Experience of extracorporeal membrane oxygenation as a bridge to lung transplantation in France

Lung transplantation in IIP: A review

The idiopathic interstitial pneumonias (IIP) encompass a large and diverse subtype of interstitial lung disease (ILD) with idiopathic pulmonary fibrosis (IPF) and non-specific interstitial pneumonia (NSIP) being the most common types. Although pharmacologic treatments are available for most types of IIP, many patients progress to advanced lung disease and require lung transplantation. Close monitoring with serial functional and radiographic tests for disease progression coupled with early referral for lung transplantation are of great importance in the management of patients with IIP. Both single and bilateral lung transplantation are acceptable procedures for IIP. Procedure selection is a complex decision influenced by multiple factors related to patient, donor and transplant centre. While single lung transplant may reduce waitlist time and mortality, the long-term outcomes after bilateral lung transplantation may be slightly superior. There are numerous complications following lung transplantation including primary graft dysfunction, chronic lung allograft dysfunction (CLAD), infections, gastroesophageal reflux disease (GERD) and airway disease that limit post-transplant longevity. The median survival after lung transplantation is 4.7 years in patients with ILD, which is less than in patients with other underlying lung diseases. Although long-term survival is limited, this intervention still conveys a survival benefit and improved quality of life in suitable IIP patients with advanced lung disease and chronic hypoxemic respiratory failure.

Canada's longest experience with extracorporeal membrane oxygenation as a bridge to lung transplantation: a case report

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is a method of enabling gas exchange through an external membrane used to treat respiratory failure in critically ill patients. ECMO as a bridge to lung transplantation has been investigated as a potential method of reducing lung transplantation waitlist mortality. Herein we describe a case of ECMO as a bridge-to-lung transplantation for the duration of 35 days, which is the longest documented length of ECMO support before successful transplantation in Canada.

CASE DESCRIPTION

The prospective recipient was a 28-year-old female suffering from stage 4 pulmonary sarcoidosis. Given an acute exacerbation of her chronic respiratory failure, ECMO had to be initiated. She remained on ECMO for 35 days until a suitable set of donor lungs became available. The recipient had a prolonged course in hospital but was successfully discharged home where she continues to have good lung function. She remains alive and well at home 5 months post-transplantation and continues to improve and gain strength.

CONCLUSION

Our case provides hope that in the future we may be able to expand the population of recipients who may be candidates for lung transplantation. This case adds to the growing literature on the role of ECMO as a bridge-to-lung transplantation with the potential to reduce patient deaths while wait-listed for lung transplantation as well as increase the number of transplantations being performed.

Extracorporeal Membrane Oxygenation Applications in Cardiac Critical Care

The use of extracorporeal membrane oxygenation therapy (ECMO) in cardiac critical care has steadily increased over the past decade. Significant improvements in the technology associated with ECMO have propagated this recent resurgence and contributed to improved patient outcomes in the fields of cardiac and transplant (heart and lung) surgery. Specifically, ECMO is being increasingly utilized as a bridge to heart and lung transplantation, as well as to ventricular assist device placement. ECMO is also employed during the administration of cardiopulmonary resuscitation, known as extracorporeal life support. In this review, we examine the recent literature regarding the applications of ECMO and also describe emerging topics involving current ECMO management strategies.

Five-year experience with intraoperative extracorporeal membrane oxygenation in lung transplantation: Indications and midterm results

BACKGROUND

Since April 2010, extracorporeal membrane oxygenation (ECMO) has replaced cardiopulmonary bypass for intraoperative support during lung transplantation at our institution. The aim of this study was to present our 5-year experience with this technique.

METHODS

Records of patients who underwent transplantation between April 2010 and January 2015 were retrospectively reviewed. Patients who underwent transplantation without ECMO formed Group A. Patients in whom the indication for ECMO support was set a priori before the beginning of the operation formed Group B. The remaining patients in whom the indication for ECMO support was set during transplantation formed Group C.

RESULTS

Among 595 patients, 425 (71%) patients (Group A) did not require intraoperative ECMO; the remaining 170 (29%) patients did. Among these patients, 95 (56%) patients formed Group B, and the remaining 75 (44%) patients comprised Group C. Pulmonary fibrosis and pre-operative dilated or hypertrophied right ventricle emerged as risk factors for the indication of non-a priori intraoperative ECMO. Patients in Groups B and C showed a higher pre-operative risk profile and higher prevalence of post-operative complications than patients in Group A. Overall survival at 1 year was 93%, 83%, and 82% and at 4 years was 73%, 68%, and 69% in Groups A, B, and C (p = 0.11). The intraoperative use of ECMO did not emerge as a risk factor for in-hospital mortality or mortality after hospital discharge.

