Landmarks in the Development of Coronary Artery Bypass Surgery
1998; Lippincott Williams & Wilkins; Volume: 98; Issue: 5 Linguagem: Inglês
10.1161/01.cir.98.5.466
ISSN1524-4539
Autores Tópico(s)Aortic Disease and Treatment Approaches
ResumoHomeCirculationVol. 98, No. 5Landmarks in the Development of Coronary Artery Bypass Surgery Free AccessOtherPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyRedditDiggEmail Jump toFree AccessOtherPDF/EPUBLandmarks in the Development of Coronary Artery Bypass Surgery René G. Favaloro René G. FavaloroRené G. Favaloro From the Institute of Cardiology and Cardiovascular Surgery of the Favaloro Foundation, Buenos Aires, Argentina. Originally published4 Aug 1998https://doi.org/10.1161/01.CIR.98.5.466Circulation. 1998;98:466–478For you to find the truth, in the first place, you have to believe in the truth with all your heart and with all your soul, and believing in the truth with all your heart and with all your soul means saying what you think is true wherever and whenever, but, most especially, at the least opportune moment. (…) Whenever wisdom is found in a scientific work, there cannot be the slightest doubt it is passion's doing, a painful passion much deeper and dearer than simple curiosity. Miguel de UnamunoSince my training as a resident in general surgery at the University Hospital in La Plata, I have been attracted by thoracic surgery. As soon as I graduated, I started traveling every Wednesday 44 miles to the Rawson Hospital in Buenos Aires, where the Finochietto brothers had organized a postgraduate program, mainly to learn lung and esophageal resections.As a resident, I lived in the hospital, where I witnessed the early attempts in thoracic surgery. In 1949, Professor Clarence Crafoord was invited by the head professor, José María Mainetti, to give lectures and operate on patients in our institution. I was extremely lucky to participate as his second assistant. Crafoord was indeed a master surgeon. I still remember today my happiness at being so close to one of the most important pioneers in thoracic and cardiovascular surgery. I was also impressed by his anesthesiologist. With a small machine (he brought his own equipment) and high doses of curare, the operation went smoothly, and certainly we learned enormously.In those days, I thought only about my work and an academic career that I had started earlier as a student assistant professor in anatomy. I was convinced that my future would be connected exclusively to the university, because I realized that teaching gave me a genuine spiritual pleasure.For several reasons, however, the main one being my refusal to sign a political declaration supporting the "national doctrine," an essential requirement at the time to be nominated for any position at the University Hospital, my destiny led me to become a country doctor in a small village in the southwest of the dry pampas in May 1950. With tremendous effort and saving every penny, I was able to build up, from an old house, a clinic with operating facilities, laboratory, and x-ray equipment. My only brother, Juan José, who was also training as a surgeon at the same University Hospital in La Plata, joined me 2 years later.The broad spectrum of general surgery (we generally dealt with emergencies) constituted most of our daily work, because our clinic was the only one in the region that was properly equipped and organized. Regular trips to Buenos Aires and La Plata and reading the most important medical journals kept us well informed of new developments. As an example, the high mortality of diffuse peritonitis, which was very common in the countryside in those days, decreased significantly when Laborit's method of pharmacological hypothermia (meperidine, promethazine, clorpromazine)12 was applied in conjunction with high doses of antibiotics and corticoids.The early contributions in cardiovascular surgery in the 1950s made a great impression on me, and although our work was gratifying, in 1960 I began to cherish the idea of traveling to the United States to train in thoracic and cardiovascular surgery. I talked to my master Professor Mainetti, who understood my feelings. After one of his many trips to the United States, he advised me to go to the Cleveland Clinic. He wrote to his friend George Crile Jr, and at the beginning of 1962 I traveled to Cleveland with my wife. I was already 38 years old, and I had as a treasure the large experience accumulated in hundreds and hundreds of operations.Crile was the first person I met at the clinic. Over the years, he would become one of my best friends. We shared many thoughts, and I always admired his humanistic idealism. He introduced me to Dr Donald B. Effler. In my broken English, I managed to explain the reason for my trip. Effler made it clear that not having the proper qualifications, mainly the certificate of the Educational Council of Foreign Medical Graduates, I could only be accepted as an observer, without receiving any payment. Because