Edward L. Bove

Staged reconstruction for hypoplastic left heart syndrome. Contemporary results.

OBJECTIVE The authors review their experience with staged reconstructive surgery for hypoplastic left heart syndrome (HLHS) and assess current outcome for this condition. SUMMARY BACKGROUND DATA Once considered a uniformly fatal condition, the outlook for newborns with HLHS has been altered dramatically with staged reconstructive procedures. Refinements in operative technique and perioperative management have been largely responsible for this improved outlook. METHODS The authors reviewed their experience with 158 consecutive patients undergoing stage 1 reconstruction with a Norwood procedure from January 1990 to August 1995. All patients had classic HLHS, defined as a right ventricular dependent circulation in association with atresia or severe hypoplasia of the aortic valve. RESULTS There were 120 hospital survivors. Among the 127 patients considered at standard risk, survival was significantly higher than that for the 31 patients with important risk factors. Adverse survival was associated most strongly with significant associated noncardiac congenital conditions and severe preoperative obstruction to pulmonary venous return. Second-stage reconstruction with the hemi-Fontan procedure was performed in 106 patients, with 103 hospital survivors and one late death. Three of the late survivors were not considered candidates for the Fontan procedure. To date, the Fontan procedure has been completed in 62 patients, with 53 survivors. Deaths after the Fontan procedure occurred early in our experience and were mostly secondary to left pulmonary artery stenosis or hypoplasia. Significant or potentially significant morbid conditions were noted in 25 of the 120 hospital survivors. Neurologic conditions were found in 6% and cardiovascular conditions in 10%, including dysrhythmia, left pulmonary artery thrombosis, and chronic pleural effusions. Among the patients considered at standard risk with typical anatomy, actuarial survival was 69 +/- 8% at 5 years. Survival was 71 +/- 17% at 5 years for standard risk patients with variant anatomy and 58 +/- 9% for the entire cohort of 158 patients. The largest decrease in survival occurred in the first month of life and late deaths primarily affected those patients in the high-risk group. CONCLUSIONS Staged reconstruction has significantly improved the intermediate-term outlook for patients with HLHS. Factors addressing improvements in early (< 1 month) first-stage survival would be expected to add significantly to an overall improved late outcome. Currently employed refinements in operative technique are associated with eliminating or reducing pulmonary artery distortion and dysrhythmia.

Outcome of pediatric patients treated with extracorporeal life support after cardiac surgery

BACKGROUND Extracorporeal life support (ECLS) has been used for over two decades in select patients after cardiac surgery. We previously described factors associated with death in this population. We now review our recent experience to reassess factors related to mortality. METHODS All pediatric patients who received ECLS support within 7 days after surgery between July 1995 and June 2001 were examined to describe clinical features associated with survival. We compared the results with our prior report to assess changes in practice and outcome. RESULTS Seventy-four patients were followed. Fifty percent survived to discharge. Hospital survival was not significantly related to patient age, cannulation site, or indication. Thirty-five percent of patients required hemofiltration while on ECLS and were significantly less likely to survive (23% vs 65%). A multivariate analysis combining all children from our prior report with the present cohort revealed that patients who received hemofiltration were five times more likely to die (odds ratio 5.01, 95% confidence interval 2.11-11.88). Children with an adequate two-ventricular repair had lower risk of death (odds ratio 0.42, 95% confidence interval 0.19-0.91) after adjusting for patient age, study period, and hours elapsed before initiation of ECLS after surgery. CONCLUSIONS Patients with an adequate two-ventricle repair have significantly higher hospital survival, whereas those with single ventricle physiology or need for dialysis have decreased survival.

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.

Usefulness of the bidirectional Glenn procedure as staged reconstruction for the functional single ventricle

The bidirectional Glenn operation may be particularly useful as an intermediate procedure before Fontan correction in high-risk patients. From October 1989 through February 1992, 50 patients 1 to 60 months old (median 12) have undergone a bidirectional Glenn operation. Diagnoses included hypoplastic left heart syndrome in 21 patients, pulmonary atresia with intact ventricular septum in 10, tricuspid valve atresia in 9, other complex univentricular heart defects in 9, and Ebsteins anomaly in 1. Mean pulmonary vascular resistance was 2.2 +/- 0.2 Wood U (range 0.5 to 7.3) and mean pulmonary artery area Nakata index was 318 +/- mm2/m2 (range 80 to 821). Additional procedures were performed in 17 patients, including pulmonary artery reconstruction in 15 (29%) and bilateral caval anastomoses in 5 (10%). There were 4 hospital deaths (8%). Two deaths resulted from myocardial infarction in patients with pulmonary atresia with intact ventricular septum and sinusoids and 1 from severe pulmonary vascular disease in a patient with hypoplastic left heart syndrome. There was 1 late death from pneumonia. Actuarial survival is 92 +/- 4% at 1 month and beyond, with a mean follow-up of 13.4 +/- 1 months. Risk factor analysis showed that pulmonary vascular resistance > 3 Wood U and pulmonary artery distortion were associated with increased mortality. Twelve patients have undergone a Fontan procedure at a mean duration after bidirectional Glenn of 18 months with 1 death (8%). The bidirectional Glenn procedure provides excellent palliation in high-risk patients and appears useful as a staging procedure before Fontan correction.

