastomosis); (2) donor pulmonary artery to recipient pulmonary artery (end-to-side anastomosis); (3) donor ascending aorta to recipient aorta (through a great vessel [end-to-end anastomosis] to provide arterial inflow to donor coronary arteries). Animals were euthanized within 1 hour after completion of transplantation.
Isolation of the right ventricle by excision of the left chambers was technically feasible. Transplantation without cardiopulmonary bypass was feasible in all cases. The isolated right heart beat well after transplantation in all animals, demonstrating sinus rhythm. Three of 4 animals were able to sustain good hemodynamics on support with epinephrine. Bleeding from the septum or aortic valve of the donor (now open to the pericardial space) was not problematic. Mean arterial pressure was 85 mm Hg (mean) at a right atrial pressure of 6 mm Hg (mean). In 2 animals the recipient superior vena cava was ligated to obligate upper body flow to pass through the accessory ventricle; hemodynamics were preserved under these circumstances.
Transplantation of an isolated right heart is feasible. Such a technique has potential as a novel therapeutic alternative for obstructive or hypoplastic lesions of the right heart in human children.
我们之前的实验室工作已实现将一个完整的供体心脏与保存的受体右心相连，构建出一个半心结构，能够应对受体的肺动脉高压。本研究中的实验探讨了相反操作的可行性：将一个孤立的供体右心添加到一个完整的保存心脏上。
八只成年杂种犬（4只供体和4只受体）用于4例经右胸切口进行的移植手术，无需体外循环（采用侧咬钳控制受体血管）。供体心脏切除左心房和左心室，留下一个孤立的供体右心。供体右心室的血液供应由供体升主动脉保留。通过右胸切口，将供体右心与受体的天然右心并行移植，采用以下吻合方式：（1）供体上腔静脉与受体上腔静脉（端侧吻合）；（2）供体肺动脉与受体肺动脉（端侧吻合）；（3）供体升主动脉与受体主动脉（通过一根大血管[端端吻合]为供体冠状动脉提供动脉流入）。动物在移植完成后1小时内安乐死。
通过切除左心室来分离右心室在技术上是可行的。所有病例中无需体外循环进行移植都是可行的。所有动物移植后孤立的右心搏动良好，显示窦性心律。4只动物中有3只在肾上腺素支持下能够维持良好的血流动力学。供体（现暴露于心包腔）的隔膜或主动脉瓣出血不成问题。平均动脉压为85毫米汞柱（平均），右心房压力为6毫米汞柱（平均）。在2只动物中，受体上腔静脉被结扎，迫使上半身血流通过辅助心室；在这些情况下血流动力学得以维持。
孤立右心的移植是可行的。这种技术作为一种针对人类儿童右心梗阻性或发育不全性病变的新型治疗选择具有潜力。
