Protective effect of plasmin in marginal donor lungs in an ex vivo lung perfusion model

Salvaging donated kidneys from prolonged warm ischemia during ex vivo hypothermic oxygenated perfusion

Prolonged warm ischemic is the main cause discarding donated organs after cardiac death. Here, we identified that prolonged warm ischemic time induced disseminated intravascular coagulation and severe capillary vasospasm after cardiac death of rat kidneys. Additionally, we found a significant accumulation of fibrinogen in a hypoxic cell culture of human umbilical vein epithelial cells and in isolated kidneys exposed to prolonged warm ischemic following flushing out of blood. However, pre-flushing the kidney with snake venom plasmin in a 90-minute warm ischemic model maximized removal of micro thrombi and facilitated the delivery of oxygen and therapeutic agents. Application of carbon monoxide releasing CORM-401 during ex vivo hypothermic oxygenated perfusion achieved multipath protective effects in prolonged warm ischemic kidneys. This led to significant improvements in perfusion parameters, restoration of the microcirculation, amelioration of mitochondrial injury, oxidative stress, and apoptosis. This benefit resulted in significantly prolonged warm ischemic kidney recipient survival rates of 70%, compared with none in those receiving ex vivo hypothermic oxygenated perfusion alone. Significantly, ex vivo hypothermic oxygenated perfusion combined with cytoprotective carbon monoxide releasing CORM-401 treatment meaningfully protected the donated kidney after cardiac death from ischemia-reperfusion injury by reducing inflammation, oxidative stress, apoptosis, and pathological damage. Thus, our study suggests a new combination treatment strategy to potentially expand the donor pool by increasing use of organs after cardiac death and salvaging prolonged warm ischemic kidneys.

Current Techniques and Indications for Machine Perfusion and Regional Perfusion in Deceased Donor Liver Transplantation

Since the advent of University of Wisconsin preservation solution in the 1980s, clinicians have learned to work within its confines. While affording improved outcomes, considerable limitations still exist and contribute to the large number of livers that go unused each year, often for fear they may never work. The last 10 years have seen the widespread availability of new perfusion modalities which provide an opportunity for assessing organ viability and prolonged organ storage. This review will discuss the role of in situ normothermic regional perfusion for livers donated after circulatory death. It will also describe the different modalities of ex situ perfusion, both normothermic and hypothermic, and discuss how they are thought to work and the opportunities afforded by them.

Real-time Lung Weight Measurement During Cellular Ex Vivo Lung Perfusion: An Early Predictor of Transplant Suitability

BACKGROUND

Increased extravascular lung water during ex vivo lung perfusion (EVLP) is associated with ischemia reperfusion injury and poor pulmonary function. A non-invasive technique for evaluating extravascular lung water during EVLP is desired to assess the transplant suitability of lungs. We investigated real-time lung weight measurements as a reliable method for assessing pulmonary functions in cellular EVLP using a porcine lung model.

METHODS

Fifteen pigs were randomly divided into 3 groups: control (no warm ischemia) or donation after circulatory death groups with 60 or 90 min of warm ischemia (n = 5, each). Real-time lung weight gain was measured by load cells positioned at the bottom of the organ chamber.

RESULTS

Real-time lung weight gain at 2 h was significantly correlated with lung weight gain as measured on a back table ( R  = 0.979, P  < 0.01). Lung weight gain in non-suitable cases (n = 6) was significantly higher than in suitable cases (n = 9) at 40 min (51.6 ± 46.0 versus -8.8 ± 25.7 g; P  < 0.01, cutoff = +12 g, area under the curve = 0.907). Lung weight gain at 40 min was significantly correlated with PaO 2 /FiO 2 , peak inspiratory pressure, shunt ratio, wet/dry ratio, and transplant suitability at 2 h ( P  < 0.05, each). In non-suitable cases, lung weight gain at 66% and 100% of cardiac output was significantly higher than at 33% ( P  < 0.05).

CONCLUSIONS

Real-time lung weight measurement could potentially be an early predictor of pulmonary function in cellular EVLP.

Exploring predisposing factors and pathogenesis contributing to injuries of donor lungs

INTRODUCTION

Lung transplantation (LTx) remains the only therapeutic strategy for patients with incurable lung diseases. However, its use has been severely limited by the narrow donor pool and potential concerns of inferior quality of donor lungs, which are more susceptible to external influence than other transplant organs. Multiple insults, including various causes of death and a series of perimortem events, may act together on donor lungs and eventually culminate in primary graft dysfunction (PGD) after transplantation as well as other poor short-term outcomes.