CONCLUSIONS

Intraoperative ECMO filled the gap between pre-operative and post-operative ECMO in lung transplantation. Although complications and in-hospital mortality were higher in patients who received ECMO, survival was similar among patients who underwent transplantation with or without ECMO.

Successful extracorporeal membrane oxygenation therapy as a bridge to sequential bilateral lung transplantation for a patient after severe paraquat poisoning

CONTEXT

Paraquat is a widely used herbicide that can cause severe to fatal poisoning in humans. The irreversible and rapid progression of pulmonary fibrosis associated with respiratory failure is the main cause of death in the later stages of poisoning. There are infrequent reports of successful lung transplants for cases of severe paraquat poisoning. We expect that this successful case will provide a reference for other patients in similar circumstances.

CASE DETAILS

A 24-year-old female was sent to the hospital approximately 2 hours after ingesting 50 ml of paraquat. She experienced rapidly aggravated pulmonary fibrosis and severe respiratory failure. On the 34th day after ingestion, she underwent intubation and invasive mechanical ventilation. The patient was evaluated for lung transplantation, and veno-venous extracorporeal membrane oxygenation (ECMO) was established as a bridge to lung transplantation on the 44th day. On the 56th day, she successfully underwent a bilateral sequential lung transplantation. Through respiratory and physical rehabilitation and nutrition support, the patient was weaned from mechanical ventilation and extubated on the 66th day. On the 80th day, she was discharged. During the 1-year follow-up, the patient was found to be in good condition, and her pulmonary function improved gradually.

CONCLUSION

We suggest that lung transplantation may be an effective treatment in the end stages of paraquat-induced pulmonary fibrosis and consequential respiratory failure. For patients experiencing a rapid progression to a critical condition in whom lung transplantation cannot be performed immediately (e.g., while awaiting a viable donor or toxicant clearance), ECMO should be a viable bridge to lung transplantation.

[The place of extra-corporeal oxygenation in pulmonary diseases]

Extra-corporeal membrane oxygenation (ECMO) effectively replaces the lung in providing oxygenation and carbon dioxide (CO2) removal. For some years, and in parallel to the H1N1 influenza pandemic, this technique has gained interest in relation to significant technological improvements, leading to new concepts of "awake and mobile ECMO" or rehabilitation with ECMO. Finally, the publication of randomized controlled trials giving encouraging results in the adult respiratory distress syndrome (ARDS) has helped to validate this technique and further studies are warranted. This general review aims to outline the definition, classification and principles of ECMO and to give some current information about the indications and possibilities of the technique to the pulmonologist and intensivist. Further possible uses for this technique include extra-corporeal removal of CO2 during hypercapnic respiratory failure and assistance during lung transplantation from the preoperative to the early postoperative period.

Lung transplantation for cystic fibrosis: results, indications, complications, and controversies

Survival in patients with cystic fibrosis (CF) has improved dramatically over the past 30 to 40 years, with mean survival now approximately 40 years. Nonetheless, progressive respiratory insufficiency remains the major cause of mortality in CF patients, and lung transplantation (LT) is eventually required. Timing of listing for LT is critical, because up to 25 to 41% of CF patients have died while awaiting LT. Globally, approximately 16.4% of lung transplants are performed in adults with CF. Survival rates for LT recipients with CF are superior to other indications, yet LT is associated with substantial morbidity and mortality (∼50% at 5-year survival rates). Myriad complications of LT include allograft failure (acute or chronic), opportunistic infections, and complications of chronic immunosuppressive medications (including malignancy). Determining which patients are candidates for LT is difficult, and survival benefit remains uncertain. In this review, we discuss when LT should be considered, criteria for identifying candidates, contraindications to LT, results post-LT, and specific complications that may be associated with LT. Infectious complications that may complicate CF (particularly Burkholderia cepacia spp., opportunistic fungi, and nontuberculous mycobacteria) are discussed.

Extracorporeal life support as bridge to lung transplantation: a systematic review

INTRODUCTION

Patients with acute respiratory failure requiring respiratory support with invasive mechanical ventilation while awaiting lung transplantation are at a high risk of death. Extracorporeal membrane oxygenation (ECMO) has been proposed as an alternative bridging strategy to mechanical ventilation. The aim of this study was to assess the current evidence regarding how the ECMO bridge influences patients' survival and length of hospital stay.

