Extracorporeal lung perfusion and ventilation to improve donor lung function and increase the number of organs available for transplantation

Evidence of Air Trapping During Ex Vivo Lung Perfusion: A Swine Experimental Lung Imaging and Mechanics Study

Ex vivo lung perfusion (EVLP) allows the ventilation and perfusion of lungs to evaluate their viability for transplantation. The aim of this study is to compare the mechanical, morphologic and functional properties of lungs during EVLP with values obtained in vivo to guide a safe mechanical ventilation strategy. Lungs from 5 healthy pigs were studied in vivo and during 4 hours of EVLP. Lung compliance, airway resistance, gas exchange, and hemodynamic parameters were collected at positive end-expiratory pressure (PEEP) of 5 cm H₂O. Computed tomography was performed at PEEP 0, PEEP 5, and total lung capacity (TLC). Lung pressure-volume (PV) curves were performed from PEEP 0 to TLC. Lung compliance decreased during EVLP (53 ± 5 mL/cm H₂O vs 29 ± 7 mL/cm H₂O, P < .05), and the PV curve showed a lower inflection point. Gas content (528 ± 118 mL vs 892 ± 402 mL at PEEP 0) and airway resistance (25 ± 5 vs 44 ± 9 cmH₂O/L∗s^-1, P < .05) were higher during EVLP. Alveolar dead space (5% ± 2% vs 17% ± 6%, P < .05) and intrapulmonary shunt (9% ± 2% vs 28% ± 13%, P < .05) increased ex vivo compared to in vivo, while the partial pressure of oxygen to inspired oxygen fraction ratio (PO₂/FiO₂) did not differ (468 ± 52 mm Hg vs 536 ± 14 mm Hg). In conclusion, during EVLP lungs show signs of air trapping and bronchoconstriction, resulting in low compliance and increased alveolar dead space. Intrapulmonary shunt is high despite oxygenation levels acceptable for transplantation.

Clinical transplantation using negative pressure ventilation ex situ lung perfusion with extended criteria donor lungs

Lung transplantation remains the best treatment option for end-stage lung disease; however, is limited by a shortage of donor grafts. Ex situ lung perfusion, also known as ex vivo lung perfusion, has been shown to allow for the safe evaluation and reconditioning of extended criteria donor lungs, increasing donor utilization. Negative pressure ventilation ex situ lung perfusion has been shown, preclinically, to result in less ventilator-induced lung injury than positive pressure ventilation. Here we demonstrate that, in a single-arm interventional study (ClinicalTrials.gov number NCT03293043) of 12 extended criteria donor human lungs, negative pressure ventilation ex situ lung perfusion allows for preservation and evaluation of donor lungs with all grafts and patients surviving to 30 days and recovered to discharge from hospital. This trial also demonstrates that ex situ lung perfusion is safe and feasible with no patients demonstrating primary graft dysfunction scores grade 3 at 72 h or requiring post-operative extracorporeal membrane oxygenation.

A Low-Cost Perfusate Alternative for Ex Vivo Lung Perfusion

BACKGROUND

Normothermic ex vivo lung perfusion (EVLP) has been used successfully to evaluate and recondition marginal donor lungs; however, multiple barriers continue to prevent its widespread adoption. We sought to develop a common hospital ingredient-derived perfusate (CHIP) with equivalent functional and inflammatory characteristics to a standard Krebs-Henseleit buffer with 8% serum albumin-derived perfusate (KHB-Alb) to improve access and reduce costs of ex vivo organ perfusion.

METHODS

Sixteen porcine lungs were perfused using negative pressure ventilation (NPV) EVLP for 12 hours in a normothermic state and were allocated equally to 2 groups: KHB-Alb vs CHIP. Physiological parameters, cytokine profiles, and edema formation were compared between treatment groups.

RESULTS

Perfused lungs in both groups demonstrated equivalent oxygenation (partial pressure of arterial oxygen/fraction of inspired oxygen ratio >350 mm Hg) and physiological parameters. There was equivalent generation of tumor necrosis factor-α and IL-6, irrespective of perfusate solution used, when comparing CHIP vs KHB-Alb. Pig lungs developed equivalent edema formation between groups (CHIP: 15.8 ± 4.8%, KHB-Alb 19.5 ± 4.4%, P > .05).

