Comparison of mechanical cardiopulmonary support strategies during lung transplantation

Concomitant Heart and Lung Surgery During Lung Transplantation

INTRODUCTION

There is limited data concerning concomitant cardiac and lung surgery outcomes during lung transplantation (LTx). While some evidence suggests that cardiac surgery during LTx has no significant impact on surgical outcomes, scarce data examines the role of concomitant lung surgery (CLS). This study compares the survival outcomes of concomitant cardiac and lung surgeries during LTx.

METHODS

A retrospective analysis of all single and double LTx patients from March 2012 to June 2023 at a single center was performed (n = 1099). Patients were stratified into three concomitant surgical groups: concomitant cardiac surgery (CCS), CLS, and no concomitant surgeries. Groups were compared on recipient demographics, diagnosis, and surgical intervention using analysis of variance and chi-square tests. Survival (5 y) was analyzed using Kaplan-Meier curves, log-rank test, and univariable Cox proportional hazard model where P value <0.05 was considered significant.

RESULTS

In total, 1099 patients were analyzed in this study; 965 had no concomitant surgery, 100 had CCS (mode: coronary artery bypass grafting, n = 75), and 34 had CLS (mode: lung volume reduction surgery, n = 14). Between the three surgical groups, there was no significant difference in body mass index (P = 0.091), total ischemic time (P = 0.194), induction (P = 0.140), or cause of death (P = 0.240). Lung allocation score and length of stay were significantly higher in the concomitant surgical groups, especially the CLS group when compared to the no concomitant surgery group (P = 0.002, P = 004). Patients with no concomitant surgery had a higher incidence of single LTx and off-pump utilization than concomitant surgical groups (P < 0.001). Kaplan-Meier curves and log-rank tests found no significant difference in survival between groups (P = 0.849). This result is supported by Cox proportional hazard model with no significant difference in mortality risk between the CCS group (P = 0.522) and CLS group (P = 0.936) compared to no concomitant surgery during LTx.

CONCLUSIONS

Our study provides promising data indicating that individuals undergoing concomitant heart or lung surgery during LTx have similar survival outcomes to those exclusively undergoing LTx. These results highlight the potential advantages of utilizing LTx to address concurrent thoracic surgical needs, such as coronary revascularization. This holds implications for optimizing patient care and decision-making when complex thoracic interventions are necessary.

Which strategy is better for lung transplantation: Cardiopulmonary bypass or extracorporeal membrane oxygenation?

Background: In lung transplantation surgery, extracorporeal life support (ECLS) is essential for safety. Various support methods, including cardiopulmonary bypass (CPB) and off-pump techniques, are used, with extracorporeal membrane oxygenation (ECMO) gaining prominence. However, consensus on the best support strategy is lacking.Purpose: This article reviews risks, benefits, and outcomes of different support strategies in lung transplantation. By consolidating knowledge, it aims to clarify selecting the most appropriate ECLS modality.Research Design: A comprehensive literature review examined CPB, off-pump techniques, and ECMO outcomes in lung transplantation, including surgical results and complications.Study Sample: Studies, including clinical trials and observational research, focused on ECLS in lung transplantation, both retrospective and prospective, providing a broad evidence base.Data Collection and/or Analysis: Selected studies were analyzed for surgical outcomes, complications, and survival rates associated with CPB, off-pump techniques, and ECMO to assess safety and effectiveness.Results: Off-pump techniques are preferred, with ECMO increasingly vital as a bridge to transplant, overshadowing CPB. However, ECMO entails hidden risks and higher costs. While safer than CPB, optimizing ECMO postoperative use and monitoring is crucial for success.Conclusions: Off-pump techniques are standard, but ECMO's role is expanding. Despite advantages, careful ECMO management is crucial due to hidden risks and costs. Future research should focus on refining ECMO use and monitoring to improve outcomes, emphasizing individualized approaches for LT recipients.

