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Ann Thorac Surg 2003;76:1398-1411
© 2003 The Society of Thoracic Surgeons
a Section of Cardiothoracic Surgery, James W. Riley Hospital for Children and Indiana University School of Medicine, Indianapolis, Indiana, USA
* Address reprint requests to Dr Brown, Section of Cardiothoracic Surgery, Indiana University School of Medicine, 545 Barnhill Dr, EH 215, Indianapolis, IN 46202-5123, USA.
e-mail: jobrown{at}iupui.edu
Presented at the Poster Session of the Thirty-ninth Annual Meeting of The Society of Thoracic Surgeons, San Diego, CA, Jan 31–Feb 2, 2003.
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METHODS: Included in this study were 508 patients ranging in ages from 1 day to 19 years, who were operated on for AS between 1960 and 2002 . Eighty-one percent (414 of 508) of the patients had left ventricular outflow tract obstruction (LVOTO) at a single level: 40 supravalvar, 242 valvar (critical AS in 85 neonates and young infants and in 157 older children), and 132 subvalvar. Nineteen percent (94 of 508) of the patients had LVOTO at more than one level. Associated congenital cardiac defects were found in 32% of the patients.
RESULTS: The overall hospital mortality rate was 8% (40/508) with neonates with critical AS having the highest mortality (33%). The late mortality was 4% for the entire group. Follow-up was 95% complete. The mean follow-up was 8.5 ± 7.1 years. In the subgroup with multilevel LVOTO (n = 94), the average intraoperative peak systolic left ventricular-aortic gradient decreased from 80 to 22 mm Hg after repair but increased progressively to 74 ± 36 mm Hg (p < 0.05) before reintervention was required. One hundred twenty-one patients (24%) underwent 151 reoperations for recurrent or residual LVOTO or aortic regurgitation. Actuarial curves predict a 20-year survival of 88% and 62% freedom from reoperation for all patients with AS. Symptomatic improvement in survivors was excellent (90% New York Heart Association class I).
CONCLUSIONS: Surgical relief of LVOTO in infants and children can be accomplished with low mortality and morbidity. Neonates with critical AS have significantly higher mortality and morbidity due to their complex anatomy and their critical presentation that affects outcome. Aortic valvotomy delays valve replacement in a significant percentage of children. The Ross procedure and mechanical aortic valve replacements have had a low mortality and morbidity in our series. Valve replacement will eventually be required in most children presenting with valvar AS and multilevel LVOTO while repair of discrete subaortic stenosis and supravalvar AS may not require reoperation in most patients. Children with LVOTO should have lifetime follow-up.
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Valvar aortic stenosis (VAS) is the most common cause of LVOTO, and open aortic valvotomy had been the preferred initial operative treatment at our institution until 2000 when balloon valvotomy was introduced and applied in most patients. Aortic stenosis occurring in the neonate or young infant is commonly referred to as neonatal critical AS. The condition accounts for less than 10% of congenital AS cases [1]. The prognosis in neonates without intervention is almost uniformly fatal. The valve is usually dysplastic and has abnormalities in the number and thickness of the cusps, in commissure development, and in cross-sectional area. The valvar abnormality is commonly accompanied by other left-sided cardiac abnormalities including abnormalities of the mitral valve and ventricular cavity, the subaortic region, the aortic arch, and the aortic isthmus. Balloon aortic valvulotomy or open surgical valvotomy are currently advocated by most centers as the procedures of choice for neonatal critical AS [3, 4]. Closed transventricular valvotomy (CTV) was the standard approach in the management of the critical neonatal AS for most neonates at our institution from 1978 to 2000. Since 2000 balloon valvotomy has largely replaced surgery for neonates and young children.
Subvalvar aortic stenosis (SAS) represents a spectrum of disease ranging from a discrete fibrous membrane to diffuse fibromuscular or tunnel LVOTO.
Localized supravalvar aortic stenosis (SVAS) is best repaired by patch aortoplasty as described in 1961 by McGoon [5] and Starr [6] and their associates and was the technique used by our group. Recent reports have advocated two or three sinus repairs [7, 8]. We agree that multi-sinus repair is helpful in selected cases [9]. Our results with SVAS have been reported previously [9].
The indications for operation and surgical techniques to treat the various types of AS are relatively well established. Although excellent clinical results are often achieved initially, surgical therapy in most cases in which the aortic valve is involved is considered palliative. Most children presenting with VAS will eventually present for valve replacement.
The purpose of this study was to retrospectively review the 40-year surgical experience with congenital AS and to evaluate early and late survival rates, morbidity, complications, and the success of various repair techniques.
