- Email: [email protected]
Neonatal Aortic Stenosis Is a Surgical Disease
Neonatal Aortic Stenosis Is a Surgical Disease Viktor Hraška Neonates with critical aortic stenosis represent a challenging group of patients with severe obstruction at a valvar level and with symptoms of heart failure. If biventricular repair is chosen, open valvotomy (OV) has been firmly established as the most effective initial treatment. In comparison with blind ballooning, OV, with exact splitting of fused commissures and shaving of obstructing nodules, can produce a better valve with a maximum valve orifice, without causing regurgitation. Thus, predictable and consistent early and longer-lasting results in any type of valve morphology are provided. Clearly superior results can be achieved in a tricuspid valve arrangement. OV not only offers a high survival benefit in the long run, but also a high quality of life, by minimizing re-interventions and preserving the native aortic valve in the majority of patients. Semin Thorac Cardiovasc Surg Pediatr Card Surg Ann 19:2-5 C 2016 Elsevier Inc. All rights reserved.
Introduction Neonates with critical aortic stenosis (AS) represent a challenging group of patients with severe obstruction at a valvar level and with symptoms of heart failure. Usually, critical AS is not a separate morphological lesion, but rather a spectrum of conditions including different degrees of hypoplasia of the left heart structures, from the mitral valve to the aortic arch.1,2 If biventricular repair is chosen, both balloon valvotomy (BV) and open valvotomy (OV) are firmly established as effective initial treatments with encouraging survival benefits. Improved early results are based on a better understanding of the limits of biventricular repair rather than on the method of treatment.1–11 However, the long-term preservation of an acceptable function of the native aortic valve appears to be superior after OV.7–9
Treatment Protocol Our treatment protocol is multidisciplinary.10 Critically ill neonates are stabilized by aggressive resuscitation, while patency of the ductus is maintained by prostaglandins. If the function of the left ventricle is depressed, a BV with a balloon o5 mm in diameter is performed to slightly increase the effective orifice area of the aortic valve with no risk of creating regurgitation. This so-called “gentle” BV is used as an intermittent step to stabilize the patient before OV. If left ventricle function is not severely depressed, OV is the method of choice. A detailed description of our technique has been published elsewhere.5 German Pediatric Cardiac Center, Sankt Augustin, Germany. Address correspondence to: Viktor Hraška, MD, PhD, German Pediatric Heart Center, Asklepios Clinic Sankt Augustin, Arnold Jansen St. 29, 53757 Sankt Augustin, Germany. E-mail: [email protected]
2
http://dx.doi.org/10.1053/j.pcsu.2015.11.002 1092-9126/& 2016 Elsevier Inc. All rights reserved.
Viktor Hraška, MD Central Message In comparison with ballooning, open valvotomy can produce a better valve with a maximum valve orifice, without causing regurgitation.
