Extracorporeal Circulation During Lung Transplantation Procedures: A Meta-Analysis

Extracorporeal membrane oxygenation vs cardiopulmonary bypass in lung transplantation: an updated meta-analysis

AIM

This meta-analysis aimed to compare the outcomes of extracorporeal membrane oxygenation (ECMO) and cardiopulmonary bypass (CPB) in lung transplantation.

METHODS

We searched PubMed, Embase, and Cochrane databases for studies comparing ECMO to CPB in lung transplantation. Odds ratios (ORs) for binary endpoints and mean differences (MDs) for continuous outcomes were calculated with 95% confidence intervals (CIs). DerSimonian and Laird random-effects model was applied for all endpoints. I2 statistics was used to assess heterogeneity.

RESULTS

Fourteen studies with a total of 1797 patients were included. ECMO was associated with significant reductions in hepatic dysfunction (OR 0.47, 95% CI 0.25-0.90), hemodialysis (OR 0.62, 95% CI 0.43-0.88), severe graft rejection (OR 0.43, 95% CI 0.23-0.78), one-year mortality (OR 0.70; 95% CI 0.51 to 0.98; p = 0.04; I2 = 13%) and tracheostomy rates (OR 0.62, 95% CI 0.46-0.86). Additionally, ECMO reduced the length of hospital stay (MD - 5.69 days, 95% CI - 9.31 to - 2.08) and ICU stay (MD - 6.02 days, 95% CI - 8.32 to - 3.71). However, ECMO was associated with longer total ischemic time (MD 61.07 min, 95% CI 3.51 to 118.62). No significant differences were observed for stroke, thromboembolic events, atrial fibrillation, or 30-day and 3-year mortality.

CONCLUSIONS

ECMO offers perioperative advantages in lung transplantation, reducing postoperative complications, one-year mortality, and recovery time compared to CPB. However, the longer total ischemic time with ECMO warrants further investigation into its long-term outcomes.

TRIAL REGISTRY

International Prospective Register of Systematic Reviews; N°: CRD42024604049; URL: https://www.crd.york.ac.uk/prospero/ .

Right ventricle free wall longitudinal strain screening of lung transplant candidates

BACKGROUND

Lung transplant (LUTX) candidates have subclinical right ventricular (RV) dysfunction, which has not yet been assessed by speckle-tracking echocardiography (STE)-derived RV free-wall longitudinal strain (RVFWLS). To evaluate the prevalence of RV dysfunction by RVFWLS and its relationship with conventional RV echocardiographic indexes in LUTX candidates.

METHODS

In a single-center prospective observational cohort study, from January 2021 to March 2023 consecutive LUTX candidates underwent cardiac catheterization, radionuclide ventriculography, standard and STE. The diagnostic accuracy of RV ejection fraction by ventriculography (RVEF), tricuspid annular plane excursion (TAPSE), fractional area change (FAC), tricuspid peak annulus systolic velocity (S') versus RVFWS were computed.

RESULTS

Thirty-four patients (female, 41%) with a mean age of 48 [36-59] years old enlisted for pulmonary fibrosis (35%) and cystic fibrosis (30%) were included. At cardiac catheterization, only 7 (23%) had pulmonary hypertension. Around 15-25% presented right heart enlargement. Tricuspid regurgitation was present in 20 (60%) of the patients. Median RVFWLS was -20.1% [-22.5%--17%], being impaired (> -20%) in 16 (47%) of the patients. RVFWLS identified the highest percentage (47%) of RV dysfunction, compared to TAPSE (32%), S' (27%), FAC (26%), and ventriculography (15%), which had very low sensitivity for detecting RV dysfunction compared to RVFWLS.

CONCLUSIONS

In patients enlisted for LUTX, RV dysfunction assessed by STE-derived RVFWLS is highly prevalent. STE can detect RV dysfunction better than standard two-dimensional echocardiography and ventriculography. Further studies are urgently needed to define the clinical implications and the prognostic value of RV dysfunction measured with RVFWLS.

[Long-COVID, severe course, with congenital bronchiectasis, Williams-Campbell syndrome. Case report]

We present a clinical observation of an 18-year-old female patient with congenital bronchiectasis combined with congenital cystic degeneration of the upper lobes of both lungs, Williams-Campbell syndrome, long-COVID, severe course. The patient was treated in infectious disease department (three times), with subsequent transfer to pulmonology department of Kursk Regional Multi-Purpose Clinical Hospital from 31.01.2023 to 02.05.2023. The patient was going to have lung transplantation, registered in Shumakov Federal Research Center of Transplantology and Artificial Organs earlier. The patient was transported by air ambulance escorted by the resuscitation team to the Shumakov Federal Research Center of Transplantology and Artificial Organs on 02.05.2023 with negative PCR COVID-19 test. The literature data on the frequency of association of these diseases, clinical features, criteria for diagnosis and treatment, indications for lung transplantation are presented.

Current status of routine use of veno-arterial extracorporeal membrane oxygenation during lung transplantation

INTRODUCTION

Recently, there has been growing experience with utilizing a veno-arterial extracorporeal membrane oxygenator (VA ECMO) routinely during lung transplantation procedures. Yet, there is a lack of consensus on the protocols, benefits, and outcomes of routine VA ECMO use in lung transplantation.

AREAS COVERED

This article presents an overview of the current status of routine use of VA ECMO during lung transplantation, including rationale, protocols, applications, and outcomes.

