Faculty Bibliography

Objective: The objective of this experimental study was to test the underlying physical laws behind a proposed novel device for failing Fontan and to investigate whether the device could be implemented theoretically to improve hemodynamics in failing Fontan circulation.
Method(s): A 4-arm setup (Figure 1) was designed and fabricated to simulate an actual Fontan circuit in the form of a junction of the superior and inferior vena cava (SVC, IVC) and the right and left pulmonary arteries (RPA, LPA). A provision for placement of an oscillating ball along the RPA-LPA path to provide a push to the fluid away from SVC and IVC was created. The setup was designed to vary the rate of oscillation of the ball, and the initial pressure of the fluid on SVC and IVC limbs. The time for pressure drop at the SVC and IVC was measured at varying oscillations of the ball and varying resistances in the RPA-LPA pathway. The test was considered positive if increasing oscillations of the ball allowed for quicker pressure drop in the SVC and IVC (indicating quicker discharge of fluid through the LPA and RPA). A total of 48 different experiments were conducted to simulate different physical conditions including without the ball and a graph of the results was plotted and analyzed to conclude (Graph 1).
Result(s): The time required for pressure drop in the experiment without the ball was the least across all set of readings. This meant that placing an oscillating ball along the RPA-LPA path obstructed fluid flow rather than enhancing it. It was also observed that increasing the rate of oscillation of the ball increased the degree of obstruction to flow.
Conclusion(s): The proposed novel method for intervention is not a suitable option for improving hemodynamics in failing Fontan circulation. (Figure Presented)

OBJECTIVE:Femoral vein homograft can be used be used as valved right ventricle to pulmonary artery conduit in the Norwood operation. We describe the results of this approach, including pulmonary artery growth and ventricular function. METHODS:A retrospective chart review of 24 consecutive neonates with hypoplastic left heart syndrome or complex single ventricle undergoing this approach between June 2012 and December 2017 was performed. Conduit valve competency and ventricular function were estimated using transthoracic echocardiogram, and pulmonary artery growth was measured using Nakata's index. Changes in ventricular function pre-Glenn and at latest follow-up were assessed by ordinal logistic regression with a general linear model to account for the correlation within the same patient over time. RESULTS:). Right ventricular function was preserved in 83% of patients at a median follow-up of 34 (interquartile range, 10-46) months. CONCLUSIONS:Femoral vein homograft as a right ventricle to pulmonary artery conduit in the Norwood operation is safe and associated with good pulmonary artery growth and preserved ventricular function as assessed by subjective echocardiography. Catheter intervention of the conduit may be necessary.

BACKGROUND:A surgical pulmonary artery band (PAB) is used to control excessive pulmonary blood flow for certain congenital heart diseases. Previous attempts have been made to develop a transcatheter, implantable pulmonary flow restrictor (PFR) without great success. We modified a microvascular plug (MVP) to be used as a PFR. The objectives of this study were to demonstrate feasibility of transcatheter implantation and retrieval of the modified MVP as a PFR, and compare PA growth while using the PFR versus PAB. METHODS AND RESULTS/RESULTS:The PFR was implanted in eight newborn piglets in bilateral branch pulmonary arteries (PAs). Immediately post-PFR implantation, the right ventricular systolic pressure increased from a median of 20-51 mmHg. Transcatheter retrieval of PFR was 100% successful at 3, 6, and 9 weeks and 50% at 12-weeks post-implant. A left PAB was placed via thoracotomy in four other newborn piglets. Debanding was performed 6-weeks later via balloon angioplasty. On follow-up, the proximal left PA diameters in the PFR and the PAB groups were similar (median 8 vs. 7.1 mm; p = 0.11); albeit the surgical band sites required repeat balloon angioplasty secondary to recurrent stenosis. By histopathology, there was grade II vessel injury in two pigs immediately post-retrieval of PFR that healed by 12 weeks. CONCLUSIONS:Transcatheter implantation and retrieval of the MVP as a PFR is feasible. PA growth is comparable to surgical PAB, which is likely to require reinterventions. The use of the MVP as a PFR in humans has to be trialed before recommending its routine use.

Mechanical circulatory support for infants with single ventricle physiology remains challenging. Utilization of a ventricular assist device (VAD) has potential advantages over extracorporeal circulatory membrane oxygenation. As such, VAD utilization in single ventricle patients with refractory heart failure continues to be explored. Herein, we describe a novel VAD strategy to support an infant with Glenn physiology who presented in cardiogenic shock related to myocardial depression of unknown etiology. This VAD configuration supported the systemic circulation independent of the Glenn circulation. Seven days of VAD support resulted in recovery of myocardial and end-organ function leading to VAD removal. The patient remains alive and free from transplantation 16 months post VAD explantation.

Infants with dextrocardia-heterotaxy syndrome pose significant surgical challenges to a successful orthotopic heart transplant. Herein we report on 2 infants with dextrocardia-heterotaxy syndrome who underwent complex heart transplantation. A combination of preoperative 3-dimensional chest computed tomography to predict optimal donor size and unique surgical technique resulted in successful outcomes.

Surgical ligation of patent ductus arteriosus can be performed safely by following standard steps of operation. Familiarity of the anatomical landmarks and simple precautions result in high degree of safety. The technique of surgical ligation varies with the age of the patient. Surgical ligation of ductus is associated with well-recognized complications, although they occur only in a small number of patients.

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.

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.