Lung transplantation for severe pulmonary hypertension--awake extracorporeal membrane oxygenation for postoperative left ventricular remodelling

Impact of Postoperative Continuous Renal Replacement Therapy in Lung Transplant Recipients

Acute kidney injury (AKI) is a common complication after lung transplant (LTx), and continuous renal replacement therapy (CRRT) is increasingly of use to critically ill patients who have developed AKI. However, the optimal timing or threshold of kidney impairment for which to commence CRRT after LTx has been uncertain. There has also been limited information on the impact of CRRT among LTx recipients (LTRs) introduced in the early posttransplant period on survival, graft function, and renal function. We aimed to review LTRs who developed AKI requiring CRRT postoperatively and followed their long-term outcomes at Tohoku University Hospital (TUH).

Extracorporeal Membrane Oxygenation as a Postoperative Left Ventricle Conditioning Tool After Lung Transplantation in Patients With Primary Pulmonary Artery Hypertension: First Polish Experience

BACKGROUND

Primary pulmonary hypertension can lead to hypertrophy of the right ventricle and ultimately to its insufficiency. Lung transplantation remains the only viable treatment for patients with certain forms of this disease. Usage of extracorporeal membrane oxygenation in veno-arterial form (VA-ECMO) after transplantation is both protective for left ventricle (enables adaptation to increased blood flow) and right ventricle (provides time to return to appropriate dimensions and in some cases to correct tricuspid regurgitaion).

CASE PRESENTATION

The case study describes 4 patients who were treated with VA-ECMO as a perioperative support. Three patients were diagnosed with idiopathic form of precapillary primary pulmonary hypertension. A fourth patient was a 49-year old woman diagnosed with hypoplastic pulmonary veins representing the postcapillary form of pulmonary hypertension. In all of the cases, VA-ECMO was introduced during the surgery (femoral vein/internal jugular vein and femoral artery) and maintained for several days after the transplantation. Regular echocardiographic and biochemical assessment in postoperative course revealed that cardiac function improved during and after such treatment among all patients. They were successfully weaned off ECMO and finally surgically explanted without any local complications. One patient was treated with awake ECMO protocol.

CONCLUSIONS

VA-ECMO was proved to be a useful tool during the transplantation and postoperative period. It helps to restore proper cardiac function, as well as prevent adverse effects of aforementioned pathologic changes of a heart.

Extracorporeal Membrane Oxygenation in Pediatric Pulmonary Hypertension

OBJECTIVE

To describe the epidemiology, critical care interventions, and mortality of children with pulmonary hypertension receiving extracorporeal membrane oxygenation.

DESIGN

Retrospective analysis of prospectively collected multicenter data.

SETTING

Data entered into the Extracorporeal Life Support Organization database between January 2007 and November 2018.

PATIENTS

Pediatric patients between 28 days and 18 years old with a diagnosis of pulmonary hypertension.

MEASUREMENTS AND MAIN RESULTS

Six hundred thirty-four extracorporeal membrane oxygenation runs were identified (605 patients). Extracorporeal membrane oxygenation support type was pulmonary (43.1%), cardiac (40.2%), and extracorporeal cardiopulmonary resuscitation (16.7%). The majority of cannulations were venoarterial (80.4%), and 30% had a pre-extracorporeal membrane oxygenation cardiac arrest. Mortality in patients with pulmonary hypertension was 51.3% compared with 44.8% (p = 0.001) in those without pulmonary hypertension. In univariate analyses, significant predictors of mortality included age less than 6 months and greater than 5 years; pre-extracorporeal membrane oxygenation cardiac arrest; pre-extracorporeal membrane oxygenation blood gas with pH less than 7.12, PaCO2 greater than 75, PaO2 less than 35, and arterial oxygen saturation less than 60%; extracorporeal membrane oxygenation duration greater than 280 hours; extracorporeal cardiopulmonary resuscitation; and extracorporeal membrane oxygenation complications including cardiopulmonary resuscitation, inotropic support, myocardial stun, tamponade, pulmonary hemorrhage, intracranial hemorrhage, seizures, other hemorrhage, disseminated intravascular coagulation, renal replacement therapy, mechanical/circuit problem, and metabolic acidosis. A co-diagnosis of pneumonia was associated with significantly lower odds of mortality (odds ratio, 0.5; 95% CI, 0.3-0.8). Prediction models were developed using three sets of variables: 1) pre-extracorporeal membrane oxygenation (age, absence of pneumonia, and pH < 7.12; area under the curve, 0.62); 2) extracorporeal membrane oxygenation related (extracorporeal cardiopulmonary resuscitation, any neurologic complication, pulmonary hemorrhage, renal replacement therapy, and metabolic acidosis; area under the curve, 0.72); and 3) all variables combined (area under the curve, 0.75) (p < 0.001).

CONCLUSIONS

Children with pulmonary hypertension who require extracorporeal membrane oxygenation support have a significantly greater odds of mortality compared with those without pulmonary hypertension. Risk factors for mortality include age, absence of pneumonia, pre-extracorporeal membrane oxygenation acidosis, extracorporeal cardiopulmonary resuscitation, pulmonary hemorrhage, neurologic complications, renal replacement therapy, and acidosis while on extracorporeal membrane oxygenation. Identification of those pulmonary hypertension patients requiring extracorporeal membrane oxygenation who are at even higher risk for mortality may inform clinical decision-making and improve prognostic awareness.

