Ralph S. Mosca

Complete Repair of Tetralogy of Fallot in the Neonate: Results in the Modern Era

ObjectiveTo review more than a decade of experience with complete repair of tetralogy of Fallot (TOF) in neonates at the University of Michigan; to assess early and late survival, perioperative complications, and the incidence of reoperation; and to analyze patient, procedural, and morphologic risk factors to determine their effects on outcome. Summary Background DataPalliation of TOF with systemic-to-pulmonary artery shunts has been the accepted standard for symptomatic neonates and infants. Complete repair has traditionally been reserved for infants older than 6 months of age because of the perception that younger and smaller infants face an unacceptably high surgical risk. ResultsA retrospective review from August 1988 to November 1999 consisted of 61 consecutive symptomatic neonates with TOF who underwent complete repair. Thirty-one patients had TOF with pulmonary stenosis, 24 had TOF with pulmonary atresia, and 6 had TOF with nonconfluent pulmonary arteries. The mean age at repair was 16 ± 13 days, and the mean weight was 3.2 ± 0.7 kg. Before surgery, 36 patients were receiving an infusion of prostaglandin, 26 were mechanically ventilated, and 11 required inotropic support. Right ventricular outflow tract obstruction was managed with a transannular patch in 49 patients and a right ventricle-to-pulmonary artery conduit in 12. Cardiopulmonary bypass time averaged 71 ± 26 minutes. Hypothermic circulatory arrest was used in 52 patients (mean 38 ± 12 minutes). After cardiopulmonary bypass, the average intraoperative right/left ventricular pressure ratio was 55% ± 13%. There were no new clinically apparent neurologic sequelae after repair. The postoperative intensive care unit stay was 9.1 ± 8 days, with 6.8 ± 7 days of mechanical ventilation. There was one hospital death from postoperative necrotizing enterocolitis on postoperative day 71 and four late deaths, only one of which was cardiac-related. Actuarial survival was 93% at 5 years. Follow-up was available for all 60 hospital survivors and averaged 62 months (range 1–141 months). Twenty-two patients required a total of 24 reoperations at an average interval of 26 months after repair. Indications for reoperation included right ventricular outflow tract obstruction (19), branch pulmonary artery stenosis (11), severe pulmonary insufficiency (4), and residual ventricular septal defect (1). The 1-month, 1-year, and 5-year freedom from reoperation rates were 100%, 89%, and 58%, respectively. ConclusionsComplete repair of TOF in the neonate is associated with excellent intermediate-term survival. Although the reoperation rate is significant, this is to be expected with the complex right ventricular outflow tract and pulmonary artery anatomy seen in symptomatic neonates and the need for conduit replacement in patients with TOF with pulmonary atresia.

Techniques and results in the management of multiple ventricular septal defects

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.

Intermediate results after complete repair of tetralogy of Fallot in neonates

From July 1988 through September 1993, 30 neonates with symptomatic tetralogy of Fallot underwent complete repair. Sixteen patients had tetralogy and pulmonary stenosis, 9 had pulmonary atresia, 3 had nonconfluent pulmonary arteries, and 2 had both pulmonary atresia and nonconfluent pulmonary arteries. The median age at operation was 11 days (mean +/- standard error of the mean, 12.6 +/- 2.9 days), with a mean weight of 3.1 +/- 0.1 kg (range 1.5 to 4.4 kg). Preoperatively, 14 patients were receiving an infusion of prostaglandin, 13 were mechanically ventilated, and 6 required inotropic support. Right ventricular outflow tract obstruction was managed by a limited transannular patch in 25 patients, infundibular muscle division with limited resection in 15, and insertion of a right ventricle-pulmonary artery valved aortic homograft conduit in 5 patients. Follow-up was complete at a median interval of 24 months (range 1 to 62 months). There were no hospital deaths and two late deaths, for 1-month, 1-year, and 5-year actuarial survivals of 100%, 93%, and 93%, respectively. The hazard function for death had a rapidly declining single phase that approached zero by 6 months after the operation. Both late deaths occurred in patients with tetralogy of Fallot and pulmonary atresia who had undergone aortic homograft conduit reconstruction, so that the only independent risk factor for death was the use of a valved homograft conduit (p < or = 0.005). Eight patients required reoperation, resulting in 1-month, 1-year, and 5-year freedom from reoperation rates of 100%, 93%, and 66%, respectively. Indications for reoperation were branch left pulmonary artery stenosis in 5 patients, residual right ventricular outflow tract obstruction in 2 patients, and severe pulmonary insufficiency in 1 patient. Independent risk factors for reoperation included an intraoperative pressure ratio between the right and left ventricles of 0.75 or greater (p = 0.01), Doppler residual left pulmonary artery stenosis of 15 mm Hg or more, or Doppler right ventricular outflow tract obstruction gradient of 40 mm Hg or more at hospital discharge (p = 0.002 and 0.02, respectively). This series demonstrates the safety of early hemodynamic repair of symptomatic tetralogy of Fallot in neonates. It also emphasizes the importance of relieving all sources of right ventricular outflow tract obstruction at the initial operation, particularly that located at the site of insertion of the ductus arteriosus, which may be difficult to diagnose in the neonate before ductal closure occurs. The safety and efficacy of valved aortic homograft conduits in neonates requires further investigation.

