Solid organ donation in a child after extracorporeal membrane oxygenation, orthotopic heart transplantation, and ventricular assist device support.

Use of high-risk or marginal donors is the most viable short-term means to boost the organ supply and bridge the widening gap between the number of patients on the waiting list for organ transplantation and the insufficient numbers of organ donors. Expansion of the donor pool requires an understanding of the impact on survival likely to result from extending one or more high risk factors. Use of extended donor pool results in shorter waiting list times and limits the morbidity and mortality associated with long-term mechanical support needed to support diseased organs. In this report, we present one such example of expanding donor pool in which a pediatric patient donated a solid organ after two heart transplants and successful use of ECMO and VAD.

Single-institution experience with interhospital extracorporeal membrane oxygenation transport: A descriptive study.

OBJECTIVE: Patients with refractory cardiopulmonary failure may benefit from extracorporeal membrane oxygenation, but extracorporeal membrane oxygenation is not available in all medical centers. We report our institution's nearly 20-yr experience with interhospital extracorporeal membrane oxygenation transport. DESIGN: Retrospective review. SETTING: Quaternary care children's hospital. PATIENTS: All patients undergoing interhospital extracorporeal membrane oxygenation transport by the Arkansas Children's Hospital extracorporeal membrane oxygenation team. INTERVENTIONS: Data (age, weight, diagnosis, extracorporeal membrane oxygenation course, hospital course, mode of transport, and outcome) were obtained and compared with the most recent Extracorporeal Life Support Organization Registry report. RESULTS: Interhospital extracorporeal membrane oxygenation transport was provided to 112 patients from 1990 to 2008. Eight were transferred between outside facilities (TAXI group); 104 were transported to our hospital (RETURN group). Transport was by helicopter (75%), ground (12.5%), and fixed wing (12.5%). No patient died during transport. Indications for extracorporeal membrane oxygenation in RETURN patients were cardiac failure in 46% (48 of 104), neonatal respiratory failure in 34% (35 of 104), and other respiratory failure in 20% (21 of 104). Overall survival from extracorporeal membrane oxygenation for the RETURN group was 71% (74 of 104); overall survival to discharge was 58% (61 of 104). Patients with cardiac failure had a 46% (22 of 48) rate of survival to discharge. Neonates with respiratory failure had an 80% (28 of 35) rate of survival to discharge. Other patients with respiratory failure had a 62% (13 of 21) rate of survival to discharge. None of these survival rates were statistically different from survival rates for in-house extracorporeal membrane oxygenation patients or for survival rates reported in the international Extracorporeal Life Support Organization Registry (p > .1 for all comparisons). CONCLUSIONS: Outcomes of patients transported by an experienced extracorporeal membrane oxygenation team to a busy extracorporeal membrane oxygenation center are very comparable to outcomes of nontransported extracorporeal membrane oxygenation patients as reported in the Extracorporeal Life Support Organization registry. As has been previously reported, interhospital extracorporeal membrane oxygenation transport is feasible and can be accomplished safely. Other experienced extracorporeal membrane oxygenation centers may want to consider developing interhospital extracorporeal membrane oxygenation transport capabilities to better serve patients in different geographic regions.

Preliminary single center North American experience with the Berlin Heart pediatric EXCOR device.

For children requiring mechanical circulatory support as a bridge to cardiac transplantation in North America, options previously were limited to extracorporeal membrane oxygenation (ECMO) or centrifugal pump ventricular assist, both of which were suitable for only very short term application and were associated with significant complications and limitations. The Berlin Heart EXCOR ventricular assist device (VAD) was recently introduced into practice in North America to address this deficiency. We report a preliminary single center experience with the EXCOR in 17 children, 13 who received only a left-sided pump and four who required biventricular support. Before EXCOR placement, six patients were on ECMO, and one was on a centrifugal VAD. Eleven children were bridged to transplantation, one was bridged to recovery, and one remains on support. Three children died during support and one died after explantation. There was one late death nearly 2 years after transplant. Complications included stroke in seven patients, two of which were ultimately fatal. Five patients required re-operations for bleeding or evacuation of hematoma. Despite a disappointing rate of neurologic morbidity, our preliminary experience with the EXCOR has been very encouraging.