Outcomes Early Outcomes Early mortality after OV is reported to be between 6% and 19%3,4,7–9 and is associated with small left-sided structures.3,4 OV is effective in restoring a nearly normal valve function. An optimal post-valvotomy functional result, defined as a peak gradient o30 mmHg and no more than mild aortic regurgitation (AR), was achieved in 93% of our patients.9 Long-term Outcomes Overall survival is between 70% and 90% at 1 year and usually remains unchanged at 5 years and 10 years of follow-up.3,4,7–9 In our cohort of patients, the 91% survival rate at 20 years confirms the excellent long-term prognosis of isolated critical AS.9 The PEDIATRIC CARDIAC SURGERY ANNUAL 2016
Neonatal Aortic Stenosis Is a Surgical Disease
Figure 1 The Kaplan-Meier curve shows freedom from reoperation according to cusp anatomy. The error bars indicate the standard error of the mean. (Reprinted with permission from Hraska et al.9)
10-year event-free survival for critical neonates is between 50% and 70%.7–9 These figures compare favorably with the 29% to 54% event-free survival at 10 years reported after BV.2,7,8 If three cusps can be constructed without producing significant AR, the need for re-intervention for recurrent stenosis and the need for re-operation is less than in patients with bicuspid valves.4 Not surprisingly, tricuspid valve morphology in our cohort of patients showed a significantly better outcome, with event-free survivals of 90% at 20 years (Fig. 1). Freedom from aortic valve replacement (AVR), taken as a surrogate for the quality of life in our cohort of newborns, was 92%, 83%, 68%, and 57% at 5, 10, 15, and 20 years of follow-up, respectively (Fig. 2). Tricuspid valve morphology showed the best outcome with 100% freedom from AVR at 20 years of follow-up (Fig. 3). These figures indicate superior long term outcomes of OV in comparison with BV regarding preservation of the native aortic valve.9
Discussion Predictable and consistent early and longer-lasting results can be accomplished by OV in any type of valve morphology, even in an asymmetric arrangement of the cusps. The exact splitting
3
Figure 3 The Kaplan-Meier curve shows freedom from AVR according to cusp anatomy. The error bars indicate the standard error of the mean. (Reprinted with permission Hraska et al.9)
of fused commissures and shaving of obstructing nodules can produce a better valve with a maximum valve orifice without causing AR. The currently used perfusion strategy with normothermic, full-flow bypass is safe, with a minimal risk of complications. OV 7–9 not only offers a high survival benefit in the long term, but in comparison with BV,2 a higher quality of life, by minimizing re-interventions and preserving the native aortic valve in the majority of patients. Clearly superior results can be achieved in a tricuspid valve arrangement. The incidence of tricuspid valve morphology, determined by echocardiography, is underestimated because of the fused commissures and bicuspid opening of the valve. In various surgical series, a tricuspid morphology with appropriately high commissures, which are able to support the free edges of the cusps, is frequently observed4 (in our cohort it was present in 44% of our patients9). In this group of neonates, OV should be the method of choice because it offers significant benefits and there is no need for AVR for many years after primary surgery. Unicuspid and bicuspid valves, by definition, have fundamental morphological and functional abnormalities; therefore reinterventions and the need for AVR are higher. Nevertheless, OV allows a more predictable outcome, with no risk of causing devastating early postprocedure severe AR, which requires a high-risk Ross salvage operation. Currently, 3D echocardiography is used to delineate the morphology of the valve, with high accuracy in the majority of cases, and it should be used to identify suitable candidates for OV (tricuspid, asymmetric unicuspid, or bicuspid valves) and for BV (symmetric bicuspid valve).11
Rebuttal
Figure 2 The Kaplan-Meier curve shows freedom from AVR after OV. The numbers of patients at risk is shown above the x-axis. The error bars indicate the standard error of the mean. (Reprinted with permission from Hraska et al.9)
At this point, a randomized study to compare the outcomes of OV to BV has not been performed. Contemporary studies have demonstrated that OV and BV are comparable with respect to survival and relief of obstruction.1–9 However, BV has become the first line of therapy for congenital AS, including neonatal AS.2,6 A recently published, robust study6 with data collected prospectively from two active, multi-institutional, pediatric
V. Hraška
