Is Extracorporeal Membrane Oxygenation Withdrawal a Safe Option After Double-Lung Transplantation?

The role of extracorporeal membrane oxygenation in thoracic anesthesia

PURPOSE OF REVIEW

Circulatory and respiratory support with extracorporeal membrane oxygenation (ECMO) has gained widespread acceptance during high-end thoracic surgery. The purpose of this review is to summarize the recent knowledge and give an outlook for future developments.

RECENT FINDINGS

A personalized approach of ECMO use is state of the art for monitoring during surgery. Personalization is increasingly applied during anesthesia for high-end surgery nowadays. This is reflected in the point of care testing (POCT) for anticoagulation and cardiac function during surgery on ECMO combining specific patient data into tailored algorithms. For optimizing protective ventilation MP (mechanical power) is a promising parameter for the future. These personalized methods incorporating numerous patient data are promising for the improvement of morbidity and mortality in high-end thoracic surgery. However, clinical data supporting improvement are not available to date but can be awaited in the future.

SUMMARY

Clinical practice during surgery on ECMO is increasingly personalized. The effect of personalization on morbidity and mortality must be examined in the future. Undoubtedly, an increase in knowledge can be expected from this trend towards personalization.

Intraoperative extracorporeal support for lung transplant: a systematic review and network meta-analysis

BACKGROUND

In the last decades, veno-arterial extracorporeal membrane oxygenation (V-A ECMO) has been gaining in popularity for intraoperative support during lung transplant (LT), being advocated for routinely use also in uncomplicated cases. Compared to off-pump strategy and, secondarily, to traditional cardiopulmonary bypass (CPB), V-A ECMO seems to offer a better hemodynamic stability and oxygenation, while data regarding blood product transfusions, postoperative recovery, and mortality remain unclear. This systematic review and network meta-analysis aims to evaluate the comparative efficacy and safety of V-A ECMO and CPB as compared to OffPump strategy during LT.

METHODS

A comprehensive literature search was conducted across multiple databases (PubMed Embase, Cochrane, Scopus) and was updated in February 2024. A Bayesian network meta-analysis (NMA), with a fixed-effect approach, was performed to compare outcomes, such as intraoperative needing of blood products, invasive mechanical ventilation (IMV) duration, intensive care unit (ICU) length of stay (LOS), surgical duration, needing of postoperative ECMO, and mortality, across different supports (i.e., intraoperative V-A (default (d) or rescue (r)) ECMO, CPB, or OffPump).

FINDINGS

Twenty-seven observational studies (6113 patients) were included. As compared to OffPump surgery, V-A ECMOd, V-A ECMOr, and CPB recorded a higher consumption of all blood products, longer IMV durations, prolonged ICU LOS, surgical duration, and higher mortalities. Comparing different extracorporeal supports, V-A ECMOd and, secondarily, V-A ECMOr overperformed CPB in nearly all above mentioned outcomes, except for RBC transfusions. The lowest rate of postoperative ECMO was recorded after OffPump surgery, while no differences were found comparing different extracorporeal supports. Finally, older age, male gender, and body mass index ≥ 25 kg/m2 negatively impacted on RBC transfusions, ICU LOS, surgical duration, need of postoperative ECMO, and mortality, regardless of the intraoperative extracorporeal support investigated.

INTERPRETATION

This comparative network meta-analysis highlights that OffPump overperformed ECMO and CPB in all outcomes of interest, while, comparing different extracorporeal supports, V-A ECMOd and, secondarily, V-A ECMOr overperformed CPB in nearly all above mentioned outcomes, except for RBC transfusions. Older age, male gender, and higher BMI negatively affect several outcomes across different intraoperative strategies, regardless of the intraoperative extracorporeal support investigated. Future prospective studies are necessary to optimize and standardize the intraoperative management of LT.

ISHLT consensus statement on the perioperative use of ECLS in lung transplantation: Part II: Intraoperative considerations

The use of extracorporeal life support (ECLS) throughout the perioperative phase of lung transplantation requires nuanced planning and execution by an integrated team of multidisciplinary experts. To date, no multidisciplinary consensus document has examined the perioperative considerations of how to best manage these patients. To address this challenge, this perioperative utilization of ECLS in lung transplantation consensus statement was approved for development by the International Society for Heart and Lung Transplantation Standards and Guidelines Committee. International experts across multiple disciplines, including cardiothoracic surgery, anesthesiology, critical care, pediatric pulmonology, adult pulmonology, pharmacy, psychology, physical therapy, nursing, and perfusion, were selected based on expertise and divided into subgroups examining the preoperative, intraoperative, and postoperative periods. Following a comprehensive literature review, each subgroup developed recommendations to examine via a structured Delphi methodology. Following 2 rounds of Delphi consensus, a total of 39 recommendations regarding intraoperative considerations for ECLS in lung transplantation met consensus criteria. These recommendations focus on the planning, implementation, management, and monitoring of ECLS throughout the entire intraoperative period.

