This is Sunday, March 4, 1973 and we are embarking on the first of a series of historic interviews, primarily concerned with preserving the thoughts and voices of those cardiac surgical pioneers that are still here while we still have the opportunity. I am W. Gerald Rainer (WGR). Marv Pomerantz (MP), Ted Sadler (TRS) and I have the distinct honor of interviewing today Dr. Henry Swan (HS). Dr. Swan is one of the pioneers in heart surgery in the Denver area, nationally and internationally. It is our thought that while we still have the opportunity to interview some of the surgeons who started heart surgery, who worked out some of the most difficult problems, and who set the ground work for routines that we now take for granted, that it would be of great value to save these for posterity.
We will try to make this as informal as possible, and to try to make it as interesting from the standpoint of personal experience. Dr. Pomerantz, Dr. Sadler and I will feel free to interrupt from time to time to ask questions, but for the most part, this is Dr. Swan's day. Dr. Henry Swan was born May 1913 and had his early education at Williams and Harvard. He was among the first group of married interns at the Peter Bent Brigham Hospital. From there, after an internship and residency, he went into World War II in the European Theater. And from there on went into the surgical disciplines, which eventually led him to the early days of cardiac surgery.
Dr. Swan, if you could begin by elaborating some on the background of the World War II days that led you into the field that you are now, we would be appreciative.
HS: Thank you, Dr. Rainer. I think that it should be emphasized, as far as my training was concerned, that the training at the Brigham Hospital was associated in a joint venture between the Brigham and the Boston Children's Hospitals. And that actually during the three years that I was in service there (almost two years were spent at Children's Hospital) and, at the end of that experience, the Harvard unit had already been called out and I was the only surgical resident at the Boston Children's Hospital for a period of about eight months. So, I had the private general surgical service, teaching surgical service and the neuro-surgical service and, as a result of that, I had a rather extraordinary operative experience in pediatric surgery and this was influential in my subsequent career. I was also there at the time when Dr. Robert Gross was developing the operation for patent ductus arteriosus. So, I had a heavy influence of the earliest days of the surgery with congenital heart disease.
After leaving the Boston Children's, I became a member of a surgical team in the Fourth Auxiliary Surgical Group and later in the Fifth Surgical Group in the European Theater, and my experience extended from D-plus one on Utah Beach to the Elbe River. We were in mobile platoons of field hospitals operating non-transportable wounded and I had a rather extensive experience in trauma surgery, which stood me in good stead in later years. And, among other incidents, I had the opportunity to operate on a man who had a fragment of a booby trap which had pierced his popliteal artery and had cut about halfway through. And the SOP (or the Standard Operating Procedure) officially required would have been to ligate the artery. But I felt that if I had been that man, I would like to have had someone try to save that artery, as the probability of my losing my foot would have been very grave. So, using some French-eye needles, which I had smuggled from Children's Hospital, and some 4-0 silk, I did a suture anastomosis of the artery. Fortunately, both for me and for the soldier, the anastomosis worked and no clot occurred and he left the hospital with a pink foot. This experience reinforced my Children's Hospital cardiac experience so that when I came back after the war to Denver, I was interested in both the field of congenital heart disease and vascular surgery.
I decided to limit myself to pediatric surgery and was just starting to do that when, at the Medical School, a new Dean had taken the reins of the University of Colorado School of Medicine and had decided to introduce full-time teaching personnel to enlarge the mission of the school which, up to that time, had been manned entirely by volunteer faculty. And so, for some reason or other, he asked me to join the faculty full-time, which I did, since it was agreed that I would have the opportunity to have as my domain all the pediatric surgery. You might be interested to know that my salary as an assistant professor and as the first full-time member of the faculty in 1946 was $5,200.00. So that's the way I got started at the University of Colorado and the origin of my interest in vascular surgery.
MP: Could you lead us into the development of your interests in cardiac surgery at the University of Colorado and the development of your department?
HS: Well, I thought the most important thing, Dr. Pomerantz, was the establishment of a research laboratory in the Department of Surgery. So, my very first effort then was to try and find some space within the geographical confines of the hospital and the medical school. And incidentally, at Colorado, the hospital and the medical school are a continuous building, a very fortunate geographic arrangement in medical education. So, we borrowed some space from the Pathology Department and I was able to get one of the first grants from what was then the U.S. Public Health Service to study the possibility of a shunt between the auricles in the treatment of mitral stenosis. This grant was in the amount of $3,600.00 and was the first research grant ever existing in the Department of Surgery. Up to that time, there had never been an article published in a responsible journal that bore the byline of "From the Department of Surgery at the University of Colorado." And so I thought that part of my job as the first full-time member of the faculty as to develop the research side of the mission of the medical school, as well as the teaching and service. So, the lab was the first thing and this, of course, very rapidly began to pay off as we turned our attention to the forum of vascular and cardiac surgery as our first endeavor, moving rapidly from there into the study of arterial grafting and the grafting of arteries, which led to early clinical application of that modality and then subsequently to the study of hypothermia.
