Editorial
Surgery for Aortic Valve Disease in Teenagers and Young Adults
Adolescence (from Latin adolescere meaning ‘‘to grow up’’) refers to a transitional stage of physical and psychological development. The period of adolescence begins in childhood and extends to young adulthood. It is typically characterized by rapid growth, with respect to both height and weight. As importantly, it is characterized by significant cognitive development and is a period of multiple transitions involving education, employment, and independence, often including transitions from one living circumstance to another. Sexual maturation, including reproductive prospects, becomes important for both males and females. In the management of adolescent patients with aortic valve disease, cardiologists and surgeons deal with a rather wide spectrum of congenital and acquired diseases involving the aortic valve, aortic root, and left ventricular outflow tract, all within the temporal context of this phase of life in which so many changes occur. The pathophysiology is influenced primarily by the relative degrees of aortic insufficiency and aortic stenosis. Regardless of etiology, aortic valve insufficiency imposes an abnormal volume load on the left ventricle (LV). Over time, adaptation to the increased preload is characterized by eccentric hypertrophy of the ventricle. In chronic aortic insufficiency, a point is reached where the ventricle cannot continue to compensate for volume overload. Ventricular dilatation occurs, and LV end-diastolic volume increases. Wall thickness to chamber size ratio of the LV decreases. This results in increased systolic wall tension, together with decreased ejection fraction, stroke volume, and ventricular emptying. Even in the absence of a major increase in the regurgitant volume, the larger end-systolic volume leads to progressively larger end-diastolic volume. The increased wall tension translates to increased myocardial oxygen demand, while oxygen delivery may be limited as a consequence of decreased coronary perfusion secondary to decreased aortic diastolic pressure. Eventually, the development of interstitial fibrosis occurs, resulting in further deterioration of the ventricle’s systolic and diastolic properties. Aortic valve stenosis, on the other hand, imposes an abnormal pressure load on the LV. Adaptation involves concentric ventricular hypertrophy which, in general, is proportional to the degree of obstruction. Mild degrees of aortic stenosis are usually well tolerated, with minimal hypertrophy and normal LV function. As the degree of obstruction progresses, hypertrophy increases. The ventricle generates higher pressures, while the increased wall thickness maintains normal wall stress.
World Journal for Pediatric and Congenital Heart Surgery 4(4) 340-341 ª The Author(s) 2013 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/2150135113505228 pch.sagepub.com
Eventually, increased wall thickness causes the ventricle to become ‘‘stiff’’ (ie, compliance is reduced), with impaired filling reflecting diastolic dysfunction. With severe valvular obstruction and significant ventricular hypertrophy, myocardial ischemia may result from the combination of limited cardiac output, reduced coronary perfusion, and increased myocardial oxygen consumption. Fibrosis may occur in areas of myocardium damaged by ischemia. In adolescent patients, a growth spurt and the accompanying increased demand for cardiac output may result in an increased systolic gradient across an abnormal aortic valve, even if the actual valvular morphology and effective orifice size change little over the same period of time. Some patients who require surgery for aortic valve disease as teenagers or young adults are undergoing valve-related intervention for the first time. In particular, this may be true of patients in regions where rheumatic fever is still an important etiology of valvular heart disease. On the other hand, many patients with congenital abnormalities of the aortic valve and LV outflow tract will have undergone one or more surgical or catheter-directed interventions as neonates, infants, or children. In a majority of instances, these interventions early in life must be considered palliative, and there is a high expectation of further surgery being required during adolescence and/or adulthood. When these patients do have indications for surgery as teenagers and young adults, the main objective is restoration of normal or near-normal valvular function in order to restore to normal the loading conditions of the LV, maximizing the likelihood of preserving ventricular function and ensuring the best chance for long-term good health of the myocardium. In choosing between valve repair and any of the available options for valve replacement, physicians must consider the anticipated durability of each particular therapeutic option and the corresponding likelihood of the patient requiring additional surgery in the future. They must also consider numerous lifestyle issues including participation in sports, travel, and childbearing as well the potential need for anticoagulation therapy and its attendant risks and benefits. Fortunately, there are numerous options available for surgical management of aortic valve disease in teenagers and young adults. The optimal choice for an individual patient remains a subject of controversy. Decision making requires access to the best available contemporary data. In this issue of World Journal for Pediatric and Congenital Heart Surgery, several important therapeutic options are discussed in articles by internationally recognized experts. The 49th annual meeting
