Long-term survival after mitral valve replacement in children aged <5 years: a multi-institutional study.

BACKGROUND: Short- and long-term outcomes after prosthetic mitral valve replacement (MVR) in children aged <5 years are ill-defined and generally perceived as poor. The experience of the Pediatric Cardiac Care Consortium (45 centers, 1982 to 1999) was reviewed. METHODS AND RESULTS: MVR was performed 176 times on 139 patients. Median follow-up was 6.2 years (range 0 to 20 years, 96% complete). Age at initial MVR was 1.9+/-1.4 years. Complications after initial MVR included heart block requiring pacemaker (16%), endocarditis (6%), thrombosis (3%), and stroke (2%). Patient survival was as follows: 1 year, 79%; 5 years, 75%; and 10 years, 74%. The majority of deaths occurred early after initial MVR, with little late attrition despite repeat MVR and chronic anticoagulation. Among survivors, the 5-year freedom from reoperation was 81%. Age-adjusted multivariable predictors of death include the presence of complete atrioventricular canal (hazard ratio 4.76, 95% CI 1.59 to 14.30), Shone's syndrome (hazard ratio 3.68, 95% CI 1.14 to 11.89), and increased ratio of prosthetic valve size to patient weight (relative risk 1.77 per mm/kg increment, 95% CI 1.06 to 2.97). Age- and diagnosis-adjusted prosthetic size/weight ratios predicted a 1-year survival of 91% for size/weight ratio 2, 79% for size/weight ratio 3, 61% for size/weight ratio 4, and 37% for size/weight ratio 5. CONCLUSIONS: Early mortality after MVR can be predicted on the basis of diagnosis and the size/weight ratio. Late mortality is low. These data can assist in choosing between MVR and alternative palliative strategies.

Sinus of Valsalva aneurysm complicating bacterial endocarditis in an infant: diagnosis with two-dimensional and Doppler echocardiography.

Sinus of Valsalva aneurysm is a rare complication of bacterial endocarditis in infancy and childhood. This report describes an infant with congenital aortic stenosis who developed bacterial endocarditis after abdominal surgery and placement of indwelling central venous catheters for long-term parenteral nutrition. Bacterial endocarditis in this infant was complicated by the development of an aneurysm of the left sinus of Valsalva. Surgical intervention was necessary because of gradual expansion of the aneurysm with compression of the adjacent right pulmonary artery and descending aorta. Two-dimensional and Doppler echocardiography proved useful for the initial diagnosis and serial follow-up of this unusual disorder and for its successful surgical management.

Long-term outcome after repair of coarctation in infancy: subclavian angioplasty does not reduce the need for reoperation.

To assess the influence of surgical technique on the need for reoperation after coarctation repair in infancy, follow-up data were analyzed for 125 consecutive infants (less than 12 months) who underwent repair of coarctation of the aorta by subclavian angioplasty or resection and end to end anastomosis. Sixty-three infants underwent coarctation repair by resection between 1960 and 1980, and 62 underwent subclavian angioplasty between 1977 and 1985. The mean age (+/- SEM) at operation for infants with subclavian flap angioplasty was 1.54 +/- 0.93 months and for infants with resection was 2.70 +/- 0.93 months (p = 0.02). There was no difference between the groups in patient weight at initial repair or the proportion of patients with complex anatomy or aortic arch hypoplasia. Follow-up duration for the subclavian flap group was 2.55 +/- 0.51 years (range 0.3 to 8.2), and for the resection group was 7.97 +/- 3.61 years (range 0.6 to 21). Indication for reoperation was the presence of a coarctation gradient at rest of 40 mm Hg or greater and arm hypertension. Reoperation was required in 5 patients in the subclavian flap group and 12 patients in the resection group. The mean reoperation rate after subclavian flap repair was 0.0356 reoperations per patient-year, and after resection was 0.0342 reoperations per patient-year (p = 0.94). To determine an individual's risk of requiring reoperation from these group measures, a reoperation risk model was developed. The risk of reoperation by the fifth postoperative year was found to be 16.3% after subclavian flap repair and 15.7% after resection.(ABSTRACT TRUNCATED AT 250 WORDS)

A reversible pulmonary artery band: preliminary experience.