EXPERT OPINION

Utilization of VA ECMO during lung transplantation has emerged as an alternative mechanical circulatory support modality to cardiopulmonary bypass, with growing evidence showing lower rates of peri-operative complications. Some groups took that further into routine application of VA ECMO during lung transplantation. The current available evidence suggests that routine utilization of VA ECMO during lung transplantation is associated with lower rates of primary graft dysfunction and improved early outcomes. Use of VA ECMO allows controlled reperfusion of the allograft and avoids an unplanned "crash" on pump in case of hemodynamic instability, which carries worse outcomes after lung transplantation. As a relatively new approach, further follow-up of growing experience, as well as prospective clinical trials, is necessary to develop a consensus about routine utilization of VA ECMO during lung transplantation.

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.

Pushing the Survival Bar Higher: Two Decades of Innovation in Lung Transplantation

Survival after lung transplantation has significantly improved during the last two decades. The refinement of the already existing extracorporeal life support (ECLS) systems, such as extracorporeal membrane oxygenation (ECMO), and the introduction of new techniques for donor lung optimization, such as ex vivo lung perfusion (EVLP), have allowed the extension of transplant indication to patients with end-stage lung failure after acute respiratory distress syndrome (ARDS) and the expansion of the donor organ pool, due to the better evaluation and optimization of extended-criteria donor (ECD) lungs and of donors after circulatory death (DCD). The close monitoring of anti-HLA donor-specific antibodies (DSAs) has allowed the early recognition of pulmonary antibody-mediated rejection (AMR), which requires a completely different treatment and has a worse prognosis than acute cellular rejection (ACR). As such, the standardization of patient selection and post-transplant management has significantly contributed to this positive trend, especially at high-volume centers. This review focuses on lung transplantation after ARDS, on the role of EVLP in lung donor expansion, on ECMO as a principal cardiopulmonary support system in lung transplantation, and on the diagnosis and therapy of pulmonary AMR.

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.

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.

Effects of Intraoperative Support Strategies on Endothelial Injury and Clinical Lung Transplant Outcomes

In lung transplantation, postoperative outcomes favor intraoperative use of extracorporeal membrane oxygenation (ECMO) over cardiopulmonary bypass (CBP). We investigated the effect of intraoperative support strategies on endothelial injury biomarkers and short-term posttransplant outcomes. Adults undergoing bilateral lung transplantation with No-Support, venoarterial (V-A) ECMO, or CPB were included. Plasma samples pre- and post-transplant were collected for Luminex assay to measure endothelial injury biomarkers including syndecan-1 (SYN-1), intercellular adhesion molecule-1 (ICAM-1), and matrix metalloprotease-9. Fifty five patients were included for analysis. The plasma level of SYN-1 at arrival in the intensive care unit was significantly higher with CPB compared to V-A ECMO and No-Support (P < 0.01). The rate of primary graft dysfunction grade 3 (PGD3) at 72 hours was 60.0% in CPB, 40.1% in V-A ECMO, and 15% in No-Support (P = 0.01). Postoperative plasma levels of SYN-1 and ICAM-1 were significantly higher in recipients who developed PGD3 at 72 hours. SYN-1 levels were also significantly higher in patients who developed acute kidney injury and hepatic dysfunction after transplant. Postoperative, SYN-1 upon intensive care arrival was found to be a significant predictive biomarker of PGD3, acute kidney injury, and hepatic dysfunction following lung transplantation. CPB is associated with higher plasma concentrations of SYN-1, a marker of endothelial glycocalyx degradation, upon arrival to the intensive care unit. Higher levels of SYN-1 are predictive of end-organ dysfunction following lung transplantation. Our data suggests that intraoperative strategies aimed at modulating endothelial injury will help improve lung transplantation outcomes.

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.

Textbook outcome in lung transplantation: Planned venoarterial extracorporeal membrane oxygenation versus off-pump support for patients without pulmonary hypertension

BACKGROUND

Planned venoarterial extracorporeal membrane oxygenation (VA ECMO) is increasingly used during bilateral orthotopic lung transplantation (BOLT) and may be superior to off-pump support for patients without pulmonary hypertension. In this single-institution study, we compared rates of textbook outcome between BOLTs performed with planned VA ECMO or off-pump support for recipients with no or mild pulmonary hypertension.

METHODS

Patients with no or mild pulmonary hypertension who underwent isolated BOLT between 1/2017 and 2/2021 with planned off-pump or VA ECMO support were included. Textbook outcome was defined as freedom from intraoperative complication, 30-day reintervention, 30-day readmission, post-transplant length of stay >30 days, 90-day mortality, 30-day acute rejection, grade 3 primary graft dysfunction at 48 or 72 hours, post-transplant ECMO, tracheostomy within 7 days, inpatient dialysis, reintubation, and extubation >48 hours post-transplant. Textbook outcome achievement was compared between groups using multivariable logistic regression.

RESULTS

Two hundred thirty-seven BOLTs were included: 68 planned VA ECMO and 169 planned off-pump. 14 (20.6%) planned VA ECMO and 27 (16.0%) planned off-pump patients achieved textbook outcome. After adjustment for prior BOLT, lung allocation score, ischemic time, and intraoperative transfusions, planned VA ECMO was associated with higher odds of textbook outcome than planned off-pump support (odds ratio 3.89, 95% confidence interval 1.58-9.90, p = 0.004).

