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As a current assessment
of our specialty of Cardiothoracic Surgery, this is one of the most
important articles ever written. It provides a note of optimism for our
future, based not on hopes or desires, but on factual data. It should
be read and taken to heart by the entire CT community around the world.
If we follow the precepts and suggestions the authors have provided,
and if their statistical predictions on thoracic surgical manpower come
to pass, then indeed all of us should sometime in the near future be
complaining once again that we do not have enough time for leisure
activities. Read, digest and enjoy!
Thomas B. Ferguson, MD
Senior Editor, CTSNet
Introduction
"Any surgeon who wishes to preserve the respect of his colleagues would never attempt to suture the heart."
- From a speech by Christian Albert Theodor Billroth at the Vienna Medical Society Meeting, 1880
"Surgery of the heart has
probably reached the limits set by Nature to all surgery: no new
method, and no new discovery, can overcome the natural difficulties
that attend a wound of the heart."
- Stephen Paget, The Surgery of the Chest, 1896
Those were not only discouraging words but genuine warnings to surgeons at the end of the 19th century that cardiac surgery was not to be a part of their future. Fortunately, the innovative surgical pioneers of the 20th century ignored such misgivings and within a relatively short period of time, produced perhaps the most rapid and dramatic changes in the treatment of one organ system in the history of medicine. Several events are viewed as heralding the beginning of modern cardiac surgery, including Rehn's first successful suture closure of a heart wound in 1896 [1], Cutler's [2] or Soutar's [3] closed procedures for mitral stenosis in the early 1920's, Gross's closure of a patent ductus arteriosus in 1938 [4], the first "blue baby operation" (Blalock-Taussig shunt) in 1944 [5], Harken's first report of the removal of multiple foreign bodies from the heart in 1946 [6], Harken and Bailey's closed mitral commissurotomy procedures in the late 1940's [7,8], Gibbon's first use of the heart-lung machine in 1953 [9] and Lillehei's first cross-circulation case in 1953 [10]. Whatever one's personal bias regarding the relative importance of those individual events, we can all agree that few specialties have produced more good for their patients and more joy of accomplishment for their practitioners than cardiothoracic surgery did during the last half of the 20th century. However, over the past few years, many cardiothoracic surgeons have begun to believe once again that the survival of our specialty is threatened [11-14]. Little wonder then, that for the first time in our history, the number of ACGME-approved positions in North American cardiothoracic surgery training programs now exceed the number of US applicants for those positions [15].
Unquestionably, many factors have combined to take some of the former luster off the specialty of cardiothoracic surgery including increasing workloads and complexity of clinical problems, decreasing reimbursement, and encroachment on the field by non-surgical specialties. Moreover, there is no parallel in all of medicine where one specialty (cardiac surgery) is so dependent upon the whims of another specialty (cardiology) that happens to control virtually all access to its patients and that is also in direct competition for those patients! Indeed, it must seem to young prospects that cardiothoracic surgery is faced with overwhelming problems that simply have no precedent or solution. Not so. This specialty faced a very similar situation in 1968 when one of the 20th century's greatest thoracic surgeons, Dr. O. Theron Clagett of the Mayo Clinic, who was very skeptical of the future of cardiac surgery, made the following statement as a Visiting Professor at Duke University:
"I don't understand all you young residents out there who are just starting your training in heart surgery…. The geneticists are going to learn how to prevent congenital heart malformations before birth, nobody has syphilis anymore, so there won't be any aneurysm surgery, and rheumatic fever is a thing of the past so valvular heart disease will disappear. You simply are not going to have anything to do!"
Like young surgeons must have felt in Paget's time, such a statement from someone of Dr. Clagett's stature was extraordinarily discouraging for those of us in the audience who dreamed of becoming cardiac surgeons, especially since we knew that we would have to labor for another 10 years before we could actually reach our goal. Adding to the consternation over our apparently dubious choice of careers was the observation that chief residents all over the country in that year of 1968 were finding it almost impossible to find a job in cardiothoracic surgery and medical student interest in the profession had already begun to fade. Then an interesting thing happened…the cardiac surgeons of that generation responded to their crisis by creating an entirely new field of surgery, coronary artery bypass grafting (CABG), that subsequently sustained the specialty for the next 3-4 decades.
