Medical research; Surgery for heart disease, part 2

The following program is produced by the University of Michigan broadcasting service under a grant of aid from the National Educational Television and Radio Center in cooperation with the National Association of educational broadcasters surgery for heart disease. The second program of three parts from the series. Human behavior social and medical research produced by the University of Michigan Broadcasting Service. These programs have been developed from interviews with men and women who have the too often unglamorous job of basic research. Research in medicine the physical sciences social sciences and the behavioral sciences. Occasionally you will hear what may seem like a strange or unfamiliar salve. These are the sounds of the participants office his laboratory or his clinic where the interviews were first conducted. The people you will hear today are Dr. Denton Cooley of Baylor University's Medical School and Dr. W. C. C. Lee of Duke University's medical school. While research

on various heart defects continue with the ultimate hope of prevention and cure research also continues on surgical techniques in order to further improve the chances of giving a patient a longer lifespan after surgery. This could be labeled corrective heart disease research. In order to establish where we now stand in this area I asked Dr. Denton Cooley what the present surgical trends were probably the most important trend in present day surgical techniques. Is the trend toward a direct approach to the lesion or the problem at hand. This would imply therefore that surgeons are discarding certain indirect. Techniques of coping with lesions arterial disease is a very good example of this. Up until the past five years a good many they are tears

Chronic a clue civilization's or chronic and treated. Palliative measures for example if there is an adequate circulation in the lower extremities a sympathetic me would be ignoring the occlusion itself as a lesion. If there was an aneurism present the operation reinforcing the wall of that aneurism would be the door trying to prevent it from rupturing by introducing something in conditions we attack the lesion directly we remove the occlusion or move the aneurism and then do some reconstructive procedure with a new vessel. And this is just the trend at present in all phases of surgery and cardiac surgery. Also where attacking the lesion it's

15 years ago. The operation of the blue baby was the. Revolutionary in cardiac surgery but the disadvantage was it was an indirect approach rather than trying to correct the intra cardiac lesions which make a patient blue effort was to stay away from the lesion and to counteract some of the secondary effects and therefore provide more circulation into the lungs by introducing another blood vessel into the lungs. This operation therefore introduced another abnormalities simulating a doctor's arterial in an effort to correct a Sandow says but not to correct the cardiac defect so therefore this was an indirect operation. Now they with the advent of open heart surgery the effort is to

correct the lesion and thereby correct not only the second but to have a totally corrected amount and this trend is present in many areas in cardiovascular surgery recently. Dr. COOLEY also speculated on the future of heart surgery. We say that we have progressed as far as we could with certain of the cardiac procedures. The question is what future trends will we witness. It's difficult of course to predict the future but I think that we have one aspect which seems fairly clear at this time and during the past four five years we have witnessed a remarkable advance in surgery the development of the mechanical heart lung

for the first time has permitted surgeons to explore beating human heart and correct various lesions on the Darrick vision. And this of course is revolution as the entire field of cardiac surgery. You know as in most new techniques the methods have been rather cumbersome and remain extremely complicated in order to do open heart surgery. Most techniques it requires are a large number of personnel a lot. Mechanical equipment and an awful lot of blood transfusion. If this project is to be extended and expanded to apply it to other forms of heart disease which are perhaps more prevalent than the ones we're treating then we're going to have to simplify the

project. Simplification of the mechanical heart lung is a definite possibility and if we can minute that it would be a welcome addition. Personally I believe that the future in heart surgery simplification whatever means possible a trend will be toward reducing the metabolic needs of the patient during surgery and reducing the burden or the workload placed on the mechanical heart. If this can be done by lowering body temperature that's one thing but one area which is not been completely explored is the use of pharmacologic agents which would reduce the metabolism and sametime. Make it possible to do open heart surgery with a minimal amount of artificial circulation and make it possible to

simplify even further the apparatus needed. Perhaps we should they develop a means of completely suspending. Metabolism if you will. Even in the central nervous system maybe this will permit us 30 minutes to an hour and which to operate under those circumstances we had not only no need for any seizure but no need for a mechanical heart lungs or any other supportive device one could simply operate upon a patient in this suspended state and do whatever he wished and then repair the organ or replace organ and have it. Useful to have a successful result. Of course the other important trend in surgery will be the development methods of homo transplantation.

It is a method of grafting organs from one individual to another. At present graphs are being done in very isolated instances. They have been successful grass for example kidney is from one identical twin to the other with what appears to be a successful take. But this of course will not be the ultimate answer in the problem of homo transplantation. What we hope to do is to understand better the foreign protein reactions which occur in home or transplanted tissue and prevent those reactions from causing the death of the transplanted organ. And I believe that this problem will be solved in the next five years.