CONCLUSIONS

At our institution, planned VA ECMO for isolated BOLT was associated with higher odds of textbook outcome than planned off-pump support among patients without pulmonary hypertension. Further investigation in a multi-institutional cohort is warranted to better elucidate the utility of this strategy.

Intraoperative Circulatory Support in Lung Transplantation: Current Trend and Its Evidence

Lung transplantation has a high risk of haemodynamic complications in a highly vulnerable patient population. The effects on the cardiovascular system of the various underlying end-stage lung diseases also contribute to this risk. Following a literature review and based on our own experience, this review article summarises the current trends and their evidence for intraoperative circulatory support in lung transplantation. Identifiable and partly modifiable risk factors are mentioned and corresponding strategies for treatment are discussed. The approach of first identifying risk factors and then developing an adjusted strategy is presented as the ERSAS (early risk stratification and strategy) concept. Typical haemodynamic complications discussed here include right ventricular failure, diastolic dysfunction caused by left ventricular deconditioning, and reperfusion injury to the transplanted lung. Pre- and intra-operatively detectable risk factors for the occurrence of haemodynamic complications are rare, and the therapeutic strategies applied differ considerably between centres. However, all the mentioned risk factors and treatment strategies can be integrated into clinical treatment algorithms and can influence patient outcome in terms of both mortality and morbidity.

A systematic review on quality of life (QoL) of patients with peritoneal metastasis (PM) who underwent pressurized intraperitoneal aerosol chemotherapy (PIPAC)

Background

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) has recently emerged as a palliative alternative for patients with unresectable peritoneal metastasis (PM). Quality of life (QoL) has increasingly been used as an endpoint to evaluate treatment outcomes. This review aims to identify evidence on how PIPAC would impact the QoL of PM patients.

Content

A systematic review was performed on articles identified from Medline, EMBASE, PsycInfo, and Web of Sciences. A meta-analysis was conducted on further selected studies. ACROBAT-NRSI was attempted to assess the risk of bias (RoB).

Summary

Nine studies using the EORTC QLQ-C30 questionnaire to assess QoL after repeated PIPAC cycles were identified. Majority was found to be moderately biased and a great extent of heterogeneity was observed. Four studies on PM from either gastric cancer (GC) or epithelial ovarian cancer (EOC) were included for meta-analysis. In 31 GC patients and 104 EOC patients, QoL remained stable in 13/14 and 11/14 EORTC QLQ-C30 scales. PIPAC was inferior to cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) in global QoL and functioning but superior in symptom reduction.

Outlook

PIPAC is a well-tolerated option for most GC and EOC patients with irresectable PM. Future trials are warranted to confirm the findings.

Intraoperative support during lung transplantation

The role of intraoperative mechanical support during lung transplantation (LTx) is essential to provide a safe hemodynamic and ventilatory status during critical intraoperative events. This hemodynamic and ventilatory stability is vital to minimize the odds of suboptimal outcomes, especially considering that, due to the scarcity of donors and the fact that more and more patients with significant comorbidities are being considered for this therapy, a more aggressive approach is often needed by the transplant centers. Hence, the attenuation of any potential injury that can happen during this complex event is paramount. While a thorough assessment of the donor and optimization of postoperative care is pursued, certainly protective intraoperative management would also contribute to better outcomes. Understanding each patient’s underlying anatomy and cardiopulmonary physiology, associated with awareness of critical events during a complicated procedure like LTx, is essential for a precise indication and safe use of support. Cardiopulmonary bypass (CPB) and veno-arterial extracorporeal membrane oxygenation (VA ECMO) have been the most common approaches used, with the latter gaining popularity more recently and we have used VA ECMO exclusively for the last decade. New technologies certainly contributed to more liberal use of VA ECMO intraoperatively, enabling a protecting and physiologic environment for the newly implanted grafts. In this setting, potential prophylactic use for lung protection during a critical period is also considered.

Intraoperative Diagnosis of Bronchovenous Fistula During Lung Transplantation Using Transesophageal Echocardiography

Bronchovenous fistula (BVF) is a rare complication and can cause arterial gas embolism in vital organs, including the heart and the brain, resulting in a high mortality rate. A 51-year-old man developed a BVF during pneumonectomy for lung transplantation, which quickly was diagnosed by transesophageal echocardiography (TEE). He required highairway-pressure ventilation due to his severely restrictive ventilatory impairment and had severe left pleural adhesion due to a history of pleurodesis. Intraoperatively, he had a coronary air embolism and required temporary treatment with central venoarterial extracorporeal membrane oxygenation (VA-ECMO), but showed no postoperative cardiac or neurologic complications. BVF may be formed during lung transplantation because lung transplantation recipients often receive high-airway-pressure ventilation and are vulnerable to bronchi and pulmonary vessel injuries during surgery. Intraoperative TEE can contribute to the early detection of air bubbles in the left heart circulation and is helpful for the prevention of arterial gas embolism.

Pulmonary arterial hypertension in adults with congenital heart disease: markers of disease severity, management of advanced heart failure and transplantation

INTRODUCTION

Pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) is a progressive, life-limiting disease.

