Faculty Bibliography

Patients born with single ventricle and L-transposition of the great arteries present challenging medical and surgical management problems. This defect is characterized by a wide variation in cardiac morphology and physiology. The clinical spectrum can range from cyanosis due to pulmonary outflow obstruction and venoarterial shunting to congestive heart failure from pulmonary over-circulation and systemic outflow tract obstruction. To avoid major operations in ill neonates and infants, earlier surgical treatment strategies concentrated on less invasive procedures that did not require cardiopulmonary bypass. Because of relatively poor initial results and a small number of patients presenting later as good candidates for the Fontan procedure, more elaborate initial palliative operations have been used. Despite their increasing complexity, these procedures more completely address the underlying anatomic and physiologic problems and have accounted for steadily improved patient survival.

This study is a retrospective review using transthoracic echocardiography to assess the success of fenestration closure as well as residual right to left shunts in 35 patients who underwent Fontan fenestration closure in the catheterization laboratory. There is a high rate of closure of the Fontan fenestration; however, other residual right to left shunts are common

BACKGROUND AND OBJECTIVES: Although survival of patients with the hypoplastic left heart syndrome treated by staged surgical palliation has improved, hemodynamic data after fenestrated Fontan operation and after fenestration closure have not been reported in this patient population. We sought to describe the hemodynamic status of these patients at cardiac catheterization performed for the purpose of fenestration closure and to compare these data with data from contemporary patients with other forms of univentricular heart. METHODS AND RESULTS: Hemodynamic responses to fenestration closure during cardiac catheterization were reviewed in 40 consecutive patients, including 20 with the hypoplastic left heart syndrome and 20 with other forms of univentricular heart defects. Hemodynamics before fenestration closure (arterial saturation and pressure, Fontan baffle saturation and pressure, pulmonary capillary wedge pressure, systemic arteriovenous oxygen content difference, and right-to-left shunt fraction) were nearly identical between the two groups. Significant (p < 0.05) changes after fenestration closure included increases in arterial saturation (9%), mean arterial pressure (3 mm Hg), and baffle pressure (1 mm Hg) and arteriovenous oxygen content difference (18 ml/L), with near elimination of right-to-left shunting. Cardiac output decreased by 21% and systemic oxygen transport by 13%, with no differences between the two patient groups. Mean baffle pressures were <17 mm Hg in 32 patients (80%). CONCLUSIONS: Hemodynamics after fenestrated Fontan operation and responses to fenestration closure in patients with the hypoplastic left heart syndrome were remarkably similar to that in patients with other univentricular heart defects

OBJECTIVES: This study evaluated postoperative weight gain in children who received albumin versus crystalloid prime for cardiopulmonary bypass (CPB). DESIGN: A retrospective case-controlled study. Children whose extracorporeal (EC) circuit prime contained albumin (group 1) were matched with those whose prime contained only crystalloid (group 2) on the basis of age, weight, and surgical repair. SETTING: A university-based medical center. PARTICIPANTS: Seventy-six children (newborn to 4 years of age) who underwent CPB for correction of a congenital heart anomaly from 1993 to 1995. Group 1 underwent surgery from October 1994 to September 1995, and group 2 from February 1993 to September 1994. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Group 1 had less weight gain on postoperative days (PODs) 1, 2 and 3 compared with group 2 (p = 0.04 on POD 1). Albumin (grams per milliliter) prime and prime volume in milliliters per kilogram were the best predictors of weight gain (p < 0.004), with prime volume being the more important. Children who weighed less than 7.5 kg received more prime volume and had greater weight gain than children who weighed 7.5 kg or greater on PODs 1, 2, and 3 (p < 0.02). CONCLUSION: Data suggest that adding albumin to the EC circuit prime and minimizing the prime volume will result in less postoperative weight gain. Further prospective study with a larger sample is warranted to determine whether albumin prime offers other clinical benefits