Protocol for venoarterial ExtraCorporeal Membrane Oxygenation to reduce morbidity and mortality following bilateral lung TransPlantation: the ECMOToP randomised controlled trial

INTRODUCTION

Lung transplantation (LTx) aims at improving survival and quality of life for patients with end-stage lung diseases. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is used as intraoperative support for LTx, despite no precise guidelines for its initiation. We aim to evaluate two strategies of VA-ECMO initiation in the perioperative period in patients with obstructive or restrictive lung disease requiring bilateral LTx. In the control 'on-demand' arm, high haemodynamic and respiratory needs will dictate VA-ECMO initiation; in the experimental 'systematic' arm, VA-ECMO will be pre-emptively initiated. We hypothesise a 'systematic' strategy will increase the number of ventilatory-free days at day 28.

METHODS AND ANALYSIS

We designed a multicentre randomised controlled trial in parallel groups. Adult patients with obstructive or restrictive lung disease requiring bilateral LTx, without a formal indication for pre-emptive VA-ECMO before LTx, will be included. Patients with preoperative pulmonary hypertension with haemodynamic collapse, ECMO as a bridge to transplantation, severe hypoxaemia or hypercarbia will be secondarily excluded. In the systematic group, VA-ECMO will be systematically implanted before the first pulmonary artery cross-clamp. In the on-demand group, VA-ECMO will be implanted intraoperatively if haemodynamic or respiratory indices meet preplanned criteria. Non-inclusion, secondary exclusion and VA-ECMO initiation criteria were validated by a Delphi process among investigators. Postoperative weaning of ECMO and mechanical ventilation will be managed according to best practice guidelines. The number of ventilator-free days at 28 days (primary endpoint) will be compared between the two groups in the intention-to-treat population. Secondary endpoints encompass organ failure occurrence, day 28, day 90 and year 1 vital status, and adverse events.

ETHICS AND DISSEMINATION

The sponsor is the Assistance Publique-Hôpitaux de Paris. The ECMOToP protocol version 2.1 was approved by Comité de Protection des Personnes Ile de France VIII. Results will be published in international peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

NCT05664204.

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.

Current and future role of double-lung transplantation for bilateral lung cancer

Technological advances have progressively enhanced the survival rate of lung transplant recipients and expanded its indications for various diseases, including the recent coronavirus disease 2019 (COVID-19). However, according to the International Society for Heart and Lung Transplantation, lung cancer constituted a mere 0.1% of the indications for lung transplantation over the past two decades. This statistic has remained stagnant, and numerous lung cancer patients continue to be excluded from lung transplantation candidacy. Contrary to the general exclusion of lung cancer patients from transplantation, the post-transplant survival rate for these patients is not inferior to that of patients with non-cancerous diseases. Furthermore, lung transplantation may offer curative treatment for patients with bilateral lung cancer whose respiratory insufficiency has advanced independently of cancer progression. This review aims to elucidate and examine the role of double lung transplantation (DLT) in bilateral lung cancer. We summarize the established indications for lung transplantation, appropriate histologic or molecular subtypes of lung cancer for transplantation, technical advances to minimize recurrence, post-DLT survival outcomes for lung cancer patients, and related translational research. We suggest that although DLT for bilateral lung cancer presents challenges, it may be considered a potential treatment option in select circumstances.

Results of Lung Transplantation for Cystic Fibrosis With Selected Donors Over 65 Years Old

Lung transplantation is limited by the shortage of suitable donors. Many programs have begun to use extended criteria donors. Donors over 65 years old are rarely reported, especially for young cystic fibrosis recipients. This monocentric study was conducted for cystic fibrosis recipients from January 2005 to December 2019, comparing two cohorts according to lung donor age (<65 years or ≥65 years). The primary objective was to assess the survival rate at 3 years using a Cox multivariable model. Of the 356 lung recipients, 326 had donors under 65 years, and 30 had donors over 65 years. Donors' characteristics did not differ significantly in terms of sex, time on mechanical ventilation before retrieval, and partial pressure of arterial oxygen/fraction of inspired oxygen ratio. There were no significant differences in post-operative mechanical ventilation duration and incidence of grade 3 primary graft dysfunction between the two groups. At 1, 3, and 5 years, the percentage of predicted forced expiratory volume in 1 s (p = 0.767) and survival rate did not differ between groups (p = 0.924). The use of lungs from donors over 65 years for cystic fibrosis recipients allows extension of the donor pool without compromising results. Longer follow-up is needed to assess the long-term effects of this practice.

