Extracorporeal Membrane Oxygenation in Lung Transplantation: Analysis of Techniques and Outcomes

Hemodynamic Monitoring During Liver Transplantation for Patients on Perioperative Extracorporeal Membrane Oxygenation (ECMO) Support: A Narrative Review

Background and Objectives: Indications for liver transplants are increasing worldwide due to the growing number of transplants performed on patients with significant cardiovascular and respiratory risk factors. Additional support for this trend comes from the growing use of marginal organs, which is made possible by donations made after circulatory death (DCD). Liver transplantation (LT) in such high-risk patients may be challenging and may require perioperative Extracorporeal Membrane Oxygenation (ECMO). There is a lack of evidence on the best hemodynamic monitoring techniques for patients undergoing ECMO support during the perioperative period of LT. This review aims to provide a comprehensive overview of the hemodynamic monitoring standards of patients supported by ECMO before, during, and after LT. Materials and Methods: Comprehensive research was conducted through the PubMed database, and 153 articles regarding patients who needed perioperative ECMO support were found. Among these, 18 articles were finally included in our analysis as the authors specified hemodynamic monitoring techniques and data. The articles included case reports, letters to the editor, and correspondence. Results: We identified 20 cases of patients supported by ECMO as a planned preoperative strategy (9 patients), as a rescue therapy during surgery (7 patients), and as a postoperative support (4 patients). Cardiac catheterism and echocardiography (transthoracic and transesophageal) were the authors' most cited hemodynamic monitoring techniques. Conclusions: Data on hemodynamic monitoring methods used to manage patients supported by ECMO during the whole perioperative period of LT are poor and derived from descriptive low-quality studies. However, a multimodal approach that includes continuous monitoring of pulmonary pressures and echocardiography can increase diagnostic accuracy and improve the decision-making process to manage this complex patient population.

Respiratory compliance related to prognostic of lung transplant patients with veno‑venous extracorporeal membrane oxygenation support

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) plays an important role in the perioperative care of critically ill lung transplant patients. However, the factors predicting prognosis are unclear. This study assessed the association between static respiratory compliance (Crs) and outcomes of lung transplant patients receiving VV-ECMO in terms of 90-day mortality. Data were retrospectively collected for patients that underwent lung transplantation with VV-ECMO support during 2022-2023. Patients were divided into two groups according to the early postoperative Crs: lower Crs (Crs < 25 ml/cmH2O) and higher Crs (Crs ≥ 25 ml/cmH2O). Differences in patient characteristics and prognosis were then compared between the two groups. Receiver operating characteristic (ROC) curve analysis was used to evaluate the value of Crs for predicting 90-day mortality and univariate Cox proportional hazard model analysis was performed to estimate risk of Crs. Data were available for a total of 85 patients, including 50 (58.8%) patients in the higher Crs group and 35 (41.2%) patients in the lower Crs group. A lower Crs was significantly associated with a longer postoperative ECMO duration (hours, 42 vs. 24; P = 0.022), longer postoperative ventilator time (days, 3.7 vs. 2.0; P = 0.003), higher application of continuous renal replacement therapy (CRRT) (20.0% vs. 6.0%; P = 0.049), higher incidence of pneumonia (42.9% vs. 20.0%; P = 0.023), and higher 90-day mortality (22.9% vs. 6.0%; P = 0.023). The area under the curve of Crs for predicting 90-day mortality was 0.661 (P = 0.034). A higher Crs was a protective factor (hazard ratio = 0.925 [0.870-0.984)] P = 0.014). For lung transplant patients receiving VV-ECMO support, Crs < 25 ml/cmH2O is associated with more complications and higher 90-day mortality. As Crs is easily obtained at the bedside, it may be useful for predicting prognosis and guiding patient management.

The comparative impact of central vs. peripheral VA-ECMO cannulation on postoperative graft dysfunction in lung transplantation: a retrospective analysis

Background

Lung transplantation (LTx) is the definitive treatment for end-stage pulmonary diseases, with venoarterial extracorporeal membrane oxygenation (VA-ECMO) used as a common perioperative support. However, it remains unclear if central (cVA-ECMO) or peripheral (pVA-ECMO) cannulation routes yield better outcomes in postoperative prognosis. This study compares the impact of these two cannulation strategies on primary graft dysfunction (PGD) incidence in LTx patients.

