Congenital Heart Surgery Nomenclature and Database Project: pediatric cardiomyopathies and end-stage congenital heart disease.

The extant nomenclature for cardiomyopathy is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. All efforts were made to include all relevant nomenclature categories using synonyms where appropriate. A functional classification based on pathophysiology is proposed. Cardiomyopathy is subdivided into: dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, right ventricular cardiomyopathy, and end-stage congenital heart disease. A comprehensive database set is presented that is based on a hierarchical scheme. Data are entered at various levels of complexity and detail that can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented that will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Tracheal allograft reconstruction: the total North American and worldwide pediatric experiences.

BACKGROUND: We reviewed both the North American and the total worldwide pediatric experience with tracheal allograft reconstruction as treatment for patients with long segment and recurrent tracheal stenosis. METHODS: The stenosed tracheal segment is opened to widely patent segments. The anterior cartilage is resected and the posterior trachealis muscle or tracheal wall remains. A temporary silastic intraluminal stent is placed and absorbable sutures secure the chemically preserved cadaveric trachea. After initial success with this technique in Europe, several North American centers have now performed the procedure. The cumulative North American experience includes 6 patients (3 adults and 3 children). Worldwide, more than 100 adults and 31 children, aged 5 months to 18 years, with severe long segment tracheal stenosis have undergone tracheal allograft reconstruction. RESULTS: In North America, 5 of 6 patients have survived, with one early death due to bleeding from a tracheal-innominate artery fistula in a previously irradiated neck. Worldwide, 26 children survived (26 of 31 = 84%) with follow-up from 5 months to 14 years. Only 1 of 26 pediatric survivors (1 of 26 = 3.8%) had a tracheostomy. CONCLUSIONS: Tracheal allograft reconstruction demonstrates encouraging short- to medium-term results for patients with complex tracheal stenosis. Allograft luminal epithelialization supports the expectation of good long-term results.

Should a bicuspid aortic valve be replaced in the presence of subvalvar or supravalvar aortic stenosis?

BACKGROUND: A bicuspid aortic valve is commonly associated with other levels of left ventricular outflow tract obstruction. Providing the bicuspid aortic valve is competent and nonobstructive, repair of subvalvar or supravalvar stenosis usually focuses on the obstructive lesions, leaving the valve in situ. The aim of this report was to examine the impact of a bicuspid aortic valve on the risk of reoperation for patients undergoing operation for subvalvar or supravalvar aortic stenosis. METHODS: Since 1976, 47 patients with supravalvar or subvalvar aortic stenosis have undergone repair. The median follow-up is 5.1 years (range, 2 months to 20.1 years). Sixteen patients (34%) had a bicuspid aortic valve that was competent and nonobstructive, and 31 (66%) had a tricuspid aortic valve. RESULTS: Reoperation was required in 9 patients (56%) with a bicuspid aortic valve, in each involving aortic valve replacement with an autograft (3), homograft (2), or prosthesis (4). Six patients (19%) with a tricuspid aortic valve required reoperation, yet only 1 required aortic valve replacement. The freedom from valve replacement was 43% (70% confidence interval, 31% to 55%) in the bicuspid aortic valve group versus 100% (70% confidence interval, 94% to 99.5%) in the tricuspid group at 5 years (p = 0.0001). The freedom from any reoperation at 5 years was 43% (70% confidence interval, 31% to 55%) in patients with a bicuspid aortic valve versus 86% (70% confidence interval, 80% to 93%) in the tricuspid group (p = 0.02). CONCLUSIONS: The data suggest that patients with subvalvar or supravalvar aortic stenosis and a bicuspid valve may be better palliated with a more definitive operation such as the Ross or Ross-Konno procedure.

Supravalvular aortic stenosis: a modification of extended aortoplasty.

A modification of the Doty extended aortoplasty for supravalvular aortic stenosis has been recently adopted. This modification, which entails placement of an additional patch in the left coronary sinus, results in a more symmetric aortic root. This technique has been applied with success to 3 patients.

Atrioventricular septal defect and tetralogy of Fallot: a 15-year experience.

