Extracorporeal life support during and after bilateral sequential lung transplantation in patients with pulmonary artery hypertension

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.

Physiotherapy for patients on extracorporeal membrane oxygenation support: How, When, and Who. An international EuroELSO survey

BACKGROUND AND PURPOSE

Extracorporeal membrane oxygenation (ECMO) continues to play an essential role in organ support in cardiogenic shock or acute respiratory distress syndrome and bridging to transplantation. The main purpose of the present survey was to define which clinical and organizational practices are adopted for the administration of physiotherapy in adult patients undergoing ECMO support worldwide.

METHODS

This international survey was conceived in November 2021. The survey launch was announced at the 10th EuroELSO (European ELSO chapter) Congress, London, May 2022.

RESULTS

The survey returned 32 questionnaires from 29 centers across 14 countries. 17 centers (53.1%) had more than 30 intensive care unit beds available and most (46.8%) were able to care for five to 10 patients on extracorporeal life support simultaneously. The predominant physiotherapist-to-patient ratio was 1:>5 (37.5%); physiotherapy was available 5/7 days and 7/7 days by 31.2% and 25% respectively. Respiratory physiotherapy was not defined by a specific protocol in most centers (46.8%) while 31.2% declared that the treatment commences less than 12 h after sedation is stopped/reduced. Mostly, early physiotherapy in non-cooperative ventilated patients was provided within the first 48 h (68.6%) and consisted of as passive range of motion, in-bed positioning, and splinting. Postural passages and sitting were provided to patients and walking was included in those advanced motor activities which are part of the treatment.

CONCLUSION

Physiotherapy in patients on ECLS is feasible, however substantial variability exists between centers with a trend of delivering not protocolized and understaffed rehabilitation practices.

Innovative use of Protek Duo during bilateral lung transplant with Veno-Arterial Extracorporeal Membrane Oxygenation assistance

V-A ECMO during bilateral lung transplantation is routinely used when extracorporeal support is needed, in particular in case of patients affected by pulmonary hypertension. We report the case of a patient successfully transplanted with V-A ECMO assistance using a percutaneous double lumen cannula as venous drainage (Protek Duo, CardiacAssist Inc., Pittsburgh, PA) and central aortic cannulation. The double lumen cannula allowed an optimal drainage of the venous system and effective emptying of right heart chambers.

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.

Pathophysiology and Treatment of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a condition in which an organic thrombus remains in the pulmonary artery (PA) even after receiving anticoagulation therapy for more than 3 months and is complicated by pulmonary hypertension (PH), leading to right-sided heart failure and death. CTEPH is a progressive pulmonary vascular disease with a poor prognosis if left untreated. The standard treatment for CTEPH is pulmonary endarterectomy (PEA), which is usually performed only in specialized centers. In recent years, balloon pulmonary angioplasty (BPA) and drug therapy for CTEPH have also shown good results. This review discusses the complex pathogenesis of CTEPH and presents the standard of care, PEA, as well as a new device called BPA, which is showing remarkable progress in efficacy and safety. Additionally, several drugs are now demonstrating established evidence of efficacy in treating CTEPH.

The American Association for Thoracic Surgery (AATS) 2022 Expert Consensus Document: The use of mechanical circulatory support in lung transplantation

OBJECTIVE

The use of mechanical circulatory support (MCS) in lung transplantation has been steadily increasing over the prior decade, with evolving strategies for incorporating support in the preoperative, intraoperative, and postoperative settings. There is significant practice variability in the use of these techniques, however, and relatively limited data to help establish institutional protocols. The objective of the AATS Clinical Practice Standards Committee (CPSC) expert panel was to review the existing literature and establish recommendations about the use of MCS before, during, and after lung transplantation.

METHODS

The AATS CPSC assembled an expert panel of 16 lung transplantation physicians who developed a consensus document of recommendations. The panel was broken into subgroups focused on preoperative, intraoperative, and postoperative support, and each subgroup performed a focused literature review. These subgroups formulated recommendation statements for each subtopic, which were evaluated by the entire group. The statements were then developed via discussion among the panel and refined until consensus was achieved on each statement.