Pulmonary artery banding has become an infrequently used surgical technique. However, if a band was developed that could be relieved without the need for open heart surgery, it is likely that pulmonary artery banding would be used more frequently in the management of infants with congenital heart disease. Such a pulmonary artery band was placed in seven 1 week old mongrel puppies by using a loop of an absorbable suture material (Vicryl). One dog died at 2 months as a result of right ventricular failure. The remaining six dogs underwent cardiac catheterization and pulmonary balloon angioplasty at 6 months of age. After measuring pulmonary artery, right ventricular and aortic pressures and performing a right ventricular angiogram, balloon angioplasty of the band site was performed. A 20 mm balloon angioplasty catheter (Medi-Tech) was used in all dogs. Balloon angioplasty decreased right ventricular pressure from 101 +/- 19 to 42 +/- 3 mm Hg (p less than 0.05) and right ventricular systolic outflow tract gradient from 59 +/- 14 to 7 +/- 2 mm Hg (p less than 0.03), and increased the size of the band site from 8.7 +/- 0.03 to 14.9 +/- 0.5 mm (p less than 0.01). All dogs were recatheterized 2 months after angioplasty and were then killed for pathologic evaluation. At follow-up catheterization, right ventricular pressure, right ventricular outflow tract gradient and pulmonary artery size at the band site remained at the values obtained immediately after angioplasty. Postmortem examination demonstrated that there was no evidence of pulmonary artery damage. Although these studies are preliminary, they suggest that a reversible pulmonary artery band can be performed.

Evaluation of a computer-assisted method for individualized anticoagulation: retrospective and prospective studies with a pharmacodynamic model.

We studied the effectiveness of a computer program based on a mathematic model of warfarin dynamics in assisting with the initial phases of anticoagulation. In retrospective evaluations the program was successful in predicting prothrombin complex activity (PCA) responses for three different groups of subjects, indicating that the model is a good representation of the physiologic system. In a prospective evaluation of the program a computer-assisted group of 10 patients was compared with a control of 10 patients who did not receive computer assistance. Because of the program's very conservative upper limits for warfarin dosage in the first few days of therapy, the computer-assisted patient require slightly more time (6 days), on the average, to first reach PCA values in the 20% to 30% therapeutic range than did the control patients (4.8 days). After the desired PCA had been achieved, however, the computer-assisted group remained within the therapeutic range for 83% of the time compared to only 60% for the control group. This difference was due primarily to much less overanticoagulation of the computer-assisted patients than of the controls.

Determination of myocardial and serum digoxin concentrations in children by specific and nonspecific assay methods.

After obtaining samples at open heart surgery, serum and right atrial digoxin concentrations were measured in 25 children by a nonspecific, direct radioimmunoassay method (NS) and by a specific method in which digoxin was separated from its metabolites by HPLC before radioimmunoassay was applied to the digoxin fraction (S). Digoxin was detectable by S assay (sensitivity 0.1 ng/g) in 16 heart specimens and 22 serum samples. The mean and range of the S/NS ratio was 0.74 (0.23 to 2.63) for serum and 0.81 (0.068 to 1.38) for atrial tissue. By NS assay the mean and range of the atrial/serum ratio was 78.1 (2.4 to 340, n = 21) and by S assay the corresponding values were 100 (10.7 to 318, n = 15). A multiple linear regression indicated that 72.5% of the variance of the heart digoxin concentrations measured by S assay were accounted for by the variables height, body weight, daily digoxin dose before operation, plasma digoxin concentration by S assay, and BUN.

Increased frequency of posttransplant lymphomas in patients treated with cyclosporine, azathioprine, and prednisone.