I had been able to save some money, I pointed out that I was not asking for a salary, only for an opportunity to learn.Most of the daily work was thoracic surgery. Only 3 or 4 open-heart operations per week, mainly for congenital diseases, were performed. Within 2 weeks, Effler invited me to scrub up in a left pneumonectomy. From then on, I collaborated with him and Dr Larry Groves, his partner. In addition, I placed Foley catheters, pushed beds back and forth to the intensive care unit according to Effler's rules (to be sure a fellow would always be present, for the safety of the patients), helped the anesthetists, and also cleaned, siliconized, and set the enormous heart-lung machine with a Key-Cross oxygenator. I did everything possible to show my gratitude.From the beginning, I was drawn to the work of Drs Mason Sones, Earl Shirey, and collaborators in the catheterization laboratory placed in the basement (the famous B10), where hundreds of cine coronary angiograms were systematically stored, together with a summary of the clinical record of each patient. At that time, studies of such precision and quality were available only at the Cleveland Clinic.3After finishing the day's work in the Department of Thoracic and Cardiovascular Surgery, I spent most of my time in B10. I had rented a small apartment just across the street. Living so close to the clinic, first, spared me from traveling through the streets and roads covered with snow most of the winter in the Ohio Great Lakes area, and second, it allowed me to prolong the review of the films in the evening and sometimes until late at night. Slowly and steadily, with the help of the fellows working in B10, I started learning how to read and interpret cine coronary angiograms.The doors of Sones' office were open most of the time. He was always willing to exchange ideas with his associates and the innumerable visitors that came from all over the world. After several weeks, I humbly introduced myself and asked for his advice in interpreting some of the movies that I could not understand because of my lack of experience. That was the beginning of a deep and everlasting friendship.After a few months of reviewing cine coronary angiograms, it became clear that there were 2 distinct groups of patients: (1) those with diffuse disease in most of the coronary branches, often with collaterals between them, and (2) those with localized obstructions, mainly at the proximal segments with good distal runoff.The analysis of the cine left ventriculogram showed a clear correlation between the severity of coronary arteriosclerosis and the state of the heart muscle. Only the right anterior oblique projection was used. Later on, mainly as a result of our observations in the operating room, I suggested to Mason that the left anterior oblique view was necessary to visualize the septum and the lateral wall.In January 1962, just before my arrival, 2 important events had occurred at the Cleveland Clinic: (1) using the patch graft technique described by Senning,4 Effler and his associates had been able to repair a severe obstruction of the left main coronary artery5 (Figure 1), and (2) in 2 patients from Canada operated on with the Vineberg technique (left internal mammary artery implantation), Sones had shown that collateral circulation arising from that systemic artery was sufficient to diminish the myocardial perfusion deficit in the territory perfused by the anterior descending branch of the left coronary artery.Therefore, since 1962, myocardial revascularization has started with (1) a direct approach in localized proximal obstructions with the patch graft technique (pericardium or saphenous vein) and (2) an indirect approach with the left internal mammary artery implant.Indirect Myocardial RevascularizationThe left internal mammary artery was meticulously dissected by means of a left posterolateral thoracotomy. A small tunnel was made on the anterolateral wall of the left ventricle where the artery was inserted. Postoperative studies performed within a year demonstrated that the patency rate and the degree of connection with the coronary circulation were directly related to the severity of the obstruction and the presence of collateral circulation. The overall results were gratifying.6Our work increased steadily. After passing the Educational Council of Foreign Medical Graduates examination, I became a junior fellow in 1963 and senior resident in 1964. In 1965, following Sewell's ideas,7 we dissected the mammary artery with the surrounding tissue, including the veins, in a short period of time and with less trauma.The midline anterior thoracotomy became a routine procedure for most of our open-heart operations, and very often when I lifted up the sternum to place the Finochietto retractor, or at the end of the operation to control some bleeding, I could see and palpate the mammary arteries. I started dissecting some portions, mainly at the level of the fourth and fifth intercostal spaces. On several