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Sixty-four neonates and young infants less than 6 months with critical VAS underwent CTV: 57 had valvar stenosis and 7 had multiple level stenosis. Following median sternotomy (n = 41) or left thoracotomy (n = 23), the LV apex was elevated out of the pericardium and a moist sponge was placed behind the heart; a mattress suture of 4-0 polypropylene with a 3 x 7-mm Pledget was placed around the LV apex. A stab wound was made in the LV apex, and a Gruntzig balloon catheter (n = 13) or serial Hegar dilators (n = 51) were passed into the left ventricle and guided through the stenotic aortic valve using digital palpation of the aortic root. Progressive dilation was carried out with successive dilators stopping either at the aortic annulus diameter or 1 mm larger based on preoperative echo (range 5 to 8 mm). Since 1999 we have performed CTV under transesophageal echocardiographic guidance and have stopped dilation when mild aortic valvar regurgitation is produced.
Twenty-seven neonates or young infants less than 6 months underwent open transaortic valvotomy using standard cardiopulmonary bypass through a median sternotomy. The frequently encountered severely dysplastic neonatal aortic valve was opened with a scalpel or spread with a hemostat. The aorta in these infants was closed using a single layer of fine running absorbable monofilament suture. Hypothermia and cardioplegia were used routinely in this group even though the periods of ischemia were usually less than 15 minutes.
The 22 patients between 1978 and 1992 who required insertion of an AAC for tunnel subaortic stenosis had a porcine (Hancock-Extracorporeal; n = 20) or St. Jude (n = 2) Dacron-valved conduit placed between the apex of the left ventricle and the descending thoracic aorta by a closed technique described previously [10]. Since 1993 the Ross-Konno procedure has replaced the AAC operation in children at our institution.
Initial aortic valve replacement (AVR) was performed in only 26 of 508 patients (5%). Mechanical aortic prostheses were used in 10 patients: Bjork-Shiley aortic prostheses (Shiley Laboratories, Irvine, CA) in 3 patients, the St. Jude aortic prostheses (St. Jude Medical Inc, St. Paul, MN) in 6 patients, and a Medtronic-Hall valve (Medtronic Inc, Minneapolis, MN) in 1 patient. One patient had an aortic homograft (CryoLife Inc, Kennesaw, GA) inserted in 1993. Since 1993, all 15 initial AVRs were performed using a pulmonary autograft (Ross procedure). All patients undergoing the Ross procedure had right ventricular outflow tract reconstruction performed with a pulmonary homograft (CryoLife Inc). One hundred nine (26 initial and 83 redo) AVRs have been performed in 98 children as initial or redo operations. The type of prostheses used is shown in Table 5. Ten Ross-Konno procedures have been performed as redo procedures. The results of AVR in children comparing the Ross with mechanical and other bioprostheses have been reported previously and are given in Tables 6 and 7 [11].
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Overall survival estimated by the Kaplan–Meier method including early mortality in all children, was 89% at 5 years and 88% at 20, 30, and 40 years (Fig 2A). Overall freedom from reoperation estimated by the Kaplan–Meier method in all children was 75% at 10 years, 65% at 20 years, 63% at 30 years, and 62% at 40 years (Fig 3A).
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There were 29 early deaths (29 of 85, 34%): 11 patients with open valvotomy and 18 patients with CTV. Seven of the 8 patients operated on before 1978 by open aortic valvotomy on cardiopulmonary bypass died. After 1978 we adopted the CTV approach in patients younger than 8 weeks. The mortality for CTV since 1985 was 9 of 52 (17%) in a group with a mean age of 6 to 8 days. The operative mortality during the same time period with open valvotomies was 0%, but the mean age of the infants was 3 months reflecting an older, more stable group with less dysplastic valves.
Forty-nine of the 55 hospital survivors (89%) included in critical AS group (< 6 months) have a mean follow-up of 9.7 ± 5.4 years; the longest has been followed 22 years. There were 6 late deaths (all 3 to 4 months postoperatively, Table 8): 2 deaths were due to chronic liver failure, 1 was due to pulmonary hypertension, and 2 were sudden and of unknown cause. The sixth patient was a 2-day-old neonate with a small left ventricle who underwent CTV that was complicated by perforation of the posterior aspect of the ascending aorta. Bleeding in this patient required placement on cardiopulmonary bypass and repair of the aortic root. The patient required extracorporeal membrane oxygenation (ECMO) support because of severe LV diastolic dysfunction before and after CTV. The patient was weaned from ECMO and was stable, although he could not be weaned from ventilatory support. An echocardiogram showed a residual gradient of approximately 25 mm Hg across the aortic valve and moderate aortic regurgitation. Orthotopic cardiac transplantation was performed, but this child died due to low cardiac output several days later secondary to pulmonary hypertension and graft failure.