Current Status of Staged Reconstruction for Hypoplastic Left Heart Syndrome

Abstract. Once considered a uniformly fatal condition, the outlook for newborns with hypoplastic left heart syndrome has been dramatically altered with staged reconstructive procedures. Refinements in operative technique and perioperative management have been largely responsible for this improved outlook. At the University of Michigan, 253 patients underwent the Norwood operation for classic hypoplastic left heart syndrome between January 1990 and November 1997. Hospital survival was 76%. Among patients considered at standard risk, survival was significantly higher (86%) than that for those patients with important risk factors (42%, p= 0.0001). Adverse survival was most strongly associated with significant associated noncardiac congenital conditions (p= 0.008) and severe preoperative obstruction to pulmonary venous return (p= 0.03). Survival following second-stage reconstruction with a hemi-Fontan or bidirectional Glenn procedure was 97%. The Fontan procedure has been completed in 94 of these patients with a hospital survival rate of 88%. Survival after the Fontan procedure improved significantly when the second stage of the reconstruction was completed with a hemi-Fontan procedure compared to a bidirectional Glenn (98% vs 81%, p= 0.05). Among the patients considered at standard risk, actuarial survival was 70% at 5 years. The largest decrease in survival occurred in the first month of life and late deaths affected primarily those patients in the high-risk group. Neurodevelopmental outcome studies demonstrated normal verbal and performance scores in the majority of patients. Staged reconstruction has significantly improved the intermediate-term outlook for patients with hypoplastic left heart syndrome. Factors addressing improvements in early first-stage survival would be expected to add significantly to an overall improved late outcome.

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.

Computational fluid dynamics in the evaluation of hemodynamic performance of cavopulmonary connections after the Norwood procedure for hypoplastic left heart syndrome.

OBJECTIVE Computational fluid dynamics have been used to study the hemodynamic performance of surgical operations, resulting in improved design. Efficient designs with minimal energy losses are especially important for cavopulmonary connections. The purpose of this study was to compare hydraulic performance between the hemi-Fontan and bidirectional Glenn procedures, as well as the various types of completion Fontan operations. METHODS Three-dimensional models were constructed of typical hemi-Fontan and bidirectional Glenn operations according to anatomic data derived from magnetic resonance scans, angiocardiograms, and echocardiograms. Boundary conditions were imposed, and fluid dynamics were calculated from a mathematic code. Power losses, flow distribution to each lung, and pressures were measured at three predetermined levels of pulmonary arteriolar resistance. Models of the lateral tunnel, total cavopulmonary connection, and extracardiac conduit completion Fontan operations were constructed, and power losses, total flow distribution, vena caval and pulmonary arterial pressures, and flow distribution of inferior vena caval return were calculated. RESULTS The hemi-Fontan and bidirectional Glenn procedures performed nearly identically, with similar power losses and nearly equal flow distributions to each lung at all levels of pulmonary arteriolar resistance. However, the lateral tunnel Fontan procedure as performed after the hemi-Fontan operation had lower power losses (6.9 mW, pulmonary arteriolar resistance 3 units) than the total cavopulmonary connection (40.5 mW) or the extracardiac conduit (42.9 mW), although the inclusion of an enlargement patch toward the right in the total cavopulmonary connection was effective in reducing the difference (10.0 mW). Inferior vena caval flow to the right lung was 52% for the lateral tunnel, compared with 19%, 30%, 19%, and 15% for the total cavopulmonary connection, total cavopulmonary connection with right-sided enlargement patch, extracardiac conduit, and extracardiac conduit with a bevel to the left lung, respectively. CONCLUSIONS According to these methods, the hemi-Fontan and bidirectional Glenn procedures performed equally well, but important differences in energy losses and flow distribution were found after the completion Fontan procedures. The superior hydraulic performance of the lateral tunnel Fontan operation after the hemi-Fontan procedure relative to any other method may be due to closer to optimal caval offset achieved in the surgical reconstruction.

Carcinoma of the Lung: Results of Treatment over Ten Years

Mediastinal lymph node dissection in conjunction with pulmonary resection was performed on 437 patients with bronchogenic carcinoma at the University of Michigan Medical Center from 1959 to 1969. The absolute five- and ten-year survival rates for patients undergoing curative resection were 36.2 and 14.4%, respectively. The five-year survival of those without nodal metastases was 49.3%, and it was 31.1% in patients with hilar metastases only. The five-year survival of patients with mediastinal metastases who received radiation therapy was 23.1%. Of the 193 patients with squamous cell carcinoma, 43% lived five years free from disease. The five-year survival of patients undergoing resection who had no hilar lymph node metastases was 53%, and it was 47.5% in those with hilar metastases only. The five-year survival in patients with mediastinal metastases who received postoperative irradiation was 34.4%.

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.

Fontan operation in the current era: a 15-year single institution experience.

Objective:Evaluate current risk factors for mortality and morbidity in patients undergoing the Fontan procedure at a single institution in the current era. Summary Background Data:An emphasis on early relief of volume and pressure overload culminating in the Fontan procedure has improved patient outcomes for patients with a single ventricle. Methods:A cross-sectional retrospective study was performed for 636 primary Fontan procedures between July 1992 and June 2007. Results:Anatomy included left ventricular hypoplasia in 64% and right ventricular hypoplasia in 36%. A lateral tunnel (LT) was performed in 92% and an extracardiac conduit (EC) in 8%. Hospital survival was 96%. Long-term survival was 97% at a mean follow-up of 50 months (range, 0–173 months). Ventricular anatomy and preoperative hemodynamics did not predict early or late survival. Longer aortic cross clamp (XC) time was associated with decreased late survival (P = 0.01). Fontan takedown was required in 3% and protein-losing enteropathy (PLE) developed in 6%. At follow-up, 98% of patients were either NYHA class I or II and 87% were in normal sinus rhythm. Patients with chest tube drainage >2 weeks had an increased risk of PLE (P < 0.0001) and diminished short- and long-term survival (P = 0.026 and P < 0.0001, respectively). Conclusions:The Fontan procedure can be performed with low risk regardless of ventricular anatomy. Duration of XC time is associated with survival. Prolonged CT drainage correlates with late PLE and diminished survival. There was a low prevalence of late rhythm disturbances and other complications.