AREAS COVERED

In this paper, we review the classification and pathophysiology of PAH-CHD, including the mechanisms of disease progression and multisystem effects of disease. We evaluate current strategies of risk stratification and the use of biological markers of disease severity, and review principles of management of PAH-CHD. The indications, timing, and the content of advanced heart failure assessment and transplant listing are discussed, along with a review of the types of transplant and other forms of available circulatory support in this group of patients. Finally, the integral role of advance care planning and palliative care is discussed.

EXPERT OPINION/COMMENTARY

All patients with PAH-CHD should be followed up in expert centers, where they can receive appropriate risk assessment, PAH therapy, and supportive care. Referral for transplant assessment should be considered if there continue to be clinical high-risk features, persistent symptoms, or acute heart failure decompensation despite appropriate PAH specific therapy. Expert management of PAH-CHD patients, therefore, requires vigilance for these features, along with a close relationship with local advanced heart failure services and a working knowledge of listing criteria, which may disadvantage congenital heart disease patients.

Lung transplantation for acute exacerbation of interstitial lung disease

BACKGROUND

Acute exacerbations of interstitial lung diseases (AE-ILD) have a high mortality rate with no effective medical therapies. Lung transplantation is a potentially life-saving option for patients with AE-ILD, but its role is not well established. The aim of this study is to determine if this therapy during AE-ILD significantly affects post-transplant outcomes in comparison to those transplanted with stable disease.

METHODS

We conducted a retrospective study of consecutive patients with AE-ILD admitted to our institution from 2015 to 2018. The comparison group included patients with stable ILD listed for lung transplant during the same period. The primary end-points were in-hospital mortality for patients admitted with AE-ILD and 1-year survival for the transplanted patients.

RESULTS

Of 53 patients admitted for AE-ILD, 28 were treated with medical therapy alone and 25 underwent transplantation. All patients with AE-ILD who underwent transplantation survived to hospital discharge, whereas only 43% of the AE-ILD medically treated did. During the same period, 67 patients with stable ILD underwent transplantation. Survival at 1 year for the transplanted patients was not different for the AE-ILD group versus stable ILD group (96% vs 92.5%). The rates of primary graft dysfunction, post-transplant hospital length-of-stay and acute cellular rejection were similar between the groups.

CONCLUSION

Patients with ILD transplanted during AE-ILD had no meaningful difference in overall survival, rate of primary graft dysfunction or acute rejection compared with those transplanted with stable disease. Our results suggest that lung transplantation can be considered as a therapeutic option for selected patients with AE-ILD.

Preclosing of the femoral artery allows total percutaneous venoarterial extracorporeal membrane oxygenation and prevents groin wound infection after lung transplantation

OBJECTIVES

In lung transplantation (LT), femoral venoarterial extracorporeal membrane oxygenation (VA-ECMO) usually requires an open approach that may be associated with severe groin wound infection. In endovascular aortic procedures, preclosing of the femoral artery (PFA) with vascular closure devices allows the percutaneous insertion and withdrawal of large-bore cannulae. We sought to evaluate whether this innovative technique could be applied in the specific setting of LT to achieve total percutaneous VA-ECMO and decrease groin wound infection.

METHODS

We conducted a retrospective study of a prospective database including patients who underwent LT in our centre from January 2011 to December 2017. Patients who underwent peripheral VA-ECMO using the PFA technique after January 2014 (PFA group, n = 106) were compared to those who underwent peripheral VA-ECMO using open cannulation and/or decannulation before January 2014 (non-PFA group, n = 48). The primary end point was the rate of technical success defined as total percutaneous VA-ECMO. Secondary end points included groin wound infections and delayed vascular complications.

RESULTS

The PFA technique was technically successful in 98 patients (92.5%). As compared with the non-PFA group, the PFA group was characterized by a similar rate of vascular complications (16.6% vs 11.3%, P = 0.360) and a decreased rate of groin wound infection (18.9% vs 0%, P < 0.001). In multivariate analysis, risk factors associated with vascular complications following PFA included female sex, peripheral arterial disease and ECMO duration.

CONCLUSIONS

In LT patients, PFA is associated with a high rate of total percutaneous VA-ECMO, thus preventing the occurrence of groin wound infection.

Ischemia-Reperfusion Injury in Lung Transplantation

Lung transplantation has been established worldwide as the last treatment for end-stage respiratory failure. However, ischemia–reperfusion injury (IRI) inevitably occurs after lung transplantation. The most severe form of IRI leads to primary graft failure, which is an important cause of morbidity and mortality after lung transplantation. IRI may also induce rejection, which is the main cause of mortality in recipients. Despite advances in donor management and graft preservation, most donor grafts are still unsuitable for transplantation. Although the pulmonary endothelium is the primary target site of IRI, the pathophysiology of lung IRI remains incompletely understood. It is essential to understand the mechanism of pulmonary IRI to improve the outcomes of lung transplantation. Therefore, we reviewed the state-of-the-art in the management of pulmonary IRI after lung transplantation. Recently, the ex vivo lung perfusion (EVLP) system has been clinically introduced worldwide. Various promising therapeutic strategies for the protection of the endothelium against IRI, including EVLP, inhalation therapy with therapeutic gases and substances, fibrinolytic treatment, and mesenchymal stromal cell therapy, are awaiting clinical application. We herein review the latest advances in the field of pulmonary IRI in lung transplantation.