Overall survival estimated by the Kaplan–Meier method including early mortality was 59% at 5, 10, 15, and 20 years (Fig 2B). Since 1985, the survival has been 85% (62/85). Five risk factors were significant on univariate analysis: presence of endocardial fibroelastosis (p = 0.05); presence of hypoplastic LV (p = 0.003); complexity of the disease (p = 0.04); aortic valve annulus of less than 5.0 mm (p = 0.01); and surgery before 1978 (p = 0.001). Of these five factors, only the presence of a hypoplastic LV (p = 0.001) and surgery before 1978 (p = 0.001) remain significant by multivariate analysis.
The mean preoperative aortic pressure gradient decreased from 68.7 ± 27.9 mm Hg to 33.5 ± 27.8 mm Hg after surgery (p = 0.012). Twenty-five of 45 patients (55%) had postoperative gradients of more than 35 mm Hg, and 17 of 45 patients (38%) had late postoperative gradients of more than 50 mm Hg at last follow-up. Aortic insufficiency (AI) was not documented before surgery; however, 34 of 45 patients (76%) had documented AI on late follow-up: it was mild in 47% (16 of 34), moderate in 32% (11 of 34), and severe in 21% (7 of 34) of patients.
Sixteen reoperations have been performed in 14 patients (14 of 55, 26%). The predominant indication for reoperation was the presence of combined stenosis with AI (9 of 14, 64%) followed by restenosis (4 of 14, 29%) or pure AI (1 of 14, 7%). One of these patients also had an aneurysm of ascending aorta. One patient required a second and a third procedure (7 and 13 years after initial surgery). Nine patients eventually required a Ross procedure, 2 had AVR with mechanical valves, 2 had repeat open valvotomies, and 1 patient had a heart transplant. The mean time from initial surgery to first reoperation was 8.0 ± 5.4 years (range 3 months to 17 years).
Overall freedom from reoperation estimated by the Kaplan–Meier method was 91% at 5 years, 82% at 10 years, 77% at 15 years, and 71% at 20 years (Fig 3B). Univariate and multivariate analysis showed the presence of CTV (p = 0.02) as the best preoperative predictors of late reoperation in survivors.
Forty-five patients (100%) were currently in NYHA functional class I or II. There was no atrioventricular block or pacemaker implantation in this group. A review of the results in several large series is shown in Table 9.
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One hundred fifty-one of the 155 hospital survivors (97%) have been followed up with a mean follow-up time of 10.3 ± 8.5 years; the longest was 41 years, and 21 patients (21 of 155, 14%) were followed for more than 20 years. One hundred forty-nine patients (149 of 151, 99%) are still alive at last contact. There were 2 late deaths at 5 and 12 years after initial procedure. Both of these patients required subsequent AVR; 1 died secondary to end-stage renal disease and massive myocardial hypertrophy, and the other died of a cardiac dysrhythmia 1 year after valve replacement surgery.
Overall survival estimated by the Kaplan–Meier method, including early mortality, was 98% at 5 years and 97% at 20, 30, and 40 years (Fig 2B).
A comparison of preoperative and immediate postoperative pressure gradients documented a decrease of the peak from 82.4 ± 27.3 mm Hg to 30.7 ± 27.8 mm Hg (p < 0.004). Thirty-one patients (31 of 155, 20%) had a late postoperative gradients of more than 50 mm Hg, and 21 additional patients (21 of 155, 16%) had late postoperative gradients of more than 35 mm Hg. The mean follow-up in this subset was 13.8 ± 10.5 years. Aortic insufficiency was documented in 32 patients (32 of 157, 20%) before surgery; however, 103 patients (103 of 155, 67%) had AI documented on late follow-up: mild in 56% (58 of 103), moderate in 27% (27 of 103), and severe in 17% (17 of 103).