It seems there are at least two future trends. One suggested by Dr. Cooley and the other suggested by last week's program one transplantation of one organ to another. We have left for next week's program the other. Hypothermia is today's discussion. Hypothermia like the heart lung machine is a reality. Dr. Will Seeley of Duke University told me how hypothermia and the heart lung machine are used in heart surgery. But the next few moments we hear part of the original interview with Dr. Seeley we use a combination of low body to. Combine with the heart lung machine. This. Technique. It was originated in our clinic. And has been carried on to the point that we are now able

to. Incorporate in the heart lung machine a heat exchanger that. Has a c. That makes it easy for us to regulate the body temp. With this latter device we lower the body temp with an extra cup or system level it and hold it at the desired temp while we are isolating the heart and lung from the cycle and then carry out a cardiac operation. And after this is finished then with a heart lung machine still running we are able to bring the body temp back up to a normal range. This. Technique. Does not for a long. Time need fall.

Thanks for fusion. It has a tremendous advantage in allowing us to use a simple oxygenate and a simple pump which. Reduces the amount of blood that has to be used to prime this pump and. Makes the entire operation much simpler and much less expensive than the conventional type of heart lung machine. Well you have given then two or three reasons why you use this reduce body temperature or hypothermia. Are there other advantages over the. Machine itself. Well of course. They probably the main reason for using hypothermia is that it is our only method of reducing the metabolism of the body

to such a point that only a very small amount of oxygen is needed in order to maintain Babeland and life. This technique has the advantage of being easy or easily reversible and these processes can in fact be slowed down or speeded up. Depending entirely on the body temperature. If one then reduces the. Temperature of the body and the cells to the point that they need very little oxygen then one has to supply very little oxygen to them. In addition if one has a very complicated type of condition to correct it is possible to obtain a field that is absolutely bloodless by cutting off the heart lung machine for a period of time. Due to the fact that the body at low temp. Cans of

by and the folk instead of a period of time without oxygen. What level do you reduce the temperature to. They bought it to do is reduce. The levels for various procedures for simple operations such as the closure of a defect between the two. Atri are they receiving chambers of the heart. We would use temperatures of 28 to 30. Degrees Centigrade which would be roughly 85 88 degrees Fahrenheit. The reason for this procedure can be done in 10 to 15 minutes. And we do not anticipate a long pumping period and therefore do not have to use low temperatures. If we do a more complicated operation such as one for a baby to talent to follow we may reduce attempt to down to 10 or 15 degrees centigrade which would be

down in the region of 40 or 50 degrees Fahrenheit. At such temperate yours we can reduce the amount of blood that we have to pump into the patient down to one fourth or one fifth of the patients. Need to Know More About attempt to go and if they do you think it is so complicated that it is necessary to have a very dry feel it is possible to cut off for long periods of time. By this I mean for periods of 5 to 15 minutes. We know from our laboratory experience that laboratory animals will tolerate a complete standstill at these temperatures for as long as one hour. Of course it is never necessary to subject a patient to this but this gives us an indication of this safety and of the limits of this technique. The question of course comes up whether Why should we prefer to reduce the

flow rate to such a degree as this. It is virtually impossible to make the haut a bloodless organ when one has circulation going. Anywhere in the body. There are communications between the. Love songs and the main artery is where the confusion is being carried out that allows blood to leak placed into the lungs and then back into the left side of the heart and into the hopper to feel in certain types of heart disease this insane types of thought as easy as communications may be very large. And even though the blood coming into the heart to the great veins has been obstructed there may be a tremendous amount of blood that collects in the heart in the area where the delicate part of the operation is being carried out. It is. The way. It is this point that sometimes leads to

serious complications and makes the operation that's effective than it should be and they are many times when it is necessary to have a nearby Ellis field in order to do it. You know you have indicated. How long can the patient be left in this subnormal position of reduced body temperature. A patient can be left in a very low body temperature for a long period of time providing that there is some psychic lation supplied to the patient where the next to coral pump oxygenated. One mushroom one must remember that. The. Need for oxygen is markedly reduced but is still present and one has to supply a certain amount of oxygen to the individual. If one keeps them at this low

temperature for a long period of time it is possible to have periods of secular to a standstill for 10 15 to 20 minutes with perfect safety because as enough oxygen available to. Supply the individual for that period of time one also has to have a pump oxygenated system available when one uses temp goes down below 20 degrees sauna grade for at these temperatures a hot action becomes ineffective and the patient's heart is unable to maintain his own cycle lation. Therefore you have to supply it by some means outside of the body. You said patients can be left this way for in some cases very long periods of time. It's my understanding from observation and reading and listening and so forth that in surgery 15 even 10 even 5 minutes could be

interpreted as a very long period of time. Many technical maneuvers can be completed in these patients in 5 10 or 15 minutes. It is also possible that to stop your pursuit into caught a part of the procedure after 10 or 15 minutes and turn the pump back on and if you use a patient for a few moments and then stop the cyclamen again I wondered if the hypothermia or cooling technique could be used in various operations. Dr Seeley said this about the use of hypothermia in surgery. This has been used in. Our clinic for sudden Deshpande neurosurgical. Said desperate neurologic disease where conventional methods of approach to these lesions would not have been feasible. In these instances the patient's temperature was reduced to

