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The Future of Cardiac Surgery: The Times, They Are a Changin'
EDITORIAL
The Future of Cardiac Surgery: The Times, They Are a Changin’ Bruce Lytle, MD, and Michael Mack, MD Cleveland Clinic Foundation, Cleveland, Ohio, Medical City Dallas Hospital, Dallas, Texas
“In times of change, the learners inherit the Earth, while the learned find themselves beautifully equipped to deal with a world that no longer exists.” Eric Hoffer
T
he last 50 years have been halcyon days for cardiac surgeons. The technological innovations of cardiopulmonary bypass and heart valve prostheses led to the development of the specialty in the early 1960s. The subsequent development of coronary bypass surgery, an effective anatomic treatment for the most common lifethreatening disease in Western society, led to an explosion in the number of cardiac operations performed and changed cardiac surgery from a specialized service performed only at major medical centers to surgery practiced at many community hospitals. The mid 1970s to the present has constituted the “industrial era” of cardiac surgery. The income generated by relatively standard and reproducible cardiac operations has fueled a dramatic expansion of the medical infrastructure in centers large and small throughout the United States. During this period of time, “cardiac surgery” has meant an operation performed through a median sternotomy with the use of cardiopulmonary bypass. The coronary bypass operation performed with this approach, the basis of cardiac surgical practice in most See page 1812 centers, is an effective operation that has produced good short-term and long-term outcomes. Any fundamental technical innovation within cardiac surgery during this period of time has been relatively modest for many reasons. There has been an understandable reluctance to tamper with success and neither the competitiveness of practice nor medical and legal considerations consistently reward technological innovation in the United States practice setting. Financial imperatives at many institutions have provided impetus for surgeons to concentrate on standard procedures that were important for the economic well-being of the institution. The changes that have occurred in bypass surgery have been mostly incremental improvements of the standard operation, including arterial grafting, off-pump surgery, small incision surgery, and endoscopic conduit harvesting. Even many of these modifications have been adopted only by a minority of surgeons. However, technical innovation in the anatomic treatAddress reprint requests to Dr Mack, 7777 Forest Ln, Suite A323, Dallas, TX 75230; e-mail: [email protected].
© 2005 by The Society of Thoracic Surgeons Published by Elsevier Inc
ment of cardiovascular disease outside of our specialty has been dramatic and profound, particularly in regard to percutaneous technologies. The disruptive technology of percutaneous transluminal intervention (PCI) of coronary artery disease has progressed from the primitive and relatively ineffective use of balloon angioplasty in the late 1970s to the reproducible and largely safe interventions employing drug-eluting stents and platelet inhibitors that are available today for the treatment of a greatly increased proportion of patients with coronary artery disease. Whether or not PCI will produce the equivalent long-term outcomes in the treatment of patients with severe life-threatening coronary artery disease that have been noted with surgery is not yet clear; but it is evident that the procedure-related risks and medium-term outcomes of PCI have become better and more consistent today so that PCI is the most common anatomic treatment for coronary artery disease. Valvular heart surgery has benefited from improvements in prostheses and in myocardial protection, but again these have been iterative improvements rather than dramatic, discontinuous, conceptual innovations in the treatment of valvular heart disease. The recent article by Lutter and colleagues [1] concerning the percutaneous treatment of valve disease published in The Annals of Thoracic Surgery puts cardiac surgeons on notice that coronary artery disease is not the only area of heart disease that may become amenable to catheter-based techniques. Multiple strategies for the percutaneous treatment of valvular heart disease have been attempted and are currently being investigated in both animal models and human subjects. In 1992, Anderson and colleagues [2], (a cardiologist working with surgeons at his institution), implanted percutaneous aortic valves in pigs. During the ensuing decade Bonhoeffer and colleagues [3] achieved multiple percutaneous implantations of valves in the pulmonic position, and Cribier and colleagues [4] have now implanted a percutaneous aortic valve in humans using a device that is undergoing further clinical investigation. Balloon valvotomy has long been used to treat mitral stenosis, but now multiple concepts in the percutaneous treatment of mitral insufficiency are undergoing clinical investigation including edge-to-edge repair and techniques of annuloplasty through the coronary sinus. Today percutaneous aortic replacement and mitral repair devices produce outcomes that are clearly inferior to the corresponding surgical approaches, but these are first generation devices and incremental improvements will make these devices more deliverable, user friendly, Ann Thorac Surg 2005;79:1470 –2 • 0003-4975/05/$30.00 doi:10.1016/j.athoracsur.2005.01.054
