Surgery Involving the Heart
1. The heart-lung machine (pump-oxygenator1) is a valuable addition to the modern operating room. This machine has made it possible to perform many operations on the heart and other thoracic organs which could not otherwise be done. There are several types of machines in use, all of which serve as2 a temporary substitute for3 the patient’s heart and lungs.
2. The machine siphons off4 the blood from the large vessels entering the heart on the right side so that no blood passes through the heart and lungs. The blood is returned to the general circulation for body distribution through one of the large arteries. While passing through the machine, the blood is oxygenated by means of5 an oxygen inlet, and carbon dioxide6 is removed by various chemical means. These are the processes that normally take place between the blood and the air in the lung tissue. While in the machine, the blood is also “defoamed” to be sure that all air bubbles are removed, since such bubbles could be fatal to the patient by obstructing blood vessels. An electric motor in the machine serves as a pump during the surgical procedure to distribute the processed blood throughout the body by means of the artery mentioned above.
3. Diseased valves may become deformed and scarred from endocarditis so that they are ineffective and often obstructive. In some cases a special small knife can be inserted into the heart chamber and the valve can be cut so that it no longer obstructs the blood flow. The valve may even become partially functional. In other cases there may be so much damage that replacement is the only resort. Substitute valves made of7 plastic materials have proved to be a lifesaving measure for many patients. Very thin butterfly valves made of dacron or other synthetic material have also been successfully used.
4. Artificial hearts or parts of hearts designed to assist the ventricles in their pumping function have not proved as successful as the artificial valves. However, research continues and it is quite possible that an effective device may soon be ready for use. More spectacular is the transplantation of a human heart from the body of a person who has recently died. Tissues of the donor and the recipient should be as closely matched as possible to avoid rejection by the recipient’s antibody mechanism. This rejection syndrome is the most serious problem related to heart transplants.
词汇：
thoracic 胸的，胸廓的 endocarditis .心内膜炎
artery 动脉 valve 瓣，瓣膜 oxygenate 氧合，充氧
dacron 漆纶 inlet .进入，入口;插入物
synthetic 合成的 defoam 去除……的泡沫
ventricle 室，心室 bubble 水泡，气泡
recipient 接受者 obstruct 阻塞，堵塞 antibody 抗体
注释：
1.pump-oxygenator：氧合气泵
2.serve as：充当，作为
3.substitute for：代替，替换
4.siphon off：吮吸出
5.by means of：用，依靠
6.carbon dioxide：二氧化碳
7.made of：由……制成的
请注意下面两个词组的区别：
be made of：由……材料制成(只是经过物理变化)
be made from：由……原料制成(需要经过化学变化)
例如：The bridge is made of steel.这座桥是用钢材造的。
Steel is made from iron.钢是由铁炼成的。
练习：
1.Paragraph 1 ______
2.Paragraph 2 ______
3.Paragraph 3 ______
4.Paragraph 4 ______
A The Heart Transplantation
B How the Heart-lung Machine Works
C A Machine Making Many Kinds of Thoracic Operations Possible
D A Temporary Substitute for the Diseased Valve
E Operations on Cardiac Valves and Substitutes for Valves
F How Every Part of the Heart Performs Its Function
5.The blood is oxygenated and carbon dioxide in it is removed ______.
6.The heart-lung machine is an essential helper for surgeons ______.
7.Endocarditis may cause valves to be damaged ______.
8.It is extremely important in heart transplantation ______.
A and finally they fail to function properly
B to perform many surgical operations on the chest
C when it passes through the heart-lung machine
D and they no longer obstruct the blood flow
E to match tissues of the donor and the recipient
F when the ineffective valves are replaced by artificial ones
答案与题解：
1.C本题答案主要在第一段第二句，该句说到没有人工心肺机许多胸外科手术就无法做。
2.B第二段详细叙述了人工心肺机的工作原理，它是如何在手术期间代替心脏的功能的。
3.E第三段讲述了缺损瓣膜的手术及其代用品。
4.A第四段主要讲心脏移植及其代用品。
5.C此问题的答案在第二段第三句，该句说的就是血液在通过人工心肺机时得以充氧并将二氧化碳排出。
6.B本题是根据第一段前两句得出的结论，它是胸外科医生必不可少的助手。
7.A第三段第一句讲的就是本题的意思。
8.E文章最后两句说组织匹配是为了避免排异反应，故它是心脏移植中最重要的事情。
译文：心脏手术
心肺机(氧合气泵)是现代化手术室中的医生必不可少的助手。如果没有人工心肺机，许多胸外科手术就无法进行。现在使用的心肺机有若干类型，它们都是暂时替代病人的心肺起作用。
心肺机将从右侧进入心脏的大血管中的血液抽出，使得没有血液流经心肺。血液又通过一根大动脉返还到整个循环当中，供身体分配。血液通过机器时经由氧气入口得以充氧，又通过各种化学方法清除二氧化碳。这就是肺组织里血液和空气之间正常发生的过程。而在机器里，血液也要被去除泡沫，以确定所有气泡都被清除，原因在于气泡会阻塞血管，对病人造成致命危险。在手术过程中，机器内的电动机充当气泵，将加工后的血液通过上述方式经动脉分送到全身。
瓣膜出了问题表现为外形受损以及由于心内膜炎而出现伤痕，从而 不能有效工作，常常产生堵塞。一些病例采用的方法是将一把专门的小刀插入心室，切割瓣膜使其不再堵塞血液流动。瓣膜甚至还能起一定作用。在其他病例当中，瓣膜严重受损，唯一可行的办法就是替换。对于众多患者，由塑料材料制成的替代瓣膜这一措施已证明能够救生。由涤纶或其他合成材料制成的超薄蝴蝶瓣膜也得以成功应用。
旨在帮助心室抽吸功能的人工心脏或心脏部件证明不如人工瓣膜有效。但是，研究工作还在继续，一种有效的装置极有可能很快投入使用。更惊人的方法是，移植刚刚逝去的人的心脏。捐献者与接受移植者的组织应尽可能匹配，以避免接受者抗体机制的排异反应。这种排异反应正是心脏移植中最重要的事情。