AIM: Atrioventricular septal defect and tetralogy of Fallot is a relatively uncommon lesion in which there is a risk of right ventricular dysfunction related to inlet and outlet valve problems. For this reason, conservative management involving an initial palliative procedure is often chosen. The aim of this report is to retrospectively review our experience with this lesion. PATIENT POPULATION: 35 patients with atrioventricular septal defect and tetralogy of Fallot have been surgically managed at this institution between January 1980 and June 1995. Twenty-one (60%) of these patients underwent 28 initial palliative shunt procedures. Fourteen (40%) patients underwent primary definitive repair. The criteria for choosing one management strategy over another was based on a number of factors, including age at presentation, anatomy of the lesion, and severity of symptoms. Of the 21 patients who underwent an initial shunt procedure, 15 have undergone definitive operation. Of the 6 patients who did not undergo definitive operation, three died (two directly related to complications of the shunt procedure), two are awaiting operation, and one was lost to follow-up. RESULTS: The primary indication for operation in all patients was cyanosis. Freedom from reoperation at 5 years after definitive operation was 65.1% for all patients; most reoperations were related to left atrioventricular valve regurgitation or residual leaks across the ventricular septal defect patch. The operative mortality at definitive operation was 10.3% (70% CL 4.5-20%) for all patients. The actuarial estimate of survival 7 years following definitive repair was 77.3% (70% CL 68.7-85.9%) for all patients. The actuarial estimate of survival at 7 years was 84.4% (70% CL 73.8-95%) in the patients undergoing primary repair and 65% (70% CL 52.4-77.6%) in patients initially palliated if the mortality of the palliative shunt procedure is included (P = 0.35). CONCLUSION: Patients with atrioventricular septal defect and tetralogy of Fallot can be successfully managed with a variety of surgical strategies. Primary repair may be a reasonable option in carefully selected patients, as this eliminates the morbidity and mortality of an initial shunt procedure and the subsequent interval between initial palliation and definitive repair.

Is a high-risk biventricular repair always preferable to conversion to a single ventricle repair?

OBJECTIVES: The aim of this report is to examine the short-and intermediate-term outcome of a complex biventricular repair compared with a single ventricle repair in patients with two functional ventricles. PATIENT POPULATION: Since 1986, 34 patients with atrioventricular concordance or discordance, ventriculoarterial discordance, ventricular septal defect, and pulmonary stenosis or atresia have undergone biventricular repair (group I). Another group of 16 patients (group II) with the same diagnoses have undergone a single ventricle repair consisting of a total cavopulmonary connection because of either a straddling atrioventricular valve (11 patients) or an uncommitted ventricular septal defect (5 patients). RESULTS: The mean length of follow-up was 3.9 years in group I and 3.0 years in group II. Freedom from reoperation at 7 years was 45.5% in group I and 100% in group II (p = 0.014). The actuarial estimate of survival at 7 years was 68.0% in group I and 93.8% in group II (p = 0.048). CONCLUSION: Short- and intermediate-term morbidity and mortality were greater in patients undergoing a biventricular repair than in a similar group of patients undergoing total cavopulmonary connection. It is unknown whether the long-term results of a total cavopulmonary connection in patients with two ventricles are as good as those obtained with a biventricular approach. However, there may be situations in which the short- and intermediate-term risks of a complex biventricular repair may outweigh the long-term disadvantages of a single ventricle approach.

Mixed total pulmonary venous drainage: still a surgical challenge.

OBJECTIVE: The aim of this report is to review the surgical experience of a single institution with a relatively large series of patients with mixed total pulmonary venous drainage. PATIENT POPULATION: Between January 1, 1971, and December 31, 1994, 232 patients with total pulmonary venous drainage underwent surgical correction. Twenty of these patients (8.6%) had mixed type total pulmonary venous drainage. Ages at operation ranged from 1 day to 46 months, with a median of 2.3 months. RESULTS: Both cardiac catheterization and echocardiography were performed before operation in 12 patients. Four patients underwent only cardiac catheterization, and another four patients underwent only echocardiography. The sensitivity and specificity for catheterization were 94% and 99%, respectively; they were 31% and 100%, respectively, for echocardiography. Severe pulmonary venous obstruction was present in three patients, all of whom underwent emergency operation. Three patients (15%), all of whom had preoperative pulmonary venous obstruction, died after operation. There were two late deaths, one of pulmonary vein stenosis and the other of probable pulmonary hypertension. The actuarial survival at 10 years was 73% for all patients; patients who survived the initial operation had a 10-year survival of 87%. CONCLUSION: The diagnosis of mixed total pulmonary venous drainage can be difficult to establish by echocardiography or at the time of operation. For patients in stable condition, cardiac catheterization may be considered if fewer than three pulmonary veins are identified by echocardiography. Pulmonary venous obstruction is relatively infrequent in this group of patients but when present impacts patient survival significantly. The long-term results with this lesion are excellent.

Late development of functional subvalvar stenosis after repair of truncus arteriosus.