CONCLUSION

A perfusate derived of common hospital ingredients provides equivalent results to a standard Krebs-Henseleit buffer with 8% serum albumin-based perfusate in NPV-EVLP.

Hyperinflation With Pulmonary Dysfunction in Donor Lungs With Smoking History During Lung Perfusion

BACKGROUND

Donor lungs with smoking history are perfused in ex vivo lung perfusion (EVLP) to expand donor lung pool. However, the impact of hyperinflation of perfused lungs in EVLP remains unknown. The aim of this study was to investigate the significance of hyperinflation, using an ex vivo measurement delta V_T, during EVLP in smoker's lungs.

MATERIALS AND METHODS

Seventeen rejected donor lungs with smoking history of median 10 pack-years were perfused for 2 h in cellular EVLP. Hyperinflation was evaluated by measuring delta V_T = inspiratory - expiratory tidal volume (V_T) difference at 1 h. All lungs were divided into two groups; negative delta V_T (n = 11, no air-trapping pattern) and positive delta V_T (n = 6, air-trapping pattern). Transplant suitability was judged at 2 h. By using lung tissue, linear intercept analysis was performed to evaluate the degree of hyperinflation.

RESULTS

The positive delta V_T group had significantly lower transplant suitability than the negative delta V_T group (16 versus 81%, P = 0.035). The positive delta V_T group was significantly associated with lower partial pressure of oxygen/fraction of inspired oxygen ratio ratio (278 versus 356 mm Hg, P = 0.049), higher static compliance (119 versus 98 mL/cm H₂O, P = 0.050), higher lung weight ratio (1.10 versus 0.96, P = 0.014), and higher linear intercept ratio (1.52 versus 0.93, P = 0.005) than the negative delta V_T group.

CONCLUSIONS

Positive delta V_T appears as an ex vivo marker of ventilator-associated lung hyperinflation of smoker's lungs during EVLP.

Current techniques and the future of lung preservation

Although lung transplant remains the only option for patients suffering from end-stage lung failure, donor supply is insufficient to meet demand. Static cold preservation is the most common method to preserve lungs in transport to the recipient; however, this method does not improve lung quality and only allows for 8 h of storage. This results in lungs which become available for donation but cannot be used due to failure to meet physiologic criteria or an inability to store them for a sufficient time to find a suitable recipient. Therefore, lungs lost due to failure to meet physiological or compatibility criteria may be mitigated through preservation methods which improve lung function and storage durations. Ex situ lung perfusion (ESLP) is a recently developed method which allows for longer storage times and has been demonstrated to improve lung function such that rejected lungs can be accepted for donation. Although greater use of ESLP will help to improve donor lung utilization, the ability to cryopreserve lungs would allow for organ banking to better utilize donor lungs. However, lung cryopreservation research remains underrepresented in the literature despite its unique advantages for cryopreservation over other organs. Therefore, this review will discuss the current techniques for lung preservation, static cold preservation and ESLP, and provide a review of the cryopreservation challenges and advantages unique to lungs.

Mobile Extracorporeal Membrane Oxygenation Teams for Organ Donation After Circulatory Death

The shortage of available organ donors is a significant problem worldwide, and various efforts have been carried out to avoid the loss of potential organ donors. Among them, organ donation from cardiocirculatory deceased donors (DCD), in which withdrawal of life-sustaining therapies is ongoing (Maastricht type III donors), is one emerging strategy. Thanks to the latest advances in transplantation and organ preservation, such as normothermic regional perfusion (NRP), ex vivo perfusion techniques, and good organization and communication among prehospital care providers, emergency departments, intensive care units, and transplantation units, DCD is rapidly increasing; it's estimated that it will increase the number of donations of lungs and splanchnic organs by more than 40%. Although Maastricht type II DCD requires a 24/7 available experienced extra corporeal membrane oxygenation (ECMO) team in the institution, Maastricht DCD type III could be organized in secondary care and spoke hospitals without in loco ECMO facilities for NRP. This article analyses a potential mobile team organization based on the hub-and-spoke model, which already exists and functions in Italy, by estimating the dimension of the controlled DCD phenomenon in Italy, coordination requirements, costs, personnel training, and education, and reporting a single center experience in Milan, Italy.