Perioperative Outcomes During Double-Lung Transplantation and Retransplantation in Cystic Fibrosis Patients: A Monocentric Cohort Study

OBJECTIVE

Life expectancy for lung-transplant patients, especially those with cystic fibrosis (CF), is leading increasingly to more retransplantations.

DESIGN

Retrospective monocentric cohort study.

SETTING

Foch University Hospital, Suresnes, France.

PARTICIPANTS

CF patients having had a primary double-lung transplantation (pLgTx) or a retransplantation (reLgTx) from 2012 to 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The authors compared the main intraoperative and early postoperative features between pLgTx (n = 258) and reLgTx (n = 24). Demographic characteristics were similar. No patients with retransplantations had a preoperative bridge with extracorporeal membrane oxygenation (ECMO); however, 23 patients had it in the pLgTx group (p = 0.24). Patients with retransplants had longer second graft ischemic time (p = 0.02), larger intraoperative bleeding volume (p = 0.001) and blood transfusion (p = 0.009 for packed red blood cells), increased blood lactate concentrations (p = 0.002), and higher norepinephrine dose at end-surgery (p = 0.001). Extracorporeal membrane oxygenation was used during surgery in 94 patients in the pLgTx group and 12 patients in the reLgTx group (p = 0.39). Extracorporeal membrane oxygenation could not be weaned after surgery in 55 patients in the pLgTx group and 4 in the reLgTx group (p = 0.54). Despite worse preoperative renal function in the reLgTx group (p < 0.001), there was no difference concerning renal replacement therapy in the intensive care unit between groups (p = 0.08). There were no differences between groups concerning the main complications, including primary graft dysfunction. Although the difference was not statistically different (p = 0.17), mortality was 3 times higher in the reLgTx group.

CONCLUSIONS

Intraoperative period of retransplantation was more convoluted but had a similar ECMO profile to primary transplantation. In addition, the early postoperative period was similar.

New Aspects of Lung Transplantation: A Narrative Overview Covering Important Aspects of Perioperative Management

The management of lung transplant patients has continued to evolve in recent years. The year 2021 was marked by the publication of the International Consensus Recommendations for Anesthetic and Intensive Care Management of Lung Transplantation. There have been major changes in lung transplant programs over the last few years. This review will summarize the knowledge in anesthesia management of lung transplantation with the most recent data. It will highlight the following aspects which concern anesthesiologists more specifically: (1) impact of COVID-19, (2) future of transplantation for cystic fibrosis patients, (3) hemostasis management, (4) extracorporeal membrane oxygenation management, (5) early prediction of primary graft dysfunction, and (6) pain management.

Evaluation of Tissue Ischemia/Reperfusion Injury in Lung Recipients Supported by Intraoperative Extracorporeal Membrane Oxygenation: A Single-Center Pilot Study

Intraoperative veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) as intraoperative hemodynamic support during lung transplantation is becoming a standard practice due to promising clinical results. Nevertheless, studies on tissue/molecular pathways investigating ischemia/reperfusion injury are still lacking. Patients receiving a bilateral lung transplantation between January 2012 and December 2018 at the University Hospital of Padova were included in this retrospective single-center observational study. The present study aimed to investigate ischemia/reperfusion injury in 51 tissue specimens obtained from 13 recipients supported by intraoperative VA-ECMO and 38 who were not. Several tissue analyses, including apoptosis evaluation and inducible nitric oxide synthase expression, were performed on the biopsies at the time of transplantation. Lung samples from the ECMO group (both pre- and post-reperfusion) were comparable, or for some parameters better, than samples from the non-ECMO group. Leukocyte margination was significantly lower in the ECMO group than in the non-ECMO group. Primary graft dysfunction, mainly at 24 and 48 h, was correlated with the tissue injury score of the post-reperfusion biopsy. The interquartile ranges for all morphological parameters showed high grade variability between pre- and post-reperfusion in the non-ECMO group. These preliminary data support the use of intraoperative ECMO based on lower lung tissue ischemia/reperfusion injury. Larger case series are mandatory to confirm our findings.

Blood Lactate During Double-Lung Transplantation: A Predictor of Grade-3 Primary Graft Dysfunction

OBJECTIVE

Many prognostic factors of grade-3 primary graft dysfunction at postoperative day 3 (PGD3-T72) have been reported, but intraoperative blood lactate level has not been studied. The present retrospective study was done to test the hypothesis that intraoperative blood lactate level (BLL) could be a predictor of PGD3-T72 after double-lung transplantation.

DESIGN

Retrospective monocentric cohort study.

SETTING

Foch University Hospital, Suresnes, France.

