Robert H. Feldt

Five- to fifteen-year follow-up after Fontan operation.

BackgroundThe purpose of this study was to estimate survival and quality of outcome and assess factors associated with outcome for patients out 5 to 15 years from their Fontan operation. Methods and ResultsWe studied 352 patients who had the Fontan operation prior to 1985. The overall 1-, 5-, and 10-year survival was 77%, 70%, and 60%, respectively. The following factors were significantly associated with lower survival: univentricular heart or complex congenital anomalies other than tricuspid atresia, early calendar year of operation, heterotaxia syndromes, early age at operation, increased pulmonary artery pressure, atrioventricular valve dysfunction, and higher (worse) New York Heart Association class. Reoperations were necessary for 103 of the 352 patients. At least 20%, of the survivors have or have had cardiac arrhythmias requiring antiarrhythmic medication or mechanical pacemaker insertion. Between 7% and 10% of the patients have had or had protein-losing enteropathy/hypoproteinemia. At 5 years postoperatively, 122 patients (34.7%) were alive with a better New York Heart Association functional classification than preoperatively. Fifty-eight patients (16.5%) were alive and in the same functional classification, but 126 (35.8%) died within the first 5 years or were in a worse functional classification. Thirty-nine patients were doing excellently and 29 patients poorly 5 years after the operation. Of the surviving patients, 43% can do as much exercise as their peers, whereas 3% are incapable of exercise. ConclusionsTo assure good functional long-term outcome in addition to survival, clinicians must exclude from selection for Fontan operation patients known to be at high risk for death or poor outcome.

Protein-losing enteropathy after the Fontan operation

Patients were observed after the Fontan operation to determine the frequency and severity of protein-losing enteropathy. A total of 427 patients who survived for 30 days after the Fontan operation, performed between 1973 and January 1987, were analyzed and, thus far, protein-losing enteropathy has developed in 47 of 427. The cumulative risk for the development of protein-losing enteropathy by 10 years was 13.4% among 30-day survivors, and 5-year survival after the diagnosis was 46%. Hemodynamic studies done coincident with the diagnosis of protein-losing enteropathy have shown increased systemic venous pressure, decreased cardiac index, increased pulmonary vascular resistance, and increased ventricular end-diastolic pressure. Medical management of protein-losing enteropathy was only partially successful. Statistical analysis has shown that factors related to protein-losing enteropathy were ventricular anatomy, increased preoperative ventricular end-diastolic pressure, longer operative bypass time, increased length of hospital stay, and postoperative renal failure. This study suggests that scrupulous selection of cases for the Fontan operation is mandatory and that certain perioperative factors may predispose to this serious complication of the Fontan procedure.

Complete atrioventricular block in patients with atrioventricular discordance.

Although patients with atrioventricular (AV) discordance (corrected transposition) have abnormal conduction pathways and may spontaneously develop high-grade AV block, no quantitative assessment of the risk of this happening is available. We reviewed the data on 107 patients with AV discordance ages 2–76 years (mean 22 years) at follow-up. Eighty-two patients (77%) had a ventricular septal defect, 57 (53%) had pulmonary stenosis, 35 (34%) had tricuspid insufficiency and 24 (23%) had dextrocardia. Twenty-three patients (22%) had complete AV block. This condition was present in four patients at birth and developed in 19 patients at ages 4 months to 53 years (mean 18.1 years). Nine of these patients had permanent pacemaker implantation, four at the onset of complete block and five an average of 11 years later. Nine patients have AV block but no pacemaker. One patient died suddenly. Detailed data analysis showed that with increasing follow-up the risk of natural onset AV block continued at a rate of approximately 2% per year after diagnosis. The presence of an intact ventricular septum made AV block more likely. We conclude that patients with AV discordance are at risk of developing complete AV block throughout their lives. With increasing age, this risk is approximately constant and is probably not significantly increased by corrective or palliative surgery if acute surgical AV block does not occur. Pacemaker implantation is not necessary in some children with spontaneous AV block.