Ex Vivo Lung Perfusion: A Review of Research and Clinical Practices

End-stage lung disease is ultimately treated with lung transplantation. However, there is a paucity of organs with an increasing number of patients being diagnosed with end-stage lung disease. Ex vivo lung perfusion has emerged as a potential tool to assess the quality and to recondition marginal donor lungs prior to transplantation with the goal of increasing the donor pool. This technology has shown promise with similar results compared with the conventional technique of cold static preservation in terms of primary graft dysfunction and overall outcomes. This review provides an update on the results and uses of this technology. The review will also summarize clinical studies and techniques in reconditioning and assessing lungs on ex vivo lung perfusion. Last, we discuss how this technology can be applied to fields outside of transplantation such as thoracic oncology and bioengineering.

Total parenteral nutrition in ex vivo lung perfusion: Addressing metabolism improves both inflammation and oxygenation

Ex vivo lung perfusion (EVLP) protocols generally limit metabolic supplementation to insulin and glucose. We sought to determine whether the addition of total parenteral nutrition (TPN) would improve lung function in EVLP. Ten porcine lungs were perfused using EVLP for 24 hours and supplemented with insulin and glucose. In the treatment group (n = 5), the perfusate was also supplemented with a continuous infusion of TPN containing lipids, amino acids, essential vitamins, and cofactors. Physiologic parameters and perfusate electrolytes were continuously evaluated. Perfusate lactate, lipid and branch chain amino acid (BCAA) concentrations were also analyzed to elucidate how substrates were being utilized over time. Lungs in the TPN group exhibited significantly better oxygenation. Perfusate sodium was more stable in the TPN group. In the control group, free fatty acids (FFA) were quickly depleted, reaching negligible levels early in the perfusion. Alternatively, BCAA in the control group rose continually over the perfusion demonstrating a shift toward proteolysis for energy substrate. In the TPN group, both FFA and BCAA concentrations remained stable at in vivo levels after initial stabilization. TNF-α concentrations were lower in the TPN group. The addition of TPN in EVLP allows for better electrolyte composition, decreased inflammation, and improved graft performance.

Ex vivo lung perfusion prior to transplantation: an overview of current clinical practice worldwide

Lung transplantation is a lifesaving treatment in numerous forms of end-stage lung disease but organ shortage remains nowadays his biggest issue. Ex vivo lung perfusion (EVLP) has recently emerged as a solution to this problem and begins to be accepted is clinical practice. In this review, we will focus on his experience worldwide. We would like to describe the technique and the criteria used to select the donors and the transplantable lungs. We will also browse the acceptance rate described in literature as well as numerous other aspects of this new tool.

Early Graft Dysfunction after Lung Transplantation

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Current state of ex-vivo lung perfusion

PURPOSE OF REVIEW

The purpose of the current report is to review the ex-vivo peer-reviewed literature published in the last 5 years and to summarize the findings.

RECENT FINDINGS

Encouraging data have been published by several centers utilizing ex-vivo lung perfusion (EVLP) as a means to identify viable grafts from the high-risk donor pool. The outcomes of transplanted lungs that were initially declined because of poor quality, but reevaluated with ex-vivo perfusion, are equivalent to standard criteria donor lungs. Further, research reports have emphasized the role of ex-vivo perfusion as a platform to improve graft quality and reduce the injurious effects of ischemia-reperfusion.

SUMMARY

Over the last 10 years, EVLP has proved its value as a reassessment tool to increase donor utilization. As short- and long-term data demonstrate the safety of EVLP, its use as a therapeutic platform is emerging, along with the promise of a new era in lung transplantation.