Downloaded from pch.sagepub.com at VIRGINIA COMMONWEALTH UNIV on March 14, 2015
341 of the Society of Thoracic Surgeons in January 2013 included a symposium on ‘‘Management of Aortic Valve Insufficiency in the Teenage Patient.’’ Each of the principle participants has contributed a manuscript addressing this subject, respectively, covering topics which include aortic valve reconstruction, prosthetic aortic valve replacement, and replacement of the aortic valve with the patient’s pulmonary valve (ie, autograft aortic valve replacement, the Ross operation). The 6th World Congress of Paediatric Cardiology and Cardiac Surgery in Cape Town, South Africa, in February 2013, featured a symposium on ‘‘Surgery for Rheumatic Valvular Disease’’ which was organized by the World Society for Pediatric and Congenital Heart Surgery. The session featured presentations on the ‘‘Pros and Cons of Cusp Extension for Surgical Treatment of
Rheumatic Aortic Valve Disease in Young Patients.’’ These positions are also articulated in articles in the current issue. We hope that these special featured articles together will serve as an important educational resource and a useful reference for those involved in the management of young patients with aortic valve disease.
Downloaded from pch.sagepub.com at VIRGINIA COMMONWEALTH UNIV on March 14, 2015
Marshall L. Jacobs, MD Editor-in-Chief, WJPCHS Division of Cardiac Surgery Department of Surgery Johns Hopkins School of Medicine Baltimore, Maryland, USA
Surgery for Aortic Valve Disease in Teenagers and Young Adults
Adolescence (from Latin adolescere meaning ‘‘to grow up’’) refers to a transitional stage of physical and psychological development. The period of adolescence begins in childhood and extends to young adulthood. It is typically characterized by rapid growth, with respect to both height and weight. As importantly, it is characterized by significant cognitive development and is a period of multiple transitions involving education, employment, and independence, often including transitions from one living circumstance to another. Sexual maturation, including reproductive prospects, becomes important for both males and females. In the management of adolescent patients with aortic valve disease, cardiologists and surgeons deal with a rather wide spectrum of congenital and acquired diseases involving the aortic valve, aortic root, and left ventricular outflow tract, all within the temporal context of this phase of life in which so many changes occur. The pathophysiology is influenced primarily by the relative degrees of aortic insufficiency and aortic stenosis. Regardless of etiology, aortic valve insufficiency imposes an abnormal volume load on the left ventricle (LV). Over time, adaptation to the increased preload is characterized by eccentric hypertrophy of the ventricle. In chronic aortic insufficiency, a point is reached where the ventricle cannot continue to compensate for volume overload. Ventricular dilatation occurs, and LV end-diastolic volume increases. Wall thickness to chamber size ratio of the LV decreases. This results in increased systolic wall tension, together with decreased ejection fraction, stroke volume, and ventricular emptying. Even in the absence of a major increase in the regurgitant volume, the larger end-systolic volume leads to progressively larger end-diastolic volume. The increased wall tension translates to increased myocardial oxygen demand, while oxygen delivery may be limited as a consequence of decreased coronary perfusion secondary to decreased aortic diastolic pressure. Eventually, the development of interstitial fibrosis occurs, resulting in further deterioration of the ventricle’s systolic and diastolic properties. Aortic valve stenosis, on the other hand, imposes an abnormal pressure load on the LV. Adaptation involves concentric ventricular hypertrophy which, in general, is proportional to the degree of obstruction. Mild degrees of aortic stenosis are usually well tolerated, with minimal hypertrophy and normal LV function. As the degree of obstruction progresses, hypertrophy increases. The ventricle generates higher pressures, while the increased wall thickness maintains normal wall stress.
