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Lung transplantation (LT) is definitive therapy for end-stage lung disease. Donor allocation based on medical urgency has led to an increased trend in the transplantation of sicker and older patients. Mechanical ventilation (MV) formerly was the only method of bridging high-acuity patients to LT. When the physiological demands of ventilatory support exceeds the capability of MV, extracorporeal membrane oxygenation (ECMO) may become necessary. Recent improvements in ECMO technology and component design have led to a resurgence of interest in its use before, during, and after LT. Survival with ECMO as a bridge to LT has improved over time, now with many centers reporting little or no difference in outcomes, and some even reporting better outcomes, as compared with MV. Extracorporeal life support may also be used intraoperatively. In many studies to date, ECMO or cardiopulmonary bypass (CPB) has been reserved for patients who became hemodynamically unstable during the procedure or patients who could not tolerate single-lung ventilation. Both methods of support are fraught with potential complications. However, multiple studies comparing ECMO with CPB have shown that intraoperative use of ECMO resulted in improved outcomes and overall survival as well as lower rates of bleeding complications. In order to further reduce complications associated with ECMO, planned intraoperative ECMO use is occasionally reserved for high-risk patients who might otherwise require CPB. Future studies will need to improve patient selection to fully take advantage of the use of ECMO in LT while minimizing its costs.

The purpose of this study was to examine outcomes and survival with mechanical ventilation (MV) and extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation (LT) using a national registry.The United Network for Organ Sharing database was analyzed for recipients in the period 2005 to 2017. Recipients were categorized into 3 groups based on pre-transplant bridging. Multivariable regression analyses examined the effect of bridging on post-LT outcomes adjusting for clinical characteristics, including era (early = 2005-2011, late = 2012-2017) and center volume.There were 21,576 LT recipients: no bridge (n = 19,783), MV (n = 1,129), and ECMO (n = 664). Mean age was 54 ± 15 years (41% female). Use of ECMO increased significantly in the late era (1% vs 5%, p0.001). Compared with no bridge, patients with MV and ECMO had greater odds for peri-operative outcomes including ventilator support48 hours, acute rejection, and dialysis. Patients with MV had reduced odds for ventilator support48 hours (p = 0.003), dialysis (p = 0.003), post-operative ECMO (p = 0.006), and greater odds for reintubation (p = 0.005) compared with ECMO. Patients in both MV (hazard raio [HR] 1.45, p0.001) and ECMO (HR 1.48, p0.001) groups had greater risk for 5-year mortality, but MV and ECMO groups did not differ (HR 0.98, p = 0.817). Risk for mortality in the ECMO group decreased in the later era (HR 0.54, p = 0.006).ECMO as a bridge to LT has increased 271%, while MV has decreased 38% over the past decade. Survival with ECMO has significantly improved and is now equivalent to survival in recipients bridged on MV. These results suggest gains in use, outcomes, and safety of ECMO in this patient cohort.

Although lung transplantation is an effective treatment for end-stage lung failure, its limitations have led to renewed interest in artificial lung support for patients with lung failure. The use of ventricular assist devices has significantly improved the quality of life and survival of patients with end-stage heart failure. In contrast, there are no devices that can be used long term as destination therapy for end-stage lung failure, and there is a strong need for them. Extracorporeal membrane oxygenation is widely used as a temporary treatment for acute lung failure and as a bridge to lung transplant. Many patients with advanced lung failure cannot return home with good quality of life once they are hospitalized. In this review, the authors discuss the history, status, and future of artificial lungs, focusing on long-term artificial respiratory support as a destination therapy. Respiratory assist devices, such as artificial lungs, could eventually become analogous to ventricular assist devices.

Purpose Practice standardization may decrease donor lung shortages, however, the cause of organ acceptance pattern variation is not known. Our objective was to compare donor call practices in diverse settings. Methods This was a prospective, multi-center study of 10 centers from 6 distinct regions. Characteristics of consecutive, first-recipient eligible, donor offers (aged ≥13) received by participating centers with definitive decisions from May 1, 2016 to October 31, 2016 were abstracted along with reasons for organ offer turn downs (as applicable) and final organ disposition. A discrepant decision was defined as a donor lung offer declined by one center that was then accepted for transplant by an alternate center. Results We evaluated 2,000 consecutive offers; the majority (89.9%) were brain dead donors (BDD). Mean transplant volume was 33 transplants/year (range 11-98). Most centers had ex vivo lung perfusion and all had extra-corporeal membrane oxygenation bridging programs. Surgeons made final acceptance determinations at all centers. Declined organs had a mean donor age of 39 years, with a mean PaO2 to FiO2 (P/f) ratio of 352. The most common primary reason for offer decline was abnormal imaging followed by a low or decreasing P/f ratio. There were 412 (20.7%) discrepant offer decisions (8.1 to 41.2% of offers depending on center). Discrepant decisions significantly differed from non-discrepant decisions by transplant center mean annual volume, donor age, absolute and decreasing P/f ratio, and donor type (BDD versus circulatory death) (p Conclusion One in five donor offers that were initially declined by one transplant center were accepted for transplantation by another, highlighting significant variability in donor practices. Key donor and center factors were associated with discrepant decisions.

Purpose The previously described University of MN Donor Lung Quality Index (UMN-DLQI) score is a consensus-based decision tool that includes 16 risk-related components receiving 0-5 points, with higher scores signifying lower risk. A score >39 is considered favorable for transplant. We evaluated the UMN-DLQI score's performance across a diversity of US lung transplant centers. Methods We modified the UMN-DLQI to include standardized response choices for all parameters to enhance inter rater consistency. A co investigator at each site was trained in UMN-DLQI scoring, including hypothetical donor test cases to ensure proficiency. We included consecutive primary donor offers (age> 11) to participating sites between May 1 and October 31, 2016 that were either accepted for transplant or turned down for quality by the participating center. UMN-DLQI scores were calculated after donor acceptance decisions. We excluded donations after circulatory death and turn downs exclusively for size, HLA, known malignancy, unmet multi-organ or laterality needs, other recipient or donor issues, or excess travel time. We explored associations between the UMN-DLQI score with discrepant donor decisions (organs turned down that were subsequently transplanted elsewhere) and recipient outcomes. Results Eleven centers participated. 183 donor organs were accepted and transplanted. Accepted donors averaged 35 years old and 16% met increased risk criteria. The median UMN-DLQI score was 43 (range 32 - 50). One in five transplanted organs scored 6 hours, donor size mismatch, or pneumonia risk (57, 53, and 61%, respectively). The mean LAS was 45.5. Conclusion Multi center use of a standardized scoring instrument offers insight into donor acceptance practices and may be useful in understanding discrepant organ decisions in lung transplantation.

For the patients with progressively decompensating acute or acute-on-chronic respiratory failure, the first-choice treatment remains as mechanical ventilation. Despite the consistent value of mechanical ventilation, the majority of lung specialists are aware of its limitations, in particular for the patients with advanced lung failure, and inherent drawbacks that augment disease progression. More recently, the concept of allowing the lungs to 'rest and recover' has been supported by quite a few clinical studies. The pressure and volume of gas delivered to the lungs are reduced compared with mechanical ventilation. Based on recent remarkable evidence and experiences using extracorporeal lung support (ECLS) before, during and after lung transplant, there is growing interest in and expectations for the use of ECLS beyond lung transplant to encompass the entire field of pulmonary medicine. The purpose of this review article is to provide an update on evolving ECLS technologies and their effectiveness and discuss the future of ECLS for advanced lung failure as a new subspecialty in cardiothoracic surgery.

Purpose Extracorporeal membrane oxygenation (ECMO) is increasingly used as a bridging strategy to lung transplantation (LT). This trend has been largely influenced by increasing acuity among recipients. The purpose of this study was to examine factors related to death prior to LT for patients on ECMO at the time of registration. Methods Patients included those who were on ECMO when registered in the United Network for Organ Sharing (UNOS) Organ Procurement and Transplantation Network Database between 2005-2017. At registration for LT, 402 adult patients were on ECMO as a bridge, 324 of whom were transplanted or died prior to LT. Multivariable logistic regression was used to examine factors associated with mortality prior to LT. Results Mean age was 44.7±15.4 years and 38% were female. In this sample, 21% died before LT (n =68) with 44% for pulmonary reasons, 15% for graft failure , 9% for cardiac arrest, 7% for infection, and 24% for other reasons. Most common indication for LT was interstitial-restrictive disease (49%) whereas pulmonary hypertension patients had highest mortality (39%) although not significant. In multivariable analysis, female gender was associated with more than double risk for mortality prior to LT (OR=2.40, P=0.005; TABLE). However, female patients were younger (39 vs 48 years, P creatinine (0.6 vs 0.8, P Conclusion Female gender and elevated serum creatinine were independently associated with higher risk for mortality in patients with ECMO as a bridge to LT.