TRS: Were you aware of the people, specifically at the Brigham or, as it turned out, Dr. Lewis' work in the field of hypothermia, or how did you get interested in this field?
HS: Well, I was of course aware of the work going on in Boston and Dr. Gross had been using stored homografts to repair coarctation of the aorta when there was a very long segment. Therefore, we got interested in that phase, the idea of homografting arteries and, of course, this subsequently became of very great importance in cardiac surgery, with the homografting of that portion of the aorta which contained the valves. And it is still of tremendous importance in the use of grafts, of living grafts for coronary disease. But the stimulus to me to enter hypothermia was a paper given by Dr. Wilfred Bigelow at the American Surgical Association at the Greenbriar Hotel. I believe that the date was about April or May of 1950. Dr. Bigelow described a series of dogs in whom he had lowered their body temperature by surface immersion in ice water, after having anesthetized the dogs and he then lowered their body temperature to about 24 or 25 degrees, as I recall. And he then opened the chest and simply clamped the vena cavae, thus occluding blood flow to the heart for 15 minutes. And then he reported that his mortality rate under that experience had been 85 percent and that ventricular fibrillation had been the chief cause of death. And so, in the midst of that meeting, this paper caused not much concern or interest. But, in flying home in my own Navion, I got to thinking over that report and I suddenly got what I felt was the message of his paper - which was that 15 percent of the dogs had lived. And that these were animals that had the blood flow to the inside of their heart occluded and, therefore, the outflow had been stopped for 15 minutes and that they were still alive! And I felt that if one could understand this modality better and prevent those deaths, that this was a golden opportunity to enter heart surgery because in 15 minutes of open-heart time, one could obviously have performed a large number of operative procedures. One could develop operative procedures successful within that limitation of time. So, that was the precise stimulus that entered our minds and caused us to turn the work in the Halsted Laboratory to a heavy emphasis on getting to understand the problems related to deep body temperature, a deep body hypothermia. That was in approximately June of 1950. By the end of 1952 (a year and a half period) over 380 dogs had been cooled and our understanding of the risks of hypothermia had improved greatly and our capacity to prevent the dreaded complication of ventricular fibrillation had gotten to a point that we felt justified to enter the clinical arena. We were not aware of the work of Dr. Lewis until late in the summer and fall of 1952. We knew that he was also working on the same problem. To his great credit must go the honor of having done the first successful open heart operation - I believe it was about late October or November of 1952. Dr. Bailey in Philadelphia also heard the paper of Dr. Bigelow and had started to use hypothermia clinically. But, unfortunately, Dr Bailey's series was short and was not successful. We did our first case under hypothermia in January 1953, and our first open repair of the pulmonic valve in February of 1953. By June, we could report a series of 13 cases of open heart repair of congenital heart disease with a mortality of just one patient. And I really believe that this report, which appeared rather quickly, I believe in August of that same year, in the Journal of the American Medical Association, was, in essence, the first successful series of open heart procedures. This served, I'm sure it was partially responsible, as a stimulus for interest throughout the country and indeed throughout the world, pursuing this modality for that purpose.
WGR: Dr. Swan, those are just exactly the sort of thoughts that we wanted to hear. What we would also like to hear from you is some description of how you felt when you approached the first clinical application of your laboratory work, namely the first open heart surgery. Did you feel pressured by the time? What precautions did you have available for unforeseen problems, things of this sort?