Ann Thorac Surg 2005;79:1470 –2
efficacious, and safer. The time course for which this improving technology will make percutaneous strategies competitive with open surgery for a wide spectrum of patients is hard to know, but it is a good bet that such improvement will occur. Percutaneous catheter-based therapy is increasingly available for the treatment of an even broader spectrum of cardiac and vascular disease. Percutaneous alcohol ablation is competitive with surgical myectomy for the treatment of hypertrophic cardiomyopathy, and although less consistently effective than surgery, this treatment has its advocates. Closure of atrial septum defects and patent foramen ovales, as well as left atrial appendage occlusion, are now possible with catheter-based devices. The percutaneous treatment of occlusive and aneurysmal vascular disease is not only possible but is becoming the dominant form of therapy and is delivered by a variety of specialties including vascular surgeons, cardiologists, interventional radiologists, neurosurgeons, and a small number of cardiac surgeons. Although the treatment of aortic arch and thoracoabdominal aneurysms with endografting is not as anatomically reliable as can be accomplished with open surgery, the decreased procedure-related morbidity of stent grafting can be of benefit to many patients who are elderly or have extensive co-morbidities. The devices, while not in infancy, are at least in early childhood. Today branched endografts are becoming available and have been used to treat both aortic arch pathology and thoracoabdominal segments. These disparate technologies, some of which are here today and some of which will be arriving in the future, have many implications for the specialty of cardiothoracic surgery. They mean that with time cardiovascular operations that are performed through a median sternotomy with the use of cardiopulmonary bypass will have a diminishing role in the treatment of heart disease. Our more traditional operations were and still are effective strategies that have helped very many patients; they are not now obsolete nor will they become so in the near future. However, alternative and less invasive anatomic treatments will continue to emerge and some will be the best choice of treatment for an increasing proportion of patients now treated with open surgery. For our specialty to maintain its position in the treatment of heart disease, cardiac surgeons will need to be able to employ alternative and multiple technologies including open, transthoracic, thoracoscopic, robotic and percutaneous technologies. We will need to be familiar with the emerging intraoperative three-dimensional imaging techniques that will be important for the deployment of new and less invasive therapeutic approaches. It is not difficult to imagine a cardiac operating room of the near future in which a combination of percutaneous, thoracoscopic, and small incisions are used simultaneously to correct complex heart disease with guidance provided by real time three-dimensional imaging. It was possible for a surgeon who finished training in the late 1970s to have a 20-year or 25-year career with very little alteration of their technical armamentarium, but that will never happen again. Adjustment to a future that involves the use of multiple
EDITORIAL LYTLE AND MACK THE FUTURE OF CARDIAC SURGERY
1471
technologies and in which rapid technological change is the norm will stress our current systems of training and practice. Today, many residency programs have a difficult enough time providing effective clinical training in many open procedures, such as valve repair, complex coronary arterial bypass grafts, off-pump coronary surgery, and homograft valve surgery. Adding requirements for percutaneous, robotic, or other technologies is unlikely to be possible for many programs. Training postgraduate surgeons in the use of emerging technologies is also difficult, particularly if those technologies involve radically different skill sets. Specialized fellowships after residency are common today, but such training is more painful and problematic for the surgeon who already has an established practice. Conceptual aspects of new technology can be conveyed with short courses and multimedia, including online presentations, but acquiring skill sets is a different matter. Today the most pressing issue of new technology relates to the development of percutaneous and catheterbased skills for cardiac surgeons. The development of technical symposia pertaining to new technology is being addressed by both The Society of Thoracic Surgeons and the American Association for Thoracic Surgery, but such efforts will really be able to provide only exposure. Computerized simulators may offer help in technical training. In individual