We have documented seven B cell lymphomas over a six-month period in 132 (5.3%) kidney and heart allograft recipients immunosuppressed with cyclosporine, azathioprine, and prednisone (triple therapy). This is a significant increase (P less than 0.0001) over the number of such tumors seen by us previously. Only 2 lymphomas had occurred in 669 cadaver and 29 living-related kidney allografts treated with azathioprine and prednisone alone (0.3%). In 160 cadaver kidney recipients treated with cyclosporine and prednisone there have been no lymphomas. Similarly in 14 living-related kidney recipients who were transplanted since the introduction of triple therapy for cadaver grafts, but continued to receive only azathioprine and prednisone, no lymphomas occurred. There seemed to be a clear relationship between this increase and the use of triple therapy. This led us to examine other possible contributing factors. A case control study has not shown any other factor that differs in patients in whom lymphomas developed. We have only been able to demonstrate Epstein Barr virus nuclear antigen in the cells of one tumor. Four of these 7 tumors were monoclonal, one polyclonal, and two indeterminate. All patients had their immunosuppression withdrawn and six received intravenous acyclovir. Three patients have shown some response but four patients died. Triple therapy is being used by many centers to reduce the level of cyclosporine toxicity. We wish to sound a note of caution that this may result in an increased incidence of posttransplant lymphomas.

Epicardial and endocardial activation in patients with endocardial cushion defect.

Epicardial and left ventricular endocardial activation were assessed in 5 patients (aged 4 months to 9.5 years) with endocardial cushion defect (ECD) during surgical repair. Epicardial activation was recorded from 40 to 47 sites over the epicardium; left ventricular endocardial activation was measured at 3 sites immediately after institution of cardiopulmonary bypass. Compared with the reported activation sequence in normal hearts, the pattern of excitation in hearts of patients with ECD was abnormal; epicardial excitation began at the left ventricular diaphragmatic surface and spread laterally and anteriorly over the anterobasal left ventricle. It then merged with right ventricular wavefronts ending along the right ventricular anterior atrioventricular groove and outflow tract. Left ventricular endocardial activation also occurred earliest in the diaphragmatic segment of the left ventricle with later wavefronts recorded laterally and anteriorly. This study demonstrates, for the first time in human subjects, correlation between left ventricular epicardial and endocardial activation in patients with ECD. The data indicate that earliest endocardial and epicardial activation occurs at the left ventricular diaphragmatic segments of the heart, and are consistent with the known posterior and inferior displacement of the specialized atrioventricular conduction system in patients with ECD.

Excitation of the double chamber right ventricle: electrophysiologic and anatomic correlation.

To examine the excitation of the double chamber right ventricle and the possibility that it results from a displaced, hypertrophied moderator band, seven patients with double chamber right ventricle were studied. All seven had pre- and postoperative electrocardiograms. Intraoperative right ventricular epicardial maps were obtained in three; right ventricular endocardial activation maps performed at postoperative catheterization were obtained in four. In the three patients studied at operation the breakthrough point of right ventricular epicardial activation was demonstrated in a normal inferior location well below the obstructing muscle band. Two patients with right bundle branch block after operation and two others with only right ventricular conduction delay on postoperative electrocardiogram demonstrated high normal right ventricular time with prolongation of activation in the right ventricular outflow or inflow region, or both, suggesting only peripheral injury. These data suggest that activation of the double chamber right ventricle is similar to that of the normal heart. In addition, the observed normal activation sequence militates against the hypothesis that the moderator band is the obstructing bundle.

Prognostic factors in valvotomy for critical aortic stenosis in infancy.

Aortic valvotomy for critical aortic stenosis in infancy has had a high mortality. To determine the factors that influence survival, we reviewed the cases of 24 infants who underwent aortic valvotomy in the first 6 months of life (mean 4 1/2 weeks) for aortic stenosis from 1978 to 1984. Cardiopulmonary bypass was used in all patients. Operative mortality was 21% (5/24), four of the five deaths occurring from low cardiac output. Analysis of preoperative factors affecting survival versus nonsurvival revealed that low ejection fraction (60% +/- 17% in survivors versus 36% +/- 2% in nonsurvivors), high left ventricular end-diastolic pressure (16 +/- 7 mm Hg in survivors versus 30 +/- 14 mm Hg in nonsurvivors), and presence of endocardial fibroelastosis (25% in survivors versus 100% in nonsurvivors) all were predictive of a poor outcome, although the small sample size indicated caution in interpreting results. Factors that did not appear to influence survival included peak systolic gradient (79 +/- 30 mm Hg in survivors versus 60 +/- 15 mm Hg in nonsurvivors) and left ventricular end-diastolic volume (37 +/- 17 cm3/m2 in survivors versus 36 +/- 7 cm3/m2 in nonsurvivors). Four patients with a left ventricular end-diastolic volume below 26 cm3/m2 survived. Postoperative gradients averaged 25 +/- 21 mm Hg at 3.4 +/- 2 years' follow-up in nine recatheterized patients. Ejection fraction of these patients increased from 45% +/- 10% to 70% +/- 11% and left ventricular end-diastolic volume increased from 37 +/- 17 to 58 +/- 5 cm3/m2. Two of 17 patients have required apical-aortic conduits; all other patients are asymptomatic. We conclude that infants with critical aortic stenosis benefit from valvotomy even with impaired left ventricular function and severely reduced left ventricular dimensions and many have nearly normal hemodynamics on late follow-up.