RESULTS

The expert panel achieved consensus on 36 recommendations for how and when to use MCS in lung transplantation. These recommendations included the use of veno-venous extracorporeal membrane oxygenation (ECMO) as a bridging strategy in the preoperative setting, a preference for central veno-arterial ECMO over traditional cardiopulmonary bypass during the transplantation procedure, and the benefit of supporting selected patients with MCS postoperatively.

CONCLUSIONS

Achieving optimal results in lung transplantation requires the use of a wide range of strategies. MCS provides an important mechanism for helping these critically ill patients through the peritransplantation period. Despite the complex nature of the decision making process in the treatment of these patients, the expert panel was able to achieve consensus on 36 recommendations. These recommendations should provide guidance for professionals involved in the care of end-stage lung disease patients considered for transplantation.

Association of Pulmonary Artery Pressure Change With Post-Lung Transplantation Survival: Retrospective Analysis of China Registry

Background

Extracorporeal membrane oxygenation (ECMO) has been used as intraoperative hemodynamic support in patients with end-stage lung diseases and pulmonary hypertension undergoing lung transplantation (LT).

Objectives

The aim of this study was to identify the association of pulmonary artery pressure change during ECMO and post-LT survival.

Methods

The study investigators collected and analyzed the data from Chinese Lung Transplantation Registry. Patients who have severe pulmonary hypertension with intraoperative ECMO support were enrolled. Post-LT mortality and morbidity were further collected and compared.

Results

A total of 208 recipients were included in the study, during which 53 deaths occurred post-LT. All the patients had severe pulmonary hypertension and were supported by intraoperative ECMO. Using eXtreme Gradient Boosting, or XGboost, model method, 20 variables were selected and ranked. Changes of mean pulmonary artery pressure at the time of ECMO support and ECMO wean-off (ΔmPAP) were related to post-LT survival, after adjusting for potential confounders (recipient age, New York Heart Association functional class status before LT, body mass index, pre-LT hypertension, pre-LT steroids, and pre-LT ECMO bridging). A nonlinear relationship was detected between ΔmPAP and post-LT survival, which had an inflection point of 35 mm Hg. Recipients with ΔmPAP ≦35 mm Hg had higher mortality rate calculated through the Kaplan-Meier estimator (P = 0.041). Interaction analysis showed that recipients admitted in LT center with high case volume (≥50 cases/year) and ΔmPAP >35 mm Hg had better long-term survival. The trend was reversed in recipients who were admitted in LT center with low case volume (<50 cases/year).

Conclusions

The relationship between ΔmPAP and post-LT survival was nonlinear. Optimal perioperative ECMO management strategy with experienced team is further warranted.

Survival and left ventricular dysfunction post lung transplantation for pulmonary arterial hypertension

PURPOSE

Bilateral lung transplantation for end-stage pulmonary arterial hypertension (PAH) is traditionally associated with higher early post-transplant mortality when compared with other indications. Changes in perioperative management, including the growing use of perioperative extracorporeal membrane oxygenation (ECMO) and an increased awareness of postoperative left ventricular dysfunction (LVD), have resulted in outcomes that are uncertain.

MATERIALS AND METHODS

We conducted a single-center, retrospective observational study at a lung transplantation center in Melbourne, Australia, from 2006 to 2019. ECMO use was categorized as preoperative, prophylactic, or rescue. Postoperative LVD was defined as a reduction in left ventricular function on echocardiography or using strict clinical criteria.

RESULTS

50 patients underwent lung transplantation for PAH. 12-month survival was 48/50 (96%). ECMO was used in 26 (52%) patients, and the use of prophylactic VA-ECMO increased over the study period. Postoperative LVD was diagnosed in 21 (42%) patients. 12-month survival and left ventricular function was no different between LVD and non-LVD groups.

CONCLUSIONS

This study showed that high survival rates can be achieved following lung transplantation for PAH. We found that ECMO utilization was common, and indications have changed over time. LVD was common but did not impact 12-month survival.

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.