institutions, cardiac surgeons have been at least partially trained in catheter-based techniques by cardiology or vascular surgery colleagues. However, truly effective training in state of the art percutaneous technologies will require fellowships months in length and a major commitment from trainees. There are now many vascular surgery-based fellowships in endografting and some will accept cardiac surgeons. Endografting of abdominal aortic aneurysms may be an important step along the way to thoracic endografting and percutaneous valve implantation. The issue of commitment is critical. Some cardiac surgeons will need to “jump off the dock” and dedicate a substantial portion of their careers to the development and use of alternative technologies, as many vascular surgeons have already done. Acquiring new skills almost certainly means giving others up. It is hard to imagine that individual cardiac surgeons will be able to maintain expertise in the multiple skill sets that would allow someone to capably perform open mitral valve repair and complex arterial grafting one day, followed by a percutaneous mitral valve repair and a branch thoracic endograft the next. We must anticipate a further subspecialization within our field based on the use of disparate technologies. For cardiac surgeons to be adept at alternative technologies will also require commitment by practices and institutions to support surgeons making this investment in the future. That may be difficult for small practices or institutions to accomplish. The accentuation of subspecialization raises the question of what “general” cardiac surgeons will do in the future and what their role will be in the many small-volume community hospital programs that currently exist. Realistically, the long-term future of that type of practice may be uncertain, both from the
1472
EDITORIAL LYTLE AND MACK THE FUTURE OF CARDIAC SURGERY
standpoint of a declining volume of coronary bypass surgery and from the need for cardiac surgical programs to support a multiplicity of technologies. This is a disruptive time in the history of cardiothoracic surgery. In the beginning, our specialty was a fount of innovation. However, our history is replete with examples of technologies that began in our specialty and evolved away as procedures became simpler and less invasive, including bronchoscopy, esophagoscopy, and many types of electrophysiology, including defibrillator and pacemaker implantation. It is tempting to say that percutaneous technologies are not within the domain of cardiac surgeons and that we as a specialty are not going to be able to move into this technological arena. If this is the case, our specialty is going to become smaller and the impact of our specialty on the anatomic treatment of heart disease is going to become much less important. There is another view, however, and that is that cardiothoracic surgeons are uniquely qualified to be able to use multiple technologies to solve complex cardiac problems including percutaneous technologies. Certainly our cardiology colleagues have become skilled and imaginative in the use of percutaneous catheter-based technologies, but they are limited to that one technological strategy. Should we choose to expand our capabilities, the future of cardiac surgery can be varied and exciting. It was never logical to think that we would be doing the same operations in the same way for the next 100 years. We all knew that at some point dramatic change would occur, and that point is now. The tremendous advantage
Ann Thorac Surg 2005;79:1470 –2
that we have is the ability to bring multiple technologies to bear, but to do that we need to renew the commitment of our specialty to technological research and development and to training our members in the use of disparate technologies. As Robert Guyton noted in his presidential address to the 40th annual meeting of The Society of Thoracic Surgeons, “If we do not embrace innovation we will become its victims” [5]. The job we face as a specialty is to embrace the possibilities that new technologies offer, to support our colleagues during periods of re-training, and to incorporate new technology safely and efficiently into clinical practice.
References 1. Lutter G, Ardehali R, Cremer J, Bonhoeffer P. Percutaneous valve replacement: current state and future prospects. Ann Thorac Surg 2004;78:2199 –206. 2. Andersen HR, Knudsen LL, Hasenkam JM. Transluminal implantation of artificial heart valves. Description of new expandable aortic valve and initial results with implantation by catheter technique in closed chest pigs. Eur Heart J 1992;13:704 – 8. 3. Bonhoeffer P, Boudjemline Y, Salliba Z, et al. Transcatheter implantation of a bovine valve in pulmonary position: a lamb study. Circulation 2000;102:813– 6. 4. Cribier A, Eltchaninoff H, Bash A, et al. Percutaneous transcatheter implantation of an aortic valve prosthesis for calcific aortic stenosis: first human case description. Circulation 2002; 106:3006 – 8. 5. Guyton R. Presidential address at the 40th annual meeting of The Society of Thoracic Surgeons. Available at www.sts.org/ 2004webcast/faculty.html, accessed October 27, 2004.