Pulmonary Hypertension and Right Ventricular Failure: Lung Transplant Versus Heart-Lung Transplant

Pulmonary arterial hypertension is a highly morbid disease with limited treatment options that improve survival and currently the only curative treatment is transplantation. There is a small body of literature comparing the efficacy of lung and heart-lung transplantation in this population. The bulk of evidence suggests that most patients with severe right ventricular failure undergoing transplant will have recovery of right ventricular function after lung transplantation. Existing data suggest that, in the absence of complex congenital heart disease or significant left ventricular dysfunction, double-lung transplant is the surgical procedure of choice.

Systemic Consequences of Pulmonary Hypertension and Right-Sided Heart Failure

Pulmonary hypertension (PH) is a feature of a variety of diseases and continues to harbor high morbidity and mortality. The main consequence of PH is right-sided heart failure which causes a complex clinical syndrome affecting multiple organ systems including left heart, brain, kidneys, liver, gastrointestinal tract, skeletal muscle, as well as the endocrine, immune, and autonomic systems. Interorgan crosstalk and interdependent mechanisms include hemodynamic consequences such as reduced organ perfusion and congestion as well as maladaptive neurohormonal activation, oxidative stress, hormonal imbalance, and abnormal immune cell signaling. These mechanisms, which may occur in acute, chronic, or acute-on-chronic settings, are common and precipitate adverse functional and structural changes in multiple organs which contribute to increased morbidity and mortality. While the systemic character of PH and right-sided heart failure is often neglected or underestimated, such consequences place additional burden on patients and may represent treatable traits in addition to targeted therapy of PH and underlying causes. Here, we highlight the current state-of-the-art understanding of the systemic consequences of PH and right-sided heart failure on multiple organ systems, focusing on self-perpetuating pathophysiological mechanisms, aspects of increased susceptibility of organ damage, and their reciprocal impact on the course of the disease.

Extracorporeal membrane oxygenation as a bridge to lung transplantation may not impact overall mortality risk after transplantation: results from a 7-year single-centre experience

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) has an important role in bridging patients to lung transplantation. In this study, we present our experience with pretransplant ECMO during the last 7 years and investigate its impact on graft outcomes.

METHODS

Records of all lung-transplanted patients at our institution between January 2010 and April 2017 were retrospectively reviewed. Graft survival was compared between patients who required pretransplant ECMO (pre-Tx ECMO+) and patients who did not (pre-Tx ECMO-). Risk factors for in-hospital mortality and graft survival were identified using a binary logistic regression and the Cox regression analyses, respectively.

RESULTS

Among the 917 patients transplanted during the study period, 68 (7%) required ECMO as a bridge to transplantation [awake strategy, n = 57 (84%) patients]. Median bridging time was 9 days. Among pre-Tx ECMO+ patients, the need for haemodialysis at any point during bridging emerged as an independent risk factor for in-hospital mortality (odds ratio 7.79, 95% confidence interval 1.21-50.24; P = 0.031). Although in-hospital mortality was significantly higher in pre-Tx ECMO+ versus pre-Tx ECMO- patients (15% vs 5%, P = 0.003), overall graft survival did not differ between groups (79% vs 90% and 61% vs 68% at 1 and 5 years, respectively, P = 0.13). Pretransplant ECMO did not emerge as a risk factor for graft survival in the multivariable analysis.

CONCLUSIONS

If applied in selected patients in a high-volume centre, pretransplant ECMO as a bridge to transplantation results in impaired, but still high in-hospital, survival and does not impact graft survival.

Rationale of Hemoadsorption during Extracorporeal Membrane Oxygenation Support

Extracorporeal membrane oxygenation (ECMO) and extracorporeal life support are increasingly used for treating various forms of shock, lung failure, protected interventions and life support including resuscitation. Most patients on ECMO are affected by a systemic inflammatory response caused by the underlying disease as well as the ECMO support itself, which contributes to vasoplegia, multi-organ failure, deterioration and death. Unfortunately, effective strategies for control of inflammation and related organ failure and shock on ECMO are lacking. Recently, a new polystyrene-based device for hemoadsorption, which aims to reduce excessive levels of inflammatory molecules such as interleukins, cytokines as well as damage- and pathogen-associated molecular patterns, has become available. Here we summarize the rationale, available data and technical aspects of polystyrene-based hemoadsorption during ECMO support, and give recommendations based on existing experience.

Double-lung versus heart-lung transplantation for precapillary pulmonary arterial hypertension: a 24-year single-center retrospective study

