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Ann Thorac Surg 1995;59:269-274
© 1995 The Society of Thoracic Surgeons
Section of Thoracic and Cardiovascular Surgery, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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Introduction |
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 TopFootnotes Introduction AcknowledgmentsReferences |
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It is with trepidation and humility that I stand at this podium, surrounded by peers, many with talents that I have both admired and attempted to emulate; I feel honored to have this opportunity to address you. I recognize that most of what I have been able to do as an academic surgeon has been accomplished with the support and help of my family, my associates, and the thoracic residents with whom I have been privileged to work. I wish to dedicate this presentation to my family, the surgeons with whom I had the privilege to train, the surgeons with whom I have worked and been part of their training at the University of Oklahoma, and my mentors, many of whom are in this audience.
The Southern Thoracic Surgical Association has been very important in my surgical career; my first scientific presentation to a national meeting was at the 1971 meeting of the STSA in Tampa, Florida. At that meeting, I was awakened rapidly to some of our uniqueness when my co-author and Past President Dr Alex Haller became a contender for the Osler Abbott Award by discussing the first seven papers of the program, including our paper. A few years later one of my residents gave a presentation on the surgical management of aortic valve endocarditis; he and I both were relieved when our nominated slide received only sharp criticism from Past President Dr Francis Robicsek, not the Tiki Award. Since that time, I have learned to fear the empty slot or slots found in the slide tray at the time of retrieval from the projectionist at the conclusion of a presentation. In reviewing the previous Presidential Addresses, the array of topics is impressive, but they provide little guidance in selecting an appropriate talk or title. Knowing that there are many in the audience more closely involved in the evolution of socioeconomic, humanistic, and educational issues and that I really am not a philosopher, I have elected to discuss congenital aortic valve disease. I have had a strong personal interest in its management, and the evolution of its surgical management has mirrored the development of cardiac surgery.
The incidence of congenital heart disease has been estimated at 4.9 to 7.4 per 1,000 live births, and the incidence of congenital aortic stenosis is estimated at 3% to 6% of patients with congenital cardiovascular defects [1]. The presence of a congenital bicuspid aortic valve frequently is not detected early in life, and it is not widely appreciated that it may actually be the most common congenital malformation of the heart. Campbell [2] has estimated the incidence of congenital bicuspid valve at 4 per 1,000 live births, whereas other estimates are higher [3]. Fenoglio and associates [4] reported that among children born with a bicuspid aortic valve, one third will have normal function throughout life, one third eventually will have calcific aortic stenosis, and one third will have aortic insufficiency. Many of the patients who require surgical treatment for aortic valve disease in adolescence or as a young adult are patients in whom progressive aortic insufficiency develops and who have a bicuspid aortic valve. Congenital aortic stenosis occurs at the valvar, subvalvar, and supravalvar level or as a combination of these levels. In this discussion, I am limiting the presentation to those patients with stenosis at the valvar or subvalvar level and those with aortic insufficiency, as they are likely to require aortic valve replacement sometime in their lifetime.
The first cardiac valvular problem for which a surgical solution was sought was congenital aortic stenosis. In 1912, Theodore Tuffier successfully operated on a 26-year-old patient with aortic stenosis [5]. Tuffier invaginated the aortic wall with his finger and was able to dilate the stenotic aortic valve. During the next 40-plus years, many surgeons developed techniques to dilate the stenotic aortic valve. These included approaches through the ascending aorta, the innominate artery, the left atrium, and the left ventricle. Our own Dr Edward Parker was involved in the development of one of the early transaortic dilators [6]. By 1956, Dr Charles Bailey and associates [7] reported their experience in 287 patients using either a triradiate transventricular dilator or a preferred supravalvular or transaortic approach using an artificial ``aortic appendage.'' Indications for the operation, choice of incision (right thoracotomy, left thoracotomy or median sternotomy), and expected results were being developed. Transventricular dilation was recommended for valvar or subvalvar congenital aortic stenosis. The first successful transventricular dilation of discrete subvalvar aortic stenosis probably was reported by Dr Alfred Blalock in 1952 [8].