below 10 degrees. Sauna grade and elation was in stop for periods of 5 to 10 minutes while a very delicate maneuver was carried out to control an aneurism within the brain. This has been done in other patients with very vascular tumors of the brain and would have been difficult to handle but that this technique. This has not been used extensively but we feel that it is a possible future use for this technique. We have also been interested in observing the effect of these low temps on patients with normal hearts. One of the big objections to the use of hypothermia in the past in Seiji has been the fact that the heart tends to very quickly. At sudden levels of hypothermia particular those below 28

degrees centigrade. This is never a problem when one is operating upon the heart because the heart is. Available and easily manipulated in this type of fibrillation can be controlled very easily with electric shock on the other hand. In those cases where the heart is not exposed and where the main operation is done it about the head or some other area of the body then one would not like to open the chest and complicate with another in station. After all we have worked out in our laboratory a method of preventing fibrillation in patients. We've found that doses of quotidian hydrochloride which is a common heart drug is very effective in preventing interact with relation even at these low temps. This was back and this was tried after a very extensive period of study in the laboratory using. Dogs as subjects and carrying out low temps and

preventing fibrillation with the quantity it would all happen in almost every instance in dogs to push them. The conditions that. You used. Attained by the heat exchange and heart lung machine by external body cooling that patients who suffer from severe liver disease can be cured through big surgical operations with the use of hyphens as a third area where we've used this technique and that is in the treatment of it is been found that drugs have asked thanked enhanced by increased body temp and it is possible to use organs by the heart lung machine with the blood exchanger and raising the temperature of the blood it is as it goes

to this organ and enhanced in the effect of the drug that is injected into the blood structure. It is also possible to the remains of the body so that. The remains of the body with this same technique. And therefore prevent some of the toxic effects some of the drugs used to combat cancer. This of course is an early colony in the investigative stage and certainly seems to hold promise for the future useful heat exchange in a poor system. Are there special procedures in preparing a patient for an operation. Particularly how is a lowered temperature achieved. A patient does not have to have any unusual preparation before undergoing a heart operation either with or without hypothermia and hypothermia is achieved by cooling the blood as it

goes into the patient. And this is done in a very ingenious way method. But is passed through. Many cubes which are surrounded by. Secular dating with aura which has its temple automatically regulated with a mixin valve. That is. At the entry into the heat exchanger and this makes an valves can be attached to a bucket of ice water or to the faucet either hot a coal and one can by regulating the temp of the water. One regulates attuned to the blood that passes through this radiator. This is really a cylinder this not much larger than a one about two and a hayseed inly. It has really the capacity of reducing the body temp to an ordinary

sideman from 37 degrees down to 20 degrees in about 12 in about 12 or 15 minutes. These methods the lung machine and the technique of hypothermia certainly seem to allay individual as major surgical advances. What are their importance as viewed by a doctor and what is needed in the future. We believe that the ultimate in open heart surgery or ultimate in cardiopulmonary bypass which has to be a pain in order to get to the heart will be in. Some method of. Reducing or. Stopping the body's metabolism Folkert of time necessary to do into cardiac part of the operation we think that this is. A first step in that direction. And with the combination of the hypothermia and the extra cup or

system one then has this technique completely one's control. And so that the temp can be increased and decreased at will and when it can be absolutely controlled. All of the techniques used in the past of life to me have been more or less have been very difficult to reverse once of modesty to reduced. We think also that this just as it stands is a major improvement over some of the conventional method of. Extra fusion. In that. It. Has certain safety factors in addition to simplistic and I might say that it's pretty safe to fact of course is it simplistic. One can even imagine situations exist in which have occurred in practice as a lung machine may break down with a body temp to it

at 20 or 30 to between 25 and 30 degrees centigrade. One has time to complete the operation and to extricate oneself from the from the predicament in the least. Depression can tolerate absence isolation for periods long enough to get the machine back to working again. Dr Seeley is in accord with Doctor cooling as they both state the need for a method by which to reduce body metabolism while performing heart surgery. These are comments by other men in the field of heart disease. Dr. Michael DeBakey said many heart conditions which only a few years ago were considered hopeless can now be treated effectively among the conditions which cannot be cured. Our aneurisms of major blood vessel. Research to solve the problem of replacement arteries by substitute by such things as Nylon dacron and teflon. About prevention Dr. Paul Dudley White

said when I first entered medicine only a small minority of Americans survive the age of 70. This is change through research. However the toughest research problems are still unsolved. There is no reason to doubt that we can protect patients by diet exercise medicine and other measures from coronary disease. Provided we fully support medical and other scientific investigators working on the problem. Dr. White optimistically concluded by saying it can be done in our time. Next week you will hear Dr. COOLEY Dr. Willis J Potts Dr. John H Gibbon Jr. and Dr. C. Walton Lilly high as they discuss transplantation on the third program about surgery for heart disease. On the next program from the series human behavior social and medical research consultant for this program was Dr. Herbert Sloan of the University of Michigan Medical School.

When Philip speaking asking that you join us next week and thanking you for being with us at this time this program has been produced by the University of Michigan broadcasting service under a grant in aid from the National Educational Television and Radio Center in cooperation with the National Association of educational broadcasters. This is the NEA E.B. Radio Network.