Transplant type for end-stage pulmonary vascular disease remains debatable. We compared recipient outcome after heart-lung (HLT) versus double-lung (DLT) transplantation. Single-center analysis (38 HLT-30 DLT; 1991-2014) for different causes of precapillary pulmonary hypertension (PH): idiopathic (22); heritable (two); drug-induced (nine); hepato-portal (one); connective tissue disease (four); congenital heart disease (CHD) (24); chronic thromboembolic PH (six). HLT decreased from 91.7% [1991-1995] to 21.4% [2010-2014]. Re-intervention for bleeding was higher after HLT; (P = 0.06) while primary graft dysfunction grades 2 and 3 occurred more after DLT; (P < 0.0001). Graft survival at 90 days, 1, 5, 10, and 15 years was 93%, 83%, 70%, 47%, and 35% for DLT vs. 82%, 74%, 61%, 48%, and 30% for HLT, respectively (log-rank P = 0.89). Graft survival improved over time: 100%, 93%, 87%, 72%, and 72% in [2010-2014] vs. 75%, 58%, 42%, 33%, and 33% in [1991-1995], respectively; P = 0.03. No difference in chronic lung allograft dysfunction (CLAD)-free survival was observed: 80% & 28% for DLT vs. 75% & 28% for HLT after 5 and 10 years, respectively; P = 0.49. Primary graft dysfunction in PH patients was lower after HLT compared to DLT. Nonetheless, overall graft and CLAD-free survival were comparable and improved over time with growing experience. DLT remains our preferred procedure for all forms of precapillary PH, except in patients with complex CHD.

Transplantation of donor lungs with pulmonary embolism - a retrospective study

Lung transplantation from donors with fulminant pulmonary arterial embolism as a cause of death remains controversial. An analysis was performed comparing preoperative characteristics and outcomes of 25 donors with a primary diagnosis of pulmonary arterial embolism to 1085 recipients of donor lungs without pulmonary arterial embolism. No early functional impairment of donor lungs with pulmonary embolism was detectable as depicted by the incidence of primary graft dysfunction immediately after surgery (P = 0.66), 24 (P = 0.79), 48 (P = 0.99) and 72 h (P = 0.99) after transplantation. Pulmonary function testing at 1 year (P = 0.003) and at last outpatient control (P < 0.05) showed superior results in the cohort receiving lungs from donors with pulmonary embolism. Incidence of chronic lung allograft dysfunction (CLAD) showed no difference within the first year after lung transplantation, however, 5 year-CLAD free survival was superior in recipients (70.4% vs. 55.1%, P = 0.006) of donor lungs with pulmonary embolism. Overall survival was similar in both groups. Lungs from donors with fulminant pulmonary embolism prior to brain death can safely be used for lung transplantation without impairing postoperative outcomes. Lung function testing shows favorable midterm results in recipients of donor lungs with pulmonary embolism.

＜Editors' Choice＞ Pulmonary Hypertension: Diagnosis, Management, and Treatment

Pulmonary hypertension (PH) is a hemodynamic state that is characterized by a resting mean pulmonary artery pressure ≧ 25 mmHg. The common forms of PH are pulmonary arterial hypertension (PAH), chronic thromboembolic pulmonary hypertension (CTEPH), PH caused by left-heart disease, and PH due to lung disease. Previously regarded as untreatable, the treatment of PAH has dramatically advanced since the introduction of the drug epoprostenol in 1999, with three-year survival rates improving from 30%-40% to over 85%. Drugs available for the specific treatment of PAH include endothelin-receptor antagonists, phosphodiesterase type 5 inhibitors, soluble guanylate cyclase stimulators, prostacyclin analogs, and prostacyclin-receptor agonists. In the past decade, management and treatment of CTEPH have also improved. While pulmonary endarterectomy used to be the only option for the treatment of CTEPH, newer treatments include a soluble guanylate cyclase stimulator, which has proven to be an efficacious targeted therapy. Other cases benefit from balloon pulmonary angioplasty.

Intensive care, right ventricular support and lung transplantation in patients with pulmonary hypertension

Intensive care of patients with pulmonary hypertension (PH) and right-sided heart failure includes treatment of factors causing or contributing to heart failure, careful fluid management, and strategies to reduce ventricular afterload and improve cardiac function. Extracorporeal membrane oxygenation (ECMO) should be considered in distinct situations, especially in candidates for lung transplantation (bridge to transplant) or, occasionally, in patients with a reversible cause of right-sided heart failure (bridge to recovery). ECMO should not be used in patients with end-stage disease without a realistic chance for recovery or for transplantation. For patients with refractory disease, lung transplantation remains an important treatment option. Patients should be referred to a transplant centre when they remain in an intermediate- or high-risk category despite receiving optimised pulmonary arterial hypertension therapy. Meticulous peri-operative management including the intra-operative and post-operative use of ECMO effectively prevents graft failure. In experienced centres, the 1-year survival rates after lung transplantation for PH now exceed 90%.

Extracorporeal membrane oxygenation after lung transplantation: risk factors and outcomes analysis

Background

Lung transplantation is the treatment of choice for end-stage pulmonary disease in selected patients. However, severe primary graft dysfunction is a significant complication of transplant and requires the implantation of an extracorporeal support. The aim of the study is to evaluate the impact of extracorporeal membrane oxygenation (ECMO) after transplant in our center.

Methods

From January 2008 till June 2018, 195 consecutive unselected patients receiving a lung transplant were considered. Mean age was 49±15 years. Main indications for transplant were idiopathic pulmonary fibrosis in 72 patients, chronic obstructive pulmonary disease in 60 patients, and cystic fibrosis in 40 patients. Prior to transplant, 18 patients were on mechanical ventilation and 14 were on ECMO.