occasions, I discussed with Mason the idea of using both mammary arteries. Somebody told him that necrosis might occur if the sternum were deprived of that blood supply. I carefully reviewed the anatomy to confirm that this was a senseless warning. In 1966, being already a staff member of the Department of Thoracic and Cardiovascular Surgery, I dissected both mammary arteries and implanted the right one on the anterolateral wall of the left ventricle parallel to the anterior descending branch and the left one on the lateral wall underneath the branches of the circumflex and right coronary artery.89 To facilitate the dissection, I designed a self-retaining retractor10 that, with some modifications, is used today in cardiovascular centers all over the world.We summarized our experience on indirect myocardial revascularization at the annual meeting of the American Association for Thoracic Surgery in 1967.11 I still believe that our new approach was a good way to ameliorate myocardial perfusion deficit. The most significant demonstrations were obtained in some patients whose repeat catheterizations showed that their left coronary arteries were totally occluded at the ostium and that their left ventricles were perfused by both implants through a sponge of collateral circulation (Figure 2).Nevertheless, we have to accept that, in retrospect, the only justified indications were the ones found among patients with diffuse disease and with collateral circulation. The recent advances in angiogenesis12131415161718 opened a new field of unlimited dreams, raising the possibility of combining, for example, the Vineberg technique with angiogenesis inductors.The dissection of the mammary artery by means of a midline anterior thoracotomy was another important landmark: it gave us the ability to accomplish combined simultaneous procedures. In 1966, we started performing ventricular aneurysmectomy, valve repair, or valve replacement with concomitant single or double implants.19Direct Myocardial RevascularizationAs I already mentioned, direct myocardial revascularization started in January 1962 with the patch graft technique. The results were gratifying on the right coronary artery. Conversely, mortality was extremely high in patients with left main trunk obstruction (11 deaths in 14 patients). We tried different operative approaches, including transection of the pulmonary artery.20 Cardioplegia was not available, and even though the aorta was clamped for ≈20 minutes, the heart muscle of the left ventricle functioned under severe chronic anoxia and could not tolerate the lack of oxygenated blood even though it lasted only a short period of time.In those years, I used to go to the operating room with both the thrill of challenge and fear in my soul. Sometimes when the kidney transplantation team was desperately looking for a donor and they saw in the surgical schedule that such a patient was ready to undergo surgery once more, they would come and ask permission to perform a crossmatch before the operation.As our experience grew, longer patch reconstructions were performed. However, the postoperative cine coronary angiograms showed that there was a direct relation between the extent of the repair and the rate of postoperative thrombosis: the longer the repair, the greater the failure. This was the consequence of the coronary artery being untouched, so that its inner surfaces retained irregularities that could disturb the flow pattern. The turbulence induced thrombosis and consequent occlusion.Early in 1967, I thought that perhaps the problem could be solved by use of segments of saphenous vein. At the Cleveland Clinic, we had gathered a broad experience in peripheral and renal artery reconstruction with that kind of graft. Why not use it at the coronary level? I discussed the idea with Mason and some of his collaborators. We decided that we should try it first in patients with totally occluded right coronary arteries with the distal segments visualized by collaterals from the left coronary artery. If the graft occluded, the patient would suffer no harm.The first operation was performed in May 1967 on a 51-year-old woman. The proximal and distal segments of the totally occluded right coronary artery were reconstructed with a segment of saphenous vein and 2 end-to-end anastomoses. Mason was very anxious to restudy the patient, and he did so 8 days later. He called me, and as soon as I finished an operation, I went to the cardiac laboratory. Mason showed me the film on the Tage-Arno viewer. I had rarely seen him so happy. The right coronary artery had been totally reconstructed, and there was an excellent distal runoff (Figure 3). A few days later he took a 16-mm movie of the preoperative and postoperative studies to a meeting in West Germany.Very early in our experience, we realized that the interposed technique presented significant limitations. A bypass from the anterolateral wall of the aorta was done on the 15th patient, as pointed out on page 337 