OBJECTIVE: The management of patients with multiple ventricular septal defects remains controversial. Primary closure, interventional catheter techniques, and palliative surgery all may have a role, and specific management guidelines remain undefined. METHODS: We reviewed the records of all 33 patients with multiple ventricular septal defects undergoing repair between January 1988 and October 1996. Pulmonary artery hypertension was present in 21 patients (group 1), and pulmonary stenosis was present in the remaining 12 (group 2). Closure was accomplished from a right atriotomy alone in most patients, although an apical left ventriculotomy was used for apical defects. Among group 1 patients, the mean age at repair was 5.9 +/- 0.9 months. Major associated anomalies included coarctation (n = 6), straddling tricuspid valve (n = 1), and critical aortic stenosis (n = 1). Reoperation was performed in two patients for residual ventricular septal defects. Among group 2 patients, the mean age at repair was 6.6 +/- 3.2 years. Major associated anomalies included tetralogy of Fallot (n = 2), pulmonary stenosis (n = 4), double-outlet right ventricle with hypoplastic left ventricle (n = 1), and isolated left ventricular hypoplasia (n = 1). Three required reoperation for residual ventricular septal defect. RESULTS: There were no early or late deaths, no episodes of heart block, and no significant residual ventricular septal defects among group 1 patients. All group 1 patients remain free of significant residual cardiovascular conditions at a mean of 23.4 +/- 5.1 months. Among group 2 patients, there was one early death in a patient with double-outlet right ventricle and left ventricular hypoplasia. Complete heart block occurred in two patients and one required late mitral valve replacement. There were no late deaths, seven remain alive without significant residual defects at a mean of 36.2 +/- 8.0 months, and two required transplantation for left ventricular failure. CONCLUSIONS: Primary repair for infants with multiple ventricular septal defects is associated with good late outcomes. The right atrial approach is satisfactory for most muscular defects, although limited apical left ventriculotomy was used for apical defects. Pulmonary artery banding should be limited to patients with complex associated defects

OBJECTIVE: Coronary physiology in infants with congenital heart disease remains unclear. Our objective was to better understand coronary physiology in infants with congenital heart disease. METHODS: We used positron emission tomography with nitrogen 13-labeled ammonia to measure myocardial perfusion at rest and with adenosine (142 micrograms/kg/min x 6 minutes) in five infants after anatomic repair of a congenital heart lesion (group I), and in five infants after Norwood palliation for hypoplastic left heart syndrome (group II). The groups were matched for age, weight, and time from the operation. RESULTS: Resting coronary flow in the left ventricle in group I was 1.8 +/- 0.2 ml/min/gm; resting flow in the right ventricle in group II was 1.0 +/- 0.3 ml/min/gm (p = 0.003). Coronary flow with adenosine was 2.6 +/- 0.5 ml/min/gm in group I and 1.5 +/- 0.7 ml/min/gm in group II (p = 0.02). Absolute coronary flow reserve was the same in both groups (1.5 +/- 0.2 in group I vs 1.6 +/- 0.3 in group II, p = 0.45). Oxygen delivery was reduced in group II compared with group I at rest (16.1 +/- 4.2 ml/min/100 gm vs 28.9 +/- 4.42 ml/min/100 gm, p = 0.02) and with adenosine (25.5 +/- 8.1 ml/min/100 gm vs 42.3 +/- 5.8 ml/min/100 gm, p = 0.02). CONCLUSIONS: Infants with repaired heart disease have higher resting flow and less coronary flow reserve than previously reported for adults. After Norwood palliation, infants have less perfusion and oxygen delivery to the systemic ventricle than do infants with a repaired lesion. This may in part explain why the outcome for patients with Norwood palliation is less favorable than for others

