Lung Transplantation After Lung Volume Reduction Surgery

Impact of Difficult Lung Transplantation on Short-Term and Long-Term Survival

BACKGROUND

Lung transplantation (LTx) is a complex operation; however, certain factors can make LTx even more challenging. A difficult LTx could adversely affect immediate and long-term outcomes. We investigate the potential use of Modifier-22 to identify difficult LTx to evaluate postoperative outcomes.

METHODS

A retrospective analysis was performed on patients who had undergone LTx between January 1, 2010, and October 1, 2018, at the University of Washington. Patients undergoing repeat LTx, other solid organ transplantation, and/or with prior major cardiothoracic surgery were excluded. Patients were classified into 2 categories: standard LTx and difficult LTx groups. We examined hospital length of stay (LOS), intensive care unit (ICU) LOS, duration on the ventilator, and 1-, 3-, and 5-year survival.

RESULTS

A total of 370 patients were identified, with 268 patients in the standard LTx group and 102 patients in the difficult LTx group. The median LOS, ICU LOS, and duration on the ventilator in the difficult LTx group was 18.0 ± 1.6 days, 6.0 ± 1.2 days, and 2.0 ± 0.9 days compared with 15.0 ± 0.8 days, 4.0 ± 0.7 days, and 1.0 ± 0.3 days in the standard LTx group, respectively (all P < .01). Kaplan-Meier analysis revealed that both groups had similar survival.

CONCLUSION

Modifier-2 can be used to identify challenging LTx. Difficult LTx negatively impacts early postoperative outcomes with longer LOS, ICU LOS, and duration on the ventilator. However, long-term survival was not affected. Clinicians should not view pleural space and anatomical complexities, which are a consequence of the underlying disease, as a risk factor for impaired survival.

Donor and recipient risk factors for the development of primary graft dysfunction following lung transplantation

Primary Graft Dysfunction (PGD) is a major cause of both short-term and long-term morbidity and mortality following lung transplantation. Various donor, recipient, and technical risk factors have been previously identified as being associated with the development of PGD. Here, we present a comprehensive review of the current literature as it pertains to PGD following lung transplantation, as well as discussing current strategies to mitigate PGD and future directions. We will pay special attention to recent advances in lung transplantation such as ex-vivo lung perfusion, thoracoabdominal normothermic regional perfusion, and up-to-date literature published in the interim since the 2016 ISHLT consensus statement on PGD and the COVID-19 pandemic.

Lung transplantation in pulmonary sarcoidosis

Sarcoidosis is a systemic inflammatory disease of unknown etiology and variable clinical course. Pulmonary sarcoidosis is the most common presentation and accounts for most morbidity and mortality related to sarcoidosis. While sarcoidosis generally has good outcomes, few patients experience chronic disease. A minority of patients progress to a specific phenotype of sarcoidosis referred to advanced pulmonary sarcoidosis (APS) which includes advanced fibrosis, pulmonary hypertension and respiratory failure, leading to high morbidity and mortality. In patients with advanced disease despite medical therapy, lung transplantation may be the last viable option for improvement in quality of life. Though post-transplant survival is similar to that of other end-stage lung diseases, it is imperative that patients are evaluated and referred early to transplant centers with experience in APS. A multidisciplinary approach and clinical experience are crucial in detecting the optimal timing of referral, initiating comprehensive transplantation evaluation and listing, discussing surgical approach, and managing perioperative and post-transplant care. This review article seeks to address these aspects of lung transplantation in APS.

Common Noninfectious Complications Following Lung Transplantation

According to the Scientific Registry of Transplant Recipients, both transplant volume and survival among lung transplant recipients are improving over time. However, the outcomes of lung transplantation remain challenged by multiple thoracic and extrathoracic complications. With improving lung transplant survival, patients experience prolonged exposure to chronic immunosuppressive agents that can lead to multiple infectious and noninfectious complications. This article focuses on most common noninfectious complications with significant clinical impact.

Bridging Therapies With Injectable Immunomodulatory Drugs in the Management of Multiple Sclerosis: A Delphi Survey of an Italian Expert Panel of Neurologists

Background

In multiple sclerosis (MS), bridging therapies are usually administered when switching from one therapy to another. Such treatments generally consist of injectable immunomodulatory drugs (interferon or glatiramer acetate), whose efficacy, safety, and tolerability data are consolidated for use even in fragile patients. We performed a nationwide survey to gather expert opinions regarding the most appropriate use of bridging therapies in MS.