Fifty-five reoperations were performed in 45 patients (45 of 155, 29%). The indications for reoperation were the recurrence of stenosis with insufficiency (26/45, 58%) followed by isolated restenosis (13/45, 29%) or pure insufficiency (4/45, 9%). Two patients required reoperation (both with mechanical AVR) one for profound hemolysis and anemia and the other for an ascending aorta aneurysm (n = 1). Eight patients required a third aortic procedure: Ross aortic root replacement in 6 and mechanical AVR in 2. Both patients with mechanical AVR previously had undergone porcine valve insertion and were reoperated (2 and 16 years after the initial surgery) due to prosthesis degeneration. Indications for the Ross procedure were recurrent AS or severe AI in all patients. Two children had a fourth procedure: one for resection of ascending aortic aneurysm and the other for autograft valvuloplasty with resection of LV pseudoaneurysm. The mean time from initial surgery to first reoperation was 11.0 ± 7.6 years, and from first to second reoperation was 6.7 ± 5.1 years. A bicuspid valve was present in 36 patients (80%) who required reoperation; this did not differ significantly from the initial population (p > 0.05).
Thirty-three patients (21%) followed for more than 25 years and 15 patients (10%) followed for more than 15 years after their initial surgery have required AVR.
Overall freedom from reoperation estimated by the Kaplan–Meier method was 80% at 10 years, 67% at 20 years, 62% at 30 years, and 61% at 40 years (Fig 3B).
One hundred forty patients (93%) are currently in NYHA functional class I or II, and 11 patients (7%) are in class III. Comparing NYHA class of reoperated and nonreoperated patients, patients who had not undergone reoperation were in a significantly better NYHA class (p = 0.02) at last follow-up. Among the patients who were NYHA class III, 1 had ventricular arrhythmia, 1 had a left anterior hemi block, and 2 had atrioventricular block and had pacemaker implantation.
A comparison of the results of several large series of children with VAS is shown in Table 11.
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Thirty-three of the 39 surviving patients with isolated SVAS (85%) were contacted within the past 2 years. The mean follow-up was 10.2 ± 5.2 years (range 6 months to 20 years). There have been no late deaths since 1987. Figure 2C shows the overall actuarial survival, including operative mortality, with 98% survival at 5, 10, 15, and 20 years. Univariate and multivariate analysis identified none of the tested variables as risk factors for death.
The mean preoperative aortic pressure gradient decreased from 86.5 ± 43.1 mm Hg to 19.4 ± 18.4 mm Hg (p = 0.001). Four patients (10%, 4 of 39) had postoperative gradients of more than 35 mm Hg, and 2 of these patients had postoperative gradients of more than 50 mm Hg at last follow-up. Aortic insufficiency was documented in 2 patients (2 of 40, 5%) before initial operation; it was documented in 7 patients (7 of 33, 21%) on late follow-up: AI was mild in 86% (6 of 7) and moderate in 1 (14%, 1 of 7).
Three reoperations were performed in 3 patients (3 of 39, 8%). Two patients with recurrent SVAS underwent redo patch aortoplasty (2 and 10 years after initial surgery), and the third patient with recurrent SVAS and moderate AI underwent a Ross procedure (11 years after initial surgery). Risk factor for reoperation by univariate analysis was the presence of late LV-aortic gradient of more than 35 mm Hg (p = 0.05). Overall freedom from reoperation estimated by the Kaplan–Meier method was 97% at 5 years, 95% at 10 years, and 92% at 20 years (Fig 3C).
Postoperatively, all patients were in NYHA class I and II. Recent echocardiographic follow-up showed the persistence of mild stenosis of the pulmonary artery branches in 2 patients with initial severe pulmonary branch stenosis that were repaired by patch enlargement at the time of initial SVAS surgery. Much of the data on this subset of patients with SVAS were previously published [9].
Subvalvar aortic stenosis
One hundred thirty-two patients (132 of 508, 24%) with isolated SAS have undergone surgical procedures. There were 110 patients (110 of 132, 83%) with discrete subaortic membrane and 22 patients (22 of 132, 17%) with diffuse tunnel-like fibromuscular obstruction. All the surgical procedures performed for SAS are shown in Table 12. An additional 73 patients had surgery for SAS as a part of their treatment for multilevel LVOTO (fibrous resection, n = 37; fibromuscular resection, n = 29; valve-sparing Konno, n = 7) (Table 10).
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One hundred twenty patients of the 126 hospital survivors (95%) were contacted within the past 2 years. The mean follow-up was 7.9 ± 6.5 years (range 6 months to 29 years). There were 8 late deaths (8 of 132, 6%): 2 patients with discrete SAS and 6 patients with tunnel type SAS. The 2 late deaths in patients with discrete SAS were of cardiac origin: 1 due to cerebrovascular accident (3 months after surgery) and 1 with congestive heart failure (7 years after surgery). Causes of the 6 late deaths in tunnel SAS group were as follows: 3 were from low cardiac output (1, 2, and 3 years after surgery, respectively); 1 was sudden of unexplained cause 5 years after repair; and 2 were related to noncardiac causes (1 due to hemoptysis 4 years after operation, and 1 due to aspiration and respiratory arrest 6 months after reoperation).