METHODS

We performed a systematic review by searching PubMed, EMBASE and the bibliographies of retrieved articles. Three reviewers independently screened citation titles and abstracts and agreement was reached by consensus. We selected studies enrolling patients who received ECMO with the intention to bridge lung transplant. We included randomized controlled trials (RCTs), case-control studies and case series with ten or more patients. Outcomes of interest included survival and length of hospital stay. Quantitative data summaries were made when feasible.

RESULTS

We identified 82 studies, of which 14 were included in the final analysis. All 14 were retrospective studies which enrolled 441 patients in total. Because of the broad heterogeneity among the studies we did not perform a meta-analysis. The mortality rate of patients on ECMO before lung transplant and the one-year survival ranged from 10% to 50% and 50% to 90%, respectively. The intensive care and hospital length of stay ranged between a median of 15 to 47 days and 22 to 47 days, respectively. There was a general paucity of high-quality data and significant heterogeneity among studies in the enrolled patients and technology used, which confounded analysis.

CONCLUSIONS

In most of the studies, patients on ECMO while awaiting lung transplantation also received invasive mechanical ventilation. Therefore, whether ECMO as an alternative, rather than an adjunction, to invasive mechanical ventilation is a better bridging strategy to lung transplantation still remains an unresolved issue. ECMO support as a bridge for these patients could provide acceptable one-year survival. Future studies are needed to investigate ECMO as part of an algorithm of care for patients with end-stage lung disease.

Extracorporeal CO2 removal as bridge to lung transplantation in life-threatening hypercapnia

In patients awaiting lung transplantation (LTX), adequate gas exchange may not be sufficiently achieved by mechanical ventilation alone if acute respiratory decompensation arises. We report on 20 patients with life-threatening hypercapnia who received extracorporeal CO2 removal (ECCO2-R) by means of the interventional lung assist (ILA®, Novalung) as bridge to LTX. The most common underlying diagnoses were bronchiolitis obliterans syndrome, cystic fibrosis, and idiopathic pulmonary fibrosis, respectively. The type of ILA was pumpless arteriovenous or pump-driven venovenous (ILA activve®, Novalung) in 10 patients each. ILA bridging was initiated in 15 invasively ventilated and five noninvasively ventilated patients, of whom one had to be intubated prior to LTX. Hypercapnia and acidosis were effectively corrected in all patients within the first 12 h of ILA therapy: PaCO2 declined from 109 (70-146) to 57 (45-64) mmHg, P < 0.0001; pH increased from 7.20 (7.06-7.28) to 7.39 (7.35-7.49), P < 0.0001. Four patients were switched to extracorporeal membrane oxygenation due to progressive hypoxia or circulatory failure. Nineteen patients (95%) were successfully transplanted. Hospital and 1-year survival was 75 and 72%, respectively. Bridging to LTX with ECCO2-R delivered by arteriovenous pumpless or venovenous pump-driven ILA is feasible and associated with high transplantation and survival rates.

Extracorporeal membrane oxygenation as a bridge to lung transplantation in the United States: an evolving strategy in the management of rapidly advancing pulmonary disease

OBJECTIVE

Improvements in technology have led to a resurgence in the use of extracorporeal membrane oxygenation as a bridge to lung transplantation. By using a national registry, we sought to evaluate how short-term survival has evolved using this strategy.

METHODS

With the use of the United Network for Organ Sharing database, we analyzed data from 12,458 adults who underwent lung transplantation between 2000 and 2011. Patients were categorized into 2 cohorts: 119 patients who were bridged to transplantation using extracorporeal membrane oxygenation and 12,339 patients who were not. The study period was divided into four 3-year intervals: 2000 to 2002, 2003 to 2005, 2006 to 2008, and 2009 to 2011. With Kaplan-Meier analysis, 1-year survival was compared for the 2 cohorts of patients in each of the time periods. A propensity score-adjusted Cox regression model was used to estimate the risk of 1-year mortality.

RESULTS

Of the total number of recipients, 4 (3.4%) were bridged between 2000 and 2002, 17 (14.3%) were bridged between 2003 and 2005, 31 (26.1%) were bridged between 2006 and 2008, and 67 were bridged (56.3%) between 2009 and 2011. Recipients bridged using extracorporeal membrane oxygenation were more likely to be younger and diabetic and to have higher serum creatinine and bilirubin levels. The 1-year survival for those bridged with extracorporeal membrane oxygenation was significantly lower in subsequent periods: 25.0% versus 81.0% (2000-2002), 47.1% versus 84.2% (2006-2008), and 74.4% versus 85.7% (2009-2011). However, this survival progressively increased with each period, as did the number of patients bridged using extracorporeal membrane oxygenation.