Results

Twenty-five patients required venous-venous ECMO after transplant. Vascular disease as cause of transplant [relative risk (RR) 7.8, 95% CI: 1.5-41, P=0.02], donor age (RR 1.6, 95% CI: 1.03-2.3, P=0.03) and need for cardiopulmonary by-pass during transplant (RR 3.1, 95% CI: 1.02-9, P=0.04) were associated with ECMO implantation. Patients requiring post-transplant ECMO received more transfusions (P<0.01), had a longer mechanical ventilation (P<0.01) and ICU stay (P<0.01) and had a higher hospital mortality (P<0.01). Post-transplant ECMO significantly influenced one- and five-year survival [hazard ratio (HR) 5.5, 95% CI: 3-10, P<0.001 and HR 3.5, 95% CI: 2-6, P<0.001, respectively]. However, conditional survival after t months is similar for patients with or without post-transplant ECMO.

Conclusions

In our experience, although ECMO is a reliable and effective strategy to support pulmonary function, severe graft dysfunction after lung transplantation still has a significant impact on early and late results.

Pulmonary Hypertension

BACKGROUND

About 1% of adults suffer from pulmonary hypertension (PH). The various types of PH differ widely with respect to their incidence, clinical significance, and treatment.

METHODS

Selective review of the literature in association with a consensus conference.

RESULTS

Pulmonary hypertension is divided into five major categories. Those that are of particular clinical relevance are pulmonary arterial hypertension, chronic thromboembolic pulmonary hypertension, and pulmonary hypertension due to left heart and lung diseases. Ten drugs from five different substance classes are now available for the treatment of PH and are often given in combination. The treatment strategy is determined by risk stratification based on the severity of disease, along with the clinical phenotype and possible accompanying illnesses. The preferred treatment for chronic thromboembolic pulmonary hypertension is surgical pulmonary endarterectomy; inoperable patients are treated with drugs and endovascular interventions. PH due to left heart and lung diseases generally calls for specific treatment of pulmonary hypertension only if there is severe right-heart strain.

CONCLUSION

The diagnosis and treatment of severe forms of PH, in particular, pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension, are complex and are best carried out in close cooperation between the local physician and specialized centers.

Targeted therapy of pulmonary arterial hypertension: Updated recommendations from the Cologne Consensus Conference 2018

In the summer of 2016, delegates from the German Respiratory Society, the German Society of Cardiology and the German Society of Pediatric Cardiology met in Cologne, Germany, to define consensus-based practice recommendations for the management of patients with pulmonary arterial hypertension (PAH). These recommendations were built on the 2015 European Pulmonary Hypertension guidelines and included new evidence, where available. The treatment algorithm for PAH was modified based on the observation that there are now many patients diagnosed with IPAH who are at an advanced age and have significant cardiopulmonary comorbidities. For patients newly diagnosed with classic forms of PAH, i.e. younger patients without significant cardiopulmonary comorbidities, the consensus-based recommendation was to use initial combination therapy as the standard approach. The use of monotherapies was no longer considered appropriate in such patients. The choice of treatment strategies should be based on the risk assessment as proposed in the European guidelines. In patients presenting with a low or intermediate risk, oral combination therapy with endothelin receptor antagonists and phosphodiesterase-5 inhibitors or soluble guanylate cyclase stimulators, respectively, should be used. In high-risk patients, triple combination therapy including a subcutaneous or intravenous prostacyclin analogue should be considered. For patients who suffer from PAH and significant cardiopulmonary comorbidities, initial monotherapy is recommended and the use of combination therapies should be considered on an individual basis. The latter recommendations are based on the scarcity of evidence supporting the use of combination therapy and the higher risk of drug-related adverse events in such patients.

Lung transplantation for idiopathic pulmonary arterial hypertension on intraoperative and postoperatively prolonged extracorporeal membrane oxygenation provides optimally controlled reperfusion and excellent outcome

OBJECTIVES

Lung transplantation for idiopathic pulmonary arterial hypertension has the highest reported postoperative mortality of all indications. Reasons lie in the complexity of treatment of these patients and the frequent occurrence of postoperative left ventricular failure. Transplantation on intraoperative extracorporeal membrane oxygenation support instead of cardiopulmonary bypass and even more the prolongation of extracorporeal membrane oxygenation into the postoperative period helps to overcome these problems. We reviewed our experience with this concept.

METHODS

All patients undergoing bilateral lung transplantation for idiopathic pulmonary arterial hypertension on intraoperative extracorporeal membrane oxygenation with or without prophylactic extracorporeal membrane oxygenation prolongation into the postoperative period between January 2000 and December 2014 were retrospectively analysed.

RESULTS

Forty-one patients entered the study. Venoarterial extracorporeal membrane oxygenation support was prolonged into the postoperative period for a median of 2.5 days (range 1–40). Ninety-day, 1-, 3- and 5-year survival rates for the patient collective were 92.7%, 90.2%, 87.4% and 87.4%, respectively. When compared with 31 patients with idiopathic pulmonary arterial hypertension transplanted in the same period of time without prolongation of extracorporeal membrane oxygenation into the postoperative period, the results compared favourably (83.9%, 77.4%, 77.4%, and 77.4%; P = 0.189). Furthermore, these results are among the best results ever reported for this particularly difficult patient population.

CONCLUSIONS

Bilateral lung transplantation for idiopathic pulmonary arterial hypertension with intraoperative venoarterial extracorporeal membrane oxygenation support seems to provide superior outcome compared with the results reported about the use of cardiopulmonary bypass. Prophylactic prolongation of venoarterial extracorporeal membrane oxygenation into the early postoperative period provides stable postoperative conditions and seems to further improve the results.

