Extracorporeal membrane oxygenation for perioperative support in pediatric heart transplantation

Extracorporeal membrane oxygenation has demonstrated effectiveness for cardiopulmonary support in a variety of clinical situations. This article reviews the cases in which extracorporeal membrane oxygenation was used as an adjunct to pediatric cardiac transplantation. Twenty children, aged 7 days to 17 years, with cardiac failure refractory to conventional therapy received extracorporeal membrane oxygenation for 6 to 192 hours. In 4 cases it was used as a bridge to transplantation; in 10 cases it facilitated resuscitation of the cardiac allograft in the immediate postoperative period; and in 6 cases it complemented therapy for severe rejection in the late postoperative period. Twelve patients survived extracorporeal membrane oxygenation, 7 of whom lived more than 8 months. One long-term survivor was in the bridge-to-transplant group, 4 in the immediate postoperative group, and 2 in the rejection group. All survivors have normal cardiac allograft function. These data suggest that extracorporeal membrane oxygenation can be used to support profound cardiac failure in the pediatric heart transplant patient as a bridge to transplantation, in the resuscitation of the cardiac allograft, or to supplement a rejecting allograft.     

Extracorporeal membrane oxygenator compatible with centrifugal blood pumps

Coil-type silicone membrane oxygenators can only be used with roller blood pumps due to the resistance from the high blood flow. Therefore, during extracorporeal membrane oxygenation (ECMO) treatment, the combination of a roller pump and an oxygenator with a high blood flow resistance will induce severe hemolysis, which is a serious problem. A silicone rubber, hollow fiber membrane oxygenator that has a low blood flow resistance was developed and evaluated with centrifugal pumps. During in vitro tests, sufficient gas transfer was demonstrated with a blood flow less than 3 L/min. Blood flow resistance was 18 mm Hg at 1 L/min blood flow. This oxygenator module was combined with the Gyro C1E3 (Kyocera, Japan), and veno-arterial ECMO was established on a Dexter strain calf. An ex vivo experiment was performed for 3 days with stable gas performance and low blood flow resistance. The combination of this oxygenator and centrifugal pump may be advantageous to enhance biocompatibility and have less blood trauma characteristics.     

Extracorporeal membrane oxygenator assistance as "bridge" to combined heart and liver transplantation

Heart transplantation is accepted worldwide as the treatment of choice for patients with end-stage heart disease who have a life expectancy of less than 1 year. Mechanical Cardiac assistance might be necessary as a bridge to transplantation and, in selected cases, to multiorgan transplantation. We report a successful case of a 15-day extracorporeal membrane oxygenator assistance as bridge to combined heart and liver transplantation in a young man with dilated cardiomyopathy and chronic hepatitis C virus infection.     

Extracorporeal membrane oxygenation as a bridge to lung transplantation

The occurrence of severe graft failure after lung transplantation which appears refractory to conventional treatment represents a difficult situation with regard to the therapeutic strategies available. Of 17 patients undergoing single lung transplantation at our center, 2 developed early graft failure. In both, temporary artificial cardiopulmonary support by means of extracorporeal membrane oxygenation became necessary as a bridge to retransplantation. Both patients were successfully retransplanted after 8 h and 232 h, respectively, of extra-corporeal support. Postoperatively, there was a variety of complications. The first patient completely recovered from temporary severe cerebral dysfunction diagnosed as "locked-in syndrome". She was discharged from hospital on the 93rd postoperative day and remains alive and well 10 months after her operation. The other patient recovered well early after retransplantation. Later, however, airway problems developed, requiring the implantation of endotracheal stents. Cachexia and several episodes of viral pneumonia contributed to the progressive deterioration of her clinical status. She finally died after being hospitalized for 5 months after the original operation. These two cases illustrate the feasibility of using extracorporeal membrane oxygenation as a bridge to pulmonary transplantation.     

Extracorporeal membrane oxygenation for perioperative support in neonatal and pediatric cardiac transplantation

