Intermediate-term results after the aortic valve replacement using bileaflet mechanical prosthetic valve in children.

OBJECTIVE: Intermediate/long-term results after aortic valve replacement using bileaflet mechanical valve in children should be clarified as a standard of treatment of aortic valve disease in children. METHODS: Forty-five patients aged under 15 years underwent 46 aortic valve replacements using bileaflet mechanical prosthetic valve. Patients' ages ranged from 1 to 15 years (9 years as a median value), and follow-up period was 9.2 years as a median value (maximum 19 years). RESULTS: In situ valve replacement was performed in 21 procedures, while annular enlargement was required in 25 procedures (Nicks 10, Yamaguchi 3, Manouguian 2, Konno 10). All patients except two received prosthesis 19mm or larger in size. There was one operative death and two late deaths. Two episodes of cerebral infarction, two valve thrombosis, two re-operations, one infective endocarditis, and one sudden death were recognized as valve-related complications in five patients. The reasons for re-operation were prosthesis-patient mismatch in one (Ross procedure) and valve thrombosis in one (re-replacement). At 15 years after the operation, re-replacement free rate, valve-related event free rate and actuarial survival rate were 94+/-4%, 86+/-6% and 92+/-4%, respectively. The transprosthetic flow velocity estimated by Doppler echocardiography at the final follow-up was well correlated with manufactured valve area index (cm(2)/body surface area). CONCLUSIONS: Although aortic annular enlargement was required in more than half of the cases, intermediate-term results after aortic valve replacement using bileaflet mechanical prosthetic valve in children was satisfactory. Indications for alternative treatment such as Ross procedure might be considered in limited cases.

Three hundred and thirty-three experiences with the bidirectional Glenn procedure in a single institute.

OBJECTIVES: Introduction of the bidirectional Glenn procedure (BDG) in low-risk Fontan candidates would improve clinical outcomes. Over the last decade, not only high-risk Fontan candidates, but all candidates underwent BDG and staged Fontan operation (TCPC) in our hospital. METHODS: Three hundred and thirty-three consecutive patients (age range, 42 days to 16 years old) underwent BDG at Fukuoka Children's Hospital Medical Center from 1992 to 2004. Diagnoses included hypoplastic left heart syndrome in 47, pulmonary atresia with intact ventricular septum in 32, tricuspid valve atresia in 35, and other complex univentricular heart defects in 219 patients (right dominant in 166, left dominant in 53). RESULTS: There were three hospital deaths and 27 late deaths (five after TCPC). Six patients underwent takedown operation. Two hundred and thirty patients underwent TCPC, while 66 patients were waiting for TCPC. In five patients, completion of TCPC was contraindicated. A univariate analysis revealed that for patients less than six months old, diagnoses besides tricuspid atresia, right ventricular morphology, mean pulmonary arterial pressure, pulmonary vascular resistance, ventricular end-diastolic pressure, atrioventricular valve regurgitation greater than moderate, atrioventricular valvuloplasty/valve replacement in concomitant procedure, and total anomalous pulmonary venous connection repair in concomitant procedure were significant predictors of death, takedown, or out of indication for completion of TCPC. A stepwise logistic regression analysis showed that mean pulmonary arterial pressure and heterotaxy were independent predictors. CONCLUSIONS: The staged strategy used for all Fontan candidates provides excellent clinical results. The main risk factor for death, takedown, or out of indication for completion of TCPC was elevated pulmonary arterial pressure. Appropriate surgical interventions such as atrioventricular valvuloplasty and total anomalous pulmonary venous connection repair, before and/or on BDG for the control of pulmonary circulation are of great importance to prevent elevation of pulmonary arterial pressure.

Expanded polytetrafluoroethylene valved conduit and patch with bulging sinuses in right ventricular outflow tract reconstruction.