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.

Clinical Risk Factors and Prognostic Model for Primary Graft Dysfunction after Lung Transplantation in Patients with Pulmonary Hypertension

RATIONALE

Pulmonary hypertension from pulmonary arterial hypertension or parenchymal lung disease is associated with an increased risk for primary graft dysfunction after lung transplantation.

OBJECTIVE

We evaluated the clinical determinants of severe primary graft dysfunction in pulmonary hypertension and developed and validated a prognostic model.

METHODS

We conducted a retrospective cohort study of patients in the multicenter Lung Transplant Outcomes Group with pulmonary hypertension at transplant listing. Severe primary graft dysfunction was defined as Pa_O2/Fi_O2 ≤200 with allograft infiltrates at 48 or 72 hours after transplantation. Donor, recipient, and operative characteristics were evaluated in a multivariable explanatory model. A prognostic model derived using donor and recipient characteristics was then validated in a separate cohort.

RESULTS

In the explanatory model of 826 patients with pulmonary hypertension, donor tobacco smoke exposure, higher recipient body mass index, female sex, listing mean pulmonary artery pressure, right atrial pressure and creatinine at transplant, cardiopulmonary bypass use, transfusion volume, and reperfusion fraction of inspired oxygen were associated with primary graft dysfunction. Donor obesity was associated with a lower risk for primary graft dysfunction. Using a 20% threshold for elevated risk, the prognostic model had good negative predictive value in both derivation and validation cohorts (89.1% [95% confidence interval, 85.3-92.8] and 83.3% [95% confidence interval, 78.5-88.2], respectively), but low positive predictive value.

CONCLUSIONS

Several recipient, donor, and operative characteristics were associated with severe primary graft dysfunction in patients with pulmonary hypertension, including several risk factors not identified in the overall transplant population. A prognostic model with donor and recipient clinical risk factors alone had low positive predictive value, but high negative predictive value, to rule out high risk for primary graft dysfunction.

Mid-term results of bilateral lung transplant with postoperatively extended intraoperative extracorporeal membrane oxygenation for severe pulmonary hypertension

OBJECTIVES

In severe pulmonary hypertension, diastolic dysfunction of the left ventricle causes significant morbidity and mortality after lung transplantation, which may be successfully reversed using a protocol based on perioperative veno-arterial extracorporeal membrane oxygenation (ECMO) and early extubation. Here, we present echocardiographic data and mid-term outcomes.

METHODS

The records of lung transplanted patients at our institution between May 2010 and January 2016 were retrospectively reviewed. Echocardiography data were collected preoperatively, at discharge, 3 and 12 months after transplantation.

RESULTS

During the study period, 717 patients underwent lung transplantation at our institution, 38 (5%) patients being transplanted for severe pulmonary hypertension. All patients underwent bilateral lung transplantation on veno-arterial ECMO cannulated in the groin, through a sternum sparing thoracotomy in 36 (95%) patients. Extubation was performed early, after a median of 2 days, and awake ECMO was extended for at least 5 days after transplantation. The survival at 3 months, 1 year and 5 years was not different in comparison to patients transplanted for other underlying diseases ( P  = 0.45). At 1 year, tricuspid valve regurgitation had disappeared in all patients. The median of the left ventricular end-diastolic dimension improved from 40 (32-44) mm preoperatively to 45 (44-47) mm at 12 months after lung transplantation ( P  < 0.05). The median of the proximal right ventricular outflow diameter decreased to 25 (23-27) mm after 12 months, compared to 48 (43-51) mm preoperatively ( P  < 0.05).

CONCLUSIONS

The routine application of a prophylactic postoperative veno-arterial ECMO protocol in patients with severe pulmonary hypertension undergoing lung transplantation decreases postoperative mortality and favours achievement of normal cardiac function after 1 year.

Recent advances in extracorporeal life support as a bridge to lung transplantation

INTRODUCTION

Invasive mechanical respiratory support in candidate bridging to transplant (BTT) has become common practice in recent years. This usually consists of mechanical ventilation, extracorporeal life support (ECLS) or a combination of both techniques. Areas covered: This review covers epidemiology, technical considerations, indications and outcome of ELCS as BTT. Published literature was identified by searching the MEDLINE bibliographic database (1946-present) and appropriate papers were reviewed. In a retrospective analysis of the period 2010-2016 (n = 92 cases of ECLS bridging, 62% ECLS only) at our institution, bridging success was 73%, with 1-year survival among patients surviving to transplant 78%, surpassing our previously published results between 2005-2009 (bridging success 58%, 1-year survival 58%, p = 0.002 and p = 0.02, respectively). Expert commentary: While ECLS success has influenced lung transplant selection criteria, bridging remains technically and ethically challenging. Candidate selection and organ allocation are crucial to achieving acceptable results.

Advanced pulmonary arterial hypertension: mechanical support and lung transplantation

The development of targeted therapies has transformed the outlook for patients with pulmonary arterial hypertension (PAH); however, some patients fail to achieve an adequate clinical response despite receiving maximal treatment. For these patients, lung transplantation remains an important therapeutic option, and recommendations for transplantation are included in the current European Society of Cardiology/European Respiratory Society guidelines for the diagnosis and treatment of pulmonary hypertension. Although lung transplantation is not without risk, overall long-term survival rates are good and substantial improvements in quality of life have been reported for lung transplant recipients. In this review, we describe the important considerations prior to, during and after transplantation, including the role of mechanical support, in patients with advanced PAH.