Methods

A retrospective analysis was performed on 153 LTx patients supported with VA-ECMO at the Wuxi Lung Transplant Center (January 2019-March 2023). Patients were divided into central (n = 31) and peripheral (n = 91) groups. Data included recipient/donor demographics, preoperative status, and follow-up outcomes. The primary outcome was PGD within 72 h after reperfusion, whereas secondary outcomes included in-hospital mortality, 1-year survival, renal support needs, ventilation duration, intensive care unit (ICU) stay, and biochemical markers.

Results

PGD incidence was significantly higher in the peripheral group, with longer ECMO duration, ventilation, and ICU stay. Central VA-ECMO showed advantages in in-hospital mortality and 1-year survival rates.

Conclusion

Central VA-ECMO cannulation may reduce postoperative complications and improve survival for LTx recipients. Prospective studies are needed to confirm these findings and refine perioperative ECMO management.

Survey of Extracorporeal Life Support Application in Lung Transplantation

INTRODUCTION

Lung transplantation has been evolving since its inception in 1963. Over recent years, literature has suggested a shift in the perioperative strategy of mechanical support toward extracorporeal membrane oxygenation (ECMO) as the preferred modality of extracorporeal life support (ECLS) in lung transplantation. The Survey of ECLS Application in Lung transplantation (SEAL) was designed to elucidate the current practice patterns of perioperative ECLS within the United States.

METHODS

In this cross-sectional study, a physician from 62 adult lung transplantation centers across the United States of America (USA) was surveyed on their institutional practices regarding the perioperative management of lung transplantation patients, with a focus on mechanical support.

RESULTS

The survey completion rate was 74% (46/62 eligible institutions). Most transplant centers utilize venoarterial (VA) ECMO (78%, 36/46) and/or venovenous (VV) ECMO (93%, 29/43) as a bridge to lung transplantation. When ECLS is used intraoperatively, 61% of (28/46) responding programs use VA ECMO as their preferred support. All programs use transesophageal echocardiography (TEE) intraoperatively, 85% (33/39) cannulate for ECMO centrally, and 74% (29/39) use a combination of inhaled and intravenous anesthesia while using ECMO intraoperatively. Most programs do not use antifibrinolytic during VA ECMO (62%, 28/45). Anticoagulation management and VA ECMO flows throughout the procedure showed considerable variation.

CONCLUSION

Data from SEAL illustrates that though there are some practice commonalities within the United States, there is also quite a bit of variability in practice. Multiple dominant practices within the USA are consistent with a recently published International Society of Heart and Lung Transplantation consensus.

ECMO for bridging lung transplantation

BACKGROUND

With the shift in donor lung allocation from blood type and waiting order to the use of the lung allocation score (LAS) system, there are increasingly more cases of ECMO bridging lung transplantation. However, there are still some problems in case selection, implementation, and management.

METHODS

We analyzed and summarized a series of data on ECMO bridging lung transplantation through an extensive literature review.

RESULTS

The improvement of the lung transplant allocation system and the progress of ECMO technology have made the ECMO bridge to lung transplant more widely used in clinical practice. The selection of bridge patients is a crucial link in the success of transplantation, and accurate assessment of the patient before transplantation is necessary. The advantages and disadvantages of different bridge strategies exist, and the appropriate bridge strategy should be selected based on the patient's situation. Bleeding and thrombosis complications often occur during ECMO circulation, and there is currently no optimal anticoagulation strategy. The predictive score for bridge post-outcome is still subject to certain limitations.