Despite the reasonable but perhaps unnecessarily pessimistic concerns of some, we believe that such an opportunity again exists in our specialty and we challenge our contemporary surgical colleagues to respond in the same way that our surgical fathers responded … not with dispiriting references to how difficult things have become but with a renewed sense of the innovative spirit that will propel us to develop new and better forms of treatment for diseases that presently go untreated by surgeons. Indeed, we should embrace the changes that are occurring in our specialty and view them not as posing a threat but as providing us with a challenge for innovation. It is time for us to recognize that the root of our current problem is neither financial nor workforce-related but rather the lack of significant, specialty-changing scientific accomplishment within our specialty during the past 20 years. Coronary artery disease was once considered to be a "medical disease" much like atrial fibrillation and heart failure are today. Our predecessors taught us the fallacy of that myth then and we should recognize its fallacy now.
Is it realistic to believe that the specialty of cardiothoracic surgery can grow over the next 5-10 years? Though current trends would indicate otherwise, the math is in our favor. Following the introduction of drug-eluting stents in 2003, CABG volume decreased by approximately 10% by 2005 and it is estimated that another 20% decrease will occur by the year 2010 [16]. Predictably, this decrease in CABG volume has been associated with an increase the complexity of the procedures [17]. Though valve surgery has increased as a proportion of overall cardiac surgical practice, its growth in absolute numbers has been small [18]. The volumes of other procedures such as thoracic aortic procedures and pediatric cardiac surgery have remained relatively stable.
Virtually all of atrial fibrillation surgery is performed as a concomitant cardiac procedure with other cardiac surgery so thus far, atrial fibrillation surgery has not resulted in a significant increase in the overall number of patients undergoing cardiac surgery. Despite that fact, approximately 20,000 concomitant surgical procedures were performed for atrial fibrillation in 2005 in a potential patient population of roughly 50,000 [19]. This "surgical patient population" represents about 2% of all patients with atrial fibrillation. However, there are approximately 3,000,000 patients in the United States with so-called "Stand-Alone" atrial fibrillation and only 10,000 of them underwent catheter ablation in 2005 and virtually none had surgery [20]. The 20,000 surgical ablation patients combined with the 10,000 catheter ablation patients means that only 1% of all US patients with atrial fibrillation are treated by any type of interventional procedure. The other 99% of patients with atrial fibrillation are treated with drugs.
Of the 5,000,000 patients in the US with heart failure, only 8% currently undergo diagnostic catheterization, 2% receive coronary artery stents, and 1% undergo cardiac surgery [21]. In other words, there are 3,000,000 people in the US with atrial fibrillation and 5,000,000 more with heart failure and there is no optimal way of treating over 99% of them! If we as cardiac surgeons could devise a satisfactory therapy for only 10% of those patients, we would add 800,000 patients to our practices, resulting in a patient population of 1.2 million which is over three times the number of people we now operate upon per year. In addition to providing significant improvement in these patients' lives, that should keep us busy for awhile!
The Adoption of New Surgical Procedures
Progress in the specialty of cardiac surgery can be roughly divided by decade as follows:
Decade of the 1940's: Palliative Congential Heart Surgery
Decade of the 1950's: Open Congenital Heart Surgery
Decade of the 1960's: Valve Surgery
Decade of the 1970's: Coronary Artery Surgery
Decade of the 1980's: Cardiac Transplantation
Mechanical
Circulatory Assistance
Cardiac
Arrhythmia Surgery
Decade of the 1990's: All of the above using Minimally Invasive Techniques
Though it is too early to know how the first decade of the 21st century will be characterized, certain principles regarding the development and adoption of new operative techniques and procedures made during the first 50 years of our specialty are likely to remain unchanged. A principle that is important but often unappreciated is that the efficacy of a surgical procedure, i.e., its cure rate, has little to do with how frequently that procedure is adopted by surgeons and applied to patients [22]. Indeed the primary determinant of adoptability is the complexity of the procedure where there is an inverse relationship between the complexity of a given surgical procedure and the rate at which it will be adopted by surgeons (Figure 1). The level of adoptability is virtually unchanged when the efficacy of that procedure is added to the equation (Figure 2).