Overall survival including early and late mortality was 90% at 5 years and 89% at 25 years (Fig 2C). Univariate and multivariate analysis identified date of operation (before 1975) as a risk factor for death (p = 0.002).
The mean preoperative aortic pressure gradient decreased from 74.7 ± 30.5 mm Hg to 29.9 ± 25.7 mm Hg (p = 0.002). No significant difference was noted in the mean preoperative LV-aortic gradients of the discrete (72.6 ± 31.3 mm Hg) and diffuse groups of patients with SAS (83.2 ± 23.3 mm Hg; p = 0.12). Although, the late mean postoperative LV-aortic gradient was better for the patients with discrete SAS (26.8 ± 24.2 mm Hg) than for the patients with diffuse type of SAS (43.9 ± 28.8 mm Hg; p = 0.02). Likewise, the proportion of patients with late postoperative LVOT gradients of more than 50 mm Hg was significantly greater in patients with tunnel obstruction (7 of 13, 54%) than for those with discrete obstruction (16 of 94, 16%; p = 0.001). Mild AI was documented in 20 patients (20 of 132, 15%) before surgery, and 31 patients had AI on late follow-up (31 of 107, 29%; p = 0.055). The AI was mild in 84% (26 of 31), moderate in 13% (4 of 31), and severe in 3% (1 of 31) of patients.
Thirty reoperations were performed in 25 surviving patients (25 of 120, 21%): 10 patients with discrete SAS required reoperations, as did 15 patients with diffuse SAS. The mean time from initial surgery to first reoperation was 7.5 ± 6.1 years (range 5 months to 25 years). Three patients underwent second reoperation (mean 2.7 ± 2.1 years) and 2 patients underwent a third reoperation (mean 2.5 ± 2.1 years). The predominant indication for reoperation was the presence of recurrent subaortic stenosis with AI (12 of 30, 40%), isolated recurrent subaortic stenosis (12 of 30, 40%), or pure AI (1 of 30, 3%). Two patients with cardiomyopathy required heart transplantation. Six patients who required an AAC initially underwent removal of the AAC due to stenosis or thrombosis (n = 4) or pseudoaneurysm at the LV anastomosis (n = 2). Two underwent late insertion of an AAC after an initial attempt to relieve SAS directly. An AVR was performed with pulmonary autograft in 5 patients (1 of them with Konno procedure), a mechanical prosthesis in 2 patients, and an aortic homograft in 1 patient. A repeat resection of subaortic membrane was performed in 10 patients (7 of them with myotomy and myectomy). Two patients required a valve-sparing Konno procedure.
Overall freedom from reoperation was 90% at 5 years, 79% at 10 years, 76% at 25 years (Fig 3C). Statistical analysis revealed that several factors could be predictors for recurrence of the SAS. In univariate analysis anatomic, surgical, and hemodynamic factors were strong predictors for recurrence. The anatomic factor was relative hypoplasia of aortic annulus less than 5 mm (p = 0.05). The presence of AAC (p = 0.02), and higher preoperative gradients across the LVOT (p = 0.04) were associated with higher rates for reoperation. The independent risk factors for reoperation by Cox multivariate regression analysis were AAC insertion (p = 0.005) and a late follow-up gradients of 43.9 ± 28.8 mm Hg in patients with tunnel SAS (p = 0.004).
Of the 120 patients with SAS in this study followed postoperatively, 100 patients had the discrete type of SAS and 20 patients had the diffuse type of SAS. No significant difference was noted between the groups in preoperatively functional class. However, postoperatively the patients with the discrete form of SAS were in a better functional class (88 in class I and 12 in class II) than the patients with the tunnel-type of SAS (12 in class I, 6 in class II, and 2 in class III; p = 0.01).
Multilevel of left ventricular outflow tract obstruction
Ninety-four patients presented with multiple levels of LVOTO had a combination of surgical techniques. The total number of initial and redo procedures performed in these 94 patients was 212 (Table 10). Eight patients with multilevel obstruction were neonates and had neonatal critical AS as part of their LVOTO.
The only early death (1 of 94, 1.1%) occurred in a 1-month-old infant who underwent a Ross-Konno procedure with an extensive aortic arch patch, atrial septal defect, and ventral septal defect closure. The death was due to intercerebral bleeding during the weaning process from ECMO support 5 days after this extensive and complex repair.