CONCLUSIONS

ECMO bridging lung transplantation is suitable for patients waiting for lung transplantation when other respiratory support is ineffective or when hemodynamic instability occurs the disease is severe and the donor organ is easily obtainable. Patients aged 65 years or older, or have reversible multiple organ dysfunction should not be included as contraindications for ECMO bridging lung transplantation.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights From 2023

This special article is the 16th in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan, and the editorial board for the opportunity to continue this series, namely the research highlights of the past year in the specialty of cardiothoracic and vascular anesthesiology. The major themes selected for 2023 are outlined in this introduction, and each highlight is reviewed in detail in the main article. The literature highlights in the specialty for 2023 begin with an update on perioperative rehabilitation in cardiothoracic surgery, with a focus on novel methods to best assess patients in the preoperative and postoperative periods, and the impact of rehabilitation on outcomes. The second major theme is focused on cardiac surgery, with the authors discussing new insights into inhaled pulmonary vasodilators, coronary revascularization surgery, and discussion of causes of coronary graft failure after surgery. The third theme is focused on cardiothoracic transplantation, with discussions focusing on bridge-to-transplantation strategies. The fourth theme is focused on mechanical circulatory support, with discussions focusing on both temporary and durable support. The fifth and final theme is an update on medical cardiology, with a focus on outcomes of invasive approaches to heart disease. The themes selected for this article are only a few of the diverse advances in the specialty during 2023. These highlights will inform the reader of key updates on various topics, leading to improved perioperative outcomes for patients with cardiothoracic and vascular disease.

Initial experience and outcomes with a hybrid extracorporeal membrane oxygenation and cardiopulmonary bypass circuit for lung transplantation

Background

The utilization of extracorporeal life support (ECLS) for intraoperative support during lung transplantation has increased over the past decade. Although veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has recently emerged as the preferred modality over cardiopulmonary bypass (CPB), many centers continue to use both forms of ECLS during lung transplantation. Our novel hybrid VA-ECMO/CPB circuit allows for seamless transition from VA-ECMO to CPB at a significant cost savings compared to a standalone VA-ECMO circuit. This study describes our initial experience and outcomes in the first 100 bilateral lung transplantations using this novel hybrid VA-ECMO/CPB circuit.

Methods

Medical records from September 2017 to May 2021 of the first 100 consecutive patients undergoing bilateral lung transplantation with intraoperative hybrid VA-ECMO support were examined retrospectively. We excluded patients with single lung transplants, retransplantations, preoperative ECLS bridging, and veno-venous (VV) ECMO and those supported with CPB only. Perioperative recipient, anesthetic, perfusion variables, and outcomes were assessed.

Results

Of the 100 patients supported with VA-ECMO, 19 were converted intraoperatively to CPB. Right ventricular dysfunction was seen in 37% of patients, and the median mean pulmonary artery pressure was 28 mm Hg. No oxygenator clotting was observed with a median heparin dose of 13,000 units in the VA-ECMO group. Primary graft dysfunction grade 3 at 72 hours was observed in 10.1% of all patients and observed 1-year mortality was 4%.

Conclusions

The use of a hybrid VA-ECMO/CPB circuit in our institution allows for rapid conversion to CPB with acceptable outcomes across a diverse recipient group at a significantly reduced cost compared to standalone VA-ECMO circuits.

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.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights from 2022

This special article is the 15th in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief Dr. Kaplan and the editorial board for the opportunity to continue this series, namely the research highlights of the past year in the specialties of cardiothoracic and vascular anesthesiology. The major themes selected for 2022 are outlined in this introduction, and each highlight is reviewed in detail in the main body of the article. The literature highlights, in the specialties for 2022, begin with an update on COVID-19 therapies, with a focus on the temporal updates in a wide range of therapies, progressing from medical to the use of extracorporeal membrane oxygenation and, ultimately, with lung transplantation in this high-risk group. The second major theme is focused on medical cardiology, with the authors discussing new insights into the life cycle of coronary disease, heart failure treatments, and outcomes related to novel statin therapy. The third theme is focused on mechanical circulatory support, with discussions focusing on both right-sided and left-sided temporary support outcomes and the optimal timing of deployment. The fourth and final theme is an update on cardiac surgery, with a discussion of the diverse aspects of concomitant valvular surgery and the optimal approach to procedural treatment for coronary artery disease. The themes selected for this 15th special article are only a few of the diverse advances in the specialties during 2022. These highlights will inform the reader of key updates on a variety of topics, leading to the improvement of perioperative outcomes for patients with cardiothoracic and vascular disease.