Currently there is a lack of consensus on guidelines in the clinical application of extracorporeal membrane oxygenation (ECMO) in neonatal and pediatric cardiac transplantation patients. In this context, given the limited data presently available through the Extracorporeal Life Support Organization (ELSO) Registry, we conducted a preliminary survey to specifically evaluate the practice of using ECMO as a bridge to cardiac transplantation or as posttransplantation therapy for failure to wean from cardiopulmonary bypass or graft failure. We received responses to our questionnaire from 95 of 118 (81%) centers located in the U.S.A. and abroad. Of the 95 centers that responded, 36 were performing neonatal/pediatric cardiac transplants, with 29 centers reporting the concomitant use of ECMO to support cardiac transplant patients. There was wide variability in the responses from the 29 centers to a selected list of relative ECMO contraindications. However, only 7 centers had specific ECMO entry criteria for cardiac transplant patients. Fifteen of the 29 centers provided relevant data on cardiac transplant patients including the proportions of neonatal (11 of 37) and pediatric (63 of 217) patients requiring ECMO; neonatal (2 of 5) and pediatric (16 of 27) patients surviving to transplant; and neonatal (1 of 5) and pediatric (12 of 27) patients surviving to hospital discharge. These findings confirm the important role of ECMO in providing perioperative support in neonatal and pediatric cardiac transplantation patients. However, the lack of consensus among centers contributes to uncertainty in the decision making process to offer ECMO and to utilize ECMO effectively in this high risk population. We recommend that institution-specific information be collected, either using the ELSO Registry (or by a similar multicentric database) to develop specific guidelines for ECMO applications in cardiac transplant patients, and to carefully monitor and follow up EMCO treated patients to further evaluate the efficacy of this limited resource.     

Respiratory support with a paracorporeal membrane oxygenator

The General Electric-Peirce Lung was used in the arteriovenous configuration as a paracorporeal respiratory assist device in dogs rendered cyanotic by left pneumonectomy and creation of a pulmonary arteriovenous shunt. The blood leaving the membrane lung was fully saturated and the extracorporeal oxygen exchange ranged from 5–20 ml/min depending on extra-corporeal flow, hematocrit and inflow saturotion. These experiments demonstrated that a paracorporeal lung can be used effectively with an AV fistula to treat chronic respiratory insufficiency in animals. Some of the experimental difficulties and the approaches to improving the results have been discussed.     

Extracorporeal life support in lung and heart–lung transplantation for pulmonary hypertension in adults

After bilateral lung and heart–lung transplantation in adults with pulmonary hypertension, hemodynamic and oxygenation deficiencies are life‐threatening complications that are increasingly managed with extracorporeal life support (ECLS). The primary aim of this retrospective study was to assess 30‐day and 1‐year survival rates in patients managed with vs without post‐operative venoarterial ECLS in 2008–2013. The secondary endpoints were the occurrence rates of nosocomial infection, bleeding, and acute renal failure. Of the 93 patients with pulmonary hypertension who received heart‐lung (n=29) or bilateral lung (n=64) transplants, 28 (30%) required ECLS a median of 0 [0–6] hours after surgery completion and for a median of 3.0 [2.0–8.5] days. Compared to ECLS patients, controls had higher survival at 30 days (95.0% vs 78.5%; P=.02) and 1 year (83% vs 64%; P=.005), fewer nosocomial infections (48% vs 79%; P=.0006), and fewer bleeding events (17% vs 43%; P=.008). The need for renal replacement therapy was not different between groups (11% vs 17%; P=.54). Venoarterial ECLS is effective in treating pulmonary graft dysfunction with hemodynamic failure after heart‐lung or bilateral lung. However, ECLS use was associated with higher rates of infection and bleeding.     

Extracorporeal membrane oxygenation after lung transplantation: evolving technique improves outcomes

Background

Severe pulmonary graft failure (PGF) is the most common cause of death within the first 30 days after lung transplantation. Extracorporeal membrane oxygenation (ECMO) may provide lifesaving temporary support; however, its longer-term efficacy is controversial.

Methods

We reviewed the use of ECMO for severe PGF after lung transplantation, and compared the outcomes between our early (1990 to 1999) and recent (2000 to 2003) experience utilizing improved initiation timing, oxygenator technology, and surgical technique.

Results

Ten transplant recipients from a total of 481 (2.1%) were managed for PGF on ECMO by a multidisciplinary team at The Alfred Hospital. Four single-lung, 3 bilateral single-lung, and 3 heart-lung recipients were supported for a mean of 96 hours (range 14 to 212 hours). In the early group (operation from 1990 to 1999, n = 4) ECMO was initiated 21 days (range 7 to 40 days) after lung transplantation and in the recent group (operation from 2000 to 2003, n = 6) after 0 to 2 days (p = 0.01). Radial-arterial blood gas analysis 12 hours after initiation of ECMO showed significantly better oxygenation in the recent group (341 ± 90 mm Hg) than in the early group (90 ± 23 mm Hg, p = 0.03). Four deaths occurred as a result of bleeding (two in each group). In the early group only 1 patient was weaned from ECMO but died. In the recent group 3 were successfully weaned and were discharged from the intensive care unit; of these patients, 2 were discharged from hospital.