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Figure 1: There is an inverse relationship between the complexity of a surgical procedure and its adoption by surgeons. Therefore, the more complex an operation, the less likely patients are to be subjected to it. |
Figure 2: The adoptability of a given surgical procedure by surgeons is not significantly affected by the efficacy of that procedure. Thus, the cure rate of a given operation has little to do with how many patients will receive it because the overwhelming determinant of the operation's adoptability is the degree of its complexity. |
The interventional treatment of atrial fibrillation offers a classic example of how this complexity-efficacy-adoptability interplay impacts our daily practices. The Maze procedure is capable of curing nearly 100% of all patients with AF if it is performed correctly [23-24]. Yet its complexity is so great that it has not been widely adopted by surgeons. Despite the fact that there are 3,000,000 people in the United States with atrial fibrillation, the theoretical number of patients who might ever be subjected to the Maze procedure would maximize at around 150,000 (Figure 3) and that is an order of magnitude larger than the number of patients who are actually receiving the procedure or one of its derivative procedures some 15 years after it was first described. Since the cure rate is so high with the Maze procedure, the number of patients cured of atrial fibrillation is essentially the number subjected to surgery. When pulmonary vein isolation alone was initially shown to be effective in treating certain types of atrial fibrillation, this much simpler procedure was applied to large numbers of patients by both interventional cardiologists and surgeons [25, 26]. The overall cure rate for pulmonary vein isolation has proven to be approximately 60% for all patients (paroxysmal, persistent and permanent) with atrial fibrillation [25-29], as opposed to the 96% long-term cure rate for the Maze procedure [23,24], but because PV isolation is so much simpler to perform, its adoptability rate has dwarfed that of the Maze procedure. Thus, despite a cure rate that is only slightly over one-half that of the Maze procedure, the theoretical number of patients who could be cured of AF by PV isolation is 8-10 times as great as with the Maze procedure (Figure 4)! These numbers document once again that the efficacy of a given procedure has little to do with its adoptability and ultimately, therefore, with the number of people who might be cured by that procedure.
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Figure 3: The Maze procedure has a cure rate of nearly 100% (A) but is maximally complex (B) on this imaginary scale. Its relative complexity (B) dictates that it will be applied to few patients (C). |
Figure 4: Pulmonary Vein Isolation has a cure rate much less than that of the Maze procedure (A) but is much less complex (B) than the Maze procedure. Its relative simplicity (B) dictates that it can be applied to more patients (C) than the Maze procedure. The result is that even though PV Isolation is much less effective than the Maze procedure, the absolute number of patients who can be cured by PV Isolation is nearly 10 times as great as that with the Maze procedure. |
In view of this complexity-efficacy-adoptability relationship, where is innovation in cardiac surgery most likely to be fruitful in the near future? The US numbers for thoracic aortic surgery and congenital heart surgery have been relatively stable for the past several years. Growth in these two areas has not been related to innovation, or lack thereof, since essentially all patients with these problems who need surgery now receive it. Recent innovations such as endovascular stenting for thoracic aortic aneurysms and catheter-based closure devices and valve implantations for congenital anomalies have the potential to decrease the number of patients undergoing surgery in these areas in the future. However, the potential decrease in thoracic aortic surgery may be offset by the aging of the population, especially since the "baby boomers" are just now entering their 60's. The percentage of the population over the age of 65 years was 4.1% in 1900 and 12.6% in 2000 and it is projected to be 20% by 2030 [30]. The US Census Bureau reports that as of July 1, 2005, there were 78.2 million "baby boomers" (born 1946-1964) and that 7,918 people turn 60 each day, a rate that corresponds to 330 people every hour [31]. These numbers will certainly translate into greater absolute numbers of patients with thoracic aortic disease in the future but the net effect on surgical volume of the competing factors of population aging and non-surgical innovation remains to be seen. The potential for innovation in the other areas of cardiac surgery varies with the specific field but overall provides fertile ground for surgeons who are inclined to accept the challenge.