Management of a pediatric patient on the Berlin Heart Excor ventricular assist device with argatroban after heparin-induced thrombocytopenia.

We report a 15-year-old male patient who developed type II heparin-induced thrombocytopenia (HIT) after 6 weeks of heparin administration and placement of a Berlin Heart Excor left ventricular assist device (LVAD).

Cardiac transplant outcomes in pediatric patients with pre-formed anti-human leukocyte antigen antibodies and/or positive retrospective crossmatch.

BACKGROUND: Children undergoing heart transplantation who have preformed anti-human leucocyte antigen (HLA) panel reactive antibodies (PRA) or positive retrospective crossmatch (XM) may be at increased risk for rejection and graft failure. We assessed outcomes of transplant recipients with either positive PRA before transplant or positive retrospective XM. METHODS: A review of 148 heart transplant patients between 1990 and 2006 was undertaken, identifying transplants in patients with pre-transplant PRA > 1% and/or a positive XM. Demographic information and detailed post-transplant outcomes including episodes of rejection, infection, and graft failure were recorded. RESULTS: There were 11 PRA positive (PRA+) transplants, 135 PRA negative (PRA-) transplants, and no PRA data on 2. There were 14 XM+ transplants, 115 XM- transplants, and no XM data on 19. Kaplan-Meier graft survival was better in XM- than XM+ patients (p < 0.015), but not different between PRA+ and PRA- Groups. Timing of first rejection and number of rejection episodes were not different between XM+ and XM- Groups or between PRA+ and PRA- Groups. Infections were not different between PRA or XM Groups. Four patients were PRA+/XM- (all PRA, 1%-10%), 7 were PRA-/XM+, and 7 were PRA+/XM+ (6 of 7 PRA >10%). CONCLUSIONS: Pediatric heart transplant patients whose retrospective XM is positive are at significantly increased risk for graft failure. Elevated pre-transplant PRA may not predict increased risk of graft failure, although markedly positive PRA (>10%) predicts a positive retrospective XM. Improved treatment for pediatric transplant patients with a positive retrospective XM is needed.

Influence of mast cells on outcome after heterotopic cardiac transplantation in rats.

Correlative data suggest that mast cells adversely affect cardiac transplantation. This study uses a mast cell-deficient rat model to directly address the role of mast cells in cardiac allotransplantation. Standardized cardiac heterotopic transplantation with cyclosporine immunosuppression was performed in mast cell-deficient and mast cell-competent rats. Rejection, ischemia, fibrosis, fibrin deposition, numbers of T-cell receptor alpha/beta positive cells, expression of transforming growth factor-beta (TGF-beta), and of endothelin-1 (ET-1) and its receptors ETA and ETB were assessed. Differences in baseline cardiac gene expression were quantified by real-time PCR in a separate group of untransplanted animals. Baseline cardiac gene expression levels of all investigated growth factors, cytokines, ET-1, ETA, and ETB were similar in mast cell-deficient and mast cell-competent rats. Surprisingly, upon heterotopic transplantation, donor heart survival was significantly reduced in mast cell-deficient rats. Moreover, in mast cell-deficient donor hearts rejection was more severe, although nonsignificant, and extracellular matrix associated TGF-beta immunoreactivity was significantly lower than in mast cell-competent donor hearts. Fibrin immunoreactive area, on the other hand, was only increased in mast cell-deficient donor hearts, but not in mast cell-competent donor hearts. Histopathological changes in all donor hearts were accompanied by increased immunoreactivity for ET-1. In conclusion, this study shows that mast cells play a protective role after cardiac transplantation.

The first successful DeBakey VAD child implantation as a bridge to transplant.

