Mark S. Bleiweis

Berlin Heart EXCOR Pediatric Ventricular Assist Device for Bridge to Heart Transplantation in US Children

Background— Recent data suggest that the Berlin Heart EXCOR Pediatric ventricular assist device is superior to extracorporeal membrane oxygenation for bridge to heart transplantation. Published data are limited to 1 in 4 children who received the device as part of the US clinical trial. We analyzed outcomes for all US children who received the EXCOR to characterize device outcomes in an unselected cohort and to identify risk factors for mortality to facilitate patient selection. Methods and Results— This multicenter, prospective cohort study involved all children implanted with the Berlin Heart EXCOR Pediatric ventricular assist device at 47 centers from May 2007 through December 2010. Multiphase nonproportional hazards modeling was used to identify risk factors for early (<2 months) and late mortality. Of 204 children supported with the EXCOR, the median duration of support was 40 days (range, 1–435 days). Survival at 12 months was 75%, including 64% who reached transplantation, 6% who recovered, and 5% who were alive on the device. Multivariable analysis identified lower weight, biventricular assist device support, and elevated bilirubin as risk factors for early mortality and bilirubin extremes and renal dysfunction as risk factors for late mortality. Neurological dysfunction occurred in 29% and was the leading cause of death. Conclusions— Use of the Berlin Heart EXCOR has risen dramatically over the past decade. The EXCOR has emerged as a new treatment standard in the United States for pediatric bridge to transplantation. Three-quarters of children survived to transplantation or recovery; an important fraction experienced neurological dysfunction. Smaller patient size, renal dysfunction, hepatic dysfunction, and biventricular assist device use were associated with mortality, whereas extracorporeal membrane oxygenation before implantation and congenital heart disease were not.

Inspiratory muscle training in a child with nemaline myopathy and organ transplantation.

Objective: To report the use of inspiratory muscle strength training to treat repeated ventilatory insufficiency in a child with nemaline myopathy who underwent cardiac and renal transplantation. Design: Case report. Setting: Pediatric intensive care unit of a tertiary care university teaching hospital. Patient: A 16-yr-old female with nemaline myopathy affecting cardiorespiratory function, recent organ transplantation, and delayed postoperative ventilatory recovery. Intervention: Inspiratory muscle strength training was provided 5 days weekly for 2 wks, accompanied by progressive weaning from noninvasive ventilation. Measurements and Main Results: Maximal inspiratory pressure increased from −36.7 cm H2O to −77.8 cm H2O, accompanied by improved inspiratory flow, volume, pressure activation and power. During the training period, the patient was weaned from continuous noninvasive ventilatory assist to her preoperative level of ventilatory function. Conclusion: Inspiratory muscle training may be a beneficial component of care for children with nemaline myopathy who experience acute ventilatory insufficiency.

Cerebral and somatic oxygen saturations after repair of tetralogy of Fallot: effects of extubation on regional blood flow.

BACKGROUND After repair of tetralogy of Fallot, some patients experience a low cardiac output state owing to right ventricular diastolic failure. Negative-pressure ventilation has been shown to improve cardiac output in these patients. What has not been evaluated is the effect of extubation and loading of the respiratory muscles on the distribution of cardiac output after repair of tetralogy of Fallot. METHODS In 23 consecutive patients undergoing repair of tetralogy of Fallot, standard hemodynamic variables, central venous oxygen saturations, and near infrared spectroscopy of the brain, mesenteric, and renal circulations were monitored for 30 minutes before and after extubation. RESULTS With extubation, the systolic blood pressure increased significantly from 96 ± 11 to 106 ± 15 mm Hg (p = 0.002) while the heart rate remained unchanged. With extubation, the central venous oxygen saturation increased significantly from 65% ± 7% to 70% ± 10% (p = 0.003). Cerebral oxygen saturations increased significantly from 67% ± 10% to 72% ± 9% (p = 0.0001), whereas mesenteric oxygenation fell significantly from 74% ± 15% to 72% ± 15% (p = 0.04). Renal oxygenation was unaffected by extubation. CONCLUSIONS Cardiac output and cerebral oxygenation increased significantly during spontaneous respiration, the latter suggesting that the brain was in or approaching an oxygen supply-dependent state before extubation. Despite the increase in cardiac output, the presumed increase in respiratory pump perfusion, as well as the concurrent increase in cerebral perfusion, came at the expense of mesenteric perfusion. Renal oxygenation remained unchanged with extubation.

Ventricular assist device implantation in the pediatric population: does pump size selection and associated hemodynamics impact outcomes?