OBJECTIVES: No specific prosthetic material is currently recognized as being the most suitable for right ventricular outflow tract reconstruction for congenital heart defects. Prosthetic valves are subject to wear and stress because they do not create vortex flow, which helps natural valves to close. We designed a fan-shaped expanded polytetrafluoroethylene valved conduit and patch with bulging sinuses that create vortex flow, making them more reliable over the long term. METHODS: Bulging sinuses were formed on a sheet of expanded polytetrafluoroethylene using a specially designed mold. Fan-shaped expanded polytetrafluoroethylene sheets (0.1 mm thick) were anastomosed to the edge of the bulging sinuses as valve leaflets, creating monocuspid, bicuspid, or tricuspid valves. These valves were implanted in 157 patients undergoing right ventricular outflow tract reconstruction (age 16 days to 45.4 years, median 2.0 years), in 48 patients as a conduit, and in 109 patients as a patch. Valve function was followed up by echocardiography for 5.6 to 63.7 months (mean 20.8 months). RESULTS: There was no mortality or morbidity, and no patients required reoperation during follow-up. No patients had stenosis, and regurgitation was less than mild in all patients with conduits and moderate in 15 patients (13.8%) with patches, but moderate regurgitation did not further develop during follow-up. Valve motion was fully maintained in all patients. CONCLUSIONS: The expanded polytetrafluoroethylene valved conduits and patches with bulging sinuses showed excellent early-to-midterm results. The valved conduits and patches seem to be promising alternatives to homografts in right ventricular outflow tract reconstruction. Their function will be followed up further.

Comparison of hemodynamics between Norwood procedure and systemic-to-pulmonary artery shunt for single right ventricle patients.

OBJECTIVE: Despite that surgical outcomes of patients with hypoplastic left heart syndrome have improved, one of the problems remaining is the high interstage mortality after a stage I Norwood procedure. The purpose of this study was to determine the hemodynamic characteristics of hypoplastic left heart syndrome after a Norwood procedure. We examined the perioperative hemodynamic differences of the staged operation between the first stage of the Norwood procedure and systemic pulmonary shunt for single right ventricle patients. METHODS: Data from 39 patients who underwent a Norwood procedure (right ventricle to pulmonary artery conduit: 19, Blalock-Taussig shunt, 20) were analyzed. There were nine early and seven interstage deaths. Bidirectional cavopulmonary shunt was performed in 15 patients and the Fontan procedure in 9 (group H). We defined the control group as 26 patients who underwent the first stage of a systemic pulmonary shunt for a single ventricle. Bidirectional cavopulmonary shunt was performed in 14 patients and the Fontan procedure in 8 (group C). We compared the perioperative hemodynamics of the staged operation between the two groups. RESULTS: Cardiothoracic ratio and single ventricular diastolic dimension before bidirectional cavopulmonary shunt were acutely increased in group H (P=0.02, <0.001). There was no significant difference between the two different types of Norwood procedures. The pulmonary artery index for the right heart bypass operation was lower in group H than in group C (P<0.001). Oxygen saturation before bidirectional cavopulmonary shunt in group H decreased (P<0.001) and thus was lower than that in group C (P=0.003). Mortality and the postoperative clinical parameters of the right heart bypass operation were not different between the two groups. CONCLUSIONS: Patients with hypoplastic left heart syndrome showed hemodynamic instability of acutely increased cardiothoracic ratio, and single ventricular diastolic dimension despite decreased oxygen saturation interstage after stage I of a Norwood procedure. This suggests that this hemodynamic characteristics in hypoplastic left heart syndrome correlates with the higher mortality before second stage palliation than in found with single right ventricle patients.

Modified Ross procedure using a conduit with a synthetic valve.