4 cardiac catheterization registries in United States, has clearly concluded that patients undergoing BV during the neonatal period are generally considered to be at a higher risk for complications with a high incidence of severe adverse events, death, and suboptimal results. Every surgeon who has ever operated on a valve in critical AS will not be surprised by this conclusion. The valve involved in critical AS differs significantly from congenital AS treated later in life. Morphological Consideration A reduced cross-section area in critical AS is the result of a deficiency in, or absence of, one or more commissures, thus leading to a unicuspid or bicuspid aortic valve, and or immaturity with myxomatous change and thickening of the valve cusps, with or without commissural fusion, and hypoplasia of the annulus. Usually, swollen asymmetric cusps, rather than fusion of the commissures, cause the obstruction.12 Ballooning relieves AS by causing a rupture along the lines of least resistance, either along the underdeveloped commissures or into the cusp tissue. It is obvious that BV addresses neither fused commissures nor myxomatous thickened cusps and nodules. An inflated balloon distributes the forces symmetrically; therefore, ballooning is particularly dangerous in asymmetric valve cusps, in unicuspid valves, and in immature and myxomatous valves, tearing the thinnest, most pliable portion of the valve. Early Outcomes Early mortality in critical AS after BV is between 9% and 14%.2,6 Acute procedural success are evenly distributed, with one third of the patients showing optimal, adequate, or inadequate results, respectively.6 In neonates, incidence of moderate or severe AR developing shortly after BV is reported to be between 7% and 33%.2,6 The procedure-related morbidity is not trivial. Twenty percent of patients experience adverse events, half of which are of high severity.6 A 15% incidence of aortic wall injury, a 2.6% incidence of procedural femoral artery damage, and a 5% incidence of injuries to the heart itself, such as rupture of the valves or myocardial perforation, were reported in the largest series.2,6 Long-Term Outcomes Overall survival is between 75% and 85% at 1 year and usually remains unchanged at 5 years and 10 years of follow-up.2 Freedom from moderate to severe AR is about 60% at 10 years.2,13 Typically, procedural AR progresses in severity over time. The survival rate, free from any aortic valve re-intervention, is between 27% and 50% at 10 years.2,13 A Melbourne group7 reported 27% freedom from re-intervention after BV, versus 65% after OV at 5 years of follow-up. Freedom from aortic valve surgery is between 50% and79% at 10 years, with an ongoing steady hazard for AVR; however, the indication criteria for AVR are not uniform.2,13 Comment Ballooning might be considered in symmetric bicuspid valves,11 but the ongoing process of fibrosis and scarring renders disrupted cusps almost irreparable, and it is likely that
functionally bicuspid valves, with an original tricuspid arrangement, remain bicuspid anyway after BV.7,10 The vast majority of the valves associated with critical AS are asymmetric; therefore unpredictable ruptures may occur. BV is a nonreversible destructive process that damages the best portion of the leaflet and leaves the thickened dysplastic portion of the valve in place. It will prevent those patients for whom simple repairs are suitable from achieving an optimal outcome.14 Optimal procedural outcomes are achieved in only one third of all patients.6 This result is clearly inferior to the more than 90% optimal procedural success achieved by OV.9 On the top of that, one third of the results are inadequate. Also worrisome is the still notable incidence of severe post-ballooning AR that requires an emergency Ross AVR, which is associated with early mortality of up to 28%.15 The re-intervention rate after BV is higher, and the need for AVR develops sooner than after OV .7,8 Delaying the re-intervention by several years is a benefit that compensates for the invasiveness of surgery. The 20% incidence of procedure-related morbidity6 is certainly not negligible, demonstrating that the “less invasive approach” is not necessarily the safest. Conclusions The protocol for isolated critical AS should be multidisciplinary, and pediatric cardiologists and pediatric cardiac surgeons should plan the treatment of each individual patient together to choose the most appropriate treatment modality based on left ventricle function, the morphology of the aortic valve, and the underlining clinical condition of the neonate. OV remains the best approach to treat neonates and should be the method of choice in tricuspid and asymmetric thickened valves. BV might be considered in symmetric, but not myxomatous, bicuspid valves.
Acknowledgment The author thanks Elizabeth Grundy for her help in preparing the manuscript.