Ninety-two of the hospital survivors (99%) were contacted within the past 2 years. The mean follow-up was 7.5 ± 6.0 years (range 6 months to 23 years). There were 5 late deaths (range 3 months to 4 years). One patient with localized SVAS and valvar aortic stenosis underwent total aortic root replacement with an aortic homograft at another institution and died 3 years after the initial conservative operation. A second late death occurred in a patient with residual SVAS and tunnel subaortic stenosis. The operative procedure for insertion of the AAC and the hospital course were unremarkable. This patient was discharged on the 14th postoperative day but returned 3 weeks later with fever and left pleural effusion. Although the pleural fluid was sterile initially, it became secondarily infected and led to a staphylococcal empyema. The infected AAC conduit was removed, and an aortoventriculoplasty (Konno procedure) was performed. The patient died of renal failure and continued sepsis 2 weeks after reoperation. The third death occurred in a child with recurrent SAS and SVAS. The death occurred 6 months postoperatively due to arrhythmia. A 19-year-old patient with severe subvalvar and valvar LVOTO became the fourth death. This patient had originally undergone resection of subvalvar membrane and open valvotomy at the age of 8 years. Eleven years later this patient underwent insertion of an AAC due to recurrent diffuse SAS. Recovery was uneventful, but 4 years later the patient died of a sudden pulmonary hemorrhage. The fifth death occurred 6 month after surgery of unknown cause.
Overall survival estimated by the Kaplan–Meier method including early mortality, was 95% at 5, 10, 15, and 20 years (Fig 2C).
The mean preoperative aortic pressure gradient decreased from 85.2 ± 30.9 mm Hg to 35.3 ± 37.2 mm Hg (p = 0.02) intraoperatively. Fourteen patients (14 of 75, 19%) had late postoperative gradients of more than 50 mm Hg, and 5 additional patients (5 of 75, 7%) had late postoperative gradients of more than 35 mm Hg. Aortic insufficiency was documented in 6 patients (6 of 94, 6%) before surgery; and 40 patients (40 of 75, 53%) had documented AI on late follow-up. In 27 it was mild (27 of 40, 67%), moderate in 9 (9 of 40, 23%), and severe in 4 (4 of 40, 10%).
Forty-seven reoperations were performed in 34 patients (34 of 93, 37%) (Table 10). The mean time from initial surgery to first reoperation was 5.1 ± 4.8 years (range 3 months to 22 years). Nine patients underwent second reoperation (mean 4.8 ± 4.6 years; range 3 months to 16 years), and 4 patients underwent a third reoperation (mean 5.0 ± 3.7 years; range 1 to 10 years). All patients with neonatal critical AS (n = 7) as part of their multilevel AS underwent reoperation 3.6 ± 2.6 years after the initial procedure. The predominant indication for reoperation was presence of recurrent SAS with AI (32%, 15 of 47) and recurrent SAS (45%, 21 of 47), or pure AI (6%, 3 of 47 of reoperations). One patient with a cardiomyopathy required heart transplantation. Six patients underwent insertion of an AAC and 6 more patients with AAC underwent removal or revision of their AAC for the following reasons: 2 were revised for AAC valve regurgitation and 4 were removed or ligated for AAC thrombosis. In 17 patients, an AVR was performed by the following techniques: 13 Ross AVRs, 3 Ross-Konno AVRs and one aortic homograft AVR. A repeat resection of a subaortic membrane was performed in 6 patients (1 with myotomy and myectomy). Four patients underwent repeat open valvotomy, 2 patients underwent aortic valvuloplasty due to severe AI, 1 patient had resection of an LV pseudoaneurysm, and 1 patient underwent resection of an ascending aortic pseudoaneurysm. Three patients required a valve-sparing Konno procedure.
Overall freedom from reoperation estimated by the Kaplan–Meier method was 66% at 5 years, 53% at 10 years, 40% at 20 years, and 39% at 25 years (Fig 3C). Statistical analysis revealed that several factors were predictors for reoperation in patients with multilevel LVOTO. In univariate analysis anatomic and surgical factors were strong predictors for the need for reoperation. Valvotomy for neonatal critical AS was a strong predictor for reoperation (p = 0.0015), as was apico-aortic conduit insertion (p = 0.005). In the multivariate Cox regression analysis AAC insertion (p = 0.0015) and the diagnosis of neonatal critical AS in infant less than 6 months (p = 0.002) were independent risk factors for reoperation.
At latest clinical evaluation, all survivors (n = 92) were in NYHA functional class I and II leading normal or near-normal lives.