The Effect of Innovation on Specific Categories of Patients
Aortic Valve Surgery
Figure 5:
Standard Aortic Valve Replacement (AVR) is not a complex operation (B)
and is therefore available to most all patients (C). It has the
added bonus of being curative (A), so its
complexity-efficacy-adoptability relationship is perhaps as close to
perfection as the specialty allows.
Aortic
valve surgery has the potential to increase substantially in the
future, though the means by which it may increase is somewhat
speculative. The contemporary complexity-efficacy-adoptability
interplay for aortic valve replacement is optimal in that the current
approaches are not complex and therefore, have been utilized by
essentially all cardiac surgeons for decades. The established
approaches are also essentially 100% curative (Figure 5).
The minimally invasive surgical techniques developed over the past 10
years may offer some marginal qualitative improvement over the older
median sternotomy approach but they have not resulted in a demonstrable
increase in the absolute number of patients undergoing the procedure.
However, the shear number of patients at risk for the development of
aortic stenosis will increase over the next 2-3 decades due to the
dramatic aging of our population. In addition, there may be significant
numbers of patients, especially women, who have such severe aortic
stenosis that they have been deemed inoperable by their primary care
physicians. It is those patients for whom the percutaneous techniques
for aortic valve replacement have been developed. Percutaneous aortic
valve replacement (AVR), either via the femoral route [32] or by a more
direct trans-apical approach [33], represents one of the most
innovative developments of the past decade. However, the very patients
who are now apparently going without standard AVR, elderly women with
aortic stenosis, are precisely the ones who have small femoral vessels
that make the current methods of femoral vessel cannulation
problematic. For that reason alone, the direct trans-apical approach
seems to be more feasible in these patients and this approach is more
likely to be performed by surgeons than by cardiologists. However, if
trans-apical AVR were eventually to be performed by cardiologists, this
particular innovation could decrease the number of aortic valve
replacements performed by surgeons in the future.
Whether a sizeable cohort of untreated patients with severe aortic stenosis actually exists and materializes for percutaneous AVR in the future remains to be seen. What seems certain, however, is that percutaneous AVR will not likely be performed in patients who are "not sick enough" to warrant open valve replacement as it is inconceivable that one would implant an artificial valve in a patient with an insignificant aortic valve gradient (assuming normal cardiac output) regardless of how non-invasive the procedure itself might be. Thus, while the potential for innovation in the field of aortic valve surgery is high, the notion that innovation itself will result in a substantial increase in the number of patients undergoing AVR by surgeons is suspect. However, it seems clear that with the aging of the population, the arrival of the "baby boomers" and the recruitment of more elderly patients for percutaneous AVR, cardiac surgeons are destined to perform more aortic valve surgery in the future than we have in the past.
Mitral Valve Surgery
Like
aortic valve replacement, standard mitral valve replacement (MVR) has
had an optimal complexity-efficacy-adoptability relationship for
several decades. By the mid-1980's, cardiac surgeons finally began to
accept the idea of repairing, rather than replacing, the mitral valve.
Subsequent studies showed the superiority of repair over replacement in
fairly well controlled clinical trials [34] and some institutions
repair the mitral valve in 80% of their patients for certain conditions
[35]. Interestingly, however, the national average for mitral valve
surgery has remained around 50% [18] and while these innovative repair
techniques have clearly benefited patients, they have not resulted in
an increase in the absolute number of patients undergoing mitral valve
surgery. Likewise, the impressive minimally invasive techniques for
mitral valve repair/replacement developed during the past decade may
have enhanced patient care qualitatively but they have not
significantly increased the number of patients treated surgically.