CONCLUSIONS

Short-term survival with the use of extracorporeal membrane oxygenation as a bridge to lung transplantation has significantly improved over the past few years.

Bridge to lung transplantation and rescue post-transplant: the expanding role of extracorporeal membrane oxygenation

Over the last several decades, the growth of lung transplantation has been hindered by a much higher demand for donor lungs than can be supplied, leading to considerable waiting time and mortality among patients waiting for transplant. This has led to the search for an alternative bridging strategy in patients with end-stage lung disease. The use of extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation as well as a rescue strategy post-transplant for primary graft dysfunction (PGD) has been studied previously, however due to initially poor outcomes, its use was not heavily instituted. In recent years, with significant improvement in technologies, several single and multi-center studies have shown promising outcomes related to the use of ECMO as a bridging strategy as well as a therapy for patients suffering from PGD post-transplant. These results have challenged our current notion on ECMO use and hence forced us to reexamine the utility, efficacy and safety of ECMO in conjunction with lung transplantation. Through this review, we will address the various aspects related to ECMO use as a bridge to lung transplantation as well as a rescue post-transplant in the treatment of PGD. We will emphasize newer technologies related to ECMO use, examine recent observational studies and randomized trials of ECMO use before and after lung transplantation, and reflect upon our own institutional experience with the use of ECMO in these difficult clinical situations.

Comparison of extracorporeal membrane oxygenation versus cardiopulmonary bypass for lung transplantation

OBJECTIVE

This study compared differences in patient outcomes and operative parameters for extracorporeal membrane oxygenation (ECMO) versus cardiopulmonary bypass (CPB) in patients undergoing lung transplants.

METHODS

Between January 1, 2008, and July 13, 2013, 316 patients underwent lung transplants at our institution, 102 requiring intraoperative mechanical cardiopulmonary support (CPB, n=55; ECMO, n=47). We evaluated survival, blood product transfusions, bleeding complications, graft dysfunction, and rejection.

RESULTS

Intraoperatively, the CPB group required more cell saver volume (1123±701 vs 814±826 mL; P=.043), fresh-frozen plasma (3.64±5.0 vs 1.51±3.2 units; P=.014), platelets (1.38±1.6 vs 0.43±1.25 units; P=.001), and cryoprecipitate (4.89±6.3 vs 0.85±2.8 units; P<.001) than the ECMO group. Postoperatively, the CPB group received more platelets (1.09±2.6 vs 0.13±0.39 units; P=.013) and was more likely to have bleeding (15 [27.3%] vs 3 [6.4%]; P=.006) and reoperation (21 [38.2%] vs 7 [14.9%]; P=.009]. The CPB group had higher rates of primary graft dysfunction at 24 and 72 hours (41 [74.5%] vs 23 [48.9%]; P=.008; and 42 [76.4%] vs 26 [56.5%]; P=.034; respectively). There were no differences in 30-day and 1-year survivals.

CONCLUSIONS

Relative to CPB, the ECMO group required fewer transfusions and had less bleeding, fewer reoperations, and less primary graft dysfunction. There were no statistically significant survival differences at 30 days or 1 year.

A novel ECMO circuit using a SYNERGY circulite pump in a swine model

Extracorporeal membrane oxygenation (ECMO) is used in the management of refractory cardiopulmonary failure. With improvements in technology, patients can be transferred between hospitals, ambulated, and supported for extended periods of time while on ECMO. The SYNERGY CircuLite micropump is a blood pump that has been used as a ventricular assist device for partial support. In this study, we assessed the blood biocompatibility of the SYNERGY blood pump in conjunction with a Quadrox D oxygenator for use in a novel ECMO circuit in a swine model. This clinical design was used to demonstrate early feasibility of this pump system. Four pigs were placed on venovenous ECMO circuit, which consisted of a SYNERGY pump, Quadrox D oxygenator, and Cobe E Pack 3/8 inch tubing. All animals survived the 6 hour ECMO run without catastrophic biocompatibility issues. There was no statistically discernible change from baseline in hematologic parameters, including hemoglobin, plasma-free hemoglobin, total bilirubin, lactate dehydrogenase, D-dimer, fibrinogen, platelets, and P-selectin. We believe that this study serves as a proof of concept and basis for further studies using the SYNERGY pump as a component of ECMO systems.

High-emergency waiting list for lung transplantation: early results of a nation-based study

OBJECTIVES

The high mortality rate observed on the regular waiting list (RWL) before lung transplantation (LTx) prompted the French organ transplantation authorities to set up in 2007 a dedicated graft allocation strategy, the so-called 'high-emergency waiting list' (HEWL), for patients with an abrupt worsening of their respiratory function. This study reports on the early results of this new allocation system.