HS: Yes, I can remember our first application of clinical hypothermia very vividly. We had achieved in the laboratory, and I think, if I may, I'd like to enlarge on that point for just a moment because I believe that cardiac surgery was the only form of human surgery which was applied after an extensive laboratory experience and based on that laboratory experience. Gastrointestinal surgery, thoracic surgery, neurosurgery and urologic surgery, all specialties in surgery, had been first tried out in man and the lessons had to be learned. I remember when I was an intern, the mortality rate for lobectomy in thoracic surgery was 15 percent. So, when heart surgery was first begun, we had behind us these almost 400 dogs as far as our experience with hypothermia. Many of those dogs had undergone cardiac procedures, opening the auricles, cutting holes between the auricles, opening the ventricle, closing it up, giving us operative and technical experience in just managing the heart. So, for example, in the first 69 patients who had open heart operation on the pulmonary valve, there were no deaths, beginning from Case One! So, I'm going to use this as an example of how it would have been desirable for all branches of surgery in the past to have had laboratory background before they began. I wasn't terribly worried about the hypothermia itself in the application of this modality to our first cases. The worry was the ability to get in and out of the heart and have control of the openings that you made, because it was clear that you weren't going to have time to sew up openings within the time limits of the open heart. Therefore, we had to begin to develop non-crushing clamps that were secure and would not slip off and which would stay on even if we had to do resuscitative procedures if ventricular fibrillation occurred with the incision still made in the pulmonary artery or in the auricle. And you had to apply electric shock and massage and more electric shock and manual compression of the heart. So, we had this technical problem of developing clamps and there were no clamps in those days designed for the purpose of staying on a portion of the heart without injuring it. So, that was part of the worry with the early patients. However, in our laboratory, we had been able to take certain defensive measures such as hyperventilation, the use of prostigmine, and the use of intravenous glucose to diminish the incidence of ventricular fibrillation in the dog. And my only basic concern was that if I applied the same measures, would it also prevent fibrillation in man? And, as it turned out, it did. Fibrillation was not a major problem, really, at any time throughout my experience with hypothermia.
WGR: I need to mention a couple of points perhaps Dr. Swan won't mention himself. One is that many of us are aware that the bathtub that was used for hypothermia at the University of Colorado has been presented to the Smithsonian Institute. Another point is when Dr. Swan mentioned flying his own Navion, most people around the world at that time knew of his accomplishments as a pilot, primarily as a plane crasher. And I can recall during the days of his operating on open heart patients at the University of Colorado when, after one such event, he had his own wheelchair rigged up to a hoist that would put him up to the operating table.
HS: Now, I'd like to straighten the record here because it is true that on occasion we (the mountain and I) happened to be on a collision course. But, Dr. Rainer, I'd like to point out also a trip in a single engine aircraft around the entire continent of South America. I believe I was the fourth individual ever to do that. Also, all the way around Alaska to Newfoundland and without any particular inclusion of those major disasters.
WGR: We wondered if the plane had been well enough preserved so that it could be in the Smithsonian alongside the bathtub?
HS: Yes, the third airplane is still well preserved.
TRS: Dr. Swan, as surgeons, I'm sure we would all be interested in knowing if you ever operated on a patient with an incorrect diagnosis - that being a remote possibility with the cardiologists with whom you were working. And, number two, were you ever tempted to go beyond what you knew, or thought, you could do with hypothermic technique?
HS: Well, I think, Dr. Sadler, I was very fortunate because our first several years of experience with open heart surgery were indeed a team venture. And Dr. S. Gilbert Blount was associated with me and he was an extremely acute diagnostician and I can honestly say that it was a very rare event indeed, in which I operated on a patient in whom his precise predictions were not verified. Now, this included such interesting complexities of diagnosis as between the atrial secundum defect, a primum defect, the presence or absence of normal pulmonary veins. Now, this falls into the second category of your question where several times early in our experience when I, indeed, found aberrant pulmonary veins which were not known to exist preoperatively. We developed various techniques and finally a successful technique for coping with that particular problem. But, on one occasion, we simply had to ligate the vein and accept the congestion of the lung which followed. Later on, after we were doing aortic valvular surgery, the distinction between subvalvular and valvular stenosis was not always diagnosable preoperatively. And on two occasions I got trapped into the effort of trying to relieve subvalvular fibrostenosis through an aortotomy above the valve, which gave adequate exposure but with resultant injury to the mitral valve. But except for these very rare instances, I was blessed with a very accurate diagnostic backup. Now this is a very important point though, because one of the things that held back the use of hypothermia worldwide as a modality for open heart surgery was the very worry that the surgeon had and he must have based this worry on experience. He (Dr. Blount) was in there frequently and finding himself operating on a patient who should not be there. So, it is true that one of the criteria for the use of hypothermia as a modality for open heart surgery is accurate diagnosis.
MP: Dr. Swan, I'd like to ask you as series of questions. First of all, approximately how many cases of open heart surgery did you perform under hypothermia and what was your operative mortality?
HS: Well, Dr. Pomerantz, I can't give precise numbers to that question but I can indicate to you that I had personally operated on over 800 by the time I retired from the surgical department at the University of Colorado. But I recall this: in 1955 the International Society of Surgery met in Copenhagen and I was asked to give a discussion of mortality and surgery in hypothermia. And, in discussing that question, I quoted our statistics, as existed, approximately three years after we began. And I recall that those numbers were that we had operated on somewhere between 380 and 400 cases at that time, with an overall mortality rate, I believe, of about 12 percent. But in the last 100 cases it was less than 6 percent, indeed, with all open heart cases.