Use of extracorporeal life support as a bridge to pediatric cardiac transplantation

BACKGROUND Extracorporeal life support (ECLS) has been used for post-cardiotomy rescue, but its use as a bridge to heart transplantation (OHT) in patients with post-surgical or end-stage ventricular failure remains controversial. METHODS Records were reviewed for patients receiving ECLS for ventricular failure from January 1991 to August 2001. Patients listed for OHT were analyzed separately. Listing for OHT requirements were improbable myocardial recovery, absence of contraindications (central nervous system damage, high pulmonary resistance, ongoing infection, etc.), and parental consent. Outcome variables included patient demographics, diagnosis, days from ECLS initiation to United Network for Organ Sharing (UNOS) listing (latency), list time, renal function, and survival to discharge. RESULTS Of 145 patients with ventricular failure who received ECLS, 21 pediatric patients were UNOS listed. Of 124 non-listed patients, 57 (46%) survived to discharge. All but 3 survivors were separated from ECLS in </=7 days. Twelve underwent OHT and 10 survived to discharge (list time, 6 days; median ECLS time, 14 days). Five had ECLS discontinued without undergoing OHT (1 later underwent OHT, 2 survived to discharge). Five experienced complications while receiving ECLS and died without undergoing OHT. Six of 9 patients who required dialysis for renal failure died. Of 11 infants listed, 4 were weaned from ECLS without undergoing OHT (2 survived to discharge), 5 had OHT (ECLS support, 4 days; 4 survived to discharge) and 2 died (ECLS support, 16 and 47 days). CONCLUSIONS (1) Extracorporeal life support can be used as a bridge to OHT (even among the infant population) for at least 2 weeks with acceptable survival and hospital discharge rates, and (2) renal insufficiency with the concomitant requirement for dialysis decreases the likelihood of survival before and after OHT.

Resting coronary flow and coronary flow reserve in human infants after repair or palliation of congenital heart defects as measured by positron emission tomography

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.

Listing and Transplanting Adults With Congenital Heart Disease

Background— An increasing number of patients with congenital heart disease (CHD) are reaching adulthood and may require heart transplantation. The survival of these patients after listing and transplantation has not been evaluated. Methods and Results— A total of 41 849 patients (aged >18 years) were listed for primary transplantation during 1995–2009. Patients with a history of CHD (n=1035; 2.5%) were compared with those with other causes (non-CHD group) (n=40 814; 97.5%); 26 055 (62.3%) reached transplantation and were subdivided into those with (reoperation group; n=10 484; 40.2%) and without (nonreoperation group; n=15 571; 59.8%) a previous sternotomy. Survival on the waiting list was similar between groups, but mechanical ventricular assistance was not associated with superior survival to transplantation among CHD patients. CHD patients were more likely to have body mass index <18.5 at transplantation (P<0.0001), were younger, and had fewer comorbidities. Early mortality among patients with CHD was high (reoperation, 18.9% versus 9.6%; P<0.0001; nonreoperation, 16.6% versus 6.3%; P<0.0001), but by 10 years, overall survival was equivalent (53.8% versus 53.6%). Analysis was limited by the lack of specific information regarding the CHD diagnosis in most patients. Conclusions— Adults with CHD have high 30-day mortality but better late survival after heart transplantation. Mechanical circulatory assistance does not improve waiting list survival in these patients. This may be due to a combination of highly complex reoperative surgery and often poor preoperative systemic health.

Outcomes after transplantation for “failed” Fontan: A single-institution experience

OBJECTIVE Despite the excellent outcomes in the current era after the Fontan procedure, it continues to have an inherent risk of failure. Cardiac transplantation provides 1 option for treating these patients; however, the indications for, timing of, and outcomes after, transplantation remain undefined. We examined our own institutional experience with transplantation for failed Fontan. METHODS The records of 155 patients transplanted for congenital heart disease at a single institution from June 1984 to September 2007 were reviewed. Of these patients, 43 had undergone a previous Fontan procedure (25 male, 15 female; median age, 14.5 years; range, 1-47; 23 classic Fontan, 13 lateral tunnel, 4 extracardiac conduit, and 3 revised to shunt). The predictors of short- and long-term survival were evaluated, and the Fontan patients were compared with all other patients with congenital heart disease (n = 129, 78 male, 51 female). RESULTS The most common indications for transplantation included protein-losing enteropathy (PLE) (39.5%), chronic heart failure (41.8%), and acute post-Fontan failure (9.3%). The transplants performed in Fontan patients were more likely to require pulmonary artery reconstruction (85.4% vs 42.9%; P < .0001) and had longer cardiopulmonary bypass times (278 vs 179 minutes; P < .0001). The 90-day mortality rate was greater in the Fontan group (35.0% vs 20.0%; P = .055). No correlation was observed between the interval from Fontan to transplantation and morality; however, renal failure was a strong predictor of early mortality (odds ratio, 10.8; 95% confidence interval, 1.5-75.7). CONCLUSIONS Transplantation is an acceptable treatment for patients with a failed Fontan. Clinical factors (instead of the indication for transplantation) appear to have the greatest correlation with early mortality.