AREAS COVERED

This review focuses on the predisposing factors contributing to injuries to the donor lungs, specifically focusing on the pathogenesis of these injuries and their impact on post-transplant outcomes. Additionally, various maneuvers to mitigate donor lung injuries have been proposed.

EXPERT OPINION

The selection criteria for eligible donors vary and may be poor discriminators of lung injury. Not all transplanted lungs are in ideal condition. With the rapidly increasing waiting list for LTx, the trend of using marginal donors has become more apparent, underscoring the need to gain a deeper understanding of donor lung injuries and discover more donor resources.

Theoretical and Practical Aspects in the Use of Bretschneider Cardioplegia

The race for an ideal cardioplegic solution has remained enthusiastic since the beginning of the modern cardiac surgery era. The Bretschneider solution, belonging to the “intracellular cardioplegic” group, is safe and practical in myocardial protection during ischemic time. Over time, some particular concerns have arisen regarding the effects on cardiac metabolism and postoperative myocardial functioning. This paper reviews the most important standpoints in terms of theoretical and practical analyses.

A translational rat model for ex vivo lung perfusion of pre-injured lungs after brain death

The process of brain death (BD) detrimentally affects donor lung quality. Ex vivo lung perfusion (EVLP) is a technique originally designed to evaluate marginal donor lungs. Nowadays, its potential as a treatment platform to repair damaged donor lungs is increasingly studied in experimental models. Rat models for EVLP have been described in literature before, yet the pathophysiology of BD was not included in these protocols and prolonged perfusion over 3 hours without anti-inflammatory additives was not achieved. We aimed to establish a model for prolonged EVLP of rat lungs from brain-dead donors, to provide a reliable platform for future experimental studies. Rat lungs were randomly assigned to one of four experimental groups (n = 7/group): 1) healthy, directly procured lungs, 2) lungs procured from rats subjected to 3 hours of BD and 1 hour cold storage (CS), 3) healthy, directly procured lungs subjected to 6 hours EVLP and 4), lungs procured from rats subjected to 3 hours of BD, 1 hour CS and 6 hours EVLP. Lungs from brain-dead rats showed deteriorated ventilation parameters and augmented lung damage when compared to healthy controls, in accordance with the pathophysiology of BD. Subsequent ex vivo perfusion for 6 hours was achieved, both for lungs of healthy donor rats as for pre-injured donor lungs from brain-dead rats. The worsened quality of lungs from brain-dead donors was evident during EVLP as well, as corroborated by deteriorated ventilation performance, increased lactate production and augmented inflammatory status during EVLP. In conclusion, we established a stable model for prolonged EVLP of pre-injured lungs from brain-dead donor rats. In this report we describe tips and pitfalls in the establishment of the rat EVLP model, to enhance reproducibility by other researchers.

The potential of ex vivo lung perfusion on improving organ quality and ameliorating ischemia reperfusion injury

Allogeneic lung transplantation (LuTx) is considered the treatment of choice for a broad range of advanced, progressive lung diseases resistant to conventional treatment regimens. Ischemia reperfusion injury (IRI) occurring upon reperfusion of the explanted, ischemic lung during implantation remains a crucial mediator of primary graft dysfunction (PGD) and early allo-immune responses. Ex vivo lung perfusion (EVLP) displays an advanced technique aiming at improving lung procurement and preservation. Indeed, previous clinical trials have demonstrated a reduced incidence of PGD following LuTx utilizing EVLP, while long-term outcomes are yet to be evaluated. Mechanistically, EVLP may alleviate donor lung inflammation through reconditioning the injured lung and diminishing IRI through storing the explanted lung in a non-ischemic, perfused, and ventilated status. In this work, we review potential mechanisms of EVLP that may attenuate IRI and improve organ quality. Moreover, we dissect experimental treatment approaches during EVLP that may further attenuate inflammatory events deriving from tissue ischemia, shear forces or allograft rejection associated with LuTx.

Ischemia-Reperfusion Injury in Lung Transplantation

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

Ex vivo lung perfusion for donor lung assessment and repair: a review of translational interspecies models

For patients with end-stage lung disease, lung transplantation is a lifesaving therapy. Currently however, the number of patients who require a transplant exceeds the number of donor lungs available. One of the contributing factors to this is the conservative mindset of physicians who are concerned about transplanting marginal lungs due to the potential risk of primary graft dysfunction. Ex vivo lung perfusion (EVLP) technology has allowed for the expansion of donor pool of organs by enabling assessment and reconditioning of these marginal grafts before transplant. Ongoing efforts to optimize the therapeutic potential of EVLP are underway. Researchers have adopted the use of different large and small animal models to generate translational preclinical data. This includes the use of rejected human lungs, pig lungs, and rat lungs. In this review, we summarize some of the key current literature studies relevant to each of the major EVLP model platforms and identify the advantages and disadvantages of each platform. The review aims to guide investigators in choosing an appropriate species model to suit their specific goals of study, and ultimately aid in translation of therapy to meet the growing needs of the patient population.