Background. Many centers have adopted balloon valvuloplasty for treatment of infants with critical aortic stenosis because of historically poor early results and a lack of long-term results with surgical valvotomy. We evaluated our results with open aortic valvotomy over the past decade, specifically examining factors influencing survival and reintervention in the current era. Methods. From 1986 to 1996, 37 infants in the first 3 months of life underwent open aortic valvotomy for critical aortic stenosis. All patients underwent cardiopulmonary bypass, valvotomy, and valve debridement under direct vision with standard techniques. Results. Early mortality was 11% (4 of 37, 70% confidence limit 7% to 20%) and all early deaths were in neonates less than 2 weeks of age. Late death occurred in 6 patients a mean of 10 +/- 12 months (range, 2 to 36 months) after valvotomy. Actuarial survival, including operative deaths was 92% +/- 6% at 1 month, 78% +/- 9% at 1 year, and 73.4% +/- 10% at 10 years. In a multifactorial regression analysis, the best predictors of death were the presence of endocardial fibroelastosis and small body surface area and the best predictor of the need for late reintervention was preoperative aortic annular size. Thirteen patients required reintervention: repeat operation in 7 patients, balloon valvuloplasty in 3 patients, and both balloon valvuloplasty and reoperation in 3 patients. Actuarial freedom from reintervention postoperatively is 97% +/- 3% at 1 month, 73% +/- 9% at 1 year, and 55% +/- 11% at 10 years. Reintervention was for recurrent left ventricular outflow obstruction in 9 patients and mixed aortic stenosis and aortic insufficiency in 4. Echocardiography 4.3 +/- 2.5 years after aortic valvotomy in survivors who have not required reintervention (n = 20) revealed a Doppler peak instantaneous systolic gradient of 37 +/- 14 mm Hg and mild or less aortic regurgitation in 16 patients and moderate aortic regurgitation in 4 patients. Conclusions. Current surgical results with critical aortic stenosis in the neonate and young infant are acceptable in terms of both late survival, reintervention, and functional results in the majority of patients. Newer interventions, such as balloon valvuloplasty, should be carefully evaluated for long-term results and should be compared more appropriately to current surgical results to determine the best treatment modality for the neonate and infant with critical aortic stenosis

BACKGROUND: The purpose of this study was to determine the incidence of moderate to severe tricuspid valve regurgitation in children with hypoplastic left heart syndrome (HLHS) undergoing staged surgical reconstruction, to assess the mechanisms responsible, and to evaluate the efficacy of surgical repair. METHODS AND RESULTS: We retrospectively reviewed clinical and echocardiographic data of 59 consecutive patients with HLHS operated on at our institution. Patients with a moderate or severe degree of tricuspid regurgitation (> or =2+) demonstrated by color flow Doppler echocardiography before the hemi-Fontan or Fontan operation who underwent tricuspid valve repair were included. Patients with HLHS and coexisting atrioventricular septal defect were excluded from the study. Severity of insufficiency was graded on a scale from 1 to 4+ by Doppler color flow mapping. Tricuspid valve morphology, degree of tricuspid valve regurgitation, and right ventricular function were assessed before and after tricuspid valvuloplasty. Eight patients (8/59; 14%) were found to have a minimum of 2+ tricuspid valve regurgitation before hemi-Fontan or Fontan operations. In five of eight patients (62%; Group A), the valve was found to be myxomatous, thickened, and redundant. There were multiple regurgitant jets in three of five (60%) patients in this group. In three of eight patients (37%; Group B), the valve had a normal echocardiographic appearance and regurgitation was the result of a lack of complete leaflet coaptation. All eight patients underwent tricuspid valvuloplasty, and all experienced a decrease in regurgitation. In five of eight (62%) patients, there was a reduction in insufficiency of two grades of severity and in three of eight (37%) patients, there was a one-grade improvement. Tricuspid valve stenosis was not documented in any of the patients after tricuspid valvuloplasty. In seven of eight (87%) patients, right ventricular function was assessed as fair before tricuspid valvuloplasty repair and improved to good in five of seven (71%) patients after the procedure. The remaining patient had good function both at baseline and after tricuspid valvuloplasty. CONCLUSIONS: Moderate to severe tricuspid valve regurgitation is a common finding in patients with HLHS undergoing staged surgical reconstruction and can result from either abnormal valve morphology or incomplete leaflet coaptation. Tricuspid valvuloplasty during either the hemi-Fontan or Fontan stages of reconstruction carries a high success rate and is associated with improved right ventricular function