Methods

An independent steering committee of Italian neurologists with expertise in MS treatment identified critical issues in the use of bridging therapies and formulated a questionnaire. This questionnaire was used to conduct a Delphi web survey, involving a panel of Italian neurologists with experience in MS treatment. Their anonymous opinions were collected in three sequential rounds. Consensus was defined as an interquartile range (IQR) ≤2.

Results

Responses were obtained from 38 experts (100%) in all three rounds. Injectable immunomodulatory drugs were considered first-line therapy in patients with mild-to-moderate disease activity and in women planning to become pregnant. In addition, the experts were confident about prescribing these drugs in patients at risk of cancer recurrence, while the panel agreed to discontinue any treatments in patients with uncontrolled cardiovascular or metabolic disorders. Moreover, bridging therapy with injectable immunomodulatory drugs was considered appropriate in order to protect the patient from disease reactivation when a prolonged washout was needed and also while waiting for the completion of the immunization schedule.

Conclusion

The results of this nationwide survey confirm that, among Italian neurologists, there was wide agreement on the use of bridging therapies with injectable immunomodulatory drugs in several conditions in order to minimize the risk of disease reactivation when a prolonged washout was required or when the immunization schedule still needed to be completed in patients planning to become pregnant and in patients at risk of cancer recurrence.

Lung Volume Reduction Followed by Lung Transplantation in Emphysema-A Multicenter Matched Analysis

Objective: The impact of previous lung volume reduction surgery (LVRS) or endoscopic lung volume reduction (ELVR) on lung transplantation (LuTX) remains unclear. This study assesses the risk of previous lung volume reduction on the outcome of a later LuTX.

Methods: Patients suffering from emphysema who underwent bilateral LuTX were included in this multicenter analysis. Study groups were defined as: previous LVRS, previous ELVR, controls. Imbalances were corrected by coarsened exact matching for center, gender, age, diagnosis, and BMI. A comparative analysis of intraoperative characteristics, perioperative outcome and long-term survival was performed.

Results: 615 patients were included (LVRS = 26; ELVR = 60). Compared to controls, LVRS patients had a higher rate of postoperative ECMO (15.4 vs. 3.9%; p = 0.006), whereas ELVR patients suffered more often from wound infections (8.9% vs. 2.5%; p = 0.018). Perioperative outcome, duration of ventilation, ICU stay, and hospital stay were comparable between groups. Bacterial colonization of the airway differed significantly between both LVR groups and controls in pre- and post-LuTX cultures. Survival was not impacted (1-/3-/5-year survival for LVRS: 92.3%/85.7%/77.1%; controls: 91.3%/82.4%/76.3%; p = 0.58 | ELVR: 93.1%/91%/91%; controls 91.2%/81.7%/75.3%; p = 0.17).

Conclusion: Lung volume reduction does not impact short and long-time survival after bilateral LuTX. Due to differences in airway colonization after LVR, caution to prevent infectious complications is warranted.

Consensus document for the selection of lung transplant candidates: An update from the International Society for Heart and Lung Transplantation

Tens of thousands of patients with advanced lung diseases may be eligible to be considered as potential candidates for lung transplant around the world each year. The timing of referral, evaluation, determination of candidacy, and listing of candidates continues to pose challenges and even ethical dilemmas. To address these challenges, the International Society for Heart and Lung Transplantation appointed an international group of members to review the literature, to consider recent advances in the management of advanced lung diseases, and to update prior consensus documents on the selection of lung transplant candidates. The purpose of this updated consensus document is to assist providers throughout the world who are caring for patients with pulmonary disease to identify potential candidates for lung transplant, to optimize the timing of the referral of these patients to lung transplant centers, and to provide transplant centers with a framework for evaluating and selecting candidates. In addition to addressing general considerations and providing disease specific recommendations for referral and listing, this updated consensus document includes an ethical framework, a recognition of the variability in acceptance of risk between transplant centers, and establishes a system to account for how a combination of risk factors may be taken into consideration in candidate selection for lung transplantation.

Analysis of Recent Literature on Lung Volume Reduction Surgery

Publication of the National Emphysema Treatment Trial (NETT) in 2003 established lung volume reduction surgery (LVRS) as a viable treatment of select patients with moderate to severe emphysema, and the only intervention since the availability of ambulatory supplemental oxygen to improve survival. Despite these findings, surgical treatment has been underused in part because of concern for high morbidity and mortality. This article reviews recent literature generated since the original NETT publication, focusing on physiologic implications of LVRS, recent data regarding the safety and durability of LVRS, and patient selection and extension of NETT criteria to other patient populations.