OBJECTIVE: In the Ross procedure, a homograft conduit is commonly used in place of an autotransplanted pulmonary valve. Homograft availability may be a problem and has resulted in a search for alternatives. We performed a modified Ross procedure for right ventricular outflow tract reconstruction with a synthetic valved conduit as an alternative to homograft. Our early results of valvular and right ventricular function were evaluated in patients who used a conduit with a synthetic valve. METHODS: Subjects consisted of 11 patients, who ranged in age from 5 to 22 years (12.0+/-4.9), and whose body weight ranged from 15.1 to 52.5 (34.3+/-14.4) kg. Indications for surgery were aortic stenosis (n=3), aortic stenosis and regurgitation (n=4), and aortic regurgitation (n=4). Right ventricular outflow tract reconstruction was performed using a hand-fashioned valved conduit prepared by sewing a 0.1 mm thick polytetrafluoroethylene sheet onto the luminal cavity of the 20-28 mm conduit. A conduit made with polytetrafluoroethylene was used in 8 patients, and a Dacron graft was used in 3 patients. RESULTS: There was no in-hospital or late mortality and angiocardiography at discharge revealed that all artificial valves remained active. The mean right atrial pressure and right ventricular end-diastolic pressure were not statistically different from preoperative values. The latest echocardiography (mean interval, 12.6 months) revealed that a mean pressure gradient across the synthetic valve was 11.4+/-11.1 mmHg and none of the patients had moderate or severe regurgitation. CONCLUSIONS: We demonstrated that a modified Ross procedure for right ventricular outflow tract reconstruction using a conduit with an appropriate synthetic valve is particularly effective in older children.

Surgical results of double-orifice left atrioventricular valve associated with atrioventricular septal defects.

BACKGROUND: Double-orifice left atrioventricular valve (LAVV) is a rare but surgically important anomaly, which is regarded as a risk factor for surgical correction of atrioventricular septal defects (AVSDs). METHODS: Of 209 consecutive patients with AVSDs, double-orifice LAVV was identified in 19 patients (9.1%, including 7 infants). Preoperative LAVV function, surgical procedures and results, incidence of postoperative LAVV dysfunction and reoperations were reviewed and compared between patients with this valve malformation (group I, n = 19) and those without it (group II, n = 190). RESULTS: There were no operative or late deaths in group I. Preoperative LAVV function was similar in both groups. The cleft was totally closed in 77.2% of group II and 47.1% of group I (p < 0.01). In partial AVSDs, freedom from postoperative LAVV insufficiency was 77.0% in group II versus 30.5% in group I at 5 years (p = 0.009) and freedom from reoperation was 89.9% in group II versus 58.3% in group I at 5 years (p = 0.012); however, there was no difference in complete AVSDs. None of the infants in group I underwent total cleft closure and 4 of them showed more than moderate LAVV insufficiency postoperatively. CONCLUSIONS: Double-orifice LAVV is a significant predictor for postoperative LAVV incompetence and reoperation in partial AVSDs, but not in complete AVSDs. Surgical procedures for the cleft should be individualized with careful intraoperative evaluation of the structure and function of this abnormal valve, especially in partial AVSDs and infants.

Total cavopulmonary connection with an extracardiac conduit: experience with 100 patients.

BACKGROUND: In the Fontan procedures total cavopulmonary connection with an extracardiac conduit is a concern. The potential benefits of an extracardiac conduit may be the avoidance of postoperative supraventricular arrhythmias over the long-term, hemodynamic benefits due to laminar flow, possibility of completion without anoxic arrest, and applicability to anomalous systemic or pulmonary venous return, or both anomalous systemic and pulmonary venous return. We demonstrate early to midterm results of total cavopulmonary connection with an extracardiac conduit. METHODS: Between March 1994 and February 2000, a total of 100 patients underwent total cavopulmonary connection with an extracardiac conduit. In 27 patients, who underwent a single stage total cavopulmonary connection operation, 7 were done without palliation. Seventy-three patients had undergone a bidirectional Glenn shunt before completion of the total cavopulmonary connection. We used an expanded polytetrafluoroethylene tube graft as the extracardiac conduit. RESULTS: Cardiopulmonary bypass time was 133.2+/-55.2 minutes. Myocardial ischemic time was 38.5+/-23.2 minutes in 40 patients who needed cardioplegic cardiac arrest for intracardiac procedures. Intraoperative fenestration was done in only 1 patient. There were no operative deaths. During follow-up of 37.3 months, there were 5 late deaths. When compared with the patients treated by the lateral tunnel technique in our institute, there was no significant difference in actuarial survival rate, but the event free rate of the extracardiac conduit group was significantly superior to the lateral tunnel group. CONCLUSIONS: Total cavopulmonary connection with the extracardiac conduit produced good results in short to midterm follow-up.