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

Background

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

Methods

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

Results

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

Conclusions

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

Extracorporeal membrane oxygenation in lung transplantation: Indications, techniques and results

The use of extracorporeal membrane oxygenation (ECMO) in the field of lung transplantation has rapidly expanded over the past 30 years. It has become an important tool in an increasing number of specialized centers as a bridge to transplantation and in the intra-operative and/or post-operative setting. ECMO is an extremely versatile tool in the field of lung transplantation as it can be used and adapted in different configurations with several potential cannulation sites according to the specific need of the recipient. For example, patients who need to be bridged to lung transplantation often have hypercapnic respiratory failure that may preferably benefit from veno-venous (VV) ECMO or peripheral veno-arterial (VA) ECMO in the case of hemodynamic instability. Moreover, in an intra-operative setting, VV ECMO can be maintained or switched to a VA ECMO. The routine use of intra-operative ECMO and its eventual prolongation in the post-operative period has been widely investigated in recent years by several important lung transplantation centers in order to assess the graft function and its potential protective role on primary graft dysfunction and on ischemia-reperfusion injury. This review will assess the current evidence on the role of ECMO in the different phases of lung transplantation, while analyzing different studies on pre, intra- and post-operative utilization of this extracorporeal support.

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.

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.

ERS International Congress 2020: highlights from the Thoracic Surgery and Transplantation Assembly

The Thoracic Surgery and Lung Transplantation Assembly of the European Respiratory Society is delighted to present the highlights from the 2020 Virtual International Congress. We have selected four sessions that discussed recent advances in a wide range of topics. From the use of robotic surgery in thoracic surgery and extracorporeal life support as a bridge to lung transplantation, to lung transplantation in the era of new drugs. The sessions are summarised by early career members in close collaboration with the assembly leadership. We aim to give the reader an update on the highlights of the conference in the fields of thoracic surgery and lung transplantation.

The first “virtual” #ERSCongress was a great success, with very diverse and important sessions on innovation and the state of the art in thoracic surgery and lung transplantation, summarised in this articlehttps://bit.ly/392uwUA

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.

Factors associated with intraoperative extracorporeal membrane oxygenation support during lung transplantation

BACKGROUND

Intraoperative Extracorporeal membrane oxygenation (ECMO) is increasingly being applied as life-support for lung transplantation patients. However, factors associated with this procedure in lung transplantation patients have not yet been characterized. The aim of this study was to identify preoperative factors of intraoperative ECMO support during lung transplantation and to evaluated the outcome of lung transplantation patients supported with ECMO.

METHODS

Patients underwent lung transplantation treated with and without ECMO in Guangzhou Institute of Respiratory Diseases between January 2015 to August 2018 were retrospectively reviewed. Patient demographics and clinical variables were collected and analyzed. Multivariate logistic regression was performed to identify factors independently associated with intraoperative extracorporeal membrane oxygenation support during lung transplantation.

RESULTS

During the study period, 138 patients underwent lung transplantation at our institution, the mean LAS was (56.63 ± 18.39) (range, 32.79 to 88.70). Fourty four patients were treated with veno-venous/veno-arterial ECMO. Among the patients, 32 patients wean successfully ECMO after operation, 12 patients remain ECMO after operation, and 32 patients (62.74%) survived to hospital discharge. In multiple analysis, the following factors were associated with intraoperative ECMO support: advanced age, high PAP before operation, duration of mechanical ventilation before operation, a higher APACHE II and primary diagnosis for transplantation. The overall survival rates at 1, 3, and 12 months were 90.91, 72.73, and 56.81% in the ECMO group, and 95.40, 82.76, and 73.56% in the non-ECMO group, respectively (log-rank P = 0.081). Patients who underwent single lung transplant had a lower survival rates in ECMO group as compared with non-ECMO group at 1, 3, and 12 months (90.47% vs 98.25, 71.43% vs 84.21, and 52.38% vs 75.44%) (log-rank P = 0.048).

CONCLUSIONS

The preoperative factors of intraoperative ECMO support during lung transplantation included age, high PAP before operation, preoperative mechanical ventilation, a higher APACHE II and primary diagnosis for transplantation based on multivariate analysis.