The use of pediatric ventricular assist devices (VADs) continues to evolve with the availability of smaller blood pumps. We examine the correlation of implanting appropriate sized blood pumps with a lower incidence of VAD related complications (VADRC). A 7-year retrospective review was undertaken for all pediatric VAD patients. Optimal VAD hemodynamics were defined as cardiac index of 2.7 L/m2 and rate of 80 beats per minute (bpm) with complete fill/empty of the blood pump. Patient/blood pump size match, VAD rate and fill/empty ratios were calculated (optimum = 1.0) and then correlated with incidence of VADRC. The study included 22 patients, mean age 9.77 years (6 mo–18 yrs) and mean body surface area (BSA) of 1.14 m2 (0.14 m2–2.32 m2), who underwent VAD implantation. VADRC included death while on support (n = 5), bleeding requiring reoperation (n = 8), hemolysis (n = 2), neurologic events (n = 2), thrombus formation (n = 3), and infection (n = 3). Six patients were bridged to transplant without any VADRC. This subset of patients had a mean blood pump size match ratio of 0.98, VAD rate ratio of 0.92 and fill/empty ratio of 1.00. Patients with VADRC (n = 16) were found to have a mean blood pump size match ratio of 0.72, VAD rate ratio of 0.72 and fill/empty ratio of 0.78. We report a series of pediatric patients with wide ranging BSA receiving VAD implantation. Selection of appropriate sized blood pumps can be correlated with decreased VADRC.

Evaluating the extracardiac Fontan conduit by multislice computed tomography: an emerging modality.

Subsequent failure of the Fontan circulation had resulted in signs of failure of the right heart, so revision was achieved by placing an extracardiac conduit between the inferior caval vein and the undersurface of the bifurcation of the pulmonary arteries. During the postoperative period, we used cardiac computed tomography to evaluate the patency of the extracardiac conduit. Figure 1 (arrow) demonstrates a cross-sectional view of the patent extracardiac conduit, while the conduit is shown in coronal view in Figure 2 (arrow). In Figure 3, we provide a three-dimensional reconstruction that clearly visualizes the external appearance of the entire Fontan circuit (arrow). Our experience highlights again the ability of cardiac computed tomography to delineate, in a non-invasive Figure 1. Figure 2.

End-organ recovery post-ventricular assist device can prognosticate survival

Background: This study examines our institutional ventricular assist devices (VADs) experience over two decades to understand trends towards predictors of mortality. Methods: Retrospective study of patients aged 0–21 years supported with a VAD from January 1996 to May 2015. Patient data was examined pre and post‐VAD implant among survivors and non‐survivors. Results: Thirty‐six patients identified (8 supported by Thoratec® VAD and 28 supported by EXCOR Berlin Heart®). Patients diagnosis included dilated cardiomyopathy (DCM) (n = 19,53%), congenital heart disease (CHD) (n = 12,33%), and other (n = 5,14%). Median age and body surface area (BSA) were 1.0 years[0–7 years] and 0.41[0.24–0.92], respectively. Survival to discharge was 75% with no deaths with DCM. The survival rate for patients with CHD was 42%. Univariate analysis showed diagnosis of CHD, smaller BSA and respiratory failure post‐implant (Intermacs criteria) as risk factors for mortality. Median duration of VAD support was lower in non‐survivors, 14 vs 63 days (p = 0.03). Renal function at time of transplant or death was normal/pRIFLE Risk category in 20(74%) of survivors and 2(22%) of non‐survivors (p = 0.06). Post‐implant, peak total bilirubin in the first week trended lower in survivors (p = 0.06). Conclusions: Persistent end‐organ impairment in the first 2 weeks after VAD placement could be a useful prognostic marker for survival to transplant. HighlightsEtiology of heart failure is a key determinant in VAD survival.Post‐VAD complications were similar between survivors and non‐survivors in this predominantly BiVAD subset.Persistent end‐organ impairment in the first 2 weeks after VAD placement could be a useful prognostic marker.Among the 13 patients in renal failure (pRIFLE), the longest need for RRT in a survivor was 22 days post‐VAD placement.

Safe sternal reentry in all age groups with the Rultract Resternotomy Retractor

In patients undergoing repeat sternotomy, the risk of injury to cardiac structures can be reduced by utilizing a technique that provides sustained visualization of structures adherent to underside of the sternum. We discuss the use of a retractor specifically designed for this purpose: the Rultract Resternotomy Retractor™.

The use of veno-venous extracorporeal membrane oxygenation for perinatal support of an infant with d-transposition of the great arteries, intact atrial and ventricular septa, and flow-restricted ductus arteriosus.

Prenatal assessment of a fetus with D-transposition of the great arteries demonstrated an absence of mixing between systemic and pulmonary circulations, and predicted lethal postnatal hypoxemia. A multidisciplinary meeting evaluated therapeutic options. After cesarean delivery, veno-venous extracorporeal membrane oxygenation was instituted in preparation for open atrial septectomy. The infant subsequently underwent an arterial switch procedure. Prenatal delineation of pulmonary and systemic circulations in the fetus with D-transposition of the great arteries influences postnatal management. Multidisciplinary planning enhanced the perinatal outcome.

Left Atrial Appendage Aneurysm Characterized by Multimodal Imaging

We present a four-year-old female with an incidental finding of a congenital left atrial appendage aneurysm who underwent surgical resection with excellent results. This case highlights the importance of multimodal imaging in the diagnosis and characterization of this rare condition.

Heart Transplant in Patient With Isolated Left Superior Vena Cava by Atrial Appendage Rotation

Orthotopic heart transplantation in patients with an isolated persistent left superior vena cava is extremely rare, and the anastomotic connection between a right-sided donor superior vena cava and left-sided recipient superior vena cava can be challenging to perform. We present a novel technique used in an infant female, using the left atrial appendage to extend the superior vena cava anastomosis.