Lung Volume Reduction Surgery Before Lung Transplantation: A Propensity-Matched Analysis

BACKGROUND

Lung volume reduction surgery (LVRS) is treatment option for chronic obstructive pulmonary disease, the second most common indication for lung transplantation (LTx) in the United States. Lung volume reduction surgery before LTx is controversial. Single-institution studies report contradicting results, and the impact of undergoing LVRS before LTx on outcomes after LTx is unclear.

METHODS

We reviewed the United Network for Organ Sharing database for all adults (aged more than 18 years) who underwent first-time LTx for chronic obstructive pulmonary disease in the lung allocation score era. We used patient demographic and clinical characteristics and lung allocation score to propensity match patients who did and patients who did not undergo LVRS before LTx. The primary exposure was prior LVRS. The primary outcome was graft failure after LTx. Unadjusted Kaplan-Meier and adjusted Cox proportional hazards models were used to assess outcomes.

RESULTS

A total of 4905 patients with chronic obstructive pulmonary disease underwent LTx between May 2005 and March 2017. Of them, 107 patients (2.2%) underwent LVRS before LTx. Propensity matching generated 212 matches (106 LVRS+LTx, and 106 LTx only). Median survival was significantly longer in the LTx only cohort (6.5 vs 3.4 years, P = .034). Lung volume reduction surgery before lung transplantation was associated with significantly increased risk of graft failure after lung transplant (hazard ratio 1.72; 95% confidence interval, 1.13 to 2.60; P = .01).

CONCLUSIONS

In this national, propensity-matched analysis of LVRS before LTx, we show that LVRS is associated with a significantly increased risk of graft failure. Patients who undergo LVRS and remain in need of LTx should be carefully assessed and followed postoperatively.

Surgical Therapies for Chronic Obstructive Pulmonary Disease

Patients with severe chronic obstructive pulmonary disease who fail maximal medical therapy and bronchoscopic interventions have surgical options to improve lung function, quality of life, and exercise performance. Carefully selected patients with upper lobe predominant emphysema can consider lung volume reduction surgery. Patients with upper lobe-predominant emphysema and low exercise performance have a survival advantage. Patients with large bulla compressing adjacent lung tissue occupying more than one-third of the lung benefit from bullectomy. Patients with advanced chronic obstructive pulmonary disease ineligible for or failing other surgical or bronchoscopic interventions can consider lung transplantation if free from major comorbidities.

Chronic Obstructive Pulmonary Disease and Lung Transplantation

Lung transplantation (LTx) has been a viable option for patients with end-stage chronic obstructive pulmonary disease (COPD), with more than 20,000 procedures performed worldwide. Survival after LTx lags behind most other forms of solid-organ transplantation, with median survival for COPD recipients being a sobering 6.0 years. Given the limited supply of suitable donor organs, not all patients with end-stage COPD are candidates for LTx. We discuss appropriate criteria for accepting patients for LTx, as well as contraindications and exclusionary criteria. In the first year post-LTx, infection and graft failure are the leading causes of death. Beyond this chronic graft rejection-currently referred to as chronic lung allograft dysfunction-represents the leading cause of death at all time points, with infection and over time malignancy also limiting survival. Referral of COPD patients to a lung transplant center should be considered in the presence of progressing disease despite maximal medical therapy. As a rule of thumb, a forced expiratory volume in 1 second < 25% predicted in the absence of exacerbation, hypoxia (PaO₂ < 60 mm Hg/8 kPa), and/or hypercapnia (PaCO₂ > 50 mm Hg/6.6 kPa) and satisfactory general clinical condition should be considered the basic prerequisites for timely referral. We also discuss salient issues post-LTx and factors that impact posttransplant survival and morbidity such as infections, malignancy, renal insufficiency, and complications associated with long-term immunosuppression.

Developments in lung transplantation over the past decade

With an improved median survival of 6.2 years, lung transplantation has become an increasingly acceptable treatment option for end-stage lung disease. Besides survival benefit, improvement of quality of life is achieved in the vast majority of patients. Many developments have taken place in the field of lung transplantation over the past decade. Broadened indication criteria and bridging techniques for patients awaiting lung transplantation have led to increased waiting lists and changes in allocation schemes worldwide. Moreover, the use of previously unacceptable donor lungs for lung transplantation has increased, with donations from donors after cardiac death, donors with increasing age and donors with positive smoking status extending the donor pool substantially. Use of ex vivo lung perfusion further increased the number of lungs suitable for lung transplantation. Nonetheless, the use of these previously unacceptable lungs did not have detrimental effects on survival and long-term graft outcomes, and has decreased waiting list mortality. To further improve long-term outcomes, strategies have been proposed to modify chronic lung allograft dysfunction progression and minimise toxic immunosuppressive effects. This review summarises the developments in clinical lung transplantation over the past decade.