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Two high-risk subgroups for recurrence and reoperation have been clearly identified. The group with the highest early mortality was the neonate and infant group less than 6 months of age [31]. The significantly higher mortality reflects several factors. First, these infants manifest severely symptomatic congestive heart failure. Second, associated cardiac anomalies more commonly affect both early and late results, especially in children with borderline hypoplastic left ventricles and endocardial fibroelastosis. Third, operative repair is often more difficult and less precise than in older patients because the neonatal valves are frequently dysplastic. This group represents one of the most challenging facets of congenital AS, and although operative methods are generally well standardized, a wide variety of surgical approaches have been advocated. We have found that transventricular closed aortic valvotomy without bypass has worked as well as or better than any other surgical or balloon valvotomy method in our neonates with critical AS (Table 9). The long-term results with respect to survival and reoperation are good and compare favorably with other forms of neonatal treatment for critical AS.
Neonates with evidence of severe aortic annulus hypoplasia, low ejection fraction, and endocardial fibroelastosis are not good candidates for surgical valvotomy and should be considered for a univentricular repair (ie, Norwood). We consider most procedures performed in neonates are palliative and reintervention is usually required within 10 years. Further long-term follow-up or perhaps a randomized trial will be needed to determine accurately which therapy (ie, transventricular valvotomy, open valvotomy, balloon aortic valvuloplasty, or even neonatal Ross-Konno procedure) will have the best long-term outcome for critical AS in the neonate and infants less than 6 months.
The other patient group at considerably higher risk for reoperation is the group with multilevel LVOTO. The choice of the first or second surgical procedure will be determined by the location and anatomy of the LVOTO and by the patient's age and size. The Ross AVR, the Ross-Konno procedure, and the valve-sparing Konno procedure are all techniques that appear to have the long-term ability to relieve LVOT pathology.
The AAC procedure performed at our institution between 1979 and 1992 provided good palliation for 25 children. There were 2 early and 8 late deaths; however, 2 patients were lost to follow-up. Eleven patients underwent removal or revisions of AAC due to degenerative insufficiency of the conduit porcine valve stenosis or thrombosis of AAC prosthesis. Four subsequently had a Ross or Ross-Konno procedure. Two patients still have their original AAC, 22 and 23 years after initial implantation, but both have had the porcine valves replaced with a mechanical prosthesis 11 years after initial AAC insertion. Our data demonstrated that the AAC was effective in relieving complex LVOTO and improvement in LV performance with acceptable midterm results [38]. Since the early 1990s the AAC procedure has been largely replaced with the Ross or Ross-Konno procedure in our practice. The AAC procedure continues to have a role in older adult patients with critical AS in whom a direct approach through median sternotomy is unattractive (ie, calcified "egg shell" ascending aorta, prior sternal wound infection, or multiple patent arterial or venous bypass grafts).
Valvotomy of the bicuspid or tricuspid aortic valves in children has several advantages over early valve replacement. It relieves most of the obstruction and preserves the native valve and offers 10 to 20 years with low reoperative rates and low thromboembolic rates without anticoagulation. As a result VAS can be surgically palliated in children until they reach adolescence or adulthood [35]. During this time, the aortic annulus will grow sufficiently in most cases to accommodate a prosthesis of adequate size. Valve replacement, if required, is almost always performed with low mortality and acceptable morbidity [31, 33, 39] (Tables 6 and 7). A major problem encountered in non-Ross AVRs in children has been the progressive restriction of prosthesis related to patient growth. The Ross AVR is the only AVR that has growth potential [39] and is the only AVR in which LV mass has returned to a normal range [11]. Our results with AVR in children have been published previously [11]. Our Ross AVR series is compared with other large groups in Table 6.
Some centers have advocated the Ross procedure as the first procedure for LVOTO. In the experience of Lambert and colleagues [37], the only factors related to late mortality in Ross AVR were the young age at the initial Ross operation and the number of prior aortic operations. With the Ross procedure, the LVOT gradient is completely relieved and there is regression of excess LV mass [11], which may improve the long-term prognosis and obviate the need for subsequent LVOT surgery. The immediate surgical risk is still high for the Ross procedure in infants. Van Son and associates [40] suggested that the first aortic valve procedure should be chosen according to the valvar anatomy, arguing in favor of valvuloplasty if the valve was trileaflet, but opting for insertion of the pulmonary autograft (Ross) in the presence of dysplastic bicuspid valves and after a failed surgical or balloon valvulotomy.
Bicuspid aortic valves represent a main cause of isolated AI, which usually presents at a young age [41]. Approximately one third of patients with a bicuspid aortic valve remains asymptomatic and enjoys a normal lifespan [42]. Therefore, it is reasonable to attempt valve repair in an effort to restore a competent aortic valve and return patients to a reasonable long-term outcome. A comparison of the results in several large series of aortic valvar patients is given in Table 11.