A 14-year-old boy with repaired transposition of the great arteries and ventricular septal defect presented with atrial flutter and severe congestive heart failure. Despite successful cardioversion and optimal medical therapy, the patient deteriorated and was supported with extracorporeal membrane oxygenation (ECMO). Two days after initiating ECMO support, we implanted the DeBakey VAD Child ventricular assist device (MicroMed Technology, Inc., Houston, TX) under the Humanitarian Device Exemption program. Later, he was able to pursue normal daily activities including physical rehabilitation and ambulation in the hospital. After 56 days, he underwent a successful cardiac transplantation. After 3 months, he had good cardiac function and no evidence of rejection. The DeBakey VAD Child device is a valuable option for cardiac support as a bridge to transplantation.

Venovenous extracorporeal membrane oxygenation for cyanotic congenital heart disease.

BACKGROUND: Severe, refractory hypoxemia complicating uncorrected cyanotic congenital heart disease is a potentially lethal condition, even when urgent surgical intervention is undertaken. When a viral pneumonia initiates hypoxemia, the likelihood of a satisfactory outcome is further reduced. We examined our policy of venovenous extracorporeal membrane oxygenation support through the hypoxic event and performing delayed surgery, if required, to separate from extracorporeal membrane oxygenation. METHODS: A single institution, retrospective review of an Institutional Review Board approved database was undertaken. Over a 6-year period, 18 instances were identified for 17 patients who became acutely hypoxemic from either inadequate pulmonary blood flow (8 instances) or a viral pneumonia (10 instances) complicating their cyanotic heart disease. Demographics, duration of venovenous extracorporeal membrane oxygenation and outcomes are reported. RESULTS: The length of venovenous extracorporeal membrane oxygenation ranged from 13.5 to 362.5 hours (mean 130 +/- 121 hours). During 10 supports, operations were performed to facilitate weaning from support. In 7 patients, extracorporeal support was weaned during this surgery. Follow-up was obtained in all patients over a period ranging from 4 months to 7 years (mean 39.0 +/- 23.0 months). There were two late deaths due to sepsis 1.4 and 2.5 months after extracorporeal support. CONCLUSIONS: Venovenous extracorporeal membrane oxygenation allows time for the recovery of acute hypoxic insult and resolution of some viral pneumonia processes. Palliative surgical procedures may be safely undertaken during extracorporeal support. Viral pneumonia is a risk for prolonged support. Venovenous extracorporeal membrane oxygenation is useful in these high-risk patients.

Mitral valve replacement in children: predictors of long-term outcome.

BACKGROUND: Mitral valve replacement (MVR) in children has been associated with a high complication rate. We sought to assess predictors of outcomes in children undergoing MVR. METHODS: A retrospective review of clinical, surgical, and echocardiographic records of patients undergoing MVR was performed. Between 1982 and 2000, 53 children underwent 76 MVR procedures at a median age of 5 years (range, 1 day to 18 years) and weight of 17 kg (range, 3 to 121 kg). Eighteen patients (34%) had more than one MVR. Previous cardiac surgery had been performed in 39 (74%), with 27 (51%) undergoing previous mitral repair. Patients were followed for 9.2 +/- 4.8 (range, 2 to 20) years. RESULTS: There were 14 patient deaths, with 6 patients dying within 30 days, and five transplants (36%). Ten-year freedom from reoperation was 66%. Long-term survivors were older at initial repair (7.0 vs 2.5 years, p = 0.02), with a lower incidence of residual cardiac lesions (3% vs 37%, p < 0.001) and a lower incidence of surgical procedures at the time of MVR (31% vs 63%, p = 0.04). Survivors had better left ventricular function preoperatively (ejection fraction, 68% vs 54%; p = 0.001) and placement of a prosthetic valve within 1 z-score of the echocardiographically measured mitral valve annulus (p = 0.02). CONCLUSIONS: Adverse outcome after MVR is common, particularly in the young child undergoing palliative surgery or requiring additional surgical procedures. Preoperative assessment of mitral valve size and ventricular function is essential for risk stratification of these patients.