Many developments have taken place in lung transplantation over the last decade: indications have broadened, donor criteria expanded, allocations systems changed, and novel therapeutic interventions implemented, leading to improved long-term survivalhttp://bit.ly/2vnpwc1

Chronic Obstructive Pulmonary Disease and the Optimal Timing of Lung Transplantation

Chronic obstructive pulmonary disease (COPD) accounts for the largest proportion of respiratory deaths worldwide and was historically the leading indication for lung transplantation. The success of lung transplantation procedures is measured as survival benefit, calculated as survival with transplantation minus predicted survival without transplantation. In chronic obstructive pulmonary disease, it is difficult to show a clear and consistent survival benefit. Increasing knowledge of the risk factors, phenotypical heterogeneity, systemic manifestations, and their management helps improve our ability to select candidates and list those that will benefit the most from the procedure.

Lung transplantation for chronic obstructive pulmonary disease: past, present, and future directions

PURPOSE OF REVIEW

Lung transplantation offers an effective treatment modality for patients with end-stage chronic obstructive pulmonary disease (COPD). The exact determination of when to refer, list, and offer transplant as well as the preferred transplant procedure type remains unclear. Additionally, there are special considerations specific to patients with COPD being considered for lung transplantation, including the implications of single lung transplantation on lung cancer risk, native lung hyperinflation, and overall survival.

RECENT FINDINGS

The International Society for Heart and Lung Transplantation's most recent recommendations rely on an assessment of COPD severity based on BODE index. Despite the lack of evidence supporting a mortality benefit of bilateral over single lung transplantation for COPD patients, the majority of transplants performed in this population remain bilateral. Some of the concerns specific to single lung transplantation remain the possibility of de novo native lung cancer and the hemodynamic and physiologic implications of acute native lung hyperinflation.

SUMMARY

COPD remains the most common worldwide indication for lung transplantation. Ongoing study is still required to assess the overall survival benefit of lung transplantation and assess the overall quality of life impact on the COPD patient population.

Lung volume reduction followed by lung transplantation-considerations on selection criteria and outcome

Lung transplantation (LuTX) and lung volume reduction (LVR), either surgical (LVRS: lung volume reduction surgery) or endoscopic (ELVR: endoscopic lung volume reduction), are established therapies in the treatment of end-stage chronic obstructive pulmonary disease (COPD) patients. Careful patient selection is crucial for each intervention. If these techniques are sequentially applied there is a paucity of available data and individual center experiences vary depending on details in selection criteria and operative technique. This review aims to summarize the published data with a focus on LuTX after LVRS. This review covers patient selection for LuTX and LVR, technical considerations, limitations and outcomes. Published literature was identified by systematic search on Medline and appropriate papers were reviewed. Seven case reports/series, 7 comparative observational studies and one multicenter database analysis incorporating a total of 284 patients with LuTX and LVR were evaluated. Prior LVR can significantly affect intraoperative and postoperative risks after subsequent LuTX. Careful patient selection and timing and the choice of appropriate techniques such as minimal invasive LVRS and using ECMO as extracorporeal support during LuTX if required can minimize those risks, ultimately leading to very good postoperative outcomes in terms of lung function and survival. LVRS has the potential to delay listing and to bridge patients to LuTX by improving their physical condition while on the waiting list. After single lung transplantation (SLuTX) contralateral LVRS can counteract the deleterious effects of native lung hyperinflation (NLH). LVR and LuTX are adjunct therapies in the treatment of end-stage COPD. The combination of both can safely be considered in selected patients.