References 1. Eicken A, Georgiev S, Balling G, et al: Neonatal balloon aortic valvuloplasty-predictive value of current risk score algorithms for treatment strategies. Catheter Cardiovasc Interv 2010;76:404-410. 2. Brown DW, Dipilato AE, Chong EC, et al: Aortic valve reinterventions after balloon aortic valvuloplasty for congenital aortic stenosis: intermediate and late follow-up. J Am Coll Cardiol 2010;56:1740-1749. 3. Agnoletti G, Raisky O, Boudjemline Y, et al: Neonatal surgical aortic commissurotomy: predictors of outcome and long-term results. Ann Thorac Surg 2006;82:1585-1592. 4. Bhabra MS, Dhillon R, Bhudia S, et al: Surgical aortic valvotomy in infancy: impact of leaflet morphology on long-term outcomes. Ann Thorac Surg 2003;76:1412-1416. 5. Hraska V, Photiadis J, Arenz C: Open valvotomy for aortic valve stenosis in newborns and infants. Multimedia Manual of Cardiothoracic Surgery. Available at: 〈http://mmcts.ctsnetjournals.org/cgi/collection/left_heart_ lesions〉. 6. Torres A, Vincent JA, Everett A, et al: Balloon valvuloplasty for congenital aortic stenosis: multi-center safety and efficacy outcome assessment. Catheter Cardiovasc Interv 2015;86:808-820. 7. Siddiqui J, Brizard CP, JC Galati, et al: Surgical Valvotomy and repair for neonatal and infant congenital aortic stenosis achieves better
Neonatal Aortic Stenosis Is a Surgical Disease
8.
9.
10. 11.
results than interventional catheterization. J Am Coll Cardiol 2013;62:2134-2140. Brown JW, Rodefeld MD, Ruzmetov M, et al: Surgical valvuloplasty versus balloon aortic dilation for congenital aortic stenosis: are evidence-based outcomes relevant? Ann Thorac Surg 2012;94:146-153. Hraska V, Sinzobahamvya N, Haun C, et al: the long-term outcome of open valvotomy for critical aortic stenosis in neonates. Ann Thorac Surg 2012;94:1519-1526. Hraska V, Schneider M: Critical aortic stenosis with severe left ventricular dysfunction. Eur J Cardiothorac Surg 2013;43:148-149. Maskatia SA, Justino H, Ing FF, et al: Aortic valve morphology is associated with outcomes following balloon valvuloplasty for congenital aortic stenosis. Catheter Cardiovasc Interv 2013;81:90-95.
5 12. Ho SY, Anderson RH: The morphology of the aortic valve with regard to congenital malformations. In: Dunn JM (ed): Cardiac Valve Disease in Children. New York, NY: Elsevier Science; 1988. pp. 3-21. 13. McElhinney DB, Lock JE, Keane JF, et al: Left heart growth, function, and reintervention after balloon aortic valvuloplasty for neonatal aortic stenosis. Circulation 2005;111:451-458. 14. d’Udekem Y: Aortic valve repair in children. Ann Cardiothorac Surg 2013;2:100-104. 15. Woods RK, Pasquali SK, Jacobs ML, et al: Aortic valve replacement in neonates and infants: An analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database. J Thorac Cardiovasc Surg 2012;144:1084-1090.
Introduction Neonates with critical aortic stenosis (AS) represent a challenging group of patients with severe obstruction at a valvar level and with symptoms of heart failure. Usually, critical AS is not a separate morphological lesion, but rather a spectrum of conditions including different degrees of hypoplasia of the left heart structures, from the mitral valve to the aortic arch.1,2 If biventricular repair is chosen, both balloon valvotomy (BV) and open valvotomy (OV) are firmly established as effective initial treatments with encouraging survival benefits. Improved early results are based on a better understanding of the limits of biventricular repair rather than on the method of treatment.1–11 However, the long-term preservation of an acceptable function of the native aortic valve appears to be superior after OV.7–9
Treatment Protocol Our treatment protocol is multidisciplinary.10 Critically ill neonates are stabilized by aggressive resuscitation, while patency of the ductus is maintained by prostaglandins. If the function of the left ventricle is depressed, a BV with a balloon o5 mm in diameter is performed to slightly increase the effective orifice area of the aortic valve with no risk of creating regurgitation. This so-called “gentle” BV is used as an intermittent step to stabilize the patient before OV. If left ventricle function is not severely depressed, OV is the method of choice. A detailed description of our technique has been published elsewhere.5 German Pediatric Cardiac Center, Sankt Augustin, Germany. Address correspondence to: Viktor Hraška, MD, PhD, German Pediatric Heart Center, Asklepios Clinic Sankt Augustin, Arnold Jansen St. 29, 53757 Sankt Augustin, Germany. E-mail: [email protected]
2
http://dx.doi.org/10.1053/j.pcsu.2015.11.002 1092-9126/& 2016 Elsevier Inc. All rights reserved.
