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.
詞匯：
thoracic 胸的，胸廓的 endocarditis .心內(nèi)膜炎
artery 動脈 valve 瓣，瓣膜 oxygenate 氧合，充氧
dacron 漆綸 inlet .進(jìn)入，入口;插入物
synthetic 合成的 defoam 去除……的泡沫
ventricle 室，心室 bubble 水泡，氣泡
recipient 接受者 obstruct 阻塞，堵塞 antibody 抗體
注釋：
1.pump-oxygenator：氧合氣泵
2.serve as：充當(dāng)，作為
3.substitute for：代替，替換
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
請注意下面兩個詞組的區(qū)別：
be made of：由……材料制成(只是經(jīng)過物理變化)
be made from：由……原料制成(需要經(jīng)過化學(xué)變化)
例如：The bridge is made of steel.這座橋是用鋼材造的。
Steel is made from iron.鋼是由鐵煉成的。
練習(xí)：
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
答案與題解：
1.C本題答案主要在第一段第二句，該句說到?jīng)]有人工心肺機(jī)許多胸外科手術(shù)就無法做。
2.B第二段詳細(xì)敘述了人工心肺機(jī)的工作原理，它是如何在手術(shù)期間代替心臟的功能的。
3.E第三段講述了缺損瓣膜的手術(shù)及其代用品。
4.A第四段主要講心臟移植及其代用品。
5.C此問題的答案在第二段第三句，該句說的就是血液在通過人工心肺機(jī)時得以充氧并將二氧化碳排出。
6.B本題是根據(jù)第一段前兩句得出的結(jié)論，它是胸外科醫(yī)生必不可少的助手。
7.A第三段第一句講的就是本題的意思。
8.E文章最后兩句說組織匹配是為了避免排異反應(yīng)，故它是心臟移植中最重要的事情。
譯文：心臟手術(shù)
心肺機(jī)(氧合氣泵)是現(xiàn)代化手術(shù)室中的醫(yī)生必不可少的助手。如果沒有人工心肺機(jī)，許多胸外科手術(shù)就無法進(jìn)行�，F(xiàn)在使用的心肺機(jī)有若干類型，它們都是暫時替代病人的心肺起作用。
心肺機(jī)將從右側(cè)進(jìn)入心臟的大血管中的血液抽出，使得沒有血液流經(jīng)心肺。血液又通過一根大動脈返還到整個循環(huán)當(dāng)中，供身體分配。血液通過機(jī)器時經(jīng)由氧氣入口得以充氧，又通過各種化學(xué)方法清除二氧化碳。這就是肺組織里血液和空氣之間正常發(fā)生的過程。而在機(jī)器里，血液也要被去除泡沫，以確定所有氣泡都被清除，原因在于氣泡會阻塞血管，對病人造成致命危險(xiǎn)。在手術(shù)過程中，機(jī)器內(nèi)的電動機(jī)充當(dāng)氣泵，將加工后的血液通過上述方式經(jīng)動脈分送到全身。
瓣膜出了問題表現(xiàn)為外形受損以及由于心內(nèi)膜炎而出現(xiàn)傷痕，從而 不能有效工作，常常產(chǎn)生堵塞。一些病例采用的方法是將一把專門的小刀插入心室，切割瓣膜使其不再堵塞血液流動。瓣膜甚至還能起一定作用。在其他病例當(dāng)中，瓣膜嚴(yán)重受損，唯一可行的辦法就是替換。對于眾多患者，由塑料材料制成的替代瓣膜這一措施已證明能夠救生。由滌綸或其他合成材料制成的超薄蝴蝶瓣膜也得以成功應(yīng)用。
旨在幫助心室抽吸功能的人工心臟或心臟部件證明不如人工瓣膜有效。但是，研究工作還在繼續(xù)，一種有效的裝置極有可能很快投入使用。更驚人的方法是，移植剛剛逝去的人的心臟。捐獻(xiàn)者與接受移植者的組織應(yīng)盡可能匹配，以避免接受者抗體機(jī)制的排異反應(yīng)。這種排異反應(yīng)正是心臟移植中最重要的事情。