The Future of Cardiac Surgery: The Times, They Are a Changin’ Bruce Lytle, MD, and Michael Mack, MD Cleveland Clinic Foundation, Cleveland, Ohio, Medical City Dallas Hospital, Dallas, Texas
“In times of change, the learners inherit the Earth, while the learned find themselves beautifully equipped to deal with a world that no longer exists.” Eric Hoffer
T
he last 50 years have been halcyon days for cardiac surgeons. The technological innovations of cardiopulmonary bypass and heart valve prostheses led to the development of the specialty in the early 1960s. The subsequent development of coronary bypass surgery, an effective anatomic treatment for the most common lifethreatening disease in Western society, led to an explosion in the number of cardiac operations performed and changed cardiac surgery from a specialized service performed only at major medical centers to surgery practiced at many community hospitals. The mid 1970s to the present has constituted the “industrial era” of cardiac surgery. The income generated by relatively standard and reproducible cardiac operations has fueled a dramatic expansion of the medical infrastructure in centers large and small throughout the United States. During this period of time, “cardiac surgery” has meant an operation performed through a median sternotomy with the use of cardiopulmonary bypass. The coronary bypass operation performed with this approach, the basis of cardiac surgical practice in most See page 1812 centers, is an effective operation that has produced good short-term and long-term outcomes. Any fundamental technical innovation within cardiac surgery during this period of time has been relatively modest for many reasons. There has been an understandable reluctance to tamper with success and neither the competitiveness of practice nor medical and legal considerations consistently reward technological innovation in the United States practice setting. Financial imperatives at many institutions have provided impetus for surgeons to concentrate on standard procedures that were important for the economic well-being of the institution. The changes that have occurred in bypass surgery have been mostly incremental improvements of the standard operation, including arterial grafting, off-pump surgery, small incision surgery, and endoscopic conduit harvesting. Even many of these modifications have been adopted only by a minority of surgeons. However, technical innovation in the anatomic treatAddress reprint requests to Dr Mack, 7777 Forest Ln, Suite A323, Dallas, TX 75230; e-mail: [email protected].
© 2005 by The Society of Thoracic Surgeons Published by Elsevier Inc
ment of cardiovascular disease outside of our specialty has been dramatic and profound, particularly in regard to percutaneous technologies. The disruptive technology of percutaneous transluminal intervention (PCI) of coronary artery disease has progressed from the primitive and relatively ineffective use of balloon angioplasty in the late 1970s to the reproducible and largely safe interventions employing drug-eluting stents and platelet inhibitors that are available today for the treatment of a greatly increased proportion of patients with coronary artery disease. Whether or not PCI will produce the equivalent long-term outcomes in the treatment of patients with severe life-threatening coronary artery disease that have been noted with surgery is not yet clear; but it is evident that the procedure-related risks and medium-term outcomes of PCI have become better and more consistent today so that PCI is the most common anatomic treatment for coronary artery disease. Valvular heart surgery has benefited from improvements in prostheses and in myocardial protection, but again these have been iterative improvements rather than dramatic, discontinuous, conceptual innovations in the treatment of valvular heart disease. The recent article by Lutter and colleagues [1] concerning the percutaneous treatment of valve disease published in The Annals of Thoracic Surgery puts cardiac surgeons on notice that coronary artery disease is not the only area of heart disease that may become amenable to catheter-based techniques. Multiple strategies for the percutaneous treatment of valvular heart disease have been attempted and are currently being investigated in both animal models and human subjects. In 1992, Anderson and colleagues [2], (a cardiologist working with surgeons at his institution), implanted percutaneous aortic valves in pigs. During the ensuing decade Bonhoeffer and colleagues [3] achieved multiple percutaneous implantations of valves in the pulmonic position, and Cribier and colleagues [4] have now implanted a percutaneous aortic valve in humans using a device that is undergoing further clinical investigation. Balloon valvotomy has long been used to treat mitral stenosis, but now multiple concepts in the percutaneous treatment of mitral insufficiency are undergoing clinical investigation including edge-to-edge repair and techniques of annuloplasty through the coronary sinus. Today percutaneous aortic replacement and mitral repair devices produce outcomes that are clearly inferior to the corresponding surgical approaches, but these are first generation devices and incremental improvements will make these devices more deliverable, user friendly, Ann Thorac Surg 2005;79:1470 –2 • 0003-4975/05/$30.00 doi:10.1016/j.athoracsur.2005.01.054