Effect of temperature of cardioplegic solution.

This study tests the hypothesis that the efficacy of cardioplegic solution depends upon its chemical constituents rather than on its temperature alone. A standard preparation of right heart bypass in the dog was utilized. Left ventricular function curves were inscribed before and after 1 hour of aortic cross-clamping. No deterioration in function was observed in nonischemic control hearts or in hearts protected with cardioplegic solution consisting of potassium chloride (25 mEq. per liter) and mannitol (12.5 Gm. per liter in 5 percent dextrose and 0.2 percent saline at either 4 degrees C or 28 degrees C. Severe myocardial depression was observed in hearts rendered ischemic for 1 hour at 28 degrees C. without protection and also in hearts perfused with 5 percent dextrose and 0.2 percent saline at 28 degrees C. without the potassium chloride and mannitol. The evidence from this study indicates that cardioplegic solution exerts a protective effect beyond that which is afforded by hypothermia.

Magnetic resonance imaging of mediastinal paraganglioma.

The magnetic resonance (MR) findings are presented of a nonfunctioning mediastinal paraganglioma on both T1- and T2-weighted magnetic resonance images. The MR characteristics of this tumor differentiate it from previously reported functioning mediastinal paragangliomas (pheochromocytoma) and from other benign mediastinal neoplasms, although mediastinal bronchogenic carcinoma may produce a similar appearance.

Effects of methylprednisolone in cardioplegic solution during coronary bypass grafting.

The effects of adding 500 mg. of methylprednisolone to each liter of cardioplegic solution were studied in patients undergoing coronary artery bypass grafts. Patients were randomly assigned to control (12 patients) or steroid-treated groups (10 patients). The cardioplegic solution was identical in the two groups except for the added methylprednisolone. Contractile element velocity (VCE and left ventricular end-diastolic pressure (LVEDP) were recorded immediately before and after perfusion in the operating room. There were no differences between the two groups with respect to these two variables or the postoperative courses. Thus this study fails to demonstrate a beneficial effect of methylprednisolone when added to cardioplegic solutions.

Aortico--left ventricular tunnel and sinus of Valsalva aneurysm. Case report with operative repair.

Aortico--left ventricular tunnel (ALVT) is a rare anomaly, only 21 such cases having appeared in the literature. This report describes a case of ALVT in which there were features characteristics of sinus of Valsalva aneurysm (SVA). Details of the operative repair are discussed.

Comparison of the effect of blood cardioplegia to crystalloid cardioplegia on myocardial contractility in man.