PARTICIPANTS

Patients having received a double-lung transplantation between 2012 and 2019. Patients transplanted twice during the study period, having undergone a multiorgan transplantation, or cardiopulmonary bypass, and those under preoperative extracorporeal membrane oxygenation, were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Analysis was performed on a cohort of 449 patients. Seventy-two (16%) patients had a PGD3-T72. Blood lactate level increased throughout surgery to reach a median value of 2.2 (1.6-3.2) mmol/L in the No-PGD3-T72 group and 3.4 (2.3-5.0) mmol/L in the PGD3-T72 group after second lung implantation. The best predictive model for PGD3-T72 was obtained adding a lactate threshold of 2.6 mmol/L at the end of surgery to the clinical model, and the area under the curve was 0.867, with a sensitivity = 76.9% and specificity = 85.4%. Repeated-measures mixed model of BLL during surgery remained significant after adjustment for covariates (F ratio= 4.22, p < 0.001 for interaction).

CONCLUSIONS

Blood lactate level increases during surgery and reaches a maximum after the second lung implantation. A value below the threshold of 2.6 mmol/L at the end of surgery has a high negative predictive value for the occurrence of a grade-3 primary graft dysfunction at postoperative day 3.

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.

Procedural mechanical support for lung transplantation

PURPOSE OF REVIEW

The use of procedural mechanical support during lung transplantation (LTx) varies between centers and the optimal support strategy is still controversially discussed. The two main questions are if cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO) should be preferred and whether mechanical support should be reserved for specific patient groups or a routine use can be recommended.

RECENT FINDINGS

Recent cohort studies have consistently shown that LTx on CPB leads to inferior outcomes when compared to venoarterial (va)-ECMO. Thus, ECMO should be preferred in lung transplantation except for special indications. Despite its higher invasiveness, ECMO offers some pivotal advantages over off-pump lung transplantation. It has been shown to remarkably reduce rates of primary graft dysfunction, supporting the concept of a routine intraoperative ECMO use in LTx.

SUMMARY

Although randomized-controlled trials addressing this question are still lacking, current evidence appears to favor the routine use of ECMO support during lung transplantation.

Comparison of mechanical cardiopulmonary support strategies during lung transplantation

INTRODUCTION

Lung transplantation outcomes are influenced by the intraoperative mechanical cardiopulmonary support strategy used. This surgery was historically done either on cardiopulmonary bypass (CPB) or off pump. Recently, there has been increased interest in intraoperative support with veno-arterial (VA) or veno-venous (VV) extracorporeal membrane oxygenation (ECMO). However, there is a lack of consensus on the relative risks, benefits and indications for each intraoperative support strategy.

AREAS COVERED

This review includes information from cohort studies, case-control studies, and case series that compare morbidity and/or mortality of two or more intraoperative cardiopulmonary support strategies during lung transplantation.

EXPERT OPINION

The optimal strategy for intraoperative cardiopulmonary support during lung transplantation remains an area of debate. Current data suggest that off pump is associated with better outcomes and could be considered whenever feasible. ECMO is generally associated with preferable outcomes to CPB, but the data supporting this association is not robust. Interestingly, whether CPB is unplanned or prolonged might influence outcomes more than the use of CPB itself. These observations can help guide surgical teams in their approach for intraoperative mechanical support strategy during lung transplantation and should serve as the basis for further investigations.

Intraoperative Implications of the Recipients' Disease for Double-Lung Transplantation

OBJECTIVES

To compare intraoperative patterns among patients based on their primary pulmonary disease (cystic fibrosis [CF], chronic obstructive pulmonary disease [COPD]/emphysema [CE], and pulmonary fibrosis [PF]) during double- lung transplantation. The following 3 major outcomes were reported: blood transfusion, extracorporeal membrane oxygenation (ECMO) management, and the possibility of immediate extubation at the end of surgery.

DESIGN

Retrospective analysis of a prospectively maintained database, including donor and recipient characteristics and intraoperative variables.

SETTING

Foch Hospital, Suresnes, France (academic center performing 60-80 lung transplantations per year).

PARTICIPANTS

Patients who underwent double- lung transplantation from 2012-2019. Patients with retransplantation, multiorgan transplantation, or surgery performed with cardiopulmonary bypass were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two hundred forty-six patients had CF, 117 had CE, and 66 had PF. No patient had primary pulmonary arterial hypertension. Blood transfusion was higher in the CF group than in the other 2 groups (red blood cells [p < 0.001], fresh frozen plasma [p = 0.004]). The CF and CE groups were characterized by a lower intraoperative requirement of ECMO (p = 0.002), and the PF group more frequently required postoperative ECMO (p < 0.001). CF and CE patients were more frequently extubated in the operating room than were PF patients (37.4%, 50.4%, and 13.6%, respectively; p < 0.001).

CONCLUSIONS

Intraoperative outcomes differed depending on the initial pathology. Such differences should be taken into account in specific clinical studies and in intraoperative management protocols.