Ex Vivo Lung Perfusion in the Rat: Detailed Procedure and Videos

Ex vivo lung perfusion (EVLP) is a promising procedure for evaluation, reconditioning, and treatment of marginal lungs before transplantation. Small animal models can contribute to improve clinical development of this technique and represent a substantial platform for bio-molecular investigations. However, to accomplish this purpose, EVLP models must sustain a prolonged reperfusion without pharmacological interventions. Currently available protocols only partly satisfy this need. The aim of the present research was accomplishment and optimization of a reproducible model for a protracted rat EVLP in the absence of anti-inflammatory treatment. A 180 min, uninjured and untreated perfusion was achieved through a stepwise implementation of the protocol. Flow rate, temperature, and tidal volume were gradually increased during the initial reperfusion phase to reduce hemodynamic and oxidative stress. Low flow rate combined with open atrium and protective ventilation strategy were applied to prevent lung damage. The videos enclosed show management of the most critical technical steps. The stability and reproducibility of the present procedure were confirmed by lung function evaluation and edema assessment. The meticulous description of the protocol provided in this paper can enable other laboratories to reproduce it effortlessly, supporting research in the EVLP field.

How to minimise ventilator-induced lung injury in transplanted lungs: The role of protective ventilation and other strategies

Lung transplantation is the treatment of choice for end-stage pulmonary diseases. In order to avoid or reduce pulmonary and systemic complications, mechanical ventilator settings have an important role in each stage of lung transplantation. In this respect, the use of mechanical ventilation with a tidal volume of 6 to 8 ml  kg(-1) predicted body weight, positive end-expiratory pressure of 6 to 8 cmH2O and a plateau pressure lower than 30 cmH2O has been suggested for the donor during surgery, and for the recipient both during and after surgery. For the present review, we systematically searched the PubMed database for articles published from 2000 to 2014 using the following keywords: lung transplantation, protective mechanical ventilation, lung donor, extracorporeal membrane oxygenation, recruitment manoeuvres, extracorporeal CO2 removal and noninvasive ventilation.

Primary graft dysfunction: lessons learned about the first 72 h after lung transplantation

PURPOSE OF REVIEW

In 2005, the International Society for Heart and Lung Transplantation published a standardized definition of primary graft dysfunction (PGD), facilitating new knowledge on this form of acute lung injury that occurs within 72 h of lung transplantation. PGD continues to be associated with significant morbidity and mortality. This article will summarize the current literature on the epidemiology of PGD, pathogenesis, risk factors, and preventive and treatment strategies.

RECENT FINDINGS

Since 2011, several manuscripts have been published that provide insight into the clinical risk factors and pathogenesis of PGD. In addition, several transplant centers have explored preventive and treatment strategies for PGD, including the use of extracorporeal strategies. More recently, results from several trials assessing the role of extracorporeal lung perfusion may allow for much-needed expansion of the donor pool, without raising PGD rates.

SUMMARY

This article will highlight the current state of the science regarding PGD, focusing on recent advances, and set a framework for future preventive and treatment strategies.

Graft downsizing during ex vivo lung perfusion: case report and technical notes

Among patients with respiratory insufficiency awaiting lung transplantation, small adult patients have a lower opportunity of receiving size-matched pulmonary grafts, because of the shortage of donors, particularly those of small size. Reducing the size of an oversized graft is one of the methods to increase the donor pool; similarly, ex vivo lung perfusion is an emerging technique aimed toward the same purpose. We describe how we combined the 2 techniques (lobar transplantation plus contralateral nonanatomic graft reduction during ex vivo lung perfusion) to overcome graft shortage in a clinical case. For the 1st time, this case report demonstrates that surgical manipulation during ex vivo lung perfusion does not affect the functional improvement in a lung previously judged to be not suitable for transplantation. The 6-month follow-up results are similar to those of standard bilateral lung transplantation.

Clinical risk factors for primary graft dysfunction in a low-volume lung transplantation center

Primary graft dysfunction (PGD) is a severe acute lung injury syndrome following lung transplantation. Previous studies of clinical risk factors, including a multicenter prospective cohort trial, have identified a number of recipient, donor, and operative variables related to Grade 3 PGD. The aim of this study was to validate these risk factors in a lung transplantation center with a low volume of procedures. We conducted a retrospective cohort study of 45 consecutive lung transplantations performed between January 2011 and September 2013. PGD was defined according to the International Society for Heart and Lung Transplantation grading scale. Risk factors were evaluated independently and the significant confounders entered into multivariable logistic regression models. The overall incidence of Grade 3 PGD was 35.5% at T24, 17.7% at T48, and 15.5% at T72. The following risk factors were associated with Grade 3 PGD at the indicated time points: recipient female gender at T24 (P=.034), mixed diagnoses at T72 (P=.047), ECMO bridge-to-lung transplantation at T24 (P=.0004) and at T48 (P=.038), donor causes of death different from stroke and trauma at T24 (P=.019) and T72 (P=.014), blood transfusions during surgery at T24 (P=.001), intraoperative venoarterial ECMO T24 (P<.0001). Multivariate analysis at T24 identified recipient female gender and intraoperative venoarterial ECMO as risk factors (P=.010 and P=.018, respectively). This study demonstrated that risk factors for severe PGD in a low-volume center were similar to international reports in prevalence and type. ECMO bridge-to-lung transplantation emerged as a risk factor previously underestimated.