Extracorporeal life support during lung transplantation

Lung transplantation surgeries are performed without extracorporeal life support (ECLS) by using an off-pump technique; however, in cases of hypoxemia or hemodynamic instability, intraoperative ECLS may be required. Cardiopulmonary bypass (CPB) has traditionally been the standard practice for ECLS but has been associated with an increased risk of bleeding in the perioperative period, increased transfusion requirements, prolonged postoperative intubation, and possibly primary graft dysfunction. More recently, because of the flexibility of using extracorporeal membrane oxygenation (ECMO) in bridging to transplantation and during postoperative recovery, its use has increased. CPB and ECMO each has advantages and disadvantages; however, because comparisons of CPB and ECMO have been limited to small retrospective observational and single-institution studies, more research is required to determine the superiority of one modality. In this review, we critically examine the pros and cons of performing lung transplantation surgery off-pump or by using the ECLS modalities of ECMO and CPB support during lung transplantation surgery.

Perioperative circulatory support for lung transplantation

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) has recently replaced cardiopulmonary bypass (CPB) as the preferred option for providing circulatory support during lung transplantation. This review aimed to summarize the previous data and to address the relative use of ECMO and CPB during lung transplantation.

METHODS

The database was searched in PubMed (Medline) using the following keywords: lung transplantation, extracorporeal membrane oxygenation, and cardiopulmonary bypass, for all relevant reports which were written in English and were published between 2000 and 2020.

REVIEW

Several reports have revealed that intraoperative use of ECMO is associated with lower blood product transfusion requirements, shorter ventilator support, and shorter length of hospital stay. During recent years, preoperative ECMO has also been used with favorable outcomes as a bridge to lung transplantation in critically ill patients.

CONCLUSIONS

The use of ECMO during lung transplantation seems to reduce postoperative complications and improve short-term outcomes, relative to CPB. However, additional data should be collected through large multicenter randomized controlled trials. Furthermore, preoperative ECMO as a bridge to lung transplantation appears to provide favorable outcomes, although additional data are also needed from experienced transplant centers.

Extracorporeal membrane oxygenation and lung transplantation

The use of extracorporeal membrane oxygenation has had a positive impact on the outcomes after lung transplantation. Extracorporeal membrane oxygenation has a role in all phases of lung transplantation-preoperative, intraoperative, and postoperative periods. It serves as a bridge to transplantation in appropriate patients awaiting lung transplantation. Extracorporeal membrane oxygenation is used as a preferred method of cardiopulmonary support in some centres during implantation; and, after lung transplantation, it can be used to salvage the implanted lung in cases of severe primary graft dysfunction or as a planned extension of intraoperative extracorporeal membrane oxygenation onto the postoperative period. It has now gained acceptance as a mandatory tool in most lung transplant units. This article reviews the history of extracorporeal membrane oxygenation and lung transplantation, their subsequent development, and the current use of extracorporeal membrane oxygenation during lung transplantation. Our institutional practice and experience are described. The implications of the current global coronavirus disease pandemic on extracorporeal membrane oxygenation and lung transplantation are also briefly discussed.

Lung Transplantation Using a Hybrid Extracorporeal Membrane Oxygenation Circuit

Extracorporeal circulation (ECC) support using intraoperative extracorporeal membrane oxygenation (ECMO) during lung transplantation (LTx) is now a routine practice for many high volume centers. Circuits that are dedicated to ECMO alone can be expensive and do not allow full cardiopulmonary bypass (CPB) to be performed. We describe our technique of instituting venoarterial ECMO during LTx using a less-expensive hybrid circuit that facilitates easy and immediate conversion to full CPB if needed, without interruption of ECC.

Right Ventricle Dysfunction in Patients With Adult Cystic Fibrosis Enlisted for Lung Transplant

Knowledge of preoperative right heart function of adult patients with cystic fibrosis (CF) awaiting lung transplant (LUTX) is limited. The echocardiography of adult patients with CF enlisted for LUTX was retrospectively analyzed and compared with standards and invasive analyses (right heart catheterization, multigated radionuclide ventriculography). We included 49 patients (reported as mean ± standard deviation; 29 ± 9 years of age; forced expiratory volume in first second of expiration, 31% ± 11% predicted; lung allocation score, 36 ± 5; invasive mean pulmonary artery pressure, 17 ± 5 mm Hg; multigated radionuclide ventriculography right ventricle [RV] ejection fraction, 50% ± 9%). Patients had increased RV end-diastolic area, RV wall thickness, and increased pulmonary artery acceleration time with subnormal tricuspid annular plane systolic excursion, tissue Doppler positive peak systolic velocity, and fraction area change. Subnormal tricuspid annular plane systolic excursion (< 23 mm), tissue Doppler positive peak systolic velocity (< 14 cm/s), and fraction area change (< 49%) had high sensitivity and negative predictive value in predicting impaired RV. EJECTION FRACTION: A good correlation between echocardiographic estimated and invasively measured systolic pulmonary artery pressure was observed (R² = 0.554, P < .001). Adults with CF awaiting LUTX have morphologic alterations of the right heart, with subclinical impairment of RV systolic function. Echocardiography may be used as a bedside, repeatable, and reliable noninvasive test to screen further deterioration in RV function while on the waiting list for LUTX. More prospective follow-up echocardiographic studies are necessary to confirm such a hypothesis.