Unlike the case in patients with aortic valve disease, there are large numbers of patients with mitral valve insufficiency who "are not sick enough" to warrant an open repair/replacement but who can benefit from a less intrusive surgical procedure. Over 30 devices are currently in various stages of development and evaluation for the percutaneous treatment of mitral insufficiency [36]. Several are based on the "Alfieri stitch" concept [37] using a clip rather than a suture to approximate the edges of the two mitral leaflets [38] while others have developed techniques for decreasing the size of the mitral annulus using devices placed inside the coronary sinus [39]. These approaches are actually recruiting additional patients but the numbers are small and the procedures are being performed primarily by cardiologists. While these approaches may work temporarily, they also have the potential to simply defer open surgery to a later date, dictate that the deferred surgery be mitral valve replacement rather than repair, and make the surgery more difficult and risky when the time comes. Thus, the current status of mitral valve surgery cries out for the development of trans-apical techniques that are capable of accomplishing definitive Carpentier-type anatomic repairs of the mitral valve. With the rapid evolution in access, visualization and imaging techniques, this is one of the most fertile areas for innovation and patient growth in all of cardiac surgery.
Atrial Fibrillation Surgery
As
mentioned above, despite almost a decade of experience, less than 1% of
all patients with atrial fibrillation are currently treated by catheter
ablation and surgery combined. This lack of growth in interventional
techniques speaks to the persistently high failure rate and
questionable safety of catheter ablation techniques [29] and to the
unacceptable degree of invasiveness of so-called "minimally invasive"
surgery for atrial fibrillation [40]. Indeed, it is hard to convince
patients that a surgical procedure is truly "minimally invasive" when
it takes over 4 hours to perform, requires general anesthesia,
dual-lumen endotracheal intubation (or intra-bronchial balloons), three
surgical incisions in each chest, the deflation of each lung
individually, bilateral incisions in the pericardium, bilateral
postoperative chest tubes and 2-3 days of hospitalization … not to
accomplish a curative Maze procedure but rather to accomplish simple
pulmonary vein isolation and left atrial appendage closure! Yet, that
is the best that we surgeons have been able to do thus far in our
efforts to compete with our cardiology colleagues who simply puncture
blood vessels to gain access to the heart for their catheter ablation
procedures. Despite the fact that a good argument can be made that
the surgical procedure actually is less invasive than the catheter
ablation procedure, it is difficult to sell that concept to patients
and it is impossible to sell it to cardiologists and industry.
Since 1998 when Haissaguerre, et al, published their seminal article showing that approximately 90% of all episodes of atrial fibrillation are initiated by "triggers" in the region of the pulmonary orifices in the left atrium [41], multiple new energy sources have been developed, first to isolate the pulmonary veins and later to create additional lesions in the left atrium. Along with the introduction of these new energy sources, there was general agreement among both cardiologists and cardiac arrhythmia surgeons at the time that the best course from that point on was to delete as many of the Maze-III lesions [42] as possible in an effort to make interventional therapy, both catheter and surgical, more feasible in larger numbers of patients. Unfortunately, this simultaneous introduction of two variables, new energy sources and new lesion patterns, dictated that when failures subsequently occurred, it would be impossible to determine the cause of those failures. Did a given approach fail to cure the atrial fibrillation because the energy source was inadequate or because the lesion pattern was inappropriate for that patient? This dilemma has been magnified by the fact that cardiologists have no way of knowing the precise location and degree of tissue destruction that they create inside the left atrium with radiofrequency catheters [43]. Over the past decade, this central fact has led to a cumulative confusion and misinterpretation of the relationship between lesion patterns and cure rates [44] and to the development of controversial concepts regarding the electrophysiology of atrial fibrillation that were then needed to explain otherwise unexplainable results [43-46]. The result is that nearly a decade after Haissaguerre's seminal article and after the infusion of billions of dollars by industry, we find ourselves employing these catheter and surgical procedures and devices in only 1% of all patients with atrial fibrillation while achieving overall long-term cure rates of only about 60% even in that small fraction of patients [27-29] (Figure 6). If these were the results of a new expensive and risky chemotherapeutic agent for cancer, the drug would have been discarded years ago in favor of a more promising approach!