The late development of subvalvar stenosis following truncus repair is described. It may occur in patients with an overriding truncal valve and a relatively small ventricular septal defect (VSD) closed with an inappropriately sized patch. Management consisted in enlarging the VSD and closing it with a large, tailored patch. Consideration should be given to enlarging the VSD at the time of original repair if the truncal valve is overriding.

Pharmacological control of pulmonary blood flow with inhaled nitric oxide after the fenestrated Fontan operation.

BACKGROUND: A transient increase in pulmonary vascular resistance can result in hemodynamic compromise after a Fontan operation. An interatrial fenestration is designed to maintain cardiac output in these circumstances but may result in severe hypoxemia and a vicious circle due to hypoxemia induced pulmonary vasoconstriction. Our aim was to determine whether inhaled nitric oxide (iNO), a selective pulmonary vasodilator, could be used to reduce pulmonary vascular resistance in desaturated patients (SaO2 < or = 85%) after a fenestrated Fontan operation. METHODS AND RESULTS: Responses to iNO (20 ppm for 15 min) were assessed in 10 consecutive children with SaO2 < or = 85% and compared with 5 with SaO2 > 85% after a fenestrated Fontan operation. Exposure to iNO resulted in a significant increase in SaO2 (from 64 +/- 5% to 82 +/- 2%, P < .01) and reduction in transpulmonary gradient (TPG) (from 12.2 +/- 1 [SEM] to 9.6 +/- 1.1, P < .01) in patients with baseline SaO2 < or = 85%. Baseline saturation was a predictor of response to iNO, with a greater response in those with lower saturations (r = -.86, P < .01). In contrast, no significant effects were noted in PaO2 or TPG (from 122 +/- 46 mm Hg and 8 +/- 1.8 to 123 +/- 43 mm Hg and 7 +/- 1.2, respectively) in patients with baseline SaO2 > 85%. CONCLUSIONS: iNO improved both oxygenation and TPG in desaturated patients after the fenestrated Fontan operation, possibly by counteracting hypoxemia-induced pulmonary vasoconstriction. A trial of iNO should be considered in clinically unstable desaturated patients after the fenestrated Fontan operation.

Nitric oxide might reduce the need for extracorporeal support in children with critical postoperative pulmonary hypertension.

BACKGROUND: Postoperative pulmonary hypertension is a life-threatening, yet reversible complication of congenital heart operations. Although inhaled nitric oxide (iNO), a selective pulmonary vasodilator, has been shown extensively to improve short-term oxygenation and hemodynamic indices in these patients, its influence on patient outcome has not been evaluated. The purpose of this study was to assess retrospectively whether patients who fulfilled our criteria for extracorporeal life support (ECLS) for critical postoperative pulmonary hypertension still required ECLS after the administration of iNO therapy. METHODS: Since January 1992, 10 patients (age 3 days to 10 months) fulfilled the criteria at our institution for ECLS for postoperative pulmonary hypertension. Of these, 5 could not be separated from cardiopulmonary bypass because of pulmonary hypertension, and 5 had critical pulmonary hypertension (pulmonary arterial pressure approaching systemic arterial pressure) causing severe cardiopulmonary compromise. RESULTS: Six of the 10 ECLS candidates had a sustained response to iNO and survived to discharge from the hospital, without the need for rescue ECLS. Three patients still required ECLS after 30 minutes, 4 hours, and 8 hours of beginning iNO because of failing cardiac output, and 2 survived. The remaining patient died after 5 days of iNO therapy, but was no longer a candidate for ECLS because of sepsis and multiorgan system failure. CONCLUSIONS: Children with critical pulmonary hypertension unresponsive to maximal conventional treatment may be managed successfully with iNO without the need for rescue ECLS. A trial of iNO should therefore be given before the use of ECLS in these patients.

Metabolic inhibition potentiates oxidant-mediated injury of the endothelial cytoskeleton.