Lung transplantation and mechanical support play key therapeutic roles in patients with advanced PAHhttp://ow.ly/mqfG30gMcMd

Intraoperative extracorporeal membrane oxygenation and the possibility of postoperative prolongation improve survival in bilateral lung transplantation

OBJECTIVES

The value of intraoperative extracorporeal membrane oxygenation (ECMO) in lung transplantation remains controversial. In our department, ECMO has been used routinely for intraoperatively unstable patients for more than 15 years. Recently, we have extended its indication to a preemptive application in almost all cases. In addition, we prolong ECMO into the early postoperative period whenever graft function does not meet certain quality criteria or in patients with primary pulmonary hypertension. The objective of this study was to review the results of this strategy.

METHODS

All standard bilateral lung transplantations performed between January 2010 and June 2016 were included in this single-center, retrospective analysis. Patients were divided into 3 groups: group I-no ECMO (n = 116), group II-intraoperative ECMO (n = 343), and group III-intraoperative and prolonged postoperative ECMO (n = 123). The impact of different ECMO strategies on primary graft function, short-term outcomes, and patient survival were analyzed.

RESULTS

The use of intraoperative ECMO was associated with improved 1-, 3-, and 5-year survival compared with non-ECMO patients (91% vs 82%, 85% vs 76%, and 80% vs 74%; log-rank P = .041). This effect was still evident after propensity score matching of both cohorts. Despite the high number of complex patients in group III, outcome was excellent with higher survival rates than in the non-ECMO group at all time points.

CONCLUSIONS

Intraoperative ECMO results in superior survival when compared with transplantation without any extracorporeal support. The concept of prophylactic postoperative ECMO prolongation is associated with excellent outcomes in recipients with pulmonary hypertension and in patients with questionable graft function at the end of implantation.

Outcomes of perioperative extracorporeal membrane oxygenation use in patients undergoing lung transplantation

Background

The aim of this single-center study is to review the transplant outcomes of patients receiving lung transplantation (LTx) using intraoperative extracorporeal membrane oxygenation (ECMO) according to the perioperative use of ECMO.

Methods

We retrospectively reviewed the transplant outcomes of 107 consecutive patients who underwent LTx using intraoperative ECMO between March 2013 and August 2016 at Severance Hospital of Yonsei University (Seoul, Korea).

Results

Patients were divided into the following three groups according to the use of perioperative ECMO: only intraoperative ECMO (n=47) or extended post-operative ECMO but no bridging and no postoperative ECMO re-implantation (secondary ECMO; n=28) as Group A (n=75); bridging ECMO without secondary ECMO (n=14) as Group B; and secondary ECMO with (n=7) or without (n=11) bridging as Group C. Baseline demographics were comparable among the three groups. The mean duration of preoperative ECMO bridging was 16.4±15.6 (n=21). After a median of 17.7 months (range, 3.1-40.9 months) for survivors, the one year overall survival (OS) rates after LTx for the three groups were 76.3%±5.2% for Group A, 59.9%±14.3% for Group B, and 14.0%±9.0% for Group C (P<0.0001). The secondary ECMO (Group C) was established a mean of 7.9±5.3 days after LTx. The main cause of secondary ECMO was acute respiratory failure from pneumonia, and the main cause of death was infection-related events.

Conclusions

Our data suggests that the use of perioperative ECMO, including its extended postoperative use during LTx, is feasible and has favorable outcomes. However, as shown by the poor survival outcome after secondary ECMO, the development of solid strategy to reduce the need for secondary ECMO implantation after LTx seems important.

Acute decompensated pulmonary hypertension

Acute right heart failure in chronic precapillary pulmonary hypertension is characterised by a rapidly progressive syndrome with systemic congestion resulting from impaired right ventricular filling and/or reduced right ventricular flow output. This clinical picture results from an imbalance between the afterload imposed on the right ventricle and its adaptation capacity. Acute decompensated pulmonary hypertension is associated with a very poor prognosis in the short term. Despite its major impact on survival, its optimal management remains very challenging for specialised centres, without specific recommendations. Identification of trigger factors, optimisation of fluid volume and pharmacological support to improve right ventricular function and perfusion pressure are the main therapeutic areas to consider in order to improve clinical condition. At the same time, specific management of pulmonary hypertension according to the aetiology is mandatory to reduce right ventricular afterload. Over the past decade, the development of extracorporeal life support in refractory right heart failure combined with urgent transplantation has probably contributed to a significant improvement in survival for selected patients. However, there remains a considerable need for further research in this field.

Acute decompensated PH is a life-threatening condition requiring specific management in a specialised centrehttp://ow.ly/non530fkhmA

Combined Heart Lung Transplantation: An Updated Review of the Current Literature

Heart lung transplantation is a viable treatment option for patients with many end-stage heart and lung pathologies. However, given the complex nature of the procedure, it is imperative that patients are selected appropriately, and the clinician is aware of the many unique aspects in management of this population. This review seeks to describe updated organ selection policies, perioperative and postoperative management strategies, monitoring of graft function, and clinical outcomes for patients after combined heart-lung transplantation in the current era.