Viktor Hraška, MD Central Message In comparison with ballooning, open valvotomy can produce a better valve with a maximum valve orifice, without causing regurgitation.
Outcomes Early Outcomes Early mortality after OV is reported to be between 6% and 19%3,4,7–9 and is associated with small left-sided structures.3,4 OV is effective in restoring a nearly normal valve function. An optimal post-valvotomy functional result, defined as a peak gradient o30 mmHg and no more than mild aortic regurgitation (AR), was achieved in 93% of our patients.9 Long-term Outcomes Overall survival is between 70% and 90% at 1 year and usually remains unchanged at 5 years and 10 years of follow-up.3,4,7–9 In our cohort of patients, the 91% survival rate at 20 years confirms the excellent long-term prognosis of isolated critical AS.9 The PEDIATRIC CARDIAC SURGERY ANNUAL 2016
Neonatal Aortic Stenosis Is a Surgical Disease
Figure 1 The Kaplan-Meier curve shows freedom from reoperation according to cusp anatomy. The error bars indicate the standard error of the mean. (Reprinted with permission from Hraska et al.9)
10-year event-free survival for critical neonates is between 50% and 70%.7–9 These figures compare favorably with the 29% to 54% event-free survival at 10 years reported after BV.2,7,8 If three cusps can be constructed without producing significant AR, the need for re-intervention for recurrent stenosis and the need for re-operation is less than in patients with bicuspid valves.4 Not surprisingly, tricuspid valve morphology in our cohort of patients showed a significantly better outcome, with event-free survivals of 90% at 20 years (Fig. 1). Freedom from aortic valve replacement (AVR), taken as a surrogate for the quality of life in our cohort of newborns, was 92%, 83%, 68%, and 57% at 5, 10, 15, and 20 years of follow-up, respectively (Fig. 2). Tricuspid valve morphology showed the best outcome with 100% freedom from AVR at 20 years of follow-up (Fig. 3). These figures indicate superior long term outcomes of OV in comparison with BV regarding preservation of the native aortic valve.9
Discussion Predictable and consistent early and longer-lasting results can be accomplished by OV in any type of valve morphology, even in an asymmetric arrangement of the cusps. The exact splitting
3
Figure 3 The Kaplan-Meier curve shows freedom from AVR according to cusp anatomy. The error bars indicate the standard error of the mean. (Reprinted with permission Hraska et al.9)
of fused commissures and shaving of obstructing nodules can produce a better valve with a maximum valve orifice without causing AR. The currently used perfusion strategy with normothermic, full-flow bypass is safe, with a minimal risk of complications. OV 7–9 not only offers a high survival benefit in the long term, but in comparison with BV,2 a higher quality of life, by minimizing re-interventions and preserving the native aortic valve in the majority of patients. Clearly superior results can be achieved in a tricuspid valve arrangement. The incidence of tricuspid valve morphology, determined by echocardiography, is underestimated because of the fused commissures and bicuspid opening of the valve. In various surgical series, a tricuspid morphology with appropriately high commissures, which are able to support the free edges of the cusps, is frequently observed4 (in our cohort it was present in 44% of our patients9). In this group of neonates, OV should be the method of choice because it offers significant benefits and there is no need for AVR for many years after primary surgery. Unicuspid and bicuspid valves, by definition, have fundamental morphological and functional abnormalities; therefore reinterventions and the need for AVR are higher. Nevertheless, OV allows a more predictable outcome, with no risk of causing devastating early postprocedure severe AR, which requires a high-risk Ross salvage operation. Currently, 3D echocardiography is used to delineate the morphology of the valve, with high accuracy in the majority of cases, and it should be used to identify suitable candidates for OV (tricuspid, asymmetric unicuspid, or bicuspid valves) and for BV (symmetric bicuspid valve).11
Rebuttal
Figure 2 The Kaplan-Meier curve shows freedom from AVR after OV. The numbers of patients at risk is shown above the x-axis. The error bars indicate the standard error of the mean. (Reprinted with permission from Hraska et al.9)
At this point, a randomized study to compare the outcomes of OV to BV has not been performed. Contemporary studies have demonstrated that OV and BV are comparable with respect to survival and relief of obstruction.1–9 However, BV has become the first line of therapy for congenital AS, including neonatal AS.2,6 A recently published, robust study6 with data collected prospectively from two active, multi-institutional, pediatric
