Extracorporeal membrane oxygenation and lung transplantation

Extracorporeal membrane oxygenation as a bridge to lung transplantation: Practice patterns and patient outcomes

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is increasingly relied on to bridge patients with respiratory failure to lung transplantation despite limited evidence for its use in this setting. This study evaluated longitudinal trends in practice patterns, patient characteristics, and outcomes in patients bridged with ECMO to lung transplant.

METHODS

A retrospective review of all adult isolated lung transplant patients in the United Network for Organ Sharing database between 2000 and 2019 was performed. Patients were classified as "ECMO" if supported with ECMO at the time of listing or transplantation and "non-ECMO" otherwise. Linear regression was used to evaluate trends in patient demographics during the study period. Trends in mortality were evaluated using Cox proportional hazards modeling, with time period as the primary covariate (2000-2004, 2005-2009, 2010-2014, or 2015-2019) and age, time on the waitlist, and underlying diagnosis as covariates.

RESULTS

The number of patients included were 40,866, of whom 1,387 (3.4%) were classified as ECMO and 39,479 (96.6%) as no ECMO. Average age and initial Lung Allocation Score increased significantly during the study period in both cohorts, but occurred at a slower rate in the ECMO population. The hazard of death was significantly lower in more recent years (2015-2019) for both the ECMO and non-ECMO cohorts (aHR (adjusted hazards ratio) 0.59, 95% confidence interval (CI) 0.37-0.96 and aHR 0.74, 95% CI 0.70-0.79) when compared to the early years (2000-2004) of the study period.

CONCLUSIONS

Post-transplantation survival for patients bridged to transplantation with ECMO demonstrates ongoing improvement despite cannulation of progressively older and sicker patients.

Update in lung transplantation: anesthetic considerations

The field of lung transplantation (LTx) has expanded rapidly since its inception in the early 1960s with the work of James Hardy and colleagues at the University of Mississippi from the work of local single specialty physicians into an international multidisciplinary specialty. Advancements throughout the next several decades have led to the completion of over 70,000 lung transplants worldwide. The unique challenges presented by patients with end-stage lung disease have both evolved and remained consistent since then, yet these challenges are being answered with major improvements and advancements in perioperative care in the 21st century. The current practice of LTx medicine is fundamentally multidisciplinary, and members of the LTx team includes surgeons, physicians, and allied health staff. The integration of anesthesiologists into the LTx team as well as the multidisciplinary nature of LTx necessitates anesthetic considerations to be closely incorporated into emerging surgical, medical, and systems techniques for patient care. This review discusses a host of emerging strategies across the spectrum of LTx, including efforts to expand the donor pool, utilization of perioperative extracorporeal life support, perioperative echocardiography, and anesthetic techniques to mitigate primary graft dysfunction that have all contributed to improved long term outcomes in LTx patients.

Lung Transplantation for Pulmonary Artery Hypertension

This manuscript discusses the role of lung transplantation in patients with pulmonary hypertension. The indications and timing for referral to a transplant unit and timing for wait-listing for lung transplantation are discussed. The type of transplantation—isolated (single or double) lung transplantation and situations when combined heart and double lung transplantation is indicated—will be elaborated. Escalation of medical therapy with the need and timing for bridging therapies such as extracorporeal membrane oxygenation until an appropriate organ becomes available will be discussed. Challenges in the postoperative period, specific to lung transplantation for pulmonary artery hypertension, will be reviewed. The outcomes following lung transplantation will also be considered in greater detail.

Experience with intraoperative extracorporeal membrane oxygenation in lung transplantation: intraoperative indicators

Background/Aim: Intraoperative extracorporeal membrane oxygenation (ECMO) is being used with increasing frequency in lung transplantation. However, the factors associated with the use of intraoperative ECMO in lung transplant patients are not yet conclusive. In this study, we aimed to determine the effective factors for providing intraoperative ECMO support in patients undergoing lung transplantation. In addition, we aimed to evaluate the effect of ECMO support on morbidity and mortality. Methods: In this retrospective cohort study evaluating lung transplant patients, patients were divided into two groups: those who received intraoperative ECMO support and those who did not. Demographic data, the lung allocation score (LAS) and pulmonary arterial pressure (PAP), intraoperative data, postoperative complications, duration of mechanical ventilation (MV), length of stay (LOS) in intensive care and hospital, and mortality rates were recorded for both groups. Factors affecting entry to ECMO were analyzed by Multivariate Logistic Regression. Results: In this period, 51.9% of 87 patients who underwent lung transplantation required intraoperative ECMO. The mean age, LAS, and PAP of the ECMO group were significantly higher than the non-ECMO group (P = 0.043, P = 0.007, and P = 0.007, respectively). In multivariate analysis, it was found that lower MAP averages were a predictive parameter in intraoperative ECMO requirements (OR: 1.091; CI: 1.009-1.179; P = 0.028). The ECMO group’s mechanical ventilation time and hospital mortality were significantly higher than the other group (P = 0.004 and P = 0.025, respectively). Conclusion: Preoperative indicators of intraoperative ECMO support were determined as age, LAS, and PAP elevation. In addition, low MAP levels and high lactate levels were always determined as intraoperative indicators in lung transplantation until the transition to ECMO support.

Extracorporeal membrane oxygenation support for lung transplantation: Initial experience in a single center in China and a literature review

Background

Extracorporeal membrane oxygenation (ECMO) is a versatile tool associated with favorable outcomes in the field of lung transplantation (LTx). Here, the clinical outcomes and complications of patients who underwent LTx with ECMO support, mainly prophylactically both intraoperatively and post-operatively, in a single center in China are reviewed.

Methods

The study cohort included all consecutive patients who underwent LTx between January 2020 and January 2022. Demographics and LTx data were retrospectively reviewed. Perioperative results, including complications and survival outcomes, were assessed.

Results

Of 86 patients included in the study, 32 received ECMO support, including 21 who received prophylactic intraoperative use of ECMO with or without prolonged post-operative use (pro-ECMO group), while the remaining 54 (62.8%) received no external support (non-ECMO group). There were no significant differences in the incidence of grade 3 primary graft dysfunction (PGD), short-term survival, or perioperative outcomes and complications between the non-ECMO and pro-ECMO groups. However, the estimated 1- and 2-year survival were superior in the pro-ECMO group, although this difference was not statistically significant (64.1% vs. 82.4%, log-rank P = 0.152; 46.5% vs. 72.1%, log-rank P = 0.182, respectively). After regrouping based on the reason for ECMO support, 30-day survival was satisfactory, while 90-day survival was poor in patients who received ECMO as a bridge to transplantation. However, prophylactic intraoperative use of ECMO and post-operative ECMO prolongation demonstrated promising survival and acceptable complication rates. In particular, patients who initially received venovenous (VV) ECMO intraoperatively with the same configuration post-operatively achieved excellent outcomes. The use of ECMO to salvage a graft affected by severe PGD also achieved acceptable survival in the rescue group.

Conclusions

Prophylactic intraoperative ECMO support and post-operative ECMO prolongation demonstrated promising survival outcomes and acceptable complications in LTx patients. Particularly, VV ECMO provided safe and effective support intraoperatively and prophylactic prolongation reduced the incidence of PGD in selected patients. However, since this study was conducted in a relatively low-volume transplant center, further studies are needed to validate the results.

The evolution of lung transplantation in India and the current scenario

Lung transplantation has come of age in India. This article aims to trace the evolution of lung transplantation in India from its humble beginnings in 1999 to the current scenario spanning a period of 22 years. Right from the passing of the Act legalising deceased organ transplantation, its amendments and rules—to the development of transplant regulatory bodies—both at national and state levels, the journey thus far has been chronicled. Description of the initial cases at sporadic centres which has now proliferated to many centres now across many states has been elaborated on. The impacts on evolution of lung transplantation by the governmental transplant organisations, non-governmental organisations, and the medical professional societies are described. Publications related to lung transplantation from India are mentioned. Situations specific to India, current scenario of lung transplantation, and future directions are discussed. A brief mention of our experience with lung transplantation has also been made.

A pandemic of acute respiratory distress syndrome-role of lung transplant in coronavirus disease-2019-associated respiratory failure

Lung transplantation may be appropriate, and may offer benefit only to a carefully selected subset of morbidly ill patients afflicted by coronavirus disease-2019. Identifying the appropriate recipient for the allocation of scarce resources, by safely navigating through the challenges that are unique to lung transplantation for coronavirus disease-2019-associated acute respiratory distress syndrome, demands a conscientious and meticulous approach. Categorizing the respiratory failure in coronavirus disease-2019 may facilitate the process of evaluation for the purpose of transplant. The progress in rescue transplants over the past two decades has greatly improved our ability to successfully perform high-risk lung transplantation.