MP: Also, next, I would like to ask you, what do you mean by hypothermia? You changed what you meant by hypothermia. Could you just fill us in a little bit on that?
HS: Yes. When I first began, we were not highly sensitized to the fact that in our superficial or surface cooling technique there would be a rather extensive slide in temperature after we removed the patient from the ice bath. And the net result was that in the first several cases, I'd say 15 or 20, we found ourselves with a rectal probe recording temperatures of 23 to 26 degrees, which was colder than our laboratory experience and it was in the range of temperature which in the laboratory was dangerous to our experimental animals. Fortunately, not a single one of those early patients suffered any known bad effect from having been cooled to a temperature which I later considered too cold to be perfectly safe. Later on, then, we adopted the temperature of 30 degrees centigrade rectal temperature as being objective with cooling and we insisted that the patient be hyperventilated to a continuous alkalotic pH, that the patient have glucose running intravenously and, that when the heart was to be stopped, a myocardial depressant (we used prostigmine) was injected. We felt that with this technique the open heart period of 8 minutes would be almost surely safe, that 6 minutes was totally 100 percent safe as far as brain damage was concerned. And that on multiple occasions, one could obtain up to 15 minutes of open heart operating time. At 30 degrees, with these various precautions, the risk of hypothermia, we felt, was approximately the same as that of ether anesthesia.
MP: Let me end my questions by asking you, in this early pioneering work, have you kept up with the families and are there any particular children or families whose development has particularly stuck in your mind?
HS: Oh yes. Yes, I kept up with many of the patients. I used this little trick: when they left the hospital and the operation was still very fresh in their mind, I would ask them would they consider that operative date (they would remember the date that they were operated on) and consider it an anniversary date for them and on that anniversary, would they please write me a letter from where ever they were and tell me how they were doing. It's amazing how many of them did just that. For example, one of the very first patients I operated upon under hypothermia for an atrial septal defect was a young lady named Clarabelle Presley. She came from Indianapolis. This was in about March of 1953 and when she came to my office, she was so out of breath that she had to walk very slowly just across my office floor to approach my desk to sit down for an interview. She had a giant atrial septal defect, a higher pulmonary resistance than we would like to operate on today. But I hear from Clarabelle every year; since then she has had several children and is getting along fine. So she is just an example of many patients that we did.
TRS: Dr. Swan, I wonder if you'd tell us your thoughts about what you think about the role of hypothermia 20 years after your original experience?
HS: Well, Dr. Sadler, that's an interesting question because, of course, hypothermia having been used extensively for open heart surgery and for some other clinical purposes such as transplantation of organs, and, in the use of post-injury to the brain, to prevent brain damage. Nonetheless, in general, it has more or less fallen from grace in the medical community. And I don't think it is extensively used anywhere in the world now with the exception of a few cardiac surgery groups which are beginning to return to the use of hypothermia and using much colder temperatures for very young children who can tolerate such temperatures well. And, at the present time, this is its most current use. It is small in scope. However, you have asked a question that has been a matter of great interest to me, and I recently have reviewed the history of clinical hypothermia throughout the course of man's existence in the world. It turns out that hypothermia over many centuries has waxed and waned in the minds of doctors in cyclic manner. Now, my own opinion is that we have to recognize that hypothermia (which I define as a body temperature lower than is normal for a normothermic animal) occurs naturally and when it does occur naturally, it is extremely dangerous and has a high mortality rate. Mountain climbers and elderly individuals in nursing homes who get significantly hypothermic are in great danger of their life. Another form of hypothermia that we've discussed here today, though, was that which has been applied deliberately by one individual on another. And this, therefore, offers the opportunity for control of multiple variables in the experience. And I feel confident that there is a promise of potential, in clinical medicine, in a variety of diseases which, as yet, have been essentially unexplored. Unfortunately, the use of hypothermia requires a very considerable basic knowledge and experience in biochemistry, bioenergetics and physiology. Therefore, I think in the future there will have to be more of a team endeavor involving the basic science-oriented personnel as well as the physician. It is unlikely that practicing doctors will be able to achieve this kind of overall knowledge to manage hypothermia well. So it remains a problem. I call it in my review of the history, "a lady with a past and a potential for the future."
WGR: Dr. Swan, thank you again for this interview this afternoon. It has been exciting for us and it's been particularly exciting for Dr. Pomerantz, Dr. Sadler and me to begin this series that we've been thinking of and planning for so long. Thank you.
Publication Date: 20-Sep-2004
Last Modified: 12-Jan-2005