METHODS

Among 11 active French LTx programmes, 7 were able to provide full outcome data by 31 December 2011. The medical records of 101 patients who were listed on the HEWL from July 2007 to December 2011 were reviewed for an intention-to-treat analysis.

RESULTS

Ninety-five patients received LTx within a median waiting time on the HEWL of 4 days (range 1-26), and 6 died before transplantation. Conditions were cystic fibrosis (65.2%), pulmonary fibrosis (24.8%), emphysema (5%) and miscellaneous (5%). The median age of the recipient was 30 years (range 16-66). Patients listed on the HEWL came from the RWL in 48.5% of the cases and were new patients in 51.5%. Forty-nine were placed under invasive ventilation and, in 26 cases, extracorporeal membrane oxygenation (ECMO) prior to transplantation was necessary as a complementary treatment. ECMO for non-intubated patients was performed in 6 cases. Eighty-one bilateral and 14 single LTx were performed, with an overall in-hospital mortality rate of 29.4%. One- and 3-year survival rates were 67.5 and 59%, respectively. Multivariate analysis shows that the use of ECMO prior to transplantation was the sole independent mortality risk factor (hazard ratio = 2.77 [95% CI 1.26-6.11]).

CONCLUSIONS

The new allocation system aimed at lowering mortality on the RWL, but also offered an access to LTx for new patients with end-stage respiratory failure. The HEWL increased the likelihood of mortality after LTx, but permitted acceptable mid-term survival rates. The high mortality associated with the use of ECMO should be interpreted cautiously.

Extracorporeal membrane oxygenation (ECMO) in cystic fibrosis

Extracorporeal membrane oxygenation (ECMO) is a potential form of therapy in cystic fibrosis. We discuss this form of treatment, particularly in relation to respiratory failure secondary to influenza in a patient with cystic fibrosis whose condition deteriorated post partum.

Extracorporeal membrane oxygenation as a bridge to lung transplantation: a long-term study

OBJECTIVES

We investigated early outcomes in patients with end-stage pulmonary disease bridged with extracorporeal membrane oxygenation (ECMO) with the intention to perform lung transplantation (LTx).

METHODS

ECMO was used as a bridge to LTx in 20 patients between 2005 and 2013. Most patients suffered from rapid progress of disease and most failed to stabilize on mechanical ventilation. Sixteen patients (10 males, median age 42 years, range 25-59) underwent LTx after ECMO support for a median of 9 (range 1-229) days. Most patients were not on the waiting list while receiving ECMO, but after being assessed were on the waiting list for a median of 6 (range 1-72) days before LTx or death occurred. Median follow-up at 535 (range 36-3074) days was 100% complete, 9 patients have been followed for >1 year and 4 patients have been bridged during 2013.

RESULTS

Four patients died on ECMO waiting for a donor and as intention-to-treat, the success for bridging was 80% (16/20) and 1-year survival was 62% (10/16, not including 4 with <1-year follow-up). For those who underwent LTx, 3 patients died in-hospital after LTx on Days 0, 16 and 82, respectively, and currently, 11/16 (69%) are alive and 1-year survival for transplanted patients was 9/12 (75%). Median ICU stay before and after LTx was 9 (range 2-229) days and 20 (range 0-53) days, respectively. At follow-up, lung function was evaluated, and mean forced expiratory volume at 1 s and forced vital capacity were 56±22% of predicted and 74±24% of predicted, respectively.

CONCLUSIONS

ECMO used as a bridge to LTx results in acceptable survival in selected patients with end-stage pulmonary disease.

Lung transplantation in patients with cystic fibrosis: special focus to infection and comorbidities

Despite advances in medical care, patients with cystic fibrosis still face limited life expectancy. The most common cause of death remains respiratory failure. End-stage cystic fibrosis can be treated with lung transplantation and is the third most common reason for which the procedure is performed. Outcomes for cystic fibrosis are better than most other lung diseases, but remain limited (5-year survival 60%). For patients with advanced disease lung transplantation appears to improve survival. Outcomes for patients with Burkholderia cepacia remain poor, although they are better for patients with certain genomovars. Controversy exists about Mycobacterium abscessus infection and appropriateness for transplant. More information is also becoming available for comorbidities, including diabetes and pulmonary hypertension among others. Extra-corporeal membrane oxygenation is used more frequently for end-stage disease as a bridge to lung transplantation and will likely be used more in the future.