Ann Thorac Surg 2005;79:1470 –2
efficacious, and safer. The time course for which this improving technology will make percutaneous strategies competitive with open surgery for a wide spectrum of patients is hard to know, but it is a good bet that such improvement will occur. Percutaneous catheter-based therapy is increasingly available for the treatment of an even broader spectrum of cardiac and vascular disease. Percutaneous alcohol ablation is competitive with surgical myectomy for the treatment of hypertrophic cardiomyopathy, and although less consistently effective than surgery, this treatment has its advocates. Closure of atrial septum defects and patent foramen ovales, as well as left atrial appendage occlusion, are now possible with catheter-based devices. The percutaneous treatment of occlusive and aneurysmal vascular disease is not only possible but is becoming the dominant form of therapy and is delivered by a variety of specialties including vascular surgeons, cardiologists, interventional radiologists, neurosurgeons, and a small number of cardiac surgeons. Although the treatment of aortic arch and thoracoabdominal aneurysms with endografting is not as anatomically reliable as can be accomplished with open surgery, the decreased procedure-related morbidity of stent grafting can be of benefit to many patients who are elderly or have extensive co-morbidities. The devices, while not in infancy, are at least in early childhood. Today branched endografts are becoming available and have been used to treat both aortic arch pathology and thoracoabdominal segments. These disparate technologies, some of which are here today and some of which will be arriving in the future, have many implications for the specialty of cardiothoracic surgery. They mean that with time cardiovascular operations that are performed through a median sternotomy with the use of cardiopulmonary bypass will have a diminishing role in the treatment of heart disease. Our more traditional operations were and still are effective strategies that have helped very many patients; they are not now obsolete nor will they become so in the near future. However, alternative and less invasive anatomic treatments will continue to emerge and some will be the best choice of treatment for an increasing proportion of patients now treated with open surgery. For our specialty to maintain its position in the treatment of heart disease, cardiac surgeons will need to be able to employ alternative and multiple technologies including open, transthoracic, thoracoscopic, robotic and percutaneous technologies. We will need to be familiar with the emerging intraoperative three-dimensional imaging techniques that will be important for the deployment of new and less invasive therapeutic approaches. It is not difficult to imagine a cardiac operating room of the near future in which a combination of percutaneous, thoracoscopic, and small incisions are used simultaneously to correct complex heart disease with guidance provided by real time three-dimensional imaging. It was possible for a surgeon who finished training in the late 1970s to have a 20-year or 25-year career with very little alteration of their technical armamentarium, but that will never happen again. Adjustment to a future that involves the use of multiple
EDITORIAL LYTLE AND MACK THE FUTURE OF CARDIAC SURGERY
1471
technologies and in which rapid technological change is the norm will stress our current systems of training and practice. Today, many residency programs have a difficult enough time providing effective clinical training in many open procedures, such as valve repair, complex coronary arterial bypass grafts, off-pump coronary surgery, and homograft valve surgery. Adding requirements for percutaneous, robotic, or other technologies is unlikely to be possible for many programs. Training postgraduate surgeons in the use of emerging technologies is also difficult, particularly if those technologies involve radically different skill sets. Specialized fellowships after residency are common today, but such training is more painful and problematic for the surgeon who already has an established practice. Conceptual aspects of new technology can be conveyed with short courses and multimedia, including online presentations, but acquiring skill sets is a different matter. Today the most pressing issue of new technology relates to the development of percutaneous and catheterbased skills for cardiac surgeons. The development of technical symposia pertaining to new technology is being addressed by both The Society of Thoracic Surgeons and the American Association for Thoracic Surgery, but such efforts will really be able to provide only exposure. Computerized simulators may offer help in technical training. In individual institutions, cardiac surgeons have been at