New Techniques for Optimization of Donor Lungs/Hearts

Injuries sustained by donor heart and lung allografts during the transplantation process are multiple and cumulative. Optimization of allograft function plays an essential role in short- and long-term outcomes after transplantation. Therapeutic targets to prevent or attenuate injury are present in the donor, the preservation process, during transplantation, and in postoperative management of the recipient. The newest and most promising methods of optimizing donor heart and lung allografts are found in alternative preservation strategies, which enable functional assessment of donor organs and provide a modality to initiate therapies for injured allografts or prevent injury during reperfusion in recipients.

Integrating Non-human Primate, Human, and Mathematical Studies to Determine the Influence of BCG Timing on H56 Vaccine Outcomes

Background

Acute lung injury (ALI) is characterized by suppressed fibrinolytic activity in bronchoalveolar lavage fluid (BALF) attributed to elevated plasminogen activator inhibitor-1 (PAI-1). Restoring pulmonary fibrinolysis by delivering tissue-type plasminogen activator (tPA), urokinase plasminogen activator (uPA), and plasmin could be a promising approach.

Objectives

To systematically analyze the overall benefit of fibrinolytic therapy for ALI reported in preclinical studies.

Methods

We searched PubMed, Embase, Web of Science, and CNKI Chinese databases, and analyzed data retrieved from 22 studies for the beneficial effects of fibrinolytics on animal models of ALI.

Results

Both large and small animals were used with five routes for delivering tPA, uPA, and plasmin. Fibrinolytics significantly increased the fibrinolytic activity both in the plasma and BALF. Fibrin degradation products in BALF had a net increase of 408.41 ng/ml vs controls (P < 0.00001). In addition, plasma thrombin–antithrombin complexes increased 1.59 ng/ml over controls (P = 0.0001). In sharp contrast, PAI-1 level in BALF decreased 21.44 ng/ml compared with controls (P < 0.00001). Arterial oxygen tension was improved by a net increase of 15.16 mmHg, while carbon dioxide pressure was significantly reduced (11.66 mmHg, P = 0.0001 vs controls). Additionally, fibrinolytics improved lung function and alleviated inflammation response: the lung wet/dry ratio was decreased 1.49 (P < 0.0001 vs controls), lung injury score was reduced 1.83 (P < 0.00001 vs controls), and BALF neutrophils were lesser (3 × 10⁴/ml, P < 0.00001 vs controls). The mortality decreased significantly within defined study periods (6 h to 30 days for mortality), as the risk ratio of death was 0.2-fold of controls (P = 0.0008).

Conclusion

We conclude that fibrinolytic therapy may be effective pharmaceutic strategy for ALI in animal models.

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.

Pharmacological Reconditioning of Marginal Donor Rat Lungs Using Inhibitors of Peroxynitrite and Poly (ADP-ribose) Polymerase During Ex Vivo Lung Perfusion

BACKGROUND

Donor lungs obtained after prolonged warm ischemia (WI) may be unsuitable for transplantation due to the risk of reperfusion injury, but could be reconditioned using ex-vivo lung perfusion (EVLP). Key processes of reperfusion injury include the formation of reactive oxygen species (ROS)/nitrogen species (RNS) and the activation of poly(adenosine diphosphate-ribose) polymerase (PARP). We explored whether rat lungs obtained after WI could be reconditioned during EVLP using the ROS/RNS scavenger Mn(III)-tetrakis (4-benzoic acid) porphyrin chloride (MnTBAP) or the PARP inhibitor 3-aminobenzamide (3-AB).

METHODS

Rat lungs obtained after 3 hours cold ischemia (CI group, control), or 1 hour WI plus 2 hours CI (WI group) were placed in an EVLP circuit for normothermic perfusion for 3 hours. Lungs retrieved after WI were treated or not with 3-AB (1 mg/mL) or MnTBAP (0.3 mg/mL), added to the perfusate. Measurements included physiological variables (lung compliance, vascular resistance, oxygenation capacity), lung weight gain, levels of proteins, lactate dehydrogenase, protein carbonyl (marker of ROS), 3-nitrotyrosine (marker of RNS), poly(adenosine diphosphate-ribose) (PAR, marker of PARP activation) and IL-6, in the bronchoalveolar lavage or the lung tissue, and histology.