Critical aortic stenosis in the neonate: A comparison of balloon valvuloplasty and transventricular dilation

The optimal treatment of critical aortic stenosis in the neonate and infant remains controversial. We compared transventricular dilation using normothermic cardiopulmonary bypass and percutaneous balloon aortic valvuloplasty with respect to early and late survival, relief of aortic stenosis, degree of aortic insufficiency, left ventricular function, and freedom from reintervention. Between July 1987 and July 1993, 30 neonates and infants underwent transventricular dilation or balloon aortic valvuloplasty for critical aortic stenosis. The patients in the transventricular dilation group (n = 21) ranged in age from 1 to 59 days (mean age 18.0 days +/- 19.1 days) and the balloon aortic valvuloplasty group (n = 9) from 1 to 31 days (mean age 10.0 days +/- 9.0 days). There were no significant differences in weight, body surface area, or aortic anulus diameter between the two groups (p = 1.0). Associated cardiovascular anomalies were more common in the transventricular dilation group (48%) than in the balloon aortic valvuloplasty group (11%). After intervention, the degree of residual aortic stenosis and insufficiency was equivalent in the two groups as assessed by postprocedural Doppler echocardiography. Ejection fraction improved within both groups (transventricular dilation 39% +/- 20.2% versus 47% +/- 22.0%; balloon aortic valvuloplasty 51% +/- 16.1% versus 62% +/- 8.4%), and there was no significant difference between groups. The left ventricular mass/volume ratio increased within both groups (p < 0.05) but with no significant difference between groups (transventricular dilation 1.4 +/- 0.5 gm/ml versus 1.8 +/- 0.6 gm/ml; balloon aortic valvuloplasty 1.1 +/- 0.6 gm/ml versus 1.7 +/- 0.4 gm/ml). Early mortality in the transventricular dilation group was 9.5% and in the balloon aortic valvuloplasty group, 11.1%. There was one late death in the transventricular dilation group. Four patients from the transventricular dilation group (19%) and two patients from the balloon aortic valvuloplasty group (22%) required reintervention for further relief of aortic stenosis. We conclude that both transventricular dilation and balloon aortic valvuloplasty provide adequate and equivalent relief of critical aortic stenosis. The treatment strategy adopted should depend on other factors, including associated cardiovascular anomalies, vascular access, preoperative condition, and the technical expertise available at each institution.

Autologous fibrin glue from intraoperatively collected platelet-rich plasma

A simple and inexpensive means of creating autologous fibrin glue is described that avoids the potential disadvantages of conventionally obtained material. This improvement may allow more widespread use of fibrin glue for operative bleeding.

The use of mechanical circulatory support as a bridge to transplantation in pediatric patients: An analysis of the United Network for Organ Sharing database

OBJECTIVES The use of mechanical circulatory support to bridge pediatric patients to cardiac transplantation presents unique challenges because of the difficult anatomy and physiology in these patients. METHODS The United Network for Organ Sharing provided deidentifed patient-level data. The study population included 2532 transplantations performed on patients less than 19 years old in status 1/1A/1B between 1995 and 2005. Mechanical circulatory support was used in 431 patients: 241 (9.5%) received ventricular assist devices, 171 (6.8%) underwent extracorporeal membrane oxygenation, and 19 (0.8%) received intra-aortic balloon pumps. RESULTS Patients supported on ventricular assist devices had similar levels of hospitalization and intensive care use and less need for inotropic support (P < .0002) than had those not needing support. Five- and 10-year posttransplantation survival was better in patients receiving ventricular assist devices and patients not receiving mechanical circulatory support than in patients receiving extracorporeal membrane oxygenation or intra-aortic balloon pumping (P < .0001). Among mechanically supported patients, patients with a body surface area of less than 0.30 (odds ratio, 1.70; 95% confidence interval, 1.18-2.43) and those requiring extracorporeal membrane oxygenation (odds ratio, 1.65; 95% confidence interval, 1.15-2.35) or intra-aortic balloon pumping (odds ratio, 1.91; 95% confidence interval, 1.02-3.56) had higher long-term mortality. The use of a ventricular assist device at transplantation did not predict higher long-term, posttransplantation mortality. CONCLUSIONS Pediatric patients requiring a pretransplantation ventricular assist device have long-term survival similar to that of patients not receiving mechanical circulatory support. Early survival among patients undergoing extracorporeal membrane oxygenation and infants is poor, reinforcing the need for improvements in device design and physiologic management of infants and neonates.