least partially trained in catheter-based techniques by cardiology or vascular surgery colleagues. However, truly effective training in state of the art percutaneous technologies will require fellowships months in length and a major commitment from trainees. There are now many vascular surgery-based fellowships in endografting and some will accept cardiac surgeons. Endografting of abdominal aortic aneurysms may be an important step along the way to thoracic endografting and percutaneous valve implantation. The issue of commitment is critical. Some cardiac surgeons will need to “jump off the dock” and dedicate a substantial portion of their careers to the development and use of alternative technologies, as many vascular surgeons have already done. Acquiring new skills almost certainly means giving others up. It is hard to imagine that individual cardiac surgeons will be able to maintain expertise in the multiple skill sets that would allow someone to capably perform open mitral valve repair and complex arterial grafting one day, followed by a percutaneous mitral valve repair and a branch thoracic endograft the next. We must anticipate a further subspecialization within our field based on the use of disparate technologies. For cardiac surgeons to be adept at alternative technologies will also require commitment by practices and institutions to support surgeons making this investment in the future. That may be difficult for small practices or institutions to accomplish. The accentuation of subspecialization raises the question of what “general” cardiac surgeons will do in the future and what their role will be in the many small-volume community hospital programs that currently exist. Realistically, the long-term future of that type of practice may be uncertain, both from the
1472
EDITORIAL LYTLE AND MACK THE FUTURE OF CARDIAC SURGERY
standpoint of a declining volume of coronary bypass surgery and from the need for cardiac surgical programs to support a multiplicity of technologies. This is a disruptive time in the history of cardiothoracic surgery. In the beginning, our specialty was a fount of innovation. However, our history is replete with examples of technologies that began in our specialty and evolved away as procedures became simpler and less invasive, including bronchoscopy, esophagoscopy, and many types of electrophysiology, including defibrillator and pacemaker implantation. It is tempting to say that percutaneous technologies are not within the domain of cardiac surgeons and that we as a specialty are not going to be able to move into this technological arena. If this is the case, our specialty is going to become smaller and the impact of our specialty on the anatomic treatment of heart disease is going to become much less important. There is another view, however, and that is that cardiothoracic surgeons are uniquely qualified to be able to use multiple technologies to solve complex cardiac problems including percutaneous technologies. Certainly our cardiology colleagues have become skilled and imaginative in the use of percutaneous catheter-based technologies, but they are limited to that one technological strategy. Should we choose to expand our capabilities, the future of cardiac surgery can be varied and exciting. It was never logical to think that we would be doing the same operations in the same way for the next 100 years. We all knew that at some point dramatic change would occur, and that point is now. The tremendous advantage
Ann Thorac Surg 2005;79:1470 –2
that we have is the ability to bring multiple technologies to bear, but to do that we need to renew the commitment of our specialty to technological research and development and to training our members in the use of disparate technologies. As Robert Guyton noted in his presidential address to the 40th annual meeting of The Society of Thoracic Surgeons, “If we do not embrace innovation we will become its victims” [5]. The job we face as a specialty is to embrace the possibilities that new technologies offer, to support our colleagues during periods of re-training, and to incorporate new technology safely and efficiently into clinical practice.
References 1. Lutter G, Ardehali R, Cremer J, Bonhoeffer P. Percutaneous valve replacement: current state and future prospects. Ann Thorac Surg 2004;78:2199 –206. 2. Andersen HR, Knudsen LL, Hasenkam JM. Transluminal implantation of artificial heart valves. Description of new expandable aortic valve and initial results with implantation by catheter technique in closed chest pigs. Eur Heart J 1992;13:704 – 8. 3. Bonhoeffer P, Boudjemline Y, Salliba Z, et al. Transcatheter implantation of a bovine valve in pulmonary position: a lamb study. Circulation 2000;102:813– 6. 4. Cribier A, Eltchaninoff H, Bash A, et al. Percutaneous transcatheter implantation of an aortic valve prosthesis for calcific aortic stenosis: first human case description. Circulation 2002; 106:3006 – 8. 5. Guyton R. Presidential address at the 40th annual meeting of The Society of Thoracic Surgeons. Available at www.sts.org/ 2004webcast/faculty.html, accessed October 27, 2004.