The first aortic valvulotomy under direct vision was in 1956; Swan and Kortz [9], using inflow occlusion and hypothermia, successfully operated on a 5-year-old girl. In the same year, Lillehei and colleagues [10] performed a similar procedure using extracorporeal circulation. In this landmark case, retrograde coronary perfusion through the coronary sinus was used for myocardial protection and prevention of coronary air embolism. The National Heart Trainee at that historic operation was Dr Vincent Gott. These hallmark procedures were preceded by many years of intense investigation of hypothermia and inflow occlusion. The contributors to the understanding and development of hypothermia by surface cooling, techniques to avoid air embolism, avoidance and management of ventricular fibrillation, and the use of extracorporeal circulation and hypothermia are many, but certainly among the leaders in this effort were Wilfred Bigelow, Ite Boerema, Henry Swan, and our honored guest Mr Donald Ross.
John Gibbon was clearly the father of the heart-lung machine. It was his idea in 1931, followed by an almost continuous research effort of almost 20 years that culminated in the first successful clinical operation on May 6, 1953. Gibbon's oxygenator was a screen oxygenator with six screens, and blood was allowed to film down each side of the screen with an oxygen and carbon dioxide gas mixture flowing between the screens. Following this success, numerous advances occurred in design and types of oxygenators, including rotating discs, bubble oxygenators, and, finally, the introduction of the membrane oxygenator by Kolff and Balzer [11].
With the advent of relatively safe oxygenators and perfusion circuits, many cardiac surgeons contributed to the knowledge base that currently allows us to operate on the aortic valve with a surgical mortality approaching that of an appendectomy or a cholecystectomy. These include hemodilution, introduced by Greer, Carey and Zuhdi in 1960 [12], and potassium-induced cardiac arrest, introduced by Dennis Melrose [13], abandoned and then reintroduced by William Gay and our distinguished guest Dr Paul Ebert in 1973 [14] and subsequently accepted worldwide. In 1959, Norman Shumway and his associates introduced surface cooling of the heart for myocardial preservation. This was followed by the introduction of topical cold arrest with iced Ringer's lactate by Hufnagel, as well as the use of an insulating pad behind the heart. The use of saline slush certainly was popularized by the clinical experiences of Francis Robicsek, Paul Sanger, and others. Jerry Buckberg introduced the use of blood as the vehicle for the cardioplegic solution in 1978. Almost all aortic valve operations now are accomplished using systemic hypothermia and cardiopulmonary bypass. Who should be credited with the introduction of this combination is not known, but certainly Frank Gollan and Ake Senning were among the earliest. Will Sealy and Glenn Young made very important contributions to the understanding of hypothermic cardiopulmonary bypass. I already have mentioned the first report of the clinical use of retrograde coronary perfusion; Dr Gott and his co-workers developed the technique, including establishing the safe perfusion pressure and flow requirements for myocardial protection. However, it, like many other advances, was not accepted widely until its reintroduction clinically by Menasché and associates [15].
The story of the development of effective valve reconstructive surgery and of valve replacement is germane to my presentation, but I only wish to mention two singular events. The first successful subcoronary implantation of a homograft aortic valve was by Mr Donald Ross on July 24, 1962 [16], and his first pulmonary autograft replacement of the aortic valve was in 1967 [17]. These two events have had a major impact on the management of congenital aortic valve disease, and I hope to convince you of this by sharing our clinical experience with you. Aortic valvulotomy or commissurotomy and resection of subvalvar aortic obstruction have proved to be palliative operations. Most of these children require a subsequent cardiac operation, and many ultimately require aortic valve replacement. The present review was conducted to delineate those factors that affect the need for reoperation and the prognosis for an individual child.
The first open aortic valvulotomy at the University of Oklahoma Hospitals was performed in January 1960, and through September 1994, 256 patients have had a surgical procedure for congenital aortic valvar or subvalvar stenosis, aortic insufficiency, or a combination of these lesions. Three patients have been lost to follow-up, and limited follow-up is available on an additional 14 patients (93% complete; median follow-up, 7.6 years; range, 1 month to 32 years). Where applicable these data have been used to analyze survival, freedom from reoperation, and freedom from aortic valve replacement. The effect of age at first operation, diagnosis, type of first operation, and type of subsequent operations on survival and life style have been assessed.