Improved early morbidity and mortality after Fontan operation: The Mayo Clinic experience, 1987 to 1992

OBJECTIVES This study sought to evaluate changes in early morbidity and mortality as well as predictors of outcome in our most recent 339 patients undergoing modified Fontan operations. BACKGROUND The Fontan operation is the preferred definitive palliation for patients with functional single ventricles. Previously reported early mortality rates after Fontan operation have been substantial. METHODS Records of 339 consecutive patients who had a Fontan operation at the Mayo Clinic between 1987 and 1992 (recent cohort) were reviewed. This cohort was compared with the previous 500 patients who had Fontan operations performed between 1973 and 1986 (early cohort). RESULTS Recently, overall early mortality after Fontan has decreased significantly compared with that for the early cohort (from 16% to 9%, p = 0.002). This decline occurred despite increased anatomic complexity of patients. Short-term posthospital survival has also improved significantly in recent patients. One-year survival improved to 88% from 79%, and 5-year survival to 81% from 73% (p = 0.006). Patients with common atrioventricular valves and those who took daily preoperative diuretic medication or had either postoperative renal failure or elevated postbypass right atrial pressure were at increased risk for early mortality. Young age was not found to be a risk factor for early mortality. Early mortality for patients with heterotaxia decreased dramatically: recent 30-day mortality was 15% compared with 41% in the early heterotaxy cohort. CONCLUSIONS Many factors may have contributed to decreased early mortality after Fontan. Improved patient selection, younger age at time of operation, refinements in surgical techniques and postoperative management may all have had important roles. Proposed technical modifications of the Fontan operation must be evaluated in light of these improved results.

Pulmonary Blood Supply in Patients With Pulmonary Atresia and Ventricular Septal Defect

The heart and lung specimens in 31 cases of pulmonary value atresia and ventricular septal defect were studied at autopsy. Three types of natural arterial blood supply to the lungs were identified: 1) ductus arteriosus (patient or ligamentous) (12 cases); 2) major collateral arteries (20 cases); and 3) diffuse small pleural arterial plexus coexisting with either ductus arteriosus or major collateral arteries (17 cases). The ductus arteriosus and major collateral arteries did not coexist in the same lung in these cases. Confluent central pulmonary arteries were present in 22 (71%) of the 31 cases, involving 7 (58%) of the 12 cases of ductus arteriosus, 14 (70%) of the 20 cases with major collateral arteries and 1 case with an aorticopulmonary window. The pulmonary trunk (atretic or patent) was identifiable in 24 (77%) of the 31 cases. A lung or lungs that connected to a ductus (or ligamentum) had a complete and unifocal intrapulmonary arterial distribution (without arborization abnormalities). Major collateral blood supply was frequently multifocal and associated with arborization abnormalities. The size of the central pulmonary arteries was not related to the type of arterial blood source but seemed to be related to the amount of blood flow actually reaching the vessels, This study demonstrated a complex systemic arterial system supplying the lungs in these cases. The size, sources and relation among the ductus, the pulmonary artery confluence, the large and small collateral vessels and the intrapulmonary system are far more varied than has ever been reported previously. Careful and thorough premortem studies are crucial if surgical intervention is contemplated.

Hypertrophic obstructive cardiomyopathy in pediatric patients: Results of surgical treatment

