Lung transplantation with lungs from donors fifty years of age and older

Comparison of Prognosis for Lung Transplantation between Older and Younger Donors: A Systematic Review and Meta-Analysis Based on Cohort Studies

PURPOSE

This meta-analysis aimed to compare the prognosis of lung transplantation recipients based on donor age.

METHODS

A detailed search was performed in PubMed, Embase, Web of Science, and the Cochrane Library for cohort studies on lung transplantation. The prognosis of lung transplant recipients was investigated based on the donor age, with the primary outcomes being 1-year overall survival (OS), 3-year OS, 5-year OS, and 5-year chronic lung allograft dysfunction (CLAD)-free survival.

RESULTS

This meta-analysis included 10 cohort studies. Among the short-term outcomes, the older donor group demonstrated no significant difference from the young donor group in primary graft dysfunction within 72 hours, use of extracorporeal membrane oxygenation, length of ventilator use, and intensive care unit hours. However, a longer hospital stay was associated with the older donor group. In terms of long-term outcomes, no difference was found between the two groups in 1-year OS, 3-year OS, and 5-year OS. Notably, patients with older donors exhibited a superior 5-year CLAD-free survival.

CONCLUSIONS

The results of this meta-analysis indicate that older donors are not inferior to younger donors in terms of long-term and short-term recipient outcomes. Lung transplantation using older donors is a potential therapeutic option after rigorous evaluation.

Extended criteria donor organ use for heart-lung transplantation in the modern era

BACKGROUND

Demand for donor hearts and lungs exceeds their supply. Extended Criteria Donor (ECD) organs are used to help meet this demand, but their impact on heart-lung transplantation outcomes is poorly characterized.

METHODS AND RESULTS

The United Network for Organ Sharing was queried for data on adult heart-lung transplantation recipients (n = 447) from 2005‒2021. Recipients were stratified based on whether they received ECD hearts and/or lungs. Morbidity was analyzed using Kruskal-Wallis, chi-square, and Fisher's exact tests. Mortality was analyzed using Kaplan-Meier estimation, log-rank tests and Cox regression. Sixty-five (14.5%) patients received two ECD organs, 134 (30.0%) received only an ECD lung, and 65 (14.5%) only an ECD heart. Recipients of two ECD organs were older, more likely to have diabetes, and more likely transplanted from 2015‒2021 (p < 0.05). Groups did not differ by pre-transplant diagnosis, intensive care unit disposition, life support use, or hemodynamics. Group five-year survival rates ranged from 54.5% to 63.2% (p = 0.428). Groups did not differ by 30-day mortality, strokes, graft rejection, or hospital length of stay.

CONCLUSIONS

Using ECD hearts and/or lungs for heart-lung transplantation is not associated with increased mortality and is a safe strategy for increasing donor organ supply in this complex patient population.

Primary graft dysfunction following lung transplantation: From pathogenesis to future frontiers

Lung transplantation is the treatment of choice for patients with end-stage lung disease. Currently, just under 5000 lung transplants are performed worldwide annually. However, a major scourge leading to 90-d and 1-year mortality remains primary graft dysfunction. It is a spectrum of lung injury ranging from mild to severe depending on the level of hypoxaemia and lung injury post-transplant. This review aims to provide an in-depth analysis of the epidemiology, pathophysiology, risk factors, outcomes, and future frontiers involved in mitigating primary graft dysfunction. The current diagnostic criteria are examined alongside changes from the previous definition. We also highlight the issues surrounding chronic lung allograft dysfunction and identify the novel therapies available for ex-vivo lung perfusion. Although primary graft dysfunction remains a significant contributor to 90-d and 1-year mortality, ongoing research and development abreast with current technological advancements have shed some light on the issue in pursuit of future diagnostic and therapeutic tools.

Lungs From Donors ≥70 Years of Age for Transplantation-Do Long-Term Outcomes Justify Their Use?

Donor shortages have led transplant centers to extend their criteria for lung donors. Accepting lung donors ≥70 years of age has previously shown good short-term outcomes; however, no mid- and long-term outcome data on these extended criteria donors has been published to date. In this study, all patients who underwent lung transplantation between 06/2010 and 12/2019 were included in the analysis, and the outcomes were compared between patients receiving organs from donors <70 years of age and patients transplanted with lungs from donors ≥70 years of age. Among the 1,168 lung-transplanted patients, 62 patients received lungs from donors ≥70 years of age. The recipient age of those receiving older organs was significantly higher, and they were more likely to suffer from obstructive lung disease. Older donors were exposed to significantly shorter periods of mechanical ventilation prior to donation, had higher Horowitz indices, and were less likely to have smoked. The postoperative time on mechanical ventilation, time on ICU, and total hospital stay were comparable. The overall survival as well as CLAD-free survival showed no differences between both groups in the follow-up period. Utilization of lungs from donors ≥70 years of age leads to excellent mid- and long-term results that are similar to organs from younger donors when the organs from older donors are carefully preselected.

Primary Graft Dysfunction: The Role of Aging in Lung Ischemia-Reperfusion