World Journal for Pediatric and Congenital Heart Surgery 4(4) 340-341 ª The Author(s) 2013 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/2150135113505228 pch.sagepub.com
Eventually, increased wall thickness causes the ventricle to become ‘‘stiff’’ (ie, compliance is reduced), with impaired filling reflecting diastolic dysfunction. With severe valvular obstruction and significant ventricular hypertrophy, myocardial ischemia may result from the combination of limited cardiac output, reduced coronary perfusion, and increased myocardial oxygen consumption. Fibrosis may occur in areas of myocardium damaged by ischemia. In adolescent patients, a growth spurt and the accompanying increased demand for cardiac output may result in an increased systolic gradient across an abnormal aortic valve, even if the actual valvular morphology and effective orifice size change little over the same period of time. Some patients who require surgery for aortic valve disease as teenagers or young adults are undergoing valve-related intervention for the first time. In particular, this may be true of patients in regions where rheumatic fever is still an important etiology of valvular heart disease. On the other hand, many patients with congenital abnormalities of the aortic valve and LV outflow tract will have undergone one or more surgical or catheter-directed interventions as neonates, infants, or children. In a majority of instances, these interventions early in life must be considered palliative, and there is a high expectation of further surgery being required during adolescence and/or adulthood. When these patients do have indications for surgery as teenagers and young adults, the main objective is restoration of normal or near-normal valvular function in order to restore to normal the loading conditions of the LV, maximizing the likelihood of preserving ventricular function and ensuring the best chance for long-term good health of the myocardium. In choosing between valve repair and any of the available options for valve replacement, physicians must consider the anticipated durability of each particular therapeutic option and the corresponding likelihood of the patient requiring additional surgery in the future. They must also consider numerous lifestyle issues including participation in sports, travel, and childbearing as well the potential need for anticoagulation therapy and its attendant risks and benefits. Fortunately, there are numerous options available for surgical management of aortic valve disease in teenagers and young adults. The optimal choice for an individual patient remains a subject of controversy. Decision making requires access to the best available contemporary data. In this issue of World Journal for Pediatric and Congenital Heart Surgery, several important therapeutic options are discussed in articles by internationally recognized experts. The 49th annual meeting
Downloaded from pch.sagepub.com at VIRGINIA COMMONWEALTH UNIV on March 14, 2015
341 of the Society of Thoracic Surgeons in January 2013 included a symposium on ‘‘Management of Aortic Valve Insufficiency in the Teenage Patient.’’ Each of the principle participants has contributed a manuscript addressing this subject, respectively, covering topics which include aortic valve reconstruction, prosthetic aortic valve replacement, and replacement of the aortic valve with the patient’s pulmonary valve (ie, autograft aortic valve replacement, the Ross operation). The 6th World Congress of Paediatric Cardiology and Cardiac Surgery in Cape Town, South Africa, in February 2013, featured a symposium on ‘‘Surgery for Rheumatic Valvular Disease’’ which was organized by the World Society for Pediatric and Congenital Heart Surgery. The session featured presentations on the ‘‘Pros and Cons of Cusp Extension for Surgical Treatment of
Rheumatic Aortic Valve Disease in Young Patients.’’ These positions are also articulated in articles in the current issue. We hope that these special featured articles together will serve as an important educational resource and a useful reference for those involved in the management of young patients with aortic valve disease.
Downloaded from pch.sagepub.com at VIRGINIA COMMONWEALTH UNIV on March 14, 2015
Marshall L. Jacobs, MD Editor-in-Chief, WJPCHS Division of Cardiac Surgery Department of Surgery Johns Hopkins School of Medicine Baltimore, Maryland, USA