of my first publication21 (Figure 4).At the beginning we proceeded slowly, because we did not know of any previous clinical application and we were concerned with the late evolution of the graft, mainly with thrombosis and dilatation. The placement of the proximal anastomoses on the anterolateral wall of the aorta ≈2 cm above the natural ostium led me to believe that the graft would remain patent because it would follow the natural coronary flow pattern. Mason restrained my premature optimism. He would say: "Let's see if they plug in 3 months. We must select the patients carefully and wait several months after the operation until we have the cineangiogram."Important landmarks were achieved in 1968.1. The bypass technique was applied to the left coronary artery distribution. The first operation was performed on a patient with severe obstruction of the left main trunk and minimal changes on the left anterior descending and circumflex branches. A single bypass to the proximal segment of the left anterior descending branch showed excellent perfusion of the entire left coronary artery in the postoperative study (Figure 5). Left main artery disease finally had been defeated.2. We combined coronary artery bypass graft (CABG) with left ventricular reconstruction (aneurysmectomy or scar tissue resection).193. CABG with concomitant valve repair or replacement was achieved, because cine coronary angiograms were regularly performed in patients with valvular disease.224. In December, we performed a double bypass to the right coronary artery and anterior descending branch of the left coronary artery, thus opening the door to multiple bypass approaches in patients with multiple vessel obstructions (Figure 6). It is worth mentioning that I had previously done a double reconstruction with the interposed technique in March 1968.20545. Emergency CABG was performed in patients with AMI.23Patients who were operated on with Vineberg's approach frequently died suddenly or within a few minutes in the immediate postoperative period as a consequence of a myocardial infarction clearly detected on the ECG. I always tried to be present at the autopsies. Careful examination of the heart could not visualize the area of the infarction, and Lawrence McCormack, head of the cardiovascular section of the Department of Pathology, used to tell me that it was very difficult to detect it by the common histological techniques. Mac (as we called McCormack) used to say "he died too suddenly." It was difficult to understand the lack of correlation between the clinical and ECG signs and the pathological findings.The literature available, mainly the contributions of Braunwald, Sonnenblick, and collaborators2425262728 and particularly an experimental study by Cox and collaborators,29 convinced me that if good, oxygenated blood could be supplied in the early hours of a myocardial infarction (and certainly CABG was able to do it), the muscle could recuperate. I shared these thoughts with all the members of our team.In those days, our work was limited because we had only 3 operating rooms. As a consequence, our patients waited for 2 to 3 months to be operated on. Those with threatening obstructions stayed across the street at the Bolton Square Hotel. As soon as we had a cancellation in our daily work, they were admitted immediately.I used to arrive at the Cleveland Clinic at ≈7 am. One day, one of the residents told me that a patient in whom a previous cine coronary angiogram showed a subtotal occlusion in the very proximal segment of a large anterior descending artery was in trouble at the hotel. We quickly went to see him and found that at ≈6 am, he had developed severe chest pain that had lasted for ≈30 minutes. He was sweating, with the typical dusky color in his extremities due to poor peripheral circulation; he was dyspneic (the lungs were full of rales) and hypotensive. It was very clear that he had suffered an AMI. The ECG confirmed an anterolateral myocardial injury.I ran to B10, and we analyzed with Mason the clinical picture and the cine angiogram he had performed. He agreed with the diagnosis. This patient was in the middle of a large anterolateral myocardial infarction. Even if he survived, he would lose a significant portion of the left ventricle. Once again I summarized to him the major experimental contributions that supported my intention to perform an emergency CABG and that I did not consider my suggestion an adventure. Finally, Mason acceded.I rushed the patient to the operating room. He was anesthetized immediately and, following our previous experience in emergency operations, we connected him to the heart-lung machine within a few minutes. When we opened the pericardium, the anterolateral wall of the left ventricle did not contract properly, and it had a bluish color. The operation went smoothly. As soon as we finished the proximal anastomosis, red, oxygenated blood went to the anterior descending coronary artery and its branches, the anterolateral wall