Bilateral Lung Transplantation for Congenital Pulmonary Arteriovenous Fistula with Intraoperative Venovenous ECMO Support: The First Case Report in China

Pulmonary arteriovenous fistula (PAVF) is a rare pulmonary vascular lesion, more than 80% of which is caused by congenital abnormal development of pulmonary capillaries. The incidence of PAVF ranges from 2/100,000 to 3/100,000, with no difference in the male and female ratio. Congenital PAVF is often associated with hereditary hemorrhagic telangiectasia (HHT). In this article, we report a patient with only congenital PAVF that was successfully treated by bilateral lung transplantation (BLT) with intraoperative venovenous extracorporeal membrane oxygenation (ECMO) support because both lungs have been affected by PAVF and secondary pulmonary hypertension. To the best of our knowledge, this is the first report of BLT for PAVF in China and the second report that explains the clinical course of a patient to receive BLT for congenital PAVF without HHT. Some investigators have proposed lung transplantation as a definitive treatment, but the results are controversial. On the basis of the current condition of this patient, we believe lung transplantation is a viable option for certain patients, but the long-term effect remains to be studied.

Anesthetic Management During Lung Transplantation - What's New in 2021?

As outcomes of lung transplantation (LTx) are improving transplant centers are pushing boundaries. There has been a steady increase in the medical complexity of lung transplant candidates. Many transplant centers are listing older patients with comorbidities, and there has been a steady rise in the number of candidates supported with extracorporeal membrane oxygenation (ECMO) as a bridge to transplantation. There has been a growing appreciation of the importance intraoperative management of potentially modifiable risk factors has on postoperative outcomes. Evidence suggests that LTx even in high-risk patients requiring perioperative ECMO can offer excellent results. This article outlines the current state-of-the-art intraoperative management of LTx.

The Year in Extracorporeal Membrane Oxygenation: Selected Highlights From 2021

This review summarizes the extracorporeal membrane oxygenation (ECMO) or extracorporeal life support literature published in 2021. This Selected Highlights article is not intended to be an exhaustive review of the literature, but rather a summarizing of key themes that developed in the ECMO literature during 2021. The primary topics presented include the following: ECMO for coronavirus disease 2019, extracorporeal cardiopulmonary resuscitation, periprocedural cardiopulmonary support with ECMO, and anticoagulation for ECMO.

Anesthetic considerations in lung transplantation: past, present and future

Lung transplantation is a very complex surgical procedure with many implications for the anesthetic care of these patients. Comprehensive preoperative evaluation is an important component of the transplant evaluation as it informs many of the decisions made perioperatively to manage these complex patients effectively and appropriately. These decisions may involve pre-emptive actions like pre-habilitation and nutrition optimization of these patients before they arrive for their transplant procedure. Appropriate airway and ventilation management of these patients needs to be performed in a manner that provides an optimal operating conditions and protection from ventilatory injury of these fragile post-transplant lungs. Pain management can be challenging and should be managed in a multi-modal fashion with or without the use of an epidural catheter while recognizing the risk of neuraxial technique in patients who will possibly be systemically anticoagulated. Complex monitoring is required for these patients involving both invasive and non-invasive including the use of transesophageal echocardiography (TEE) and continuous cardiac output monitoring. Management of the patient's hemodynamics can be challenging and involves managing the systemic and pulmonary vascular systems. Some patients may require extra-corporeal lung support as a planned part of the procedure or as a rescue technique and centers need to be proficient in instituting and managing this sophisticated method of hemodynamic support.

Practical considerations for developing a lung transplantation anesthesiology program

The advancement in lung transplantation outcomes has been secondary to ongoing improvements within multiple medical specialties. The recent emergence of literature describing the impact of anesthetic management on perioperative outcomes has led to the beginnings of formalized training fellowships within lung transplantation anesthesiology. Practical considerations for the development of a lung transplantation anesthesiology program, both clinical and educational, are herein described.