V. Hraška
4 cardiac catheterization registries in United States, has clearly concluded that patients undergoing BV during the neonatal period are generally considered to be at a higher risk for complications with a high incidence of severe adverse events, death, and suboptimal results. Every surgeon who has ever operated on a valve in critical AS will not be surprised by this conclusion. The valve involved in critical AS differs significantly from congenital AS treated later in life. Morphological Consideration A reduced cross-section area in critical AS is the result of a deficiency in, or absence of, one or more commissures, thus leading to a unicuspid or bicuspid aortic valve, and or immaturity with myxomatous change and thickening of the valve cusps, with or without commissural fusion, and hypoplasia of the annulus. Usually, swollen asymmetric cusps, rather than fusion of the commissures, cause the obstruction.12 Ballooning relieves AS by causing a rupture along the lines of least resistance, either along the underdeveloped commissures or into the cusp tissue. It is obvious that BV addresses neither fused commissures nor myxomatous thickened cusps and nodules. An inflated balloon distributes the forces symmetrically; therefore, ballooning is particularly dangerous in asymmetric valve cusps, in unicuspid valves, and in immature and myxomatous valves, tearing the thinnest, most pliable portion of the valve. Early Outcomes Early mortality in critical AS after BV is between 9% and 14%.2,6 Acute procedural success are evenly distributed, with one third of the patients showing optimal, adequate, or inadequate results, respectively.6 In neonates, incidence of moderate or severe AR developing shortly after BV is reported to be between 7% and 33%.2,6 The procedure-related morbidity is not trivial. Twenty percent of patients experience adverse events, half of which are of high severity.6 A 15% incidence of aortic wall injury, a 2.6% incidence of procedural femoral artery damage, and a 5% incidence of injuries to the heart itself, such as rupture of the valves or myocardial perforation, were reported in the largest series.2,6 Long-Term Outcomes Overall survival is between 75% and 85% at 1 year and usually remains unchanged at 5 years and 10 years of follow-up.2 Freedom from moderate to severe AR is about 60% at 10 years.2,13 Typically, procedural AR progresses in severity over time. The survival rate, free from any aortic valve re-intervention, is between 27% and 50% at 10 years.2,13 A Melbourne group7 reported 27% freedom from re-intervention after BV, versus 65% after OV at 5 years of follow-up. Freedom from aortic valve surgery is between 50% and79% at 10 years, with an ongoing steady hazard for AVR; however, the indication criteria for AVR are not uniform.2,13 Comment Ballooning might be considered in symmetric bicuspid valves,11 but the ongoing process of fibrosis and scarring renders disrupted cusps almost irreparable, and it is likely that
functionally bicuspid valves, with an original tricuspid arrangement, remain bicuspid anyway after BV.7,10 The vast majority of the valves associated with critical AS are asymmetric; therefore unpredictable ruptures may occur. BV is a nonreversible destructive process that damages the best portion of the leaflet and leaves the thickened dysplastic portion of the valve in place. It will prevent those patients for whom simple repairs are suitable from achieving an optimal outcome.14 Optimal procedural outcomes are achieved in only one third of all patients.6 This result is clearly inferior to the more than 90% optimal procedural success achieved by OV.9 On the top of that, one third of the results are inadequate. Also worrisome is the still notable incidence of severe post-ballooning AR that requires an emergency Ross AVR, which is associated with early mortality of up to 28%.15 The re-intervention rate after BV is higher, and the need for AVR develops sooner than after OV .7,8 Delaying the re-intervention by several years is a benefit that compensates for the invasiveness of surgery. The 20% incidence of procedure-related morbidity6 is certainly not negligible, demonstrating that the “less invasive approach” is not necessarily the safest. Conclusions The protocol for isolated critical AS should be multidisciplinary, and pediatric cardiologists and pediatric cardiac surgeons should plan the treatment of each individual patient together to choose the most appropriate treatment modality based on left ventricle function, the morphology of the aortic valve, and the underlining clinical condition of the neonate. OV remains the best approach to treat neonates and should be the method of choice in tricuspid and asymmetric thickened valves. BV might be considered in symmetric, but not myxomatous, bicuspid valves.