RESULTS

In comparison to the CI group, the lungs from the WI group displayed higher protein carbonyls, 3-nitrotyrosine, PAR, lactate dehydrogenase and proteins in bronchoalveolar lavage, lung weight gain, perivascular edema, as well as reduced static compliance, but similar oxygenation. All these alterations were markedly attenuated by 3-AB and MnTBAP.

CONCLUSIONS

After EVLP, lungs obtained after WI exhibit oxidative stress, PARP activation, and tissue injury, which are suppressed by pharmacological inhibitors of ROS/RNS and PARP.

Models of Lung Transplant Research: a consensus statement from the National Heart, Lung, and Blood Institute workshop

Lung transplantation, a cure for a number of end-stage lung diseases, continues to have the worst long-term outcomes when compared with other solid organ transplants. Preclinical modeling of the most common and serious lung transplantation complications are essential to better understand and mitigate the pathophysiological processes that lead to these complications. Various animal and in vitro models of lung transplant complications now exist and each of these models has unique strengths. However, significant issues, such as the required technical expertise as well as the robustness and clinical usefulness of these models, remain to be overcome or clarified. The National Heart, Lung, and Blood Institute (NHLBI) convened a workshop in March 2016 to review the state of preclinical science addressing the three most important complications of lung transplantation: primary graft dysfunction (PGD), acute rejection (AR), and chronic lung allograft dysfunction (CLAD). In addition, the participants of the workshop were tasked to make consensus recommendations on the best use of these complimentary models to close our knowledge gaps in PGD, AR, and CLAD. Their reviews and recommendations are summarized in this report. Furthermore, the participants outlined opportunities to collaborate and directions to accelerate research using these preclinical models.

Primary graft dysfunction: pathophysiology to guide new preventive therapies

INTRODUCTION

Primary graft dysfunction (PGD) is a common complication of lung transplantation characterized by acute pulmonary edema associated with bilateral pulmonary infiltrates and hypoxemia in the first 3 post-operative days. Development of PGD is a predictor of poor short- and long-term outcomes after lung transplantation, but there are currently limited tools to prevent its occurrence. Areas covered: Several potentially modifiable donor, recipient, and operative risk factors for PGD have been identified. In addition, basic and translational studies in animals and ex vivo lung perfusion systems have identified several biomarkers and mechanisms of injury in PGD. In this review, we outline the clinical and genetic risk factors for PGD and summarize experimental data exploring PGD mechanisms, with a focus on strategies to reduce PGD risk and on potential novel molecular targets for PGD prevention. Expert commentary: Because of the clinical importance of PGD, development of new therapies for prevention and treatment is critically important. Improved understanding of the pathophysiology of clinical PGD provides a framework to explore novel agents to prevent or reverse PGD. Ex vivo lung perfusion provides a new opportunity for rapid development of therapeutics that target this devastating complication of 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.

Plasmin-loaded echogenic liposomes for ultrasound-mediated thrombolysis

Plasmin, a direct fibrinolytic, shows a significantly superior hemostatic safety profile compared to recombinant tissue plasminogen activator (rtPA), the only FDA-approved thrombolytic for the treatment of acute ischemic stroke. The improved safety of plasmin is attributed to the rapid inhibition of free plasmin by endogenous plasmin inhibitors present in very high concentrations (1 μM). However, this rapid inhibition prevents the intravenous (IV) administration of plasmin. In emergency situations, catheter-based local administration is not practical. There is a need for an alternative technique for IV administration of plasmin. A possible solution is the encapsulation of plasmin in echogenic liposomes (ELIP) for protection from inhibitors until ultrasound (US)-triggered release at the clot site. ELIP are bilayer phospholipid vesicles with encapsulated gas microbubbles. US induces oscillation and collapse of the gas bubbles, which facilitates ELIP rupture and delivery of the encapsulated contents. Plasmin-loaded ELIP (PELIP) were manufactured and characterized for size, gas and drug encapsulations, and in vitro thrombolytic efficacy using a human whole blood clot model. Clots were exposed to PELIP with and without exposure to US (center frequency 120 kHz, pulse repetition frequency 1667 Hz, peak-to-peak pressure of 0.35 MPa, 50 % duty cycle). Thrombolytic efficacy was calculated by measuring the change in clot width over a 30-min treatment period using an edge detection MATLAB program. The mean clot lysis obtained with PELIP in the presence of US exposure was 31 % higher than that obtained without US exposure and 15 % higher than that obtained with rtPA treatment (p < 0.05).The enhanced clot lysis is attributed to the US-mediated release of plasmin from the liposomes.