started to contract, and after ≈25 minutes of support with partial extracorporeal circulation, the patient was off bypass. The blood pressure improved and remained within normal limits. The following day he was extubated and had an uneventful recuperation. He was restudied within 10 days, and the cine left ventriculogram demonstrated a small, localized area of deterioration on the anterolateral wall (Figure 7). The left ventricular end-diastolic pressure was normal. This was indeed a gratifying experience.When I wrote the monograph in 1970, in the chapter dedicated to this subject I predicted: "Personally, I do hope that in the future, patients with acute myocardial infarction will be treated in the same way as those patients with a 'dead leg' from acute thrombosis or embolization of the peripheral circulation are now treated. Those patients are admitted under the direction of a combined surgical and medical team. Emergency angiography is performed and surgical intervention is routinely done, with total recovery in a significant number of them. Further clinical experience will be necessary to substantiate this point of view."20,p128 Today, with the introduction of fibrinolytic agents in combination with CABG or angioplasty in the acute or subacute phase of a myocardial infarction, this has become a reality for some patients.In 1971 we reported in the American Journal of Cardiology23 the operation performed in 18 impending infarctions and 11 acute infarctions. In one of the conclusions, we said: "When operations are performed within 6 hours of an acute myocardial infarction most of the heart muscle can be preserved." It still surprises me today—only 11 patients with AMI were operated on. We concluded: "Cardiovascular surgeons are at the threshold of a more aggressive surgical approach in the treatment of patients with acute coronary insufficiency. Further clinical experience will be necessary to substantiate the views presented here."By the end of 1968, the largest series in the world (171 patients) had been accumulated. I summarized the advances in an article accepted for publication in the Journal of Thoracic and Cardiovascular Surgery in December 1968.30In 1969 we gained more confidence as a consequence of promising results on midterm survival compiled by Sheldon et al.3132 The excellent contributions by Johnson et al33343536 in Milwaukee, showing that bypasses could be placed in the distal segments of the coronary artery distribution, widened the scope of indications for CABG surgery.By December 1969, we had operated on 570 patients, and this surgical experience was presented at the Sixth Annual Meeting of the Society of Thoracic Surgeons in Atlanta.37 For the first time, we reported that the coronary arteries, mainly the anterior descending artery, could occasionally be found inside the myocardial muscle. The proper technique to overcome the problem was described. In the same presentation, we emphasized the need to use magnifying lenses to perform good distal anastomoses in small coronary arteries (we applied them even in arteries of 1-mm diameter). The overall mortality rate, including all the combined procedures, was 5.4%. It is interesting to note that 50% of the patients received single or double mammary artery implants. It was hard for us to stop using Vineberg's technique because of our previous clinical experience with it. Careful reading of the cineangiogram helped us to combine the direct and indirect approaches. By June 1970, 1086 bypasses had been performed, with an overall mortality rate of 4.2%.I read our next presentation at the Fifth Annual Meeting of the American Association for Thoracic Surgery in Washington, DC, in April 1970.38 It concerned the application of the coronary bypass technique to the left coronary artery and its divisions. We insisted on the use of magnifying lenses and the "nontouch technique," ie, no dissection of the coronary arteries was needed to perform the distal anastomosis: the pericardium was cut on top by a No. 15 bistoury blade before the artery was opened. As a consequence, the stitches (we were using interrupted sutures) incorporated the epicardium and some of the subepicardial fat, a very important detail that surprised the hundreds of visitors at the Cleveland Clinic.The use of cephalic or basilic arm veins as an alternative when the saphenous vein was not available was also discussed. There was a steady decrease in the number of combined single and double internal mammary implantations as a direct consequence of the growth of multiple bypass surgery. By August 1970, 196 patients had undergone double, triple, and quadruple grafts, with a 4.1% hospital mortality. Eleven cardiovascular centers contributed to the discussion, and it was very gratifying to see the growth of CABG surgery.In the same year, as a consequence of the superb work of George Green in New York City,39 I started using the direct mammary-coronary anastomosis. I talked to Green on several occasions, and he told