Acknowledgment The author thanks Elizabeth Grundy for her help in preparing the manuscript.
References 1. Eicken A, Georgiev S, Balling G, et al: Neonatal balloon aortic valvuloplasty-predictive value of current risk score algorithms for treatment strategies. Catheter Cardiovasc Interv 2010;76:404-410. 2. Brown DW, Dipilato AE, Chong EC, et al: Aortic valve reinterventions after balloon aortic valvuloplasty for congenital aortic stenosis: intermediate and late follow-up. J Am Coll Cardiol 2010;56:1740-1749. 3. Agnoletti G, Raisky O, Boudjemline Y, et al: Neonatal surgical aortic commissurotomy: predictors of outcome and long-term results. Ann Thorac Surg 2006;82:1585-1592. 4. Bhabra MS, Dhillon R, Bhudia S, et al: Surgical aortic valvotomy in infancy: impact of leaflet morphology on long-term outcomes. Ann Thorac Surg 2003;76:1412-1416. 5. Hraska V, Photiadis J, Arenz C: Open valvotomy for aortic valve stenosis in newborns and infants. Multimedia Manual of Cardiothoracic Surgery. Available at: 〈http://mmcts.ctsnetjournals.org/cgi/collection/left_heart_ lesions〉. 6. Torres A, Vincent JA, Everett A, et al: Balloon valvuloplasty for congenital aortic stenosis: multi-center safety and efficacy outcome assessment. Catheter Cardiovasc Interv 2015;86:808-820. 7. Siddiqui J, Brizard CP, JC Galati, et al: Surgical Valvotomy and repair for neonatal and infant congenital aortic stenosis achieves better
Neonatal Aortic Stenosis Is a Surgical Disease
8.
9.
10. 11.
results than interventional catheterization. J Am Coll Cardiol 2013;62:2134-2140. Brown JW, Rodefeld MD, Ruzmetov M, et al: Surgical valvuloplasty versus balloon aortic dilation for congenital aortic stenosis: are evidence-based outcomes relevant? Ann Thorac Surg 2012;94:146-153. Hraska V, Sinzobahamvya N, Haun C, et al: the long-term outcome of open valvotomy for critical aortic stenosis in neonates. Ann Thorac Surg 2012;94:1519-1526. Hraska V, Schneider M: Critical aortic stenosis with severe left ventricular dysfunction. Eur J Cardiothorac Surg 2013;43:148-149. Maskatia SA, Justino H, Ing FF, et al: Aortic valve morphology is associated with outcomes following balloon valvuloplasty for congenital aortic stenosis. Catheter Cardiovasc Interv 2013;81:90-95.
5 12. Ho SY, Anderson RH: The morphology of the aortic valve with regard to congenital malformations. In: Dunn JM (ed): Cardiac Valve Disease in Children. New York, NY: Elsevier Science; 1988. pp. 3-21. 13. McElhinney DB, Lock JE, Keane JF, et al: Left heart growth, function, and reintervention after balloon aortic valvuloplasty for neonatal aortic stenosis. Circulation 2005;111:451-458. 14. d’Udekem Y: Aortic valve repair in children. Ann Cardiothorac Surg 2013;2:100-104. 15. Woods RK, Pasquali SK, Jacobs ML, et al: Aortic valve replacement in neonates and infants: An analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database. J Thorac Cardiovasc Surg 2012;144:1084-1090.