Impact of Left Ventricular Diastolic Dysfunction on Lung Transplantation Outcome in Patients With Pulmonary Arterial Hypertension

Diastolic dysfunction may influence perioperative outcome, early graft function, and long-term survival. We compared the outcomes of double lung transplantation (DLTx) for patients with pulmonary arterial hypertension (PAH) with preoperative left ventricular (LV) diastolic dysfunction with the outcomes of patients without diastolic dysfunction. Of 116 consecutive patients with PAH (who underwent transplantation between January 1995 and December 2013), 44 met our inclusion and exclusion criteria. Fourteen (31.8%) patients with diastolic dysfunction pretransplantation had a higher body mass index (29 [IQR 21.5-32.6] vs 22.4 [IQR 19.9-25.3] kg/m² ) and mean pulmonary arterial pressure (54.6 ± 10 mmHg vs 47 ± 11.3 mmHg) and right atrial pressure (16.5 ± 5.2 mmHg vs 10.6 ± 5.2 mmHg). The patients received extracorporeal life support more frequently (33% vs 7% [p = 0.02]), had worse APACHE II scores (21.7 ± 7.4 vs 15.3 ± 5.3 [p = 0.02]), and a trend toward worse ventilator-free days (2.5 [IQR 6.5-32.5] vs 17 [IQR 3-23] [p = 0.08]). There was no effect on development of primary graft dysfunction or intensive care unit/hospital survival. One-year survival was worse (hazard ratio [HR] 4.45, 95% confidence interval [CI] 1.3-22, p = 0.02). Diastolic dysfunction was the only variable that correlated with overall survival (HR 5.4, 95% CI 1.3-22, p = 0.02). Diastolic dysfunction leads to early postoperative morbidity and worse survival in patients with PAH after DLTx.

[Update pulmonary arterial hypertension : Definitions, diagnosis, therapy]

The term pulmonary arterial hypertension comprises a group of pulmonary vascular diseases of different etiologies that are characterized by similar precapillary vascular remodeling processes and result in exertional dyspnea and right heart insufficiency. The specific pharmacological treatment approach considers the risk of mortality and phenotypical properties and includes treatment with phosphodiesterase type 5 inhibitors, endothelin receptor antagonists and prostanoids, as well as with more novel substances, such as a soluble guanylyl cyclase stimulator and an oral prostacyclin receptor agonist. The prognosis of the disease is mainly determined by the right heart insufficiency for which there is currently no specific pharmacological treatment. Lung transplantation may be offered as a last option. This review provides an overview of the current European guidelines from 2015 and the recommendations of the Cologne Consensus Conference for pulmonary hypertension from 2016.

Diastolic Dysfunction Increases the Risk of Primary Graft Dysfunction after Lung Transplant

RATIONALE

Primary graft dysfunction (PGD) is a significant cause of early morbidity and mortality after lung transplant and is characterized by severe hypoxemia and infiltrates in the allograft. The pathogenesis of PGD involves ischemia-reperfusion injury. However, subclinical increases in pulmonary venous pressure due to left ventricular diastolic dysfunction may contribute by exacerbating capillary leak.

OBJECTIVES

To determine whether a higher ratio of early mitral inflow velocity (E) to early diastolic mitral annular velocity (é), indicative of worse left ventricular diastolic function, is associated with a higher risk of PGD.

METHODS

We performed a retrospective cohort study of patients in the Lung Transplant Outcomes Group who underwent bilateral lung transplant at our institution between 2004 and 2014 for interstitial lung disease, chronic obstructive pulmonary disease, or pulmonary arterial hypertension. Transthoracic echocardiograms obtained during evaluation for transplant listing were analyzed for E/é and other measures of diastolic function. PGD was defined as PaO2/FiO2 less than or equal to 200 with allograft infiltrates at 48 or 72 hours after reperfusion. The association between E/é and PGD was assessed with multivariable logistic regression.

MEASUREMENTS AND MAIN RESULTS

After adjustment for recipient age, body mass index, mean pulmonary arterial pressure, and pretransplant diagnosis, higher E/é and E/é greater than 8 were associated with an increased risk of PGD (E/é odds ratio, 1.93; 95% confidence interval, 1.02-3.64; P = 0.04; E/é >8 odds ratio, 5.29; 95% confidence interval, 1.40-20.01; P = 0.01).

CONCLUSIONS

Differences in left ventricular diastolic function may contribute to the development of PGD. Future trials are needed to determine whether optimization of left ventricular diastolic function reduces the risk of PGD.

[Extracorporeal life support in thoracic surgery: What are the indications and the pertinence?]

INTRODUCTION

In thoracic surgery, extracorporeal life support (ECLS) technologies are used in cases of severe and refractory respiratory failure or as intraoperative cardiorespiratory support. The objectives of this review are to describe the rationale of ECLS techniques, to review the pulmonary diseases potentially treated by ECLS, and finally to demonstrate the efficacy of ECLS, using recently published data from the literature, in order to practice evidence based medicine.

STATE OF THE ART

ECLS technologies should only be undertaken in expert centers. ECLS allows a protective ventilatory strategy in severe ARDS. In the field of lung transplantation, ECLS may be used successfully as a bridge to transplantation, as intraoperative cardiorespiratory support or as a bridge to recovery in cases of severe primary graft dysfunction. In general thoracic surgery, ECLS technology seems to be safe and efficient as intraoperative respiratory support for tracheobronchial surgery or for severe respiratory insufficiency, without significant increase in perioperative risk.

