Faculty Bibliography

BACKGROUND:Numerous advances in surgical techniques and understanding of single-ventricle physiology have resulted in improved survival. We sought to determine the influence of various demographic, perioperative, and patient-specific factors on the survival of single-ventricle patients following stage 1 palliation at our institution. METHODS:We conducted a retrospective study of all single-ventricle patients who had undergone staged palliation at our institution over an 8-year period. Data were collected from the Society of Thoracic Surgeons Congenital Heart Surgery database and from patient charts. Information on age, weight at stage 1 palliation, prematurity, genetic abnormalities, non-cardiac anomalies, ventricular dominance, and type of palliation was collected. Information on mortality and unplanned reinterventions was also collected. RESULTS:A total of 72 patients underwent stage 1 palliation over an 8-year period. There were 12 deaths before and one death after stage 2 palliation. There was no hospital mortality following Glenn or Fontan procedures. On univariate analysis, low weight at the time of stage 1 palliation and prematurity were found to be risk factors for mortality following stage 1 palliation. However, multivariable Cox regression analysis revealed weight at stage 1 palliation to be a strong predictor of mortality. The type of stage 1 palliation did not have any influence on the outcome. No difference in survival was noted following the Glenn procedure. CONCLUSION/CONCLUSIONS:Low weight has a deleterious impact on survival following stage 1 palliation. This is mitigated by stage 2 palliation. The type of stage 1 palliation itself has no bearing on the outcome.

Studies in adult HT have demonstrated improved cardiac function in the recipient following administration of T3 to the donor. The purpose of this experiment was to assess the effects of T3 on the function of the immature donor heart following HT in a piglet model. A total of 32 piglets were divided into 16 donors and 16 recipients. Following creation of brain death, half of the donor piglets were randomized to receive three doses of T3 (0.2 μg/kg) along with hydrocortisone (1 mg/kg). The donor hearts were then transplanted into the recipient piglets on CPB. Duration of survival off CPB, inotrope score, and EF of heart following CPB were evaluated. There were no differences between the two groups in age, weight, pre-brain death EF, T3 levels, and CPB times. Post-CPB survival times were inversely related to the ischemic times in both groups (Pearson r=-0.80, P<.001), and this relationship was not influenced by T3. There was no difference in inotrope score, EF, or biochemical assessment between the two groups. Administration of T3 in combination with hydrocortisone to the brain-dead donor confers no beneficial effect on myocardial function or survival following HT in a piglet model.

Extracorporeal membrane oxygenation was instituted as an aid to in-hospital cardiopulmonary resuscitation (E-CPR) nearly 23 years ago, this led to remarkable improvement in survival considering the mortality rate associated with conventional cardiopulmonary resuscitation (CPR). Given this success, one begins to wonder whether the time has come for expanding the use of E-CPR to outside hospital cardiac arrests especially in the light of development of newer extracorporeal life support devices that are small, mobile, and easy to assemble. This editorial will review recent studies on this subject and address some key guidelines and limitations of this evolving and promising technology.

A 9-year-old child presented with syncope during exercise. He received a diagnosis of congenital atresia of the left main coronary artery by angiography. He underwent successful coronary artery bypass grafting. On the third postoperative day, he experienced acute, precordial chest pain. An urgent computed tomographic scan showed an unrecognized anomalous origin of the right coronary artery (RCA) with a 1.5-cm intramural course. He was taken back to the operating room to undergo unroofing of the RCA. This case highlights the difficulty involved in making two rare diagnoses that can cause the same exact symptoms in a patient and the surgical challenges associated with it.

BACKGROUND:The polytetrafluoroethylene tube used as right ventricle to pulmonary artery conduit in the stage 1 Norwood operation is associated with risks of suboptimal branch pulmonary artery growth, thrombosis, free insufficiency, and long-term right ventricular dysfunction. Our experience with use of valved femoral vein homograft as right ventricle to pulmonary artery conduit is described. METHODS:Between June 2012 and December 2015, 15 neonates with hypoplastic left heart syndrome or complex single ventricle underwent stage 1 Norwood operation with valved segment of femoral vein homograft as right ventricle to pulmonary artery conduit. The median age at surgery was 3 days and the mean weight was 3 kg. The size of the femoral vein homograft was 5 mm in 8 patients and 6 mm in 7 patients. RESULTS:). No patient had thrombosis of conduit. Most femoral vein conduits remained competent in the first month after stage 1 Norwood operation, although most became incompetent by 3 months. Catheter intervention on the conduit was necessary in 7 patients. Right ventricular function was preserved in most patients at follow-up. CONCLUSIONS:The use of femoral vein homograft as right ventricle to pulmonary artery conduit in the Norwood operation is safe and associated with good pulmonary artery growth and preserved ventricular function. Balloon dilation of the conduit may be necessary during the interstage period.

BACKGROUND:The porcine small intestinal extracellular matrix reportedly has the potential to differentiate into viable myocardial cells. When used in tetralogy of Fallot repair, it may improve right ventricular function. We evaluated right ventricular function after repair of tetralogy of Fallot with extracellular matrix versus bovine pericardium. METHOD/METHODS:Subjects with non-transannular repair of tetralogy of Fallot with at least 1 year of follow-up were selected. The extracellular matrix and bovine pericardium groups were compared. We used three-dimensional right ventricular ejection fraction, right ventricle global longitudinal strain, and tricuspid annular plane systolic excursion to assess right ventricular function. RESULTS:The extracellular matrix group had 11 patients, whereas the bovine pericardium group had 10 patients. No differences between the groups were found regarding sex ratio, age at surgery, and cardiopulmonary bypass time. The follow-up period was 28±12.6 months in the extracellular matrix group and 50.05±17.6 months in the bovine pericardium group (p=0.001). The mean three-dimensional right ventricular ejection fraction (55.7±5.0% versus 55.3±5.2%, p=0.73), right ventricular global longitudinal strain (-18.5±3.0% versus -18.0±2.2%, p=0.44), and tricuspid annular plane systolic excursions (1.59±0.16 versus 1.59±0.2, p=0.93) were similar in the extracellular matrix group and in the bovine pericardium group, respectively. Right ventricular global longitudinal strain in healthy children is reported at -29±3% in literature. CONCLUSION/CONCLUSIONS:In a small cohort of the patients undergoing non-transannular repair of tetralogy of Fallot, there was no significant difference in right ventricular function between groups having extracellular matrix versus bovine pericardium patches followed-up for more than 1 year. Lower right ventricular longitudinal strain noted in both the groups compared to healthy children.

OBJECTIVES/OBJECTIVE:The primary objective of this study was to demonstrate that pulmonary artery (PA) debanding via cardiac catheterization using balloon angioplasty is feasible and safe in swine. The secondary objectives were to determine the acute and long-term effects of this therapy. DESIGN/METHODS:This is a chronic survival experimental study in newborn swine. BACKGROUND:PA bands are used in infants for transient palliation of congenital heart defects with excessive pulmonary blood flow. Although rare, if these defects should close spontaneously or become hemodynamically insignificant, a sternotomy and occasionally cardiopulmonary bypass may still be required for band removal. Alternatively, debanding could be accomplished through less invasive methods. INTERVENTIONS/METHODS:The main pulmonary artery was banded in three piglets, and the left pulmonary artery in five piglets via mini-thoracotomy at a mean weight of 2.5 kg. Following a threefold increase in weight, the piglets underwent PA debanding via balloon angioplasty. Four piglets were sacrificed to evaluate the acute effects. The remainder were followed to evaluate long-term effects. Histopathology was performed on all piglets. OUTCOME MEASURES/METHODS:Reintervention rates. Histopathologic consequences of high pressure balloon angioplasty used for PA debanding acutely and after reinterventions. RESULTS:Debanding was performed at a mean weight of 8.1 ± 2.23 kg. The median preintervention gradient across the band was 18 mm Hg. Debanding was successful in all piglets. The median postintervention gradient was 3.5 mm Hg. All piglets in the long-term model required re-interventions for recurrent stenosis at mean weights of 26 ± 1.6 and 61 ± 3.2 kg. Histopathology demonstrated vessel wall injury in only one piglet. CONCLUSIONS:Endovascular PA debanding can be safely achieved in a swine model. Angioplasty following debanding may be necessary for recurrent stenosis. This catheter-based therapy may provide a less-invasive alternative to surgery.

Left thoracic sympathectomy has been shown to be an effective treatment for adults with long QT syndrome who are refractory to medical therapy. We report the successful use of left thoracic sympathectomy for the management of a 10-week-old premature baby with long QT syndrome and heart failure from a large ventricular septal defect and patent ductus arteriosus.

Neonatal arterial switch operation for simple dextro-transposition of the great arteries (d-TGA) has almost eliminated the occurrence of pulmonary vascular obstructive disease compared to patients who underwent Mustard or Senning procedure at an older age. We report a case of a neonate with d-TGA and intact ventricular septum who underwent arterial switch operation and yet developed severe pulmonary vascular obstructive disease within two months.