The aim of this study was to determine if exposure of cells to oxidants and metabolic inhibition, conditions which are present during ischemia-reperfusion, act synergistically to produce cytoskeletal disruption. Adherent bovine pulmonary artery endothelial cells were subjected to metabolic inhibition by incubating the cells in glucose-free buffer containing 650 nM oligomycin for 2 hr. Cells were rescued from metabolic inhibition by washing the cells with buffer containing 5.5 mM glucose and were simultaneously exposed to 0, 25, 100, or 5000 microM H2O2. At various time points during recovery from metabolic inhibition the microfilaments and microtubules were stained for microscopic evaluation. Intracellular ATP levels were determined by the luciferin/luciferase assay. Cells that were not metabolically inhibited showed minimal microfilament disruption at lower doses of H2O2. Cells that were subjected to metabolic inhibition but not exposed to H2O2 showed microfilament disruption after 2 hr of metabolic inhibition, but normal microfilament architecture was seen in over 95% of the cells by 1 hr after recovery from metabolic inhibition. Cells that were metabolically inhibited and then exposed to doses of H2O2 as low as 25 microM showed marked microfilament disruption at 1 and 2 hr after the metabolic inhibition was relieved. The microtubules were distorted, but did not depolymerize except when exposed to concentrations of H2O2 > or = 5000 microM. Metabolic inhibition appeared to selectively potentiate the effect of subsequent oxidant exposure and the potentiation largely affected microfilament architecture with secondary effects on microtubule morphology and endothelial cell shape.

Extracorporeal membrane oxygenation as a bridge to definitive tracheal surgery in children.

Extracorporeal membrane oxygenation was used as a bridge for three infants with complicated long segment congenital tracheal stenosis to tracheal homograft transplantation with cadaveric tracheal homograft and for one child, with an extensive traumatic tracheal laceration caused by aspiration of a sharp foreign body, to definitive tracheal repair. In all four cases mechanical ventilation was impossible and death almost certain without extracorporeal membrane oxygenation.

Combined Rastelli and atrial switch procedure: anatomic and physiologic correction of discordant atrioventricular connection associated with ventricular septal defect and left ventricular outflow tract obstruction.

OBJECTIVE: To evaluate our early experience with the combined Rastelli and atrial switch operation for repair of discordant atrioventricular connection associated with ventricular septal defect and left ventricular outflow tract obstruction. METHODS: Detailed study of the first three cases including preoperative assessment, operative procedure, postoperative progress and follow-up. RESULTS: All three patients survived and remained in sinus rhythm. Postoperative ITU/hospital stay was 2/8, 5/10 and 33/45 days. The third patient developed a venous pathway obstruction and required balloon dilatation with stenting on the 25th postoperative day. All three patients were well at follow-up examination 21, 6 and 5 months after operation. CONCLUSIONS: We believe that this operation is likely to become the operation of choice for this combination of lesions. More experience and longer follow-up is needed.

Nitric oxide is superior to prostacyclin for pulmonary hypertension after cardiac operations.

BACKGROUND: Severe pulmonary hypertension is still a cause of morbidity and mortality in children after cardiac operations. The objective of this study was to compare the vasodilator properties of inhaled nitric oxide, a novel pulmonary vasodilator, and intravenous prostacyclin in the treatment of severe postoperative pulmonary hypertension. METHODS: Thirteen children (aged 3 days to 12 months) with severe pulmonary hypertension after cardiac operations were given inhaled nitric oxide (20 ppm x 10 minutes) and intravenous prostacyclin (20 ng.kg-1.min-1 x 10 minutes) in a prospective, randomized cross-over study. RESULTS: Both nitric oxide and prostacyclin resulted in a reduction in pulmonary arterial pressure, although the mean pulmonary arterial pressure was significantly lower during nitric oxide therapy (28.5 +/- 2.9 mm Hg) than during prostacyclin therapy (35.4 +/- 2.1 mm Hg; p < 0.05). The mean pulmonary to systemic arterial pressure ratio was also significantly lower during nitric oxide than prostacylin administration (0.46 +/- 0.04 versus 0.68 +/- 0.05; p < 0.01), due mainly to only prostacyclin lowering systemic blood pressure. CONCLUSIONS: Inhaled nitric oxide was a more effective and selective pulmonary vasodilator than prostacyclin and should be considered as the preferred treatment for severe postoperative pulmonary hypertension.

Long-term follow-up of extended aortoplasty for supravalvular aortic stenosis.