PERSPECTIVE

The indications for ECLS are going to increase. Future improvements both in scientific knowledge and bioengineering will improve the prognosis of patients treated with ECLS for respiratory failure. Multicenter randomized controlled trials will refine the indications for ECLS and improve the global care strategies for these patients.

CONCLUSION

ECLS is an efficient therapeutic strategy that will improve the prognosis of patients suffering from, or exposed to, the risks of severe respiratory failure.

Cannulation techniques for extracorporeal life support

The article reviews cannulation strategy for different modes of extracorporeal life support. Technical aspects, pitfalls and complications are discussed for central and peripheral extracorporeal membrane oxygenation (VA, VV, VAV, VVA), biventricular assist device support and extracorporeal CO₂ removal.

State of the Art of Combined Heart-Lung Transplantation for Advanced Cardiac and Pulmonary Dysfunction

Over the last several decades, significant advances and improvements in care of transplant patients have resulted in markedly improved outcomes. A number of options are available for patients with advanced cardiopulmonary dysfunction requiring transplantation. There is a debate about when isolated heart or isolated lung transplantation is no longer possible or advisable and combined heart-lung transplantation is justified. Organ availability and allocation severely limit the latter option to very few well-selected patients. We review practice patterns, trends, and outcomes after triple-organ heart-lung transplant (HLTx) worldwide, as well as our own experience with heart-lung transplant in the modern era.

State of the Art: Bridging to lung transplantation using artificial organ support technologies

Lung transplantation increasingly is being performed in recipients of higher risk and acuity. A subset of these patients has severely abnormal gas exchange and/or right ventricular dysfunction, such that artificial organ support strategies are required to bridge patients to lung transplantation. We review the rationales and currently used and potential strategies for bridging to lung transplantation and characterize bridging outcomes. Based on physiologic reasoning and a study of the existing literature, we provide a working strategy for bridging to lung transplantation.

Diagnostics, monitoring and outpatient care in children with suspected pulmonary hypertension/paediatric pulmonary hypertensive vascular disease. Expert consensus statement on the diagnosis and treatment of paediatric pulmonary hypertension. The European Paediatric Pulmonary Vascular Disease Network, endorsed by ISHLT and DGPK

Pulmonary hypertension (PH) is a condition of multiple aetiologies with underestimated prevalence and incidence. Indeed, despite access to modern therapies, pulmonary hypertensive vascular disease (PHVD) remains a progressive, usually life-limiting condition, severely impacting on the patients' well-being. We herein provide practical, expert consensus recommendations on the initial diagnostic work-up, clinical management and follow-up of children and adolescents with PH/PHVD, including a diagnostic algorithm. The major topics and methods that need to be tailored and put into context of the individual patient include PH classification, clinical signs and symptoms, basic diagnostic and advanced imaging measures (ECG, chest X-ray, transthoracic echocardiography, cardiac magnetic resonance, chest CT angiography, cardiac catheterisation, ventilation-perfusion lung scan, abdominal ultrasound), lung function tests, 6 min walk and cardiopulmonary exercise testing, sleep study (polysomnography), laboratory/immunological tests, considerations for elective surgery/ general anaesthesia, physical education and exercise, flying on commercial airplanes, vaccinations, care of central intravenous lines and palliative care. Due to the complexity of PH/PHVD, the clinical care has to be multidisciplinary and coordinated by a dedicated specialist paediatric PH centre, not only to decrease mortality but to allow children with PH/PHVD to reach a reasonable quality of life.

Prolonged Mechanical Ventilation After Lung Transplantation-A Single-Center Study

This single-center study examines the incidence, etiology, and outcomes associated with prolonged mechanical ventilation (PMV), defined as time to definite spontaneous ventilation >21 days after double lung transplantation (LTx). A total of 690 LTx recipients between January 2005 and December 2012 were analyzed. PMV was necessary in 95 (13.8%) patients with decreasing incidence during the observation period (p < 0.001). Independent predictors of PMV were renal replacement therapy (odds ratio [OR] 11.13 [95% CI, 5.82-21.29], p < 0.001), anastomotic dehiscence (OR 8.74 [95% CI 2.42-31.58], p = 0.001), autoimmune comorbidity (OR 5.52 [95% CI 1.86-16.41], p = 0.002), and postoperative neurologic complications (OR 5.03 [95% CI 1.98-12.81], p = 0.001), among others. Overall 1-year survival was 86.0% (90.4% for LTx between 2010 and 2012); it was 60.7% after PMV and 90.0% in controls (p < 0.001). Conditional long-term outcome among hospital survivors, however, did not differ between the groups (p = 0.78). Multivariate analysis identified renal replacement therapy (hazard ratio [HR] 3.55 [95% CI 2.40-5.25], p < 0.001), post-LTx extracorporeal membrane oxygenation (HR 3.47 [95% CI 2.06-5.83], p < 0.001), and prolonged inotropic support (HR 1.95 [95% CI 1.39-2.75], p < 0.001), among others, as independent predictors of mortality. In conclusion, PMV complicated 14% of LTx procedures and, although associated with increased in-hospital mortality, outcomes among patients surviving to hospital discharge were unaffected.