The demographics of this population are as follows: 196 patients (76%) were male and 60 (24%) were female. Seventy had an aortic valve operation before age 1 year, and an additional 58 had surgical treatment by age 5 years, for a combined total of 51%. Median age of patients at first aortic valve operation was 4.9 years, with a range of 0 to 26 years. The median age at first aortic valve operation has decreased: 10.4 years for the 1960s, 4.5 years for the 1970s, 4.1 years for the 1980s, and 3.4 years for the 1990s. One hundred seventy patients had valvar aortic stenosis, 67 had subvalvar stenosis, and 19 had aortic insufficiency. Twenty-two had an associated coarctation of the aorta and 19 had an associated ventricular septal defect. The first aortic valve operation was an aortic valvulotomy or valvuloplasty in 146 patients, a subvalvar resection in 67, and an aortic valve replacement in 43. As in most cardiac centers, initial operative treatment in patients with valvar aortic stenosis at the University of Oklahoma has been an open aortic valvulotomy using cardiopulmonary bypass, attempting to restore near-normal function of the diseased aortic valve. In patients with subvalvar aortic stenosis, a subvalvar resection of the obstructing membrane is accomplished. In the more recent years, patients with relatively small gradients have undergone elective resection of their subvalvar obstruction combined with a left ventricular myomectomy in hopes of avoiding the development of recurrent obstruction or the development of aortic valve insufficiency from the poststenotic turbulence impacting on the valve. Early in our experience, many patients underwent multiple reoperations or reoperation was delayed to avoid aortic valve replacement with a prosthetic valve.
Patients excluded from analysis in this study include those patients with aortic stenosis associated with hypoplastic left heart syndrome, those who had associated significant cardiac defects such as double-outlet right ventricle, truncus arteriosus, or interrupted aortic arch, and those patients in whom subvalvular aortic stenosis developed after correction of an atrioventricular septal defect or closure of a ventricular septal defect. Included were those patients with associated coarctation of the aorta, aortic insufficiency associated with a ventricular septal defect, and aortic stenosis and mild to moderate congenital mitral valve abnormalities.
Actuarial survival of the 249 patients in whom adequate follow-up was available was 72% ± 7% at 22 years (Fig 1
). Follow-up in this group of patients was a mean of 9.1 years with a maximum of 32.6 years. Twelve patients died at their first operation for an operative mortality of 4.8%. There were 17 late deaths; nine of these were associated with reoperation. In the remaining eight, which of these were cardiac related could not be determined. The timing and freedom from reoperation in the surviving 237 patients is shown as an actuarial analysis in Figure 2. At 20.5 years only 27% ± 5% have not required reoperation. The late survival and the requirement for reoperation clearly are affected by the severity of the underlying abnormality and the ability of the surgeon to correct the defect. To assess the effect of the severity of the congenital abnormality, the patients were analyzed by looking at those patients who required their first operation before age 1 year, at 1 to 5 years, and at more than 5 years of age. The analysis of those less than 1 year of age as compared with those between 1 and 5 years demonstrates an increased early mortality and reoperation rate in those operated before age 1 year, but by 8 years postoperative the survival and freedom from reoperation are similar (Fig 3). Due to the limited number of patients in these age groups with more than 8 years of follow-up, further analysis was accomplished with the two groups combined. Freedom from reoperation or late death in the 128 patients who had their first operation before age 5 years was 13% ± 5%. In the 121 patients having their first operation after age 5 years, the freedom from reoperation or death was 55% ± 6% at 15 years (p = 0.001) (Fig 4). In the early years of this series of patients, children younger than 5 years rarely had surgical treatment for aortic valve disease. However, since 1970 the frequency for the first operation occurring before age 5 years has remained relatively constant, ranging between 55% and 59% of the operations during the decades of the 1970s, 1980s, and 1990s. A group of patients of particular concern are those with neonatal aortic stenosis. Thirty-one patients less than or equal to 30 days of age at the time of operation are included in this series. Twenty-five survived their first operation, and there have been no late deaths. Seventeen have required additional procedures: 2 had a balloon valvuloplasty, 1 had a repeat aortic valve commissurotomy, and fourteen have undergone pulmonary autograft replacement of their aortic valve.