Extended aortoplasty is an operation that was designed to provide a symmetric reconstruction of the aortic root in patients with supravalvular aortic stenosis. The aim of this report is to provide long-term follow-up of the original cohort of 15 patients who underwent extended aortoplasty between 1975 and 1983. Follow-up was obtained in 14 patients. One patient was lost to follow-up 3 years after operation; he was included in this report. An echocardiogram, chest radiograph, and electrocardiogram were obtained for each surviving patient. The median length of follow-up was 141 months (range 36 to 238). The median preoperative gradient was 90 mm Hg (range 55 to 150). The median immediate postoperative gradient was 20 mm Hg (range 0 to 50, p < 0.05 compared with preoperative gradient) and the median long-term gradient was 32 mm Hg (range 6 to 96, p < 0.05 compared with preoperative gradient; p = not significant compared with immediate postoperative gradient). Two patients died: one of left ventricular failure after a subsequent aortic valve replacement and one of chronic left ventricular failure. The Kaplan-Meier estimate of survival at 218 months for all patients was 77.4% (70% confidence limits 62% to 93%). The estimated freedom from reoperation for all patients was 69% at 218 months (70% confidence limits 56% to 82%). Univariate analysis revealed that the presence of a bicuspid valve is a significant risk factor for reoperation (p = 0.038), but not for death (p = 0.51). The Kaplan-Meier estimate of freedom from reoperation for patients with a bicuspid aortic valve was 42.9% at 141 months (70% confidence limits 21% to 65%). Extended aortoplasty provides effective long-term relief of the pressure gradient across the supravalvular ridge. However, a significant number of patients require subsequent operations, particularly those with a bicuspid aortic valve.

Extracorporeal life support for respiratory failure after multiple trauma.

Respiratory failure may complicate multiple trauma and can add significant morbidity, mortality, and cost to the care of such patients. We used extracorporeal life support (ECLS) to treat 24 patients with multiple trauma who, after their injury, developed respiratory failure refractory to conventional ventilatory management. Injuries in these patients were the result of motor vehicle crashes (16 patients), pedestrian versus car collisions (3 patients), gunshots (2 patients), stabs (1 patient), and a recreational vehicle crash (1 patient). Patients were placed on venovenous or venoarterial ECLS, using continuous systemic anticoagulation with heparin, and percutaneous cannulation where possible. Average time on ECLS was 287 +/- 43 hours (12 +/- 1.8 days). The major complication was bleeding, which occurred in 75% of patients. Fifteen patients survived to be discharged from the hospital (63% survival). Early intervention (mechanical ventilation < or = 5 days prior to ECLS) was associated with good outcome. Despite risks of anticoagulation in patients with multiple injuries, ECLS can be life-saving in cases of respiratory failure refractory to conventional mechanical ventilation.

Inhibition of organic anion transport in endothelial cells by hydrogen peroxide.

ATP loss is a prominent feature of cellular injury induced by oxidants or ischemia. How reduction of cellular ATP levels contributes to lethal injury is still poorly understood. In this study we examined the ability of H2O2 to inhibit in a dose-dependent manner the extrusion of fluorescent organic anions from bovine pulmonary artery endothelial cells. Extrusion of fluorescent organic anions was inhibited by probenecid, suggesting an organic anion transporter was involved. In experiments in which ATP levels in endothelial cells were varied by treatment with different degrees of metabolic inhibition, it was determined that organic anion transport was ATP-dependent. H2O2-induced inhibition of organic anion transport correlated well with the oxidant's effect on cellular ATP levels. Thus H2O2-mediated inhibition of organic anion transport appears to be via depletion of ATP, a required substrate for the transport reaction. Inhibition of organic anion transport directly by probenecid or indirectly by metabolic inhibition with reduction of cellular ATP levels was correlated with similar reductions of short term viability. This supports the hypothesis that inhibition of organic anion transport after oxidant exposure or during ischemia results from depletion of ATP and may significantly contribute to cytotoxicity.

Use of extracorporeal life support in patients with congenital heart disease.

OBJECTIVES: To review a large experience with extracorporeal life support in patients with congenital heart disease. To determine the major causes of mortality and morbidity in order to improve the results of using this technology in this patient population. DESIGN: Retrospective chart review. PATIENTS: Twenty-five patients between the ages of 1 day and 8 yrs. These patients had congenital heart disease and were clinically felt to be at high risk for death caused by cardiac failure or by respiratory failure complicated by congenital heart disease. INTERVENTIONS: All patients in this report were placed on extracorporeal life support to allow recovery of myocardial or pulmonary function. MEASUREMENTS AND MAIN RESULTS: Of these 25 patients, 52% were weaned from bypass support and 40% survived to discharge. Patients who were not weaned from extracorporeal life support characteristically suffered from irreversible neurologic injury, multiple organ failure, or bleeding complications. Only one patient died of irreversible cardiac failure. CONCLUSIONS: Extracorporeal life support can be useful in supporting patients with congenital heart disease with life-threatening cardiac or pulmonary failure. Improvements in limiting neurologic and bleeding complications may lead to improvements in the use of extracorporeal life support for this indication. However, prospective, randomized studies are needed to appreciate the role of extracorporeal life support in these patients.