Clinical management of lung volume reduction in end stage emphysema patients

Following the evaluation of surgical lung volume reduction (LVR) in the National Emphysema Treatment (NETT) trial, different endoscopic LVR procedures have been developed for severe emphysema. Among those, endobronchial valve placement is the best evaluated method. All these therapies aim at reducing hyperinflation and at improving respiratory mechanics. It has been shown that these procedures can improve quality of life, lung function and exercise capacity in a significant and clinically meaningful way in suitable patients. Optimal medical therapy, physical rehabilitation, smoking cessation and respiratory insufficiency assessments should been thoroughly evaluated by a multi-disciplinary team before considering any LVR procedure. Clinical experience is necessary to decide if a patient is an appropriate candidate for a surgical or an interventional LVR procedure, to choose the optimal treatment strategy and to provide a high-level of care after the intervention, particularly when complications such as pneumothorax or persistent air leak occur in this already severely ill patient population. High volume emphysema care centers, providing a broad spectrum of different LVR procedures and involving a multidisciplinary team in the diagnostic process, are best suited to provide an optimal outcome. The aim of this manuscript is to describe the structures and procedures required to achieve the best possible outcome even in patients with advanced stage of their emphysema disease, including patients who are candidates for lung transplantation.

Lung volume reduction surgery or bronchoscopic lung volume reduction: is there an algorithm for allocation?

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the world with the annual number of deaths increasing every year. Alterations in chest wall mechanics, respiratory muscle mechanics, and impaired cardiac function that result from increased air-trapping are well known sequelae of COPD and contribute to increased morbidity and mortality. A reduction in hyperinflation can improve cardiopulmonary function. In selected patients with COPD and an emphysema phenotype, lung volume reduction surgery (LVRS) has demonstrated improvements in symptom burden and mortality. Minimally invasive bronchoscopic techniques that reduce end-expiratory lung volume have shown improvements in lung function, dyspnea and quality of life. In this review, we review selection criteria, risks, and benefits of surgical and bronchoscopic lung volume reduction (BLVR). Recommendations are provided to guide treatment decisions based on the current literature.

Lung transplantation: indications and contraindications

The selection of appropriate recipients for lung transplantation is an evolving discipline. As experience with the procedure has developed over the last decades, the identification of transplant candidates has also changed as transplant centers strive to safely provide the therapy to as many patients possible. The International Society for Heart and Lung Transplantation (ISHLT) has developed three editions of recipient selection guidelines. Published in 1998, 2006, and 2015, these guidelines represented the best information relevant to the appropriate selection of lung transplant candidates. A discussion of areas supported by the most robust scientific data will be undertaken, but in many aspects of recipient selection, there is a paucity of data upon which to rely. Therefore, it is ultimately the prerogative and responsibility of individual centers to determine, after carefully weighing the best evidence available, whether a patient is deemed a suitable candidate at a specific program. All possible indications and contraindications for transplantation will be reviewed with attention also given to the appropriate timing of referral and listing of patients with advanced lung disease to a transplant center.

Pre-anaesthetic evaluation of the patient with end-stage lung disease

Lung transplantation is a viable alternative for end-stage lung diseases, which offers good quality of life and survival outcomes for recipients. The aims of pre-assessment for potential lung transplant recipients are to assess fitness for surgery, optimise co-morbidities, commence interventions or investigations, weigh risk-benefit ratio, plan appropriate analgesia and obtain informed consent. The assessment information is gathered from the medical record, patient interview, physical examination and pre-operative tests. A comprehensive workup includes cardiopulmonary evaluation, haematological, biochemical, microbiological and immunological investigations. Most of the evidence regarding lung transplantation is gleaned from retrospective data from single, multi-centre or multinational registries. The lack of good quality evidence means that the guidelines are based on expert consensus.

Overview of Lung Transplantation, Heart-Lung Transplantation, Liver-Lung Transplantation, and Combined Hematopoietic Stem Cell Transplantation and Lung Transplantation

Lung transplantation (LTx) has evolved to represent the therapy of choice for many patients with end-stage lung diseases. Appropriate candidate selection for LTx is an important determinant of a positive outcome from transplantation. Posttransplantation survival has steadily improved, but long-term survival continues to be a challenge with a median survival of 5.8 years. Similarly, combined heart-lung transplantation and simultaneous liver-lung transplantation has been performed successfully in select patients who are not expected to survive either organ transplant alone. Moreover, LTx has been performed in patients who develop end-stage pulmonary complications following hematopoietic stem cell transplantation.