me that I would need at least 100 hours in the laboratory to learn how to use the microscope (that is the way he did the operation). I thought that this approach would never popularize mammary-coronary bypass, and I decided to dissect the left mammary artery and connect it to the anterior descending artery with the routine interrupted suture technique, with only the help of the lenses that we used in our daily work (Figure 8). After I left the Cleveland Clinic in 1971, Loop et al emphasized and standardized this method and demonstrated the excellent results on long-term follow-up.My book Surgical Treatment of Coronary Arteriosclerosis,20 highlighted by Effler's introduction, appeared the same year. I analyzed all the experience gained at the Cleveland Clinic. Chapter 2, which dealt with the analysis of the coronary anatomy and its correlation with cine coronary angiography in its different projections, was very helpful, as testified to by the comments of the innumerable letters I received.The Sixth World Congress of Cardiology was held at the Royal Festival Hall and Queen Elizabeth Hall in London in 1970. I was invited to participate in a symposium dedicated to coronary artery surgery together with Ray Heimbecker, Arthur Vineberg, and Charles Friedberg. The organizing committee gave us one of the smallest rooms. The cardiac adrenergic mechanism was to be discussed at the same time in the main auditorium. From the very beginning of the Congress, I felt the tremendous interest our session had aroused among the participants. When I arrived an hour before the meeting to organize all my slides, the room was already packed with hundreds of doctors, taking all the seats, some sitting in the central aisle on the floor, and others standing against the lateral walls. When we were on the podium, ready to start, the doors were closed. As the first speaker, Heimbecker, started his presentation, we could clearly hear the loud voices of the doctors who were complaining because they had been unable to enter the auditorium. The lateral doors finally crushed due to the pressure from outside and innumerable physicians jumped into the room. Somebody managed to protect the fragile body of Paul Dudley White, who was standing right in front of us. It was impossible to go on with the session. After talking with us, the secretary of the congress addressed the audience and promised to repeat the symposium at 6 pm. We knew in advance that it would be impossible, because a discussion cannot be repeated and, besides, Friedberg was traveling back to America that same evening. However, the secretary's words calmed the audience down, and the round table recommenced. Heimbecker presented his work on resection of AMI, and Vineberg summarized his experience. Finally, Friedberg and I discussed CABG surgery. He was an outstanding speaker who knew how to sprinkle his statements with good humor. He started by saying: "These cardiac surgeons are unique. When the heart has a hole they close it, when the heart doesn't have a hole they open one." We all laughed at his comments, but when I presented the number of procedures performed at the Cleveland Clinic and the perioperative mortality rate, Charlie voiced some doubts about "such a low mortality," which was difficult for him to accept. I flared up and invited anybody who so desired to go to the Cleveland Clinic to check our files. Some physicians did visit us on their way back to their native countries and were able to confirm the honest work performed at our institution.I believe the Sixth World Congress had a big impact and opened the doors for the worldwide use of CABG. Thousands of doctors from all over the world were exposed to a critical analysis that showed the benefit of this new approach among patients with severe coronary arteriosclerosis.That week, Donald Ross invited me to perform some operations at the National Heart Hospital in London. I agreed, and the first coronary artery bypasses in England were performed with his help. Most of the outstanding cardiovascular surgeons from Europe watched the surgery from behind us, almost on top of our shoulders, and participated in informal discussions between operations, most of them held in a pub opposite the hospital, where we exchanged knowledge and friendship.In 1970, I decided to return to my home country. It was a difficult decision. I gave serious thought to this matter and finally considered that my work and my duties were needed in Latin America. One day in October, late in the afternoon, I wrote my letter of resignation to Effler. I closed the envelope with tears in my eyes and left it on his desk. I wrote:"… as you know, there is no real cardiovascular surgery in Buenos Aires…"Destiny has put on my shoulders once more a difficult task. I am going to dedicate the last one third of my life to build a thoracic and cardiovascular center in Buenos Aires. At this particular time, the circumstances indicate that I am the only one with the possibi
Referência(s)