Acute kidney injury after ex vivo lung perfusion (EVLP)

BACKGROUND

Ex vivo lung perfusion (EVLP) identifies viability for marginal organs but complicates and lengthens lung transplantation surgery. Preliminary evidence supports equivalency for EVLP-assisted versus traditional (non-EVLP) procedures regarding graft function, postoperative course, mortality, and survival. However, acute kidney injury (AKI), a common serious complication of lung transplantation, has not been assessed. We tested the hypothesis that EVLP-assisted and non-EVLP lung transplantations are associated with different AKI rates.

METHODS

Demographic, procedural, and renal data were gathered for 13 EVLP-viable lung transplantations and a non-EVLP group matched 4:1 for single versus double, pulmonary disease, and age. AKI was defined by AKI Network (AKIN) criteria and peak creatinine rise relative to baseline (Δ%Cr) during the 1st 10 postoperative days. Chi-square was performed for AKIN and 2-tailed t test for %ΔCr.

RESULTS

Patient and procedural characteristics were similar between the groups. One non-EVLP patient required postoperative dialysis. AKI rates were also similar, as assessed by both AKIN (EVLP 7/13 (54%) vs non-EVLP 32/52 (62%); P = .61) and %ΔCr (EVLP 91 ± 81% vs non-EVLP 72 ± 62%; P = .63).

CONCLUSIONS

We did not observe different AKI rates between EVLP-assisted and traditional lung transplant procedures. Although 1 non-EVLP patient required dialysis, AKI rates were otherwise similar. These findings further support EVLP as a strategy to expand the organ pool and reduce concerns for high-renal risk recipients. The small sample size and retrospective design are limitations. However, our sample size is similar to other reports, and it is the first to analyze AKI after EVLP-assisted lung transplantation. Larger multicenter prospective studies are needed.

Shear stress-related mechanosignaling with lung ischemia: lessons from basic research can inform lung transplantation

Cessation of blood flow represents a physical event that is sensed by the pulmonary endothelium leading to a signaling cascade that has been termed "mechanotransduction." This paradigm has clinical relevance for conditions such as pulmonary embolism, lung bypass surgery, and organ procurement and storage during lung transplantation. On the basis of our findings with stop of flow, we postulate that normal blood flow is "sensed" by the endothelium by virtue of its location at the interface of the blood and vessel wall and that this signal is necessary to maintain the endothelial cell membrane potential. Stop of flow is sensed by a "mechanosome" consisting of PECAM-VEGF receptor-VE cadherin that is located in the endothelial cell caveolae. Activation of the mechanosome results in endothelial cell membrane depolarization that in turn leads to activation of NADPH oxidase (NOX2) to generate reactive oxygen species (ROS). Endothelial depolarization additionally results in opening of T-type voltage-gated Ca(2+) channels, increased intracellular Ca(2+), and activation of nitric oxide (NO) synthase with resultant generation of NO. Increased NO causes vasodilatation whereas ROS provide a signal for neovascularization; however, with lung transplantation overproduction of ROS and NO can cause oxidative injury and/or activation of proteins that drive inflammation and cell death. Understanding the key events in the mechanosignaling cascade has important lessons for the design of strategies or interventions that may reduce injury during storage of donor lungs with the goal to increase the availability of lungs suitable for donation and thus improving access to lung transplantation.

The billion cell construct: will three-dimensional printing get us there?

Effective utilization of three-dimensional printing for tissue and organ engineering remains nontrivial. Here, Jordan Miller identifies key challenges and discusses conceptual targets on the horizon.