Our study has some limitations. The 5% of patients who we lost to follow-up could alter our findings to a small degree. The Ross procedure was introduced at our institution in 1993. During the last 15 years the technique of the Ross procedure has changed to a mini root replacement and the technique may improve the long-term results [43].
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  A. Toscano, L. Pasquini, R. Iacobelli, R. M. Di Donato, F. Raimondi, A. Carotti, V. Di Ciommo, and S. P. Sanders Congenital supravalvar mitral ring: an underestimated anomaly. J. Thorac. Cardiovasc. Surg., March 1, 2009; 137(3): 538 - 542. [Abstract] [Full Text] [PDF]
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B. Alsoufi, Z. Al-Halees, C. Manlhiot, B. W. McCrindle, M. Al-Ahmadi, A. Sallehuddin, C. C. Canver, Z. Bulbul, M. Joufan, and B. Fadel Mechanical valves versus the Ross procedure for aortic valve replacement in children: Propensity-adjusted comparison of long-term outcomes. J. Thorac. Cardiovasc. Surg., February 1, 2009; 137(2): 362 - 370.e9. [Abstract] [Full Text] [PDF]
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 R. Hetzer, E. B. M. D. Walter, M. Hubler, V. Alexi-Meskishvili, Y. Weng, N. Nagdyman, and F. Berger Modified Surgical Techniques and Long-Term Outcome of Mitral Valve Reconstruction in 111 Children Ann. Thorac. Surg., August 1, 2008; 86(2): 604 - 613. [Abstract] [Full Text] [PDF]
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 B. Alsoufi, T. Karamlou, B. W. McCrindle, and C. A. Caldarone Management options in neonates and infants with critical left ventricular outflow tract obstruction Eur. J. Cardiothorac. Surg., June 1, 2007; 31(6): 1013 - 1021. [Abstract] [Full Text] [PDF]
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K. R. Kanter, P. M. Kirshbom, and B. E. Kogon Redo Aortic Valve Replacement in Children Ann. Thorac. Surg., November 1, 2006; 82(5): 1594 - 1597. [Abstract] [Full Text] [PDF]
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R. Sodian, C. Lueders, L. Kraemer, W. Kuebler, M. Shakibaei, B. Reichart, S. Daebritz, and R. Hetzer Tissue Engineering of Autologous Human Heart Valves Using Cryopreserved Vascular Umbilical Cord Cells Ann. Thorac. Surg., June 1, 2006; 81(6): 2207 - 2216. [Abstract] [Full Text] [PDF]
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G. B. Luciani, A. Favaro, G. Casali, F. Santini, and A. Mazzucco Ross Operation in the Young: A Ten-Year Experience Ann. Thorac. Surg., December 1, 2005; 80(6): 2271 - 2277. [Abstract] [Full Text] [PDF]
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J. W. Brown, M. Ruzmetov, A. C. Fiore, M. D. Rodefeld, D. A. Girod, and M. W. Turrentine Long-Term Results of Apical Aortic Conduits in Children With Complex Left Ventricular Outflow Tract Obstruction Ann. Thorac. Surg., December 1, 2005; 80(6): 2301 - 2308. [Abstract] [Full Text] [PDF]
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 T. Karamlou, K. Jang, W. G. Williams, C. A. Caldarone, G. Van Arsdell, J. G. Coles, and B. W. McCrindle Outcomes and Associated Risk Factors for Aortic Valve Replacement in 160 Children: A Competing-Risks Analysis Circulation, November 29, 2005; 112(22): 3462 - 3469. [Abstract] [Full Text] [PDF]
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J. W. Brown, M. Ruzmetov, P. Vijay, M. H. Hoyer, D. Girod, M. D. Rodefeld, and M. W. Turrentine Operative Results and Outcomes in Children With Shone's Anomaly Ann. Thorac. Surg., April 1, 2005; 79(4): 1358 - 1365. [Abstract] [Full Text] [PDF]
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U. C. Sharma, P. Barenbrug, S. Pokharel, W. R. M. Dassen, Y. M. Pinto, and J. G. Maessen Systematic review of the outcome of aortic valve replacement in patients with aortic stenosis Ann. Thorac. Surg., July 1, 2004; 78(1): 90 - 95. [Abstract] [Full Text] [PDF]
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= patients <6 months of age; 
= patients >6 months of age. (C) Actuarial survival according to level of obstruction. 
= subvalvar aortic stenosis (SAS); • = multilevel aortic stenosis (MULTI).