Utilization of extracorporeal membrane oxygenation in DCD and DBD lung transplants: a 2-year single-center experience

Donation after circulatory death (DCD) has the potential to expand the lung donor pool. We aimed to assess whether DCD affected the need for perioperative extracorporeal membrane oxygenation (ECMO) and perioperative outcomes in lung transplantation (LTx) as compared to donation after brain death (DBD). All consecutive LTxs performed between April 2017 and March 2019 at our tertiary center were analyzed. Donor and recipient preoperative characteristics, utilization of ECMO, and perioperative clinical outcomes were compared between DCD and DBD LTx. Multivariate models (frequentist and Bayes) were fitted to evaluate an independent effect of DCD on the intra- and postoperative need for ECMO. Out of 105 enrolled patients, 25 (23.8%) were DCD LTx. Donors' and preoperative recipients' characteristics were comparable between the groups. Intraoperatively, mechanical circulatory support (MCS) was more common in DCD LTx (56.0% vs. 36.2%), but the adjusted difference was minor (RR = 1.16, 95% CI 0.64-2.12; P = 0.613). MCS duration, and first and second lung ischemia time were longer in the DCD group. Postoperatively, DCD recipients more commonly required ECMO (32.0% vs. 7.5%) and the difference remained considerable after adjustment for the pre- and intraoperative covariates: RR = 4.11 (95% CI 0.95-17.7), P = 0.058, Bayes RR = 4.15 (95% CrI 1.28-13.0). Sensitivity analyses (two DCD-DBD matching procedures) supported a higher risk of postoperative ECMO need in DCD patients. Incidence of delayed chest closure, postoperative chest drainage, and renal replacement therapy was higher in the DCD group. Early postoperative outcomes after DCD LTx appeared generally comparable to those after DBD LTx. DCD was associated with a higher need for postoperative ECMO which could influence clinical outcomes. However, as the DCD group had a significantly higher use of EVLP with more common ECMO preoperatively, this might have contributed to worse outcomes in the DCD group.

Anesthetic management of lung transplantation: Results from a multicenter, cross-sectional survey by the society for advancement of transplant anesthesia

BACKGROUND

Current protocols for the perioperative care of lung transplant (LTX) recipients lack rigorous evidence and are often empiric, based upon institutional preferences. We surveyed LTX anesthesiologists to determine the most common practices.

METHODS

We developed a survey of 40 questions regarding perioperative care of LTX recipients using Qualtrics software. The survey was sent out to members of the Society of Cardiovascular Anesthesiologists performing LTX at geographically diverse sites to facilitate data collection for as many practices as possible.

RESULTS

The responses were center-weighed (127 responses, 85% from academic settings). The clamshell approach was commonly used (70%). Cardiopulmonary bypass was preferred by 56%, ex vivo lung perfusion utilized by 43%, and 49.4% indicated they use lungs from donation after circulatory determination of death. Most (69%) used oximetric pulmonary artery catheters, 60% used tissue oximetry, and 89.3% utilized transesophageal echocardiography. Inhaled nitric oxide was preferred by 48%, restrictive fluid management by 48%, and systemic analgesia advocated by 49% of participants. Inspired oxygen concentration <30% was applied to the new lung on reperfusion by 28% of the respondents.

CONCLUSION

Variations in healthcare delivery and utilization for LTX recipients indicate gaps in knowledge and potential opportunities to improve the quality of care.

Use of Extracorporeal Membrane Oxygenation for Major Cardiopulmonary Resections

BACKGROUND

In thoracic surgery, utilization of extracorporeal membrane oxygenation (ECMO) is mainly established for patients undergoing lung transplantation. The aim of our study was to summarize our single-center experience with intraoperative use of veno-venous- or veno-arterial-ECMO in patients undergoing complex lung surgery involving the main carina, or the left atrium or the descending aorta.

METHODS

A total of 24 patients underwent combined complex lung, carinal, aortal, or left atrial resections. In cases of carinal resection, percutaneous veno-venous, jugular-femoral cannulation was considered suitable. For combined resection of lung and descending aorta, a percutaneous femoral veno-arterial cannulation was used. In cases of extended left atrial resection, a percutaneous jugular-femoral veno-venous-arterial cannulation was favored.

RESULTS

Procedures were divided into three groups: carinal resections and reconstruction (n = 8), resections of the descending aorta and left lung (n = 7), resections of lung and left atrium (n = 9). No intraoperative complications occurred. Overall 30-day mortality was 25%. A complete resection was achieved in 18 patients. Median survival was 12 months. One- and 5-year survival were 48.1 and 22.7%, respectively.

CONCLUSION

The present study shows that intraoperative use of ECMO for extended carinal, aortic, or atrial resections is feasible with minimal intraoperative complications allowing surgeons increased operating-field safety. Perioperative mortality is high, but this is rather an attribute of local extended disease and patient comorbidities.

Extracorporeal Membrane Oxygenation During Adult Noncardiac Surgery and Perioperative Emergencies: A Narrative Review

Over the last decade, the use of extracorporeal membrane oxygenation (ECMO) has increased significantly. In some centers, ECMO has been deployed to manage perioperative emergencies and plays a role in facilitating high-risk thoracic, airway, and trauma surgery, which may not be feasible without ECMO support. General anesthesiologists who usually manage these cases may not be familiar with the initiation and management of patients on ECMO. This review discusses the use of ECMO in the operating room for thoracic, airway, and trauma surgery, as well as obstetric and perioperative emergencies.