Between April 1975 and May 1995, 25 pediatric patients on one hospital service underwent extended left ventricular septal myectomy because of hypertrophic obstructive cardiomyopathy. Ages ranged from 2 months to 20 years (mean, 11.2 years). Seventeen patients had moderate to severe mitral valve insufficiency. Medical therapy had failed in all patients and one patient had undergone dual-chamber pacemaker implantation without improvement. Left ventricular outflow tract gradients ranged from 50 to 154 mm Hg (mean, 99.9 +/- 25.2). Concomitant cardiac procedures included mitral valve repair (n = 2), automatic implantable cardioverter defibrillator implantation (n = 1), and closure of atrial septal defect (n = 1). Intraoperative premyectomy left ventricular outflow tract gradients ranged from 20 to 117 mm Hg (mean, 60.4 + 26.2) and postmyectomy gradients ranged from 0 to 20 mm Hg (mean, 6.6 +/- 5.9). Postmyectomy mitral insufficiency was reduced to a regurgitant fraction of 0% to 12%, and no patient required mitral valve replacement. One patient required a pacemaker because of complete heart block; on subsequent follow-up, normal sinus rhythm had returned. There was no early mortality and no instance of aortic or mitral valve injury or ventricular septal defect. Follow-up ranged from 10 months to 20 years (mean, 6.4 years). There were no late deaths. Left ventricular outflow tract gradients by echocardiography were a mean of 14.2 mm Hg with a median of 5.0 mm Hg. All patients had normal sinus rhythm. Reoperation because of recurrent left ventricular outflow tract obstruction was necessary in two patients at 3.2 years and 12.4 years after initial myectomy, respectively. All patients but one have New York Heart Association class I or II function. We conclude that extended septal myectomy is a safe and effective means of relieving cardiac symptoms and left ventricular outflow tract obstruction in pediatric patients with severe hypertrophic obstructive cardiomyopathy unresponsive to medical management, and late survivorship compares favorably with the natural history of the disease.

The Atrioventricular Conduction System in Persistent Common Atrioventricular Canal Defect Correlations with Electrocardiogram

Serial histologic sections of the atrioventricular (A-V) conduction system were studied in four hearts with persistent common A-V canal, and the anatomic findings were related to the abnormal ECG patterns. Two hearts were examples of the partial form and two of the complete form of A-V canal. The major anatomic abnormalities were: (1) postero-inferior displacement of the A-V node; (2) relatively short distances between the A-V node and the origin of the left bundle branching; (3) marked posteroinferior displacement of the left bundle branching system; and (4) relative hypoplasia of the anterior (superior) left bundle branches. The anatomic configuration of the A-V conduction system in A-V canal could result in relatively early impulse propagation to the posterior aspect of the ventricular septum as suggested by reported electrophysiologica studies. The anatomic findings are considered to be related closely to the known ECG patterns of A-V canal.

Use of Heparin in the Treatment of Protein-Losing Enteropathy After Fontan Operation for Complex Congenital Heart Disease

Protein-losing enteropathy (PLE) is a serious complication of the Fontan operation and is associated with pronounced mortality. Medical management of PLE has been only partially successful. A recent report noted dramatic improvement in patients with PLE within 3 weeks of subcutaneous administration of heparin. We report a case of reversal of PLE with resolution of clinical symptoms and normalization of serum albumin, total protein, and fecal alpha1-antitrypsin values after several months of heparin treatment. Our findings substantiate those recently reported but suggest that reversal of PLE may necessitate more than a few weeks of heparin therapy.

Anomalous ventricular myocardial patterns in a child with complex congenital heart disease

Abstract Unusual ventricular myocardial patterns in a child are described. These patterns, demonstrated by angiocardiography, were associated with complex, congenital heart disease. Autopsy confirmed the bizarre, spongy myocardial patterns present in both ventricles. One explanation for the abnormal myocardial pattern observed in this case is failure of the normal differentiation of the primitive ventricular wall into compact myocardium. Thus, this case may have represented persistence of an embryonal pattern.

Apparent interruption of atrial conduction pathways after surgical repair of transposition of great arteries

Abstract Apparent interruption of the atrial conduction (internodal) pathways after the Senning operation, the Mustard procedure or the creation of an atrial septal defect was sought in the hearts of 49 patients with transposition of the great arteries, and the findings were correlated with postoperative dysrhythmias. The results indicate that (1) extensive disturbance of the atrial septal connections between the sinus and atrioventricular nodes frequently is associated with serious dysrhythmia, and (2) disruption of the region of the middle atrial conduction pathway, especially when coupled with damage to another pathway, is frequently associated with dysrhythmia, most commonly nodal rhythm.