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). This series clearly indicates the palliative nature of conservative operative approaches to congenital valvar aortic stenosis or discrete subvalvar stenosis. In most patients with valvar aortic stenosis, progressive deformity of their aortic valve will develop with recurrent stenosis or aortic insufficiency. And of those patients with subvalvar obstruction, many will have recurrent obstruction or progressive aortic insufficiency and require aortic valve replacement. The progressive nature of this lesion has been recognized previously, but due to their limited follow-up, a more favorable outlook has been predicted [18]. The long-term effect of earlier operation on discrete subvalvar stenosis before the development of aortic insufficiency and the performance of a left ventricular myomectomy at the time of subvalvar membrane resection cannot be answered in our patients because of the limited nature of the follow-up of this practice.
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). Although these patient populations are from two different periods, and many patient variables went into the decision to reoperate or to replace the patient's aortic valve, the use of the pulmonary autograft or an allograft appears to have decreased the need for reoperation and has improved survival in the limited follow-up available. The success of the pulmonary autograft has led to a significant change in referral patterns. Comparison of the actuarial freedom from reoperation or death in the patients grouped by decade demonstrates that the time lapse between first operation and reoperation has tended to decrease (Fig 8).
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The evolution of surgery for congenital aortic valve disease has tended to mirror that which has occurred in cardiac surgery. This evolution has brightened the outlook and enhanced the likelihood that children born with an abnormal aortic valve can have a more normal life expectancy and life style.
I thank the Association for the privilege and honor that you have given me as your forty-first President.
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Acknowledgments |
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TopFootnotesIntroductionAcknowledgmentsReferences |
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Footnotes |
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TopFootnotesIntroductionAcknowledgmentsReferences |
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Address reprint requests to Dr Elkins, Section of Thoracic and Cardiovascular Surgery, University of Oklahoma Health Sciences Center, PO Box 26901, Oklahoma City, OK 73190.
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References |
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TopFootnotesIntroductionAcknowledgmentsReferences |
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This article has been cited by other articles:
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  J. H. Oury, B. G. Hardy, H. H. Luo, M. Maxwell, and C. M.G. Duran Expanding indications for the Ross procedure Ann. Thorac. Surg., October 1, 1999; 68(4): 1403 - 1406. [Abstract] [Full Text] [PDF]
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J. A. Hawkins, L. L. Minich, L. Y. Tani, R. W. Day, V. E. Judd, R. E. Shaddy, and E. C. McGough Late Results and Reintervention After Aortic Valvotomy for Critical Aortic Stenosis in Neonates and Infants Ann. Thorac. Surg., June 1, 1998; 65(6): 1758 - 1762. [Abstract] [Full Text] [PDF]
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L. A Durham III, S. E. desJardins, R. S. Mosca, and E. L. Bove Ross Procedure With Aortic Root Tailoring for Aortic Valve Replacement in the Pediatric Population Ann. Thorac. Surg., August 1, 1997; 64(2): 482 - 486. [Abstract] [Full Text]
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J. A. Hawkins, L. L. Minich, R. E. Shaddy, L. Y. Tani, G. S. Orsmond, J. E. Sturtevant, and E. C. McGough Aortic Valve Repair and Replacement After Balloon Aortic Valvuloplasty in Children Ann. Thorac. Surg., May 1, 1996; 61(5): 1355 - 1358. [Abstract] [Full Text]
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 V. M. Reddy, H. A. Rajasinghe, D. F. Teitel, G. S. Haas, F. L. Hanley, and S. b. B. B. Roe AORTOVENTRICULOPLASTY WITH THE PULMONARY AUTOGRAFT: THE "ROSS-KONNO" PROCEDURE J. Thorac. Cardiovasc. Surg., January 1, 1996; 111(1): 158 - 167. [Abstract] [Full Text]
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