Intraoperative Extracorporeal Support during Lung Transplantation: Not Just for the High-Risk Patient

The use of intraoperative mechanical support during lung transplantation has traditionally been a controversial topic. Trends for intraoperative mechanical support strategies swing like a pendulum. Historically, cardiopulmonary bypass (CPB) was the modality of choice during transplantation. It provides full hemodynamic support including oxygenation and decarboxylation. Surgical exposure is improved by permitting the drainage of the heart and provides more permissive retraction. CPBs contain drainage reservoirs with hand-held pump suction catheters promoting blood conservation through collection and re-circulation. But CPB has its disadvantages. It is known to cause systemic inflammation and coagulopathy. CPB requires high doses of heparinization, which increases bleeding risks. As transplantation progressed, off-pump transplantation began to trend as a preferable option. ECMO, however, has many of the benefits of CPB with less of the risk. Outcomes were improved with ECMO compared to CPB. CPB has a higher blood transfusion requirement, a higher need for post-operative ECMO support, a higher re-intubation rate, high rates of kidney injury and need for hemodialysis, longer ICU stays, higher incidences of PGD grade 3, as well as overall in-hospital mortality when compared with ECMO use. The focus now shifts to using intraoperative mechanical support to protect the graft, helping to reduce ischemia-reperfusion injury and allowing for lung protective ventilator settings. Studies show that the routine use of ECMO during transplantation decreases the rate of primary graft dysfunction and many adverse outcomes including ventilator time, need for tracheostomy, renal failure, post-operative ECMO requirements, and others. As intraoperative planned ECMO is considered a safe and effective approach, with improved survival and better overall outcomes compared to both unplanned ECMO implementation and off-pump transplantation, its routine use should be taken into consideration as standard protocol.

Perioperative Circulatory Support and Management for Lung Transplantation: A Case-Based Review

Lung transplantation (LTx) historically was performed with cardiopulmonary bypass (CPB) or Off-pump. Recent data suggest an increased interest in extracorporeal membrane oxygenation (ECMO) as perioperative circulatory support by many lung transplantation centers worldwide. However, there are no established guidelines for anesthetic management for LTx. We present a patient with a history of systemic sclerosis and interstitial lung disease complicated by acute onset of systemic pulmonary hypertension and right heart failure undergoing LTx. We aim to discuss perioperative circulatory support, including ECMO bridge to LTx, and how best to consider the varied intraoperative strategies of CPB vs ECMO vs off-pump during LTx, intraoperative maintenance, and coagulation management.

Critical Care Management of the Lung Transplant Recipient

Lung transplantation is often the only treatment option for patients with severe irreversible lung disease. Improvements in donor and recipient selection, organ allocation, surgical techniques, and immunosuppression have all contributed to better survival outcomes after lung transplantation. Nonetheless, lung transplant recipients still experience frequent complications, often necessitating treatment in an intensive care setting. In addition, the use of extracorporeal life support as a means of bridging critically ill patients to lung transplantation has become more widespread. This review focuses on the critical care aspects of lung transplantation, both before and after surgery.

Current status and training needs of trainee anesthesiologists in lung transplantation anesthesia in China: A single-center survey

Background

Perioperative management involving anesthesiologists plays an important role in prognosis of recipients after lung transplantation. Since the development of lung transplantation, the demand for specialized anesthesiologists continues to increase. As the largest lung transplant center in China, the Wuxi People's Hospital was tasked with trainee anesthesiologists throughout the country in lung transplantation anesthesia. This study aimed to evaluate the current status and training needs of anesthesiologists for the anesthetic management of lung transplantation in Wuxi People's Hospital between 2015 to 2020.

Methods

Overall, 53 trainee anesthesiologists for lung transplantation from 35 hospitals were investigated anonymously in our survey. The questionnaire included the anesthesiologists' demographic information, level of satisfaction, training needs and current status in their hospitals. We divided the doctors into two groups depending on the trainee anesthesiologists' seniority and professional title: intermediate and senior. Survey data were compared between the groups.

Results

Significantly more doctors in senior-level positions had clinical research experience than did doctors in intermediate-level positions (P = 0.041). All doctors were highly or very highly satisfied with the training received. Doctors in intermediate-level positions preferred training periods of 4-6 months, while those in senior-level positions preferred 1-3 months of training (P = 0.044). Most doctors considered theoretical courses to be lacking (69.0%), followed by a lack of scenario simulation teaching (54.8%). The most desirable programs were transesophageal echocardiography (TEE, 71.4%) and extracorporeal membrane oxygenation (ECMO, 64.3%). ECMO technology was available in the hospitals of 95.2% of respondents; however, only 2.4% of doctors said the anesthesiology department took charge of perioperative ECMO. Significantly more senior-level doctors chose calibrated pulse contour analysis (P = 0.018) and significantly more intermediate-level ones chose TEE (P = 0.049). Disappointingly, 21.4% doctors reported a lack of certification evaluation for trainee anesthesiologists at their hospitals.