The myocardial protection achieved by blood cardioplegia was compared to that achieved by crystalloid cardioplegia in a randomized prospective series of patients having coronary bypass operations. Group BCP (n = 15) was protected with 10 degrees C blood containing potassium, 30 mEq/L; Group KCP (n = 9) by an electrolyte solution at 4 degrees C with mannitol, 25 gm/L, and potassium, 26 mEq/L, and group MgKCP (n = 9) by an electrolyte solution at 4 degrees C containing magnesium, 30 Meq/L, and potassium, 19.6 mEq/L. The three groups were comparable in regard to age, sex, preoperative left ventricular function, symptoms, propranolol use, previous myocardial infarction, number of vessels bypassed, and duration of ischemic arrest. In each patient cardiac output, left ventricular end-diastolic pressure (LVEDP), and maximum contractile element velocity (Vpm) were recorded before and after the ischemic period. All operations were performed in an identical manner with one continuous period of aortic cross-clamping averaging 52.9 minutes. No significant alterations in myocardial function were observed after ischemia within the BCP or KCP groups. However, patients receiving MgKCP had significant (p = 0.02) depression in Vpm from 2.86 +/- 7.8 to 2.04 +/- 3.6 second-1 and increase (p < 0.05) in LVEDP from 9.4 +/- 2.2 to 13.4 +/- 5.2 mm Hg. Analysis of variance between groups showed that Vpm decreased significantly (p < 0.05) and LVEDP increased significantly (p < 0.05) in the MgKCP group by comparison to the BCP group. Patients receiving BCP experienced spontaneous defibrillation more frequently (p < 0.02) and received nitroprusside postoperatively more often (p < 0.05) than patients in the other two groups. From these results we conclude that blood cardioplegia provides excellent protection during myocardial ischemia, probably better than one of the two crystalloid solutions tested but no better than the other crystalloid solution. Because the three solutions differed from one another in several respects, no conclusion can be reached about the efficacy of any one ingredient.

Liver fibrosis (cardiac cirrhosis) five years after modified Fontan operation for tricuspid atresia.

A 15-year-old girl was found to have severe liver fibrosis on liver biopsy at the time of cholecystectomy, 5 1/2 years following a modified Fontan procedure (right atrial-right ventricular conduit) for tricuspid atresia. Postoperative right atrial pressures were consistently elevated above 13 mm Hg and this, in part, may have been due to progressive mild conduit stenosis. Because of increasing symptoms, the patient underwent successful revision of the conduit at the age of 15 years. It is suggested that sustained systemic venous hypertension caused the striking morphologic changes in the liver and that this serious complication may significantly affect the long-term prognosis of patients surviving the Fontan procedure.

Pulmonary resection for fungal infection in children undergoing bone marrow transplantation.

Recipients of bone marrow transplants for hematologic malignancies are at risk for a variety of infectious complications. We have reviewed our experience with six patients 2 to 15 years of age who developed significant fungal infections of the lungs before or after bone marrow transplant. No patient was known to have active fungal or bacterial infection at the time bone marrow transplant was performed. In two patients fungal infections were diagnosed before bone marrow transplant, and operations were performed to permit bone marrow transplant under optimal conditions. Four patients had pulmonary mycoses discovered after bone marrow transplant, and underwent operation 12 to 24 days following transplant. Operations consisted of lobectomy (three), multiple unilateral wedge resections (one), staged segmentectomy and contralateral wedge resection (one), and staged bilateral wedge resection (one). Survival following bone marrow transplant was achieved for 6 months and 11 months in patients undergoing lung resection before transplant, and for 24, 30, 39, and 60 days in patients undergoing lung resections after transplant. Bone marrow transplant recipients are at high risk of pulmonary mycoses, and a vigorous search for occult fungal infections should be carried out before transplant. Aggressive operative treatment of fungal infections of the lungs combined with antifungal chemotherapy before transplant may offer the best hope of extended survival.

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.

Pedicled right atrial-pericardial tissue conduit for bypass of the obstructed superior vena cava in children.

Surgical relief of superior vena caval obstruction with flaps constructed from pedicled right atrium and pedicled pericardium has been performed successfully in 2 children aged 1 and 13 years. Long-term conduit patency 43 and 24 months after the operation has been achieved with this technique, despite continued growth of both patients.

Correction of truncus arteriosus in the neonate using a nonvalved conduit.

Successful correction of truncus arteriosus in two neonates, both 4 days of age, is described. Nonvalved polytetrafluoroethylene (PTFE) conduits were used because of the small size of the infants. Both recovered from operation with no signs right ventricular failure and remain well. Catheterization data on one patient show satisfactory hemodynamics 1 year after operation with only residual branch pulmonary artery stenosis. These data suggest that a conduit valve is not essential in the correction of truncus arteriosus even in the neonate.