Compensatory lung growth after bilobectomy in emphysematous rats

Lung volume reduction surgery (LVRS) is an option for emphysematous patients who are awaiting lung transplantation. LVRS reduces nonfunctional portions of lung tissues and favors the compensatory lung growth (CLG) of the remaining lobes. This phenomenon diminishes dyspnea and improves both the respiratory mechanics and quality of life for the patients. An animal model of elastase-induced pulmonary emphysema was used to investigate the structural and functional lung response after LVRS. Bilobectomy was performed six weeks after elastase instillation. Two weeks after bilobectomy, CLG effects were evaluated by lung mechanics and histomorphometric analysis. After bilobectomy, the emphysematous animals presented decreased mean linear intercepts, increased elastic fiber proportion, and increased alveolar surface density, total volumes of airspace, tissue and respiratory region and absolute surface area. We conclude that bilobectomy promoted CLG in emphysematous animals, resulting in alveolar architecture repair.

Repeated lung volume reduction surgery is successful in selected patients

OBJECTIVES

Lung volume reduction surgery (LVRS) improves dyspnoea, quality of life and may even prolong survival in carefully selected patients with end-stage emphysema. The benefit may be sustained for several years and vanishes with the natural progression of the disease. Data on repeated surgical treatment of emphysema are scarce. The aim of this study was to evaluate the safety, effects and outcomes of repeated LVRS (Re-LVRS) in patients no longer benefiting from their initial LVRS.

METHODS

Between June 2002 and December 2013, 22 patients (9 females) with advanced emphysema underwent Re-LVRS at a median of 60 months (25-196) after their initial LVRS. While initial LVRS was performed thoracoscopically as a bilateral procedure, Re-LVRS was performed unilaterally by a video-assisted thoracoscopic technique in 19 patients and, due to adhesions, by thoracotomy in 3 patients. Pulmonary function test (PFT) was performed at 3 and 12 months postoperatively.

RESULTS

Lung function at Re-LVRS was similar to that prior to the first LVRS. The 90-day mortality rate was 0%. The first patient died 15 months postoperatively. The median hospitalization time after Re-LVRS was significantly longer compared with the initial LVRS [14 days, interquartile range (IQR): 11-19, vs 9 days, IQR: 8-14; P = 0.017]. The most frequent complication was prolonged air leak with a median drainage time of 11 days (IQR: 6-13); reoperations due to persistent air leak were necessary in 7 patients (32%). Five patients (23%) had no complications. Lung function and Medical Research Council (MRC) score improved significantly for up to 12 months after Re-LVRS, with results similar to those after initial bilateral LVRS. The average increase in the forced expiratory volume in 1 s (FEV1) was 25% (a 7% increase over the predicted value or 0.18 l) at 3 months, and the mean reduction in hyperinflation, assessed by relative decrease in RV/TLC (residual volume/total lung capacity), was 12% at 3 months (a decrease of 8% in absolute ratios). The mean MRC breathlessness score decreased significantly after 3 months (from 3.7 to 2.2).

CONCLUSIONS

Re-LVRS can be performed successfully in carefully selected patients as a palliative treatment. It may be performed as a bridge to transplantation or in patients with newly diagnosed intrapulmonary nodules or during elective cardiac surgery. Morbidity is acceptable and outcomes may be satisfactory with significantly improved lung function and reduced dyspnoea for at least 12 months postoperatively.

A consensus document for the selection of lung transplant candidates: 2014--an update from the Pulmonary Transplantation Council of the International Society for Heart and Lung Transplantation

The appropriate selection of lung transplant recipients is an important determinant of outcomes. This consensus document is an update of the recipient selection guidelines published in 2006. The Pulmonary Council of the International Society for Heart and Lung Transplantation (ISHLT) organized a Writing Committee of international experts to provide consensus opinion regarding the appropriate timing of referral and listing of candidates for lung transplantation. A comprehensive search of the medical literature was conducted with the assistance of a medical librarian. Writing Committee members were assigned specific topics to research and discuss. The Chairs of the Writing Committee were responsible for evaluating the completeness of the literature search, providing editorial support for the manuscript, and organizing group discussions regarding its content. The consensus document makes specific recommendations regarding the timing of referral and of listing for lung transplantation. These recommendations include discussions not present in previous ISHLT guidelines, including lung allocation scores, bridging to transplant with mechanical circulatory and ventilator support, and expanded indications for lung transplantation. In the absence of high-grade evidence to support decision making, these consensus guidelines remain part of a continuum of expert opinion based on available studies and personal experience. Some positions are immutable. Although transplant is rightly a treatment of last resort for end-stage lung disease, early referral allows proper evaluation and thorough patient education. Subsequent waiting list activation implies a tacit agreement that transplant offers a significant individual survival advantage. It is both the challenge and the responsibility of the transplant community globally to ensure organ allocation maximizes the potential benefits of a scarce resource, thereby achieving that advantage.