Extracorporeal Membrane Oxygenation and Lung Transplantation: Initial Experience at a Single Brazilian Center

OBJECTIVE

To report initial experience from the use of extracorporeal membrane oxygenation (ECMO) in patients who received lung transplantation.

METHODS

Retrospective study of a single tertiary center in the Brazilian state of São Paulo, a national reference in lung transplantation, based on the prospective collection of data from electronic medical records. The period analyzed extended from January 2009 (beginning of the program) until December 2018.

RESULTS

A total of 75 lung transplants were performed, with ECMO used in 8 (10.7%) cases. Of the patients, 4 (50%) were female. The mean age was 46.4±14.3 years. The causes of the end-stage lung disease that led to transplantation were pulmonary arterial hypertension in 3 (37.5%) patients, bronchiectasis in 2 (25%) patients, pulmonary fibrosis in 2 (25%) patients, and pulmonary emphysema in 1 (12.5%) patient. In our series, 7 (87.5%) cases were sequential bilateral transplantations. Prioritization was necessary in 4 (50%) patients, and in 1 patient, ECMO was used as a bridge to transplantation. The ECMO route was central in 4 (50%), peripheral venovenous in 2 (25%) and peripheral venoarterial in 2 (25%) patients. The mean length of the intensive care unit (ICU) stay was 14±7.5 days and of the hospital stay was 34.1±34.2 days. The mean ECMO duration was 9.3±6.6 days with a 50% decannulation rate. Three patients were discharged (37.5%).

CONCLUSION

Lung transplantation requires complex treatment, and ECMO has allowed extending the indications for transplantation and provided adjuvant support in the clinical management of these patients.

Bilateral lung transplantation on intraoperative extracorporeal membrane oxygenator: An observational study

OBJECTIVE

Intraoperative extracorporeal membrane oxygenation (ECMO) is usually reserved to support patients during complex lung transplantation. We hypothesized that a routine application of intraoperative ECMO in all patients improves primary graft function.

METHODS

Patients receiving a bilateral lung transplantation between November 2016 and July 2018 at the Medical University of Vienna were included in this prospective, single-center observational study. All transplantations were uniformly performed on central venoarterial ECMO support, with the possibility to extend ECMO into the early postoperative period whenever graft function did not meet established quality criteria at the end of implantation. Primary graft dysfunction (PGD) grades were evaluated at 24, 48, and 72 hours after transplantation. Perioperative complications and survival outcome were assessed.

RESULTS

A total of 159 patients were included in the study. At 24 hours post-transplantation, 38.4% (n = 61) of patients were already extubated, 48.4% (n = 77) were classified as PGD0, 4.4% (n = 7) as PGD1, 3.1% (n = 5) as PGD2, 2.5% (n = 4) as PGD3, and 3.1% (n = 5) were "ungradable" due to prophylactic postoperative prolongation of ECMO. At 72 hours after transplantation, 76.7% (n = 122) of the patients were extubated, as opposed to only 1.3% (n = 2) of patients classified as PGD3. The median time of mechanical ventilation was 29 hours (interquartile range, 17-58). The 90-day-mortality was 3.1%, and 2-year survival was 86%.

CONCLUSIONS

Routine use of intraoperative ECMO resulted in excellent primary graft function and mid-term outcome in patients undergoing lung transplantation. To the best of our knowledge, the herein measured PGD rates are the lowest reported in the literature to date. Our results advocate a routine intraoperative use of ECMO in bilateral lung transplantation.

Intraoperative extracorporeal membrane oxygenation for lung transplantation in cystic fibrosis patients: Predictors and impact on outcome

BACKGROUND

Predictors and outcomes of intraoperative extracorporeal membrane oxygenation (ECMO) during lung transplantation (LUTX) for cystic fibrosis (CF) are unknown.

METHODS

We retrospectively collected the clinical data at enlistment of the CF patients who underwent double LUTX from January 2013 to December 2018 at an Italian tertiary referral center. We compared blood transfusions, incidence of primary graft dysfunction (PGD), duration of mechanical ventilation, intensive care unit (ICU) length of stay (LOS), hospital LOS and survival of ECMO and non-ECMO patients. Chi-square, Kruskal-Wallis, and log-rank tests were used.

RESULTS

Twenty-eight (40%) of the 70 included patients needed intraoperative central veno-arterial ECMO with postoperative veno-venous prolongation in 6 subjects. Lower right ventricle ejection fraction (p = 0.013, OR 0.92(0.86-0.98)), higher oxygen requirement (p = 0.026, OR 1.39(1.01-1.90)), lower body surface area (p = 0.044, OR 0.05(0.00-1.03)), and CF-related diabetes (p = 0.044, OR 2.81(1.03-7.66)) were associated with intraoperative ECMO. Compared to non-ECMO patients, ECMO patients needed almost fivefold intraoperative transfusion (2227 mL vs. 570 mL, p<0.001) and had PGD grade > 0 at 72 h more frequently (16/57% vs. 12/28%, p = 0.017, OR 3.33(1.22-9.09)). Mechanical ventilation, ICU LOS and hospital LOS were significantly longer in ECMO patients. Survival at follow-up (651(326-1277) days) of ECMO and non-ECMO patients was 78% vs. 83%, respectively (OR 0.73 (0.21-2.46), p = 0.616, log-rank test p = 0.498).