Novel thermographic detection of regional malperfusion caused by a thrombosis during ex vivo lung perfusion

OBJECTIVES

Although ex vivo lung perfusion (EVLP) has been clinically applied as a novel rig to evaluate marginal donor lungs, no parameters have been reported to objectively detect regional lung damage during EVLP. The aim of this study was to investigate whether regional donor lung malperfusion-related damage caused by a thrombus could be detected by thermography during EVLP.

METHODS

Lewis rats were divided into two groups: the Thrombosis group and the Control group (n = 6 in each group). All rats were heparinized and the lungs were flushed with 20 ml of Steen solution. In the Thrombosis group, a 30-mg artificial thrombus was inserted into the left main pulmonary artery. All the lungs were perfused and ventilated using the EVLP system. Perfusion flow was increased every 2 min up to 10 ml/min. The lungs were evaluated by collecting thermographical and physiological data during EVLP.

RESULTS

Pulmonary artery pressure was higher and lung compliance was lower in the Thrombosis group compared with those in the Control group (P = 0.0005 and <0.0001, respectively). Macroscopically, no differences were seen between the perfused area and the malperfused area, whereas significant differences were detected between them by thermography. The surface temperature of both lungs in the Control group and the right lungs in the Thrombosis group rose with increasing perfusion flow, whereas the surface temperature of the left lungs in the Thrombosis group did not rise (P < 0.0001).

CONCLUSIONS

Although physiological data could possibly imply the existence of thrombi in the Thrombosis group, it could not reveal which area was obstructed by thrombi; however, thermography could detect a malperfused region. Thermographical evaluation may become a promising strategy to detect regional damage in donor lungs.

Cardioprotection: a review of current practice in global ischemia and future translational perspective

The idea of protecting the heart from ischemic insult during heart surgery to allow elective cardiac arrest is as old as the idea of cardiac surgery itself. The current gold standard in clinical routine is a high potassium regimen added either to crystalloid or blood cardioplegic solutions inducing depolarized arrest. Ongoing patient demographic changes with increasingly older, comorbidly ill patients and increasing case complexity with increasingly structurally abnormal hearts as morphological correlate paired with evolutions in pediatric cardiac surgery allowing more complex procedures than ever before redefine requirements for cardioprotection. Many, in part adversarial, regimens to protect the myocardium from ischemic insults have entered clinical routine; however, functional recovery of the heart is still often impaired due to perfusion injury. Myocardial reperfusion damage is a key determinant of postoperative organ functional recovery, morbidity, and mortality in adult and pediatric patients. There is a discrepancy between what current protective strategies are capable of and what they are expected to do in a rapidly changing cardiac surgery community. An increased understanding of the molecular players of ischemia reperfusion injury offers potential seeds for new cardioprotective regimens and may further displace boundaries of what is technically feasible.

Plasmin administration during ex vivo lung perfusion ameliorates lung ischemia-reperfusion injury

BACKGROUND

Donor lung thrombus is considered a significant etiology for primary graft dysfunction (PGD). We hypothesized that thrombolysis in ex vivo lung perfusion (EVLP) before lung transplantation could alleviate ischemia-reperfusion injury (IRI), resulting in a decreased incidence of PGD.

METHODS

Rats were divided into control (n = 5), non-plasmin (n = 7) and plasmin (n = 7) groups. In the non-plasmin and plasmin groups, cardiac arrest was induced by withdrawal of ventilation without heparinization. After 120 minutes of warm ischemia, the lungs were ventilated and flushed. Hearts and both lungs were excised en bloc. The lungs were perfused and ventilated in the EVLP for 30 minutes, and plasmin or placebo was administered on EVLP initiation. The lungs were then stored at 4°C for 90 minutes and finally perfused with rat blood for 80 minutes. We assessed physiologic and histologic findings during reperfusion and the correlation between physiologic data during EVLP and after reperfusion.

RESULTS

Physiologic results were better in the plasmin group than in the non-plasmin group. The plasmin group lungs had fewer signs of histologic injury. Caspase-3 and -7 activity in the plasmin group was lower in the non-plasmin group. Pulmonary vascular resistance (PVR) during EVLP correlated with that at the end of reperfusion.

CONCLUSIONS

Plasmin administration during EVLP protected the donor lungs after reperfusion. We also found that several physiologic values in EVLP may be predictive markers of lung function after reperfusion.