Pediatric arteriovenous extracorporeal membrane oxygenation (ECMO) as a bridge to cardiac transplantation.

BACKGROUND: Since 1990, extracorporeal membrane oxygenation (ECMO) has been used as a bridge to cardiac transplantation in 47 patients. METHODS: A review of the ECMO database, approved by the Arkansas Children's Hospital institutional review board, forms the basis of this report. We made statistical comparison using Fisher's exact probability testing. The ECMO circuitry was a roller occlusion pump with computer-assisted perfusion system technology. RESULTS: Thirty-two (68%) patients underwent transcatheter septostomy for cardiac decompression. Diagnosis at presentation was either congenital heart disease (CHD, n = 15) or cardiomyopathy (n = 32). Ages ranged from 1 day to 22 years old (median, 18 months old), and weight ranged from 2.9 to 100 kg (median, 10 kg). The average duration of support was 242 hours (range, 22-1078 hours). Overall long-term survival was 47%, with 16 (34%) patients successfully bridged to cardiac transplantation (of which 9 [56%] survived) and 13 (28%) successfully weaned from ECMO. Patients undergoing ECMO after cardiotomy had 31% survival. Survival was improved significantly (p < 0.02) in patients with cardiomyopathy (59%) vs those with CHD (20%). Patients with cardiomyopathy underwent 8 transplantations with 7 survivors (88%), whereas in the CHD group, there were 8 transplantations with only 2 survivors (25%), p < 0.05. Sub-analysis of the cardiomyopathy group revealed that patients with acute cardiomyopathy in association with documented viral illness had a 75% chance of being weaned from ECMO without undergoing transplantation. Complications during ECMO occurred in 45% of survivors and were more frequent in non-survivors. Infectious complications were most frequent, followed by neurologic complications, technical ECMO problems, and renal insufficiency. CONCLUSIONS: Patients with cardiomyopathy has a better prognosis than did those with CHD when using ECMO as a bridge to transplantation or survival. Complications are significant and increase with the duration of support. Extracorporeal membrane oxygenation for salvage and subsequent transplantation in this high-risk group of patients requires critical review. Alternative support options must be developed in the pediatric population that will allow improved outcomes, comparable with outcomes achieved in the adult population.

The extracardiac Fontan procedure without cardiopulmonary bypass: technique and intermediate-term results.

BACKGROUND: The extracardiac Fontan procedure (ECF) usually requires cardiopulmonary bypass (CPB). In this report, the results and techniques of this procedure without CPB at a single institution are presented. METHODS: Between August 1992 and December 2001, ECF without CPB was achieved in 24 of 44 patients undergoing an ECF. Mean age at surgery was 5.9 +/- 2.9 years, and mean weight was 20.7 +/- 12.6 kg. Diagnoses were tricuspid atresia in 9 patients, single-ventricle with pulmonary outflow tract obstruction in 7, pulmonary atresia/intact septum in 5, and other complex single-ventricle physiology in 3. Initial palliation was by arterial to pulmonary artery shunt in 21 and pulmonary artery banding in 1. A bidirectional cavopulmonary connection was created in 23 patients. A temporary inferior vena caval-to-atrial shunt was used to complete the procedure without CPB. Median graft size was 16 mm (range 14 to 20 mm). RESULTS: There was no early mortality, and 68% of patients were discharged without complications. Complications included persistent cyanosis in 4 patients, persistent pleural effusions in 2 (one chylous), and phrenic nerve injury in 1. Median postoperative hospital stay was 16 days (range 10 to 50) days. At a mean follow-up of 44 +/- 28 months, there was no conduit obstruction. One patient died 11 months postoperatively, and 1 patient received a heart transplant 26 months post-ECF. CONCLUSIONS: At intermediate term follow-up, the ECF without CPB appears to be safe and technically reproducible in selected cases. Ongoing follow-up of these patients is necessary to document the theoretical advantages of avoiding CPB.