How structure relates to function—across spatial scales, from the single molecule to the whole organism—is a central theme in biology. Bioengineers, however, wrestle with the converse question: will function follow form? That is, we struggle to approximate the architecture of living tissues experimentally, hoping that the structure we create will lead to the function we desire. A new means to explore the relationship between form and function in living tissue has arrived with three-dimensional printing, but the technology is not without limitations.

A standardized model of brain death, donor treatment, and lung transplantation for studies on organ preservation and reconditioning

BACKGROUND

We set a model of brain death, donor management, and lung transplantation for studies on lung preservation and reconditioning before transplantation.

METHODS

Ten pigs (39.7 ± 5.9 Kg) were investigated. Five animals underwent brain death and were treated as organ donors; the lungs were then procured and cold stored (Ischemia). Five recipients underwent left lung transplantation and post-reperfusion follow-up (Graft). Cardiorespiratory and metabolic parameters were collected. Lung gene expression of cytokines (tumor necrosis factor alpha (TNFα), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interferon gamma (IFNγ), high mobility group box-1 (HMGB-1)), chemokines (chemokine CC motif ligand-2 (CCL2-MCP-1), chemokine CXC motif ligand-10 (CXCL-10), interleukin-8 (IL-8)), and endothelial activation markers (endothelin-1 (EDN-1), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), selectin-E (SELE)) was assessed by real-time polymerase chain reaction (PCR).

RESULTS

Tachycardia and hypertension occurred during brain death induction; cardiac output rose, systemic vascular resistance dropped (P < 0.05), and diabetes insipidus occurred. Lung-protective ventilation strategy was applied: 9 h after brain death induction, PaO2 was 192 ± 12 mmHg at positive end-expiratory pressure (PEEP) 8.0 ± 1.8 cmH2O and FiO2 of 40%; wet-to-dry ratio (W/D) was 5.8 ± 0.5, and extravascular lung water (EVLW) was 359 ± 80 mL. Procured lungs were cold-stored for 471 ± 24 min (Ischemia) at the end of which W/D was 6.1 ± 0.9. Left lungs were transplanted and reperfused (warm ischemia 98 ± 14 min). Six hours after controlled reperfusion, PaO2 was 192 ± 23 mmHg (PEEP 8.7 ± 1.5 cmH2O, FiO2 40%), W/D was 5.6 ± 0.4, and EVLW was 366 ± 117 mL. Levels of IL-8 rose at the end of donor management (BD, P < 0.05); CCL2-MCP-1, IL-8, HMGB-1, and SELE were significantly altered after reperfusion (Graft, P < 0.05).

CONCLUSIONS

We have set a standardized, reproducible pig model resembling the entire process of organ donation that may be used as a platform to test in vivo and ex vivo strategies of donor lung optimization before transplantation.

Advances in lung preservation

After a brief review of conventional lung preservation, this article discusses the rationale behind ex vivo lung perfusion and how it has shifted the paradigm of organ preservation from conventional static cold ischemia to the utilization of functional normothermia, restoring the lung's own metabolism and its reparative processes. Technical aspects and previous clinical experience as well as opportunities to address specific donor organ injuries in a personalized medicine approach are also reviewed.

Primary graft dysfunction

Primary graft dysfunction (PGD) is a syndrome encompassing a spectrum of mild to severe lung injury that occurs within the first 72 hours after lung transplantation. PGD is characterized by pulmonary edema with diffuse alveolar damage that manifests clinically as progressive hypoxemia with radiographic pulmonary infiltrates. In recent years, new knowledge has been generated on risks and mechanisms of PGD. Following ischemia and reperfusion, inflammatory and immunological injury-repair responses appear to be key controlling mechanisms. In addition, PGD has a significant impact on short- and long-term outcomes; therefore, the choice of donor organ is impacted by this potential adverse consequence. Improved methods of reducing PGD risk and efforts to safely expand the pool are being developed. Ex vivo lung perfusion is a strategy that may improve risk assessment and become a promising platform to implement treatment interventions to prevent PGD. This review details recent updates in the epidemiology, pathophysiology, molecular and genetic biomarkers, and state-of-the-art technical developments affecting PGD.