CONCLUSION

Pre-operative risk assessment and clinical planning should be done according to the predictors above. While undeniably useful as a life-saving procedure, ECMO during LUTX for CF is associated with worsened short-term outcomes. ECMO should be implemented weighing its risk and benefits.

Perioperative Management of Bleeding and Transfusion for Lung Transplantation

Perioperative allogeneic blood product transfusion is common in lung transplantation and has various implications on the short- and long-term outcomes of lung recipients. This review summarizes the effect of transfusion on outcomes including primary graft dysfunction, chronic lung allograft dysfunction, and all-cause mortality. We outline known risk factors for increased transfusion requirement in lung transplantation and present current evidence regarding the effect of hemostatic agents including antifibrinolytics, recombinant factor VII, and prothrombin complex concentrates. Finally, we highlight the roles of point-of-care coagulation testing and goal-directed transfusion strategies in reducing transfusion requirements in lung transplantation.

Traditional and non-traditional anticoagulation management during extracorporeal membrane oxygenation

Unfractionated heparin (UFH) is the anticoagulant of choice during extracorporeal membrane oxygenation (ECMO) support. Despite its favorable pharmacologic properties, management of heparin anticoagulation during ECMO remains a major challenge. To date, little is known about the optimal monitoring strategy or the heparin dose offering the best safety/efficacy profile. Therefore, it remains unclear if the heparin dose should be adapted to target a specific "clotting time" [e.g., activated clotting time (ACT) or activated partial thromboplastin time (aPTT)] or a heparin concentration, measured by coagulation factor anti-Xa assay. In addition, no study has compared the relevance of modern viscoelastic coagulation tests over the single value of a clotting time or heparin concentration value. Although guidelines for anticoagulation during ECMO support have been published, the absence of evidence limits the quality of the recommendations provided, which explains the major intra- and inter-institutional variability observed. Large prospective multicenter trials are urgently needed to investigate the optimal anticoagulation management strategy during ECMO support.

Early Graft Dysfunction after Lung Transplantation

PURPOSE OF REVIEW

Primary graft dysfunction is an acute lung injury syndrome occurring immediately following lung transplantation. This review aims to provide an overview of the current understanding of PGD, including epidemiology, immunology, clinical outcomes and management.

RECENT FINDINGS

Identification of donor and recipient factors allowing accurate prediction of PGD has been actively pursued. Improved understanding of the immunology underlying PGD has spurred interest in identifying relevant biomarkers. Work in PGD prediction, severity stratification and targeted therapies continue to make progress. Donor expansion strategies continue to be pursued with ex vivo lung perfusion playing a prominent role. While care of PGD remains supportive, ECMO has established a prominent role in the early aggressive management of severe PGD.

SUMMARY

A consensus definition of PGD has allowed marked advances in research and clinical care of affected patients. Future research will lead to reliable predictive tools, and targeted therapeutics of this important syndrome.

Extracorporeal support, during and after lung transplantation: the history of an idea

During recent years, continuous technological innovation has provoked an increase of extracorporeal life support (ECLS) use for perioperative cardiopulmonary support in lung transplantation. Initial results were disappointing, due to ECLS-specific complications and high surgical risk of the supported patients. However, the combination of improved patient management, multidisciplinary team work and standardization of ECLS protocols has recently yielded excellent results in several case series from high-volume transplant centres. Therein, it was demonstrated that, although the prevalence of complications remains higher in supported patients, there may be no difference in long-term graft function between supported and non-supported patients. These results are important, because most of the patients who require ECLS support in lung transplantation are young and have no other chance to survive, but to be transplanted. Moreover, there is no device for "bridging to destination" therapy in lung transplantation. Of note, the evidence in favour of ECLS support in lung transplantation was never validated by randomized controlled trials, but by everyday experience at the patient bed-side. Here, we review the state-of-the-art ECLS evidence for intraoperative and postoperative cardiopulmonary support in lung transplantation.

ECMO-assisted resection of huge thoracic mass

Some advanced thoracic malignancy cannot be resected safely by using of conventional ventilation, so some sort of cardiopulmonary support is needed for hemodynamic and ventilation management of the patient. Using extracorporeal membrane oxygenation (ECMO) in comparing with cardiopulmonary bypass has some advantages. Three patients with huge thoracic tumors with different ages experienced major surgery in our center by using ECMO in order to face major complications mainly due to the size of mass to achieve better hemostatic stabilities, lower bleeding, and injuries to main airways and secure oxygenation. This is the first case series in Iran, as our best knowledge that explains cases of huge chest mass which were operated perfectly by using ECMO and short ICU stay and interestingly no major complications.

Noteworthy Literature Published in 2017 for Thoracic Transplantation Anesthesiologists

Thoracic organ transplantation constitutes a significant proportion of all transplant procedures. Thoracic solid organ transplantation continues to be a burgeoning field of research. This article presents a review of remarkable literature published in 2017 regarding perioperative issues pertinent to the thoracic transplant anesthesiologists.

Anesthetic management of the patient with extracorporeal membrane oxygenator support

The use of short-term mechanical circulatory support in the form of extracorporeal membrane oxygenation (ECMO) in adult patients has increased over the last decade. Cardiothoracic anesthesiologists may care for these patients during ECMO placement and for procedures while ECMO support is in place. An understanding of ECMO capabilities, indications, and complications is essential to the anesthesiologist caring for these patients. Below we review the anesthetic considerations for the implantation of ECMO and concerns when caring for patients on ECMO.