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| Figure 6: If the 3 million patients in the US with atrial fibrillation were represented as the Empire State Building (1,453 ft, 110 stories), all combined catheter and surgical ablation (8 ft.) would currently not reach the ceiling of the first floor. Only 5 ft. of those patients (60%) would be cured of their AF. | Table I: Timeline for the development of interventional procedures for cardiac arrhythmias. |
Thus, despite the current popularity of interventional treatment for atrial fibrillation, the field remains open to the development of a simple and practical way of treating the 99% of patients who now must depend solely on drugs to control their arrhythmia. If the past 40 years of clinical electrophysiology has taught us anything, it is that surgeons will have to develop these new interventional approaches. This seemingly self-serving statement is supported by the fact that surgeons first developed the interventional techniques to treat all other types of cardiac arrhythmias years before interventional cardiologists learned better ways to intervene (Table I). One intriguing possibility for the development of a surgical procedure to treat atrial fibrillation that is comparable in "invasiveness" to catheter ablation is endoscopic intrapericardial surgery [47]. It is clearly safer to apply any ablative energy from the epicardial side of the atrium than from the endocardial side where it can penetrate into surrounding structures such as the esophagus [48] and phrenic nerves [49]. This raises the prospect of off-pump surgery but unfortunately, most of the available energy sources are not capable of producing uniformly transmural lesions when applied epicardially off-pump because of either the "cooling sink" effect or the "heat-sink" effect of the intracavitary blood. Newer energy sources may be capable of overcoming this and other more subtle limitations and if so, the endoscopic placement of epicardial lesions via the subxiphoid approach for the treatment of atrial fibrillation will become a reality. Because this approach avoids the pleural spaces, neither endotracheal intubation nor general anesthesia would be necessary, paving the way for these procedures to be performed on an outpatient basis. Historically, any procedure that requires the visualization, identification and manipulation of anatomy (except that inside anatomic tubes such as the bronchi and the gastrointestinal tract) has remained in the hands of surgeons (e.g., laparoscopic surgery). Indeed, the visualization and manipulation of anatomy is the very definition of the term "surgery."
Procedures in which images, rather than anatomy, are manipulated usually end up in the hands of non-surgeons (e.g., coronary angioplasty). Thus, if endoscopic techniques are developed for the treatment of atrial fibrillation in which the energy is applied from the epicardium, it will likely remain in the hands of surgeons. Because there are vast numbers of patients with atrial fibrillation who cannot be treated by any of the contemporary catheter or surgical approaches, such endoscopic atrial fibrillation procedures may well become the most common type of cardiac surgery performed in the future. If that speculation proves to be true, the "crisis" in cardiac surgery will not be a lack of enough cases for the available surgeons to perform but rather a lack of enough surgeons to perform the available cases.
Heart Failure Surgery
Figure 7:
Projected growth of congestive heart failure (CHF) in the US.
Currently, there are approximately 5 million patients in the US with
heart failure and that number is expected to reach 10 million in
another 13 years.
There
are approximately 5 million people in the United States with heart
failure, a number is projected to double by the year 2020 (Figure 7),
and one-half million new cases of heart failure are diagnosed each year
[50, 51]. Therapy still depends primarily on drugs that are of limited
effectiveness in that one-half of the patients will be dead within 5
years of the time of their first diagnosis. There have been many
attempts at interventional therapy for heart failure including
re-synchronization, heart transplantation, internal mechanical
circulatory assistance (pulsatile assist, continuous flow and
counterpulsation devices), external mechanical circulatory assistance,
and various types of cardiac surgery including coronary artery bypass
grafting, cardiomyoplasty, mitral annuloplasty, the "surgical
ventricular restoration" (SVR) procedures and various combinations of
these procedures. All of these approaches have their own limitations
and successes. Despite mixed results, the most frequent interventional
procedure performed today is re-synchronization therapy. The beneficial
effect on cardiac hemodynamics of synchronization between atrial and
ventricular contraction (A-V synchrony) has been recognized for
decades. However, the added benefit of synchronized contraction between
the two ventricles has been touted only within the past few years
[52]. The physiology that drives this market and the end-points
that are used to determine clinical improvement are somewhat vague and
may explain why it is difficult to predict which patients will benefit
from re-synchronization therapy and which ones will not.