Conclusions

Extracorporeal membrane oxygenation results have improved with advances in oxygenator technology and surgical techniques. The procedure can allow resolution of early PGF after lung transplantation.     

Extracorporeal membrane oxygenation for support of children after hematopoietic stem cell transplantation: the Extracorporeal Life Support Organization experience

Purpose

Extracorporeal membrane oxygenation (ECMO) is a means of respiratory and hemodynamic support for patients failing conventional therapies. Children requiring hematopoietic stem cell transplantation who develop complications during therapy may require ECMO. Such patients pose medical and ethical challenges for clinicians considering initiation of ECMO. The authors review the outcomes of these patients and propose recommendations.

Methods

The Extracorporeal Life Support Organization Registry was queried for all patients younger than 18 years with an International Classification of Diseases, Ninth Revision, or Current Procedural Terminology code related to bone or stem cell transplant.

Results

Nineteen children in the registry met inclusion criteria. The median age was 9.6 years (7 months to 17.5 years). Initiation of ECMO was for pulmonary support (n = 17), cardiac support (n = 1), or cardiopulmonary resuscitation (n = 1). The median duration of ECMO support was 5.1 days (range, 30 hours to 42 days). Pulmonary infections included 3 parainfluenza, 2 Pneumocystis carinii, 1 influenza A, and 1 respiratory syncytial virus. Overall, 15 (79%) died during their ECMO run, whereas only 4 (21%) survived to come off ECMO. Furthermore, of those who survived their ECMO run, only one patient survived to discharge from the hospital. Risk factors for death on ECMO include development of renal complications and development of multiorgan dysfunction.

Conclusion

Patients who require ECMO for cardiopulmonary support after hematopoietic stem cell transplantation have a poor prognosis. Clinicians must be cautious in presenting this option to parents and present them with appropriate expectations in this high-risk population.     

Extracorporeal photochemotherapy for Epstein-Barr virus-associated lymphoma after lung transplantation.

Posttransplantation lymphoproliferative disorder (PTLD) is a serious complication after transplantation of solid organs. Highest incidence rates have been reported for lung transplant recipients. With the current treatment strategy for early onset PTLD, a reduction of immunosuppressive drugs, mortality of lung transplant recipients with PTLD remains high, due to both, incomplete control of PTLD and transplant rejection. We present a lung transplant recipient with a history of acute rejection and Epstein Barr virus-associated posttransplantation malignant non-Hodgkin's lymphoma. Extracorporeal photochemotherapy, in combination with a moderate reduction of immunosuppressive therapy, resulted in complete disappearance of PTLD. After a first year of follow-up, no further rejection and no recurrence of PTLD have occurred. Treatment with ECP, with its beneficial effects on both, rejection after organ transplantation and malignant lymphoma, may be a particularly valuable approach for the treatment of PTLD in patients after lung transplantation, with its increased risk for transplant rejection.     

Combination of membrane oxygenator support and pulmonary lavage for acute respiratory failure.

A 24-year-old woman with chronic granulocytic leukemia and alveolar proteinosis required extracorporeal membrane oxygenator support for respiratory failure refractory to conventional therapy. During perfusion, each lung was lavaged with 10 L. of normal saline. The lavage led to marked clearing of the lungs and improvement in pulmonary function. Extracorporeal support was terminated successfully after 54 hours. The patient died 2 weeks later with bone marrow insufficiency and overwhelming sepsis. Pulmonary lavage is technically feasible during venovenous oxygenator bypass, and may be of value, since such lavage debrides alveoli as well as the bronchial tree. Because pulmonary lavage provides a possible means of improving pulmonary function, it seems worthy of consideration as an adjunct to membrane oxygenator support.     

Extracorporeal membrane oxygenation versus cardiopulmonary bypass during lung transplantation: a meta-analysis

Background

We reviewed the available literature on patients undergoing lung transplantation supported by cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO).

Methods

A systematic literature search was performed in three databases, in accordance with the PRISMA guidelines. Meta-analyses were used to compare the outcomes of ECMO and CPB procedures.

Results

Seven observational studies met the inclusion criteria incorporating 785 patients. ECMO support showed lower rate of primary graft dysfunction, bleeding, renal failure requiring dialysis, tracheostomy, intraoperative transfusions, intubation time, and hospital stay. Total support time was greater for the ECMO-supported group. No difference was reported between operative and ischemic time.

Conclusions

The present study indicates that the intraoperative use of ECMO is associated with increased efficacy and safety, regarding short-term outcomes, compared to CPB. Well-designed, randomized studies, comparing ECMO to CPB, are necessary to assess their clinical outcomes further.