Conclusions

Different training programs should be set up according to the trainee anesthesiologists' level of seniority and training needs. Theoretical courses and scenario simulation training must be added to improve the training program. Moreover, the training of TEE and ECMO requires greater attention. Finally, a standardized completion assessment is required for trainee anesthesiologists.

Lung Transplantation in COVID-19 patients: What we have learned so far

Coronavirus-19 (COVID-19) can result in irrecoverable acute respiratory distress syndrome (ARDS) or life-limiting fibrosis for which lung transplantation is currently the only viable treatment. COVID-19 lung transplantation has transformed the field of lung transplantation, as before the pandemic, few transplants had been performed in the setting of infectious disease or ARDS. Given the complexities associated with COVID-19 lung transplantation, it requires strict patient selection with an experienced multidisciplinary team in a high-resource hospital setting. Current short-term outcomes of COVID-19 lung transplantation are promising. However, follow-up studies are needed to determine long-term outcomes and whether these patients may be predisposed to unique complications.

Clinical Characteristics and Outcomes of Patients With COVID-19-Associated Acute Respiratory Distress Syndrome Who Underwent Lung Transplant

Importance

Lung transplantation is a potentially lifesaving treatment for patients who are critically ill due to COVID-19-associated acute respiratory distress syndrome (ARDS), but there is limited information about the long-term outcome.

Objective

To report the clinical characteristics and outcomes of patients who had COVID-19-associated ARDS and underwent a lung transplant at a single US hospital.

Design, Setting, and Participants

Retrospective case series of 102 consecutive patients who underwent a lung transplant at Northwestern University Medical Center in Chicago, Illinois, between January 21, 2020, and September 30, 2021, including 30 patients who had COVID-19-associated ARDS. The date of final follow-up was November 15, 2021.

Exposures

Lung transplant.

Main Outcomes and Measures

Demographic, clinical, laboratory, and treatment data were collected and analyzed. Outcomes of lung transplant, including postoperative complications, intensive care unit and hospital length of stay, and survival, were recorded.

Results

Among the 102 lung transplant recipients, 30 patients (median age, 53 years [range, 27 to 62]; 13 women [43%]) had COVID-19-associated ARDS and 72 patients (median age, 62 years [range, 22 to 74]; 32 women [44%]) had chronic end-stage lung disease without COVID-19. For lung transplant recipients with COVID-19 compared with those without COVID-19, the median lung allocation scores were 85.8 vs 46.7, the median time on the lung transplant waitlist was 11.5 vs 15 days, and preoperative venovenous extracorporeal membrane oxygenation (ECMO) was used in 56.7% vs 1.4%, respectively. During transplant, patients who had COVID-19-associated ARDS received transfusion of a median of 6.5 units of packed red blood cells vs 0 in those without COVID-19, 96.7% vs 62.5% underwent intraoperative venoarterial ECMO, and the median operative time was 8.5 vs 7.4 hours, respectively. Postoperatively, the rates of primary graft dysfunction (grades 1 to 3) within 72 hours were 70% in the COVID-19 cohort vs 20.8% in those without COVID-19, the median time receiving invasive mechanical ventilation was 6.5 vs 2.0 days, the median duration of intensive care unit stay was 18 vs 9 days, the median post-lung transplant hospitalization duration was 28.5 vs 16 days, and 13.3% vs 5.5% required permanent hemodialysis, respectively. None of the lung transplant recipients who had COVID-19-associated ARDS demonstrated antibody-mediated rejection compared with 12.5% in those without COVID-19. At follow-up, all 30 lung transplant recipients who had COVID-19-associated ARDS were alive (median follow-up, 351 days [IQR, 176-555] after transplant) vs 60 patients (83%) who were alive in the non-COVID-19 cohort (median follow-up, 488 days [IQR, 368-570] after lung transplant).