 |
| Figure 8: Effect of ventricular dysynchrony on the cardiac index under controlled experimental conditions with normal ventricles. Optimal re-synchronization from + 40 msec causes an increase in cardiac index of only 0.3 L/min/M2. (See text for further discussion). L/min/M2 = Liters per minute per square meter of body surface area; RV = right ventricle; LV = left ventricle; msec = milliseconds. |
Since cardiac transplantation is not possible in the vast majority of patients who need it, there has been a resurgence of recent interest in the so-called SVR group of operations in which grossly dilated ischemic cardiomyopathic ventricles are surgically down-sized and reshaped from their acquired globular form to the more physiologic cone shape [58-62]. Associated mitral valve abnormalities are also addressed at the time of surgery as are coronary arteries that need to be bypassed. The results of this approach are similar to the results of cardiac transplantation in that the operative mortality rate is around 5% and the 5-year survival rate for both is 70% [51]. Though this surgery is highly effective and carries an acceptable risk in these critically ill patients, its complexity suggests that it will not be widely adopted by surgeons, at least for several years. However, there may be less invasive ways of surgically correcting these problems and if so, the new techniques would add to the future "problem" of not having enough cardiac surgeons to perform the available surgery.
Coronary Artery Bypass Grafting (CABG)
Following
the clinical introduction of drug-eluting stents in 2003 there was a
13% decrease in the number of CABG's performed in the United States
from 306,000 to 267,000 and that number is predicted to drop another
21% to 209,000 by 2010 [16, 63]. Few prognosticators believe that we
will ever again see the level of CABG surgery that was present just a
few years ago. But is that notion immutable? Surprisingly, only 11% of
all patients with ischemic cardiomyopathy and heart failure currently
undergo cardiac catheterization including 8% who have cardiac
catheterization without angioplasty/stenting, 2% who have cardiac
catheterization with angioplasty/stenting, and 1% who have cardiac
catheterization followed by coronary artery bypass grafting [21].
However, two-thirds of patients with heart failure due to ischemic
cardiomyopathy have hibernating myocardium [64] and could therefore, be
reasonably expected to improve with angioplasty/stenting or CABG. In
the past, there has been no quick, accurate, non-invasive and
economical way of distinguishing between patients with and without
hibernating myocardium. Cardiac MRI may be capable of overcoming that
problem and if so, the number of heart failure patients who would then
undergo PTCI and or CABG would increase dramatically.
 |
| Figure 9: If Cardiac MRI were routinely employed in all patients with Ischemic Cardiomyopathy and only 50% of those with recoverable myocardium underwent a followup diagnostic cardiac catheterization (Cath), it would generate over 560,000 new interventional angioplasty/stent procedures for cardiologists and over 370,000 new CABG's for cardiac surgeons. |
Attracting Residents and Students into the Specialty
The
above discussion has attempted to make the case that cardiothoracic
surgery is not only a viable specialty but one whose best years may lie
in the future. This notion depends not only on surgical volume and
innovation but also on attracting the best and brightest to our
specialty. Predicting manpower needs is always complicated but consider
the following. The mortality rate from cardiovascular disease has
plummeted over the last several years leading to extended survival for
many people [51]. Despite the concerns of many cardiac surgeons
regarding the viability of our future as a specialty, many others share
our concern about an impending crisis of the opposite type. For
example, medical schools are being encouraged to increase their numbers
and some states are financing the creation of new medical schools to
meet this perceived impending need. An AATS/STS workforce survey
commissioned by the AAMC predicts a future shortage of cardiothoracic
surgeons, even in the most conservative of circumstances in which there
is no future increase in coronary artery bypass surgery and the future
graduation rate remains stable at 130 residents per year [65]. As has
been suggested in this paper, we believe that there actually will be an
increase in patients requiring coronary artery surgery and with the
significant decrease in resident applicants in the last 3 years
(including this current year), a shortage of cardiothoracic surgeons
seems inevitable.
There are multiple ways to address this important issue and that will be the topic of a special AATS/STS joint conference in the summer of 2007. Many of the preliminary ideas for innovative solutions would require an additional manuscript for proper explanation but a few of the more practical solutions can be scaled across most all of the existing residency programs. Among the most important changes to be advocated is that leaders in our specialty should recognize that cardiothoracic surgery remains a vibrant profession and that despite the current environment they should embrace the opportunities for change and continue the innovative process that has been characteristic of the specialty since its birth. Providing good role models has been and will remain a primary reason for an individual to choose the specialty.
In addition, innovative programs for both undergraduate and graduate students can encourage individuals to enter medicine, surgery, and cardiothoracic surgery. At Johns Hopkins two programs have been introduced to develop an interest in our specialty, one at the undergraduate level and one for medical students. In 2002, in collaboration with the Johns Hopkins University Premedical Advisory Office, a three-week rotation on the Cardiac and Thoracic Surgical services was established for four undergraduate students.. The Premedical Office selected students from both premedical and bioengineering majors. After the initial year there were nearly 100 undergraduate applicants for these four positions. During the initial four years of the program, eighteen undergraduate students with a defined curriculum rotated onto the two clinical cardiac surgical services. The curriculum included rounding with the senior residents, observing in the operating room and intensive care units, and attending all educational conferences, grand rounds, and various other informational and educational meetings [66]. Seventeen of the eighteen students completed questionnaires following their rotations. Nine indicated a joint interest in premedical science and bioengineering and six in this group were undecided about medical school before their rotation. However, all six students made the decision to go to medical school following their 3-week rotation on the cardiothoracic surgical services. Four of the 17 students indicated that they planned to complete training in a surgical specialty and two of them said they would consider cardiothoracic surgery. Overall, all seventeen of the undergraduate students were extremely enthusiastic about their 3-week tour and seven of them indicated that this rotation was the most rewarding experience that they had had in their 3 years of college. All seventeen students were eventually admitted to medical school. Since this initial report, four additional students rotated through the program in 2006 and all have been subsequently admitted to medical school.
A similar experience was developed for medical students to spend time in the cardiac surgery research laboratory at Johns Hopkins. Follow-up is available on fourteen medical/premedical students who rotated to the research laboratory for at least one summer since 2004. Each student was assigned a particular clinical research project. All fourteen students presented their work at the end of the summer. This work resulted in at least one publication for each of these students. One particular medical student who began as an undergraduate student, currently has 15 scientific publications and has had 7 presentations at major cardiothoracic surgical meetings.
It is too early to know how many of these students will eventually
end up in cardiothoracic surgery but these students all feel
enthusiastic about the specialty. Similarly, within the general surgery
residency program at Johns Hopkins since 2004, six categorical
residents have declared an interest in cardiothoracic surgery and have
either been admitted to cardiothoracic surgery residency programs or
are in the application process. Although these programs have been
developed at Johns Hopkins, they are not unique as other institutions
have introduced similar programs. The method requires a positive and
supportive environment, development of programs attractive to students
and residents and an interaction with cardiac surgeons beginning at the
undergraduate level.
Summary
The
demise of cardiac surgery was predicted before its birth, similar
predictions continued during its most explosive years of development
and have perhaps now reached their pinnacle just as the specialty
prepares for its next era. Despite the pessimistic outlook espoused by
many in our profession, the decreasing caseload for most cardiac
surgeons, and the paucity of new recruits to the specialty, the most
exciting, productive and challenging days of cardiac surgery might
actually lie ahead. It is almost certain that the aging of the
population, the influx of the baby-boomer generation, and the
development of newer imaging modalities and interventional therapeutic
capabilities will have the effect of creating more work than the
present number of cardiac surgeons can handle. Even the most cursory
assessment of the numbers suggests an oncoming supply/demand problem.
Indeed, the crisis that our specialty faces in the near future is not
that the specialty is finally dying, as predicted for the past 150
years, but that we are not training enough cardiac surgeons to cope
with the vast increase in the numbers of cardiac surgical patients who
are likely to need our services during the next decade. Fortunately,
our more thoughtful leaders and our more productive innovators are
quite busy in preparing our specialty for that impending crisis.