Faculty Bibliography

OBJECTIVE:To evaluate differences in interstage growth of pulmonary arteries between use of polytetrafluoroethylene and femoral vein homograft as Sano shunt during stage-I Norwood palliation. METHODS:A retrospective review of all patients who survived to the second stage following Norwood-Sano operation at two institutions was performed. Either polytetrafluoroethylene or the valved segment of femoral vein homograft was used for construction of the Sano shunt. The size of pulmonary arteries was compared at pre-Glenn catheterisation. RESULTS:A total of 48 neonates with the diagnosis of hypoplastic left heart syndrome or its variants comprised the study population. Femoral vein homograft of 5-6 mm diameter was used in 14 and polytetrafluoroethylene graft of 5 mm was used in 34 patients. The two groups were comparable in terms of preoperative demographics and age at time of pre-Glenn catheterisation (3.9±0.7 versus 3.4±0.8 months, p=0.06). Patients who received femoral vein homograft demonstrated a significantly higher pre-Glenn Nakata index [264 (130-460) versus 165 (108-234) mm2/m2, p=0.004]. The individual branch pulmonary arteries were significantly larger in the femoral vein group (right, 7.8±3.6 versus 5.0±1.2, p=0.014; left, 7.2±2.1 versus 5.6±1.9, p=0.02). There were no differences in cardiac index, Qp:Qs, ventricular end-diastolic pressure or systemic oxygen saturations. CONCLUSIONS:Utilisation of a valved segment of femoral vein homograft as right ventricle to pulmonary artery conduit during Norwood-Sano operation confers better interstage growth of the pulmonary arteries. Further studies are needed to evaluate the impact of femoral vein homograft on single ventricle function.

Respiratory symptoms are prevalent in vascular ring anomalies, including double aortic arch, which is considered the most common type of vascular ring. However, respiratory failure owing to critical airway obstruction in the neonatal period is rare with few reported cases in the literature. We report a case of a newborn patient who required emergent intubation within the first few hours of life and was later discovered to have a double aortic arch.

BACKGROUND:Ebstein anomaly (EA) encompasses a broad spectrum of morphology and clinical presentation. Those who are symptomatic early in infancy are generally at highest risk, but there are limited data regarding multicentric practice patterns and outcomes. We analyzed multiinstitutional data concerning operations and outcomes in neonates and infants with EA. METHODS:Index operations reported in The Society of Thoracic Surgeons Congenital Heart Surgery Database (2010 to 2016) were potentially eligible for inclusion. Analysis was limited to patients with diagnosis of EA and less than 1 year of age at time of surgery (neonates ≤30 days, infants 31 to 365 days). RESULTS:The study population included 255 neonates and 239 infants (at 95 centers). Among neonates, median age at operation was 7 days (interquartile range, 4 to 13 days) and the majority required preoperative ventilation (61.6%, n = 157). The most common primary operation performed among neonates was Ebstein repair (39.6%, n = 101), followed by systemic-to-pulmonary shunt (20.4%, n = 52) and tricuspid valve closure (9.4%, n = 24). Overall neonatal operative mortality was 27.4% (n = 70), with composite morbidity-mortality of 51.4% (n = 48). For infants, median age at operation was 179 days (interquartile range, 108-234 days); the most common primary operation for infants was superior cavopulmonary anastomosis (38.1%, n = 91) followed by Ebstein repair (15.5%, n = 37). Overall operative mortality for infants was 9.2% (n = 22) with composite morbidity-mortality of 20.1% (48). CONCLUSIONS:Symptomatic EA in early infancy is very high risk and a variety of operative procedures were performed. A dedicated prospective study is required to more fully understand optimal selection of treatment pathways to guide a systematic approach to operative management.

Hypoplastic left heart syndrome (HLHS) is the second most common congenital heart disease associated with congenital diaphragmatic hernia (CDH). The reported survival rate of neonates with CDH and HLHS is only 1%-5%. We review our experience with CDH and HLHS and compare our outcomes with published literature. Retrospective review of all neonates with CDH and HLHS at our institution over a 10-year period was performed. The morphology of cardiac and diaphragm defects, clinical course, treatment strategies, and outcomes were reviewed, and an algorithmic approach was proposed. Five patients with CDH and HLHS were treated between 2006 and 2016. All had mitral stenosis with aortic stenosis. Four patients had a left-sided Bochdalek diaphragmatic hernia and 1 patient had a large bilateral Morgagni hernia. Two (2/4) of the Bochdalek hernias were associated with significant pulmonary hypoplasia and required patch closure of the CDH; both were palliated with percutaneous ductal stents and both died. Three patients underwent primary Norwood operation followed by repair of less severe CDH defect. All 3 patients are currently well and have survived bidirectional Glenn anastomosis; one patient is well after Fontan operation. Successful palliation of neonates with HLHS and associated CDH is possible in the current era. Outcome is determined primarily by the severity of the CDH and the degree of associated pulmonary hypoplasia. An algorithmic team approach is helpful in management of this difficult group of patients.

BACKGROUND:Exosomes arise from viable cancer cells and may reflect a different biology than circulating cell-free DNA (cfDNA) shed from dying tissues. We compare exosome-derived DNA (exoDNA) to cfDNA in liquid biopsies of patients with pancreatic ductal adenocarcinoma (PDAC). PATIENTS AND METHODS:Patient samples were obtained between 2003 and 2010, with clinically annotated follow up to 2015. Droplet digital PCR was performed on exoDNA and cfDNA for sensitive detection of KRAS mutants at codons 12/13. A cumulative series of 263 individuals were studied, including a discovery cohort of 142 individuals: 68 PDAC patients of all stages; 20 PDAC patients initially staged with localized disease, with blood drawn after resection for curative intent; and 54 age-matched healthy controls. A validation cohort of 121 individuals (39 cancer patients and 82 healthy controls) was studied to validate KRAS detection rates in early-stage PDAC patients. Primary outcome was circulating KRAS status as detected by droplet digital PCR. Secondary outcomes were disease-free and overall survival. RESULTS:KRAS mutations in exoDNA, were identified in 7.4%, 66.7%, 80%, and 85% of age-matched controls, localized, locally advanced, and metastatic PDAC patients, respectively. Comparatively, mutant KRAS cfDNA was detected in 14.8%, 45.5%, 30.8%, and 57.9% of these individuals. Higher exoKRAS MAFs were associated with decreased disease-free survival in patients with localized disease. In the validation cohort, mutant KRAS exoDNA was detected in 43.6% of early-stage PDAC patients and 20% of healthy controls. CONCLUSIONS:Exosomes are a distinct source of tumor DNA that may be complementary to other liquid biopsy DNA sources. A higher percentage of patients with localized PDAC exhibited detectable KRAS mutations in exoDNA than previously reported for cfDNA. A substantial minority of healthy samples demonstrated mutant KRAS in circulation, dictating careful consideration and application of liquid biopsy findings, which may limit its utility as a broad cancer-screening method.

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.

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.