Conclusions and Relevance

In this single-center case series of 102 consecutive patients who underwent a lung transplant between January 21, 2020, and September 30, 2021, survival was 100% in the 30 patients who had COVID-19-associated ARDS as of November 15, 2021.

Central, peripheral ECMO or CPB? Comparsion between circulatory support methods used during lung transplantation

BACKGROUND

Chronic obstructive pulmonary disease, cystic fibrosis and usual interstitial pneumonia are three most common indications for lung transplantation (LuTx) in Poland. As a result of irreversible destruction of pulmonary parenchyma and extended respiratory insufficiency that appear afterwards, it is crucial to estimate the reserve of gas exchange in each lung before and during surgery. Altering conditions of gas exchange require adaptation in circulatory system as well. In some of the cases the use of extracorporeal life support appears to be necessary to undergo the transplantation successfully. Cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO) used during operation allow to replace the function of heart and lung, but they are also related to complications in the form of acute kidney failure, bleeding, heart arrhythmias or thromboembolic complications.

METHODS

We reviewed 77 LuTx from 2009 to 2020 performed at the Department of Thoracic Surgery and Transplantation. 40/77 (51%) patients required intraoperative extracorporeal assistance: 8 required CBP and 32 required ECMO. In the ECMO group 14/32 (44%) patients had peripheral cannulation and 18/32 (56%) had central one. We have calculated the survival rates and reviewed postoperative complications after lung transplantations. Cumulative Kaplan-Meier survival curves were calculated. Differences between the groups were evaluated by the Chi- square analysis for discontinuous variables and t-test for continuous variables.

RESULTS

The use of intraoperative central extracorporeal membrane oxygenator was associated with increased survival rates comparing to patients without external support (30-days, 1-year, 3-years, 5-years rates: 78%, 66%, 66%, 66% vs 83%, 65%, 59%, 44% respectively). Furthermore, survival was enhanced comparing to peripheral ECMO or cardiopulmonary bypass as well (50%, 41%, 41%, 33%; 75%, 50%, 50%, 38% respectively). Acute kidney injury and thromboembolic complications occurred statistically more often in case of patients that underwent lung transplantation with support devices (p = 0.005, p = 0.02 respectively). Frequency of other complications was comparable among groups.

CONCLUSIONS

The use of central extracorporeal membrane oxygenation should be favorized over peripheral cannulation or cardiopulmonary bypass. CPB should be no longer used during LuTx. Trial registration Not applicable.

Evolution of Recipient Characteristics Over 3 Decades and Impact on Survival After Lung Transplantation

BACKGROUND

Lung transplantation (LTx) is a definitive treatment for end-stage lung disease. Herein, we reviewed our center experience over three decades to examine the evolution of recipient characteristics and contemporary predictors of survival for LTx.

METHODS

We retrospectively reviewed the data of LTx procedures performed at our institution from 1/1990 to 1/2019 (n=1819). The cohort is divided into three eras; I: 1990-1998 (n=152), II: 1999-2008 (n=521), III: 2009-2018 (n=1146). Uni- and multivariate analyses of survival in era III were performed.

RESULTS

Pulmonary fibrosis has become the leading indication for LTx (13% in Era I, 57% in Era III). Median recipient age increased (Era I: 46 years - Era III: 61 years) as well as intraoperative mechanical circulatory support (Era I: 0% - Era III: 6%). Higher lung allocation score (LAS) was associated with primary graft dysfunction (PGD) (p<0.0001), postoperative ECMO (p<0.0001), and in-hospital mortality (p=0.002). In Era III, hypoalbuminemia, thrombocytopenia, and high PGD grade were multivariate predictors of early mortality. The 5-year survival in Era II (55%) and III (55%) were superior to Era I (40%, p<0.001). Risk factors for late mortality in era III included recipient age, chronic allograft dysfunction, renal dysfunction, high MELD score, and single LTx.

CONCLUSIONS

In this longitudinal single-center study, recipient characteristics have evolved to include sicker patients with greater complexity of procedures and risk for postoperative complications but without significant impact on hospital mortality or long-term survival. With advancing surgical techniques and perioperative management, there is room for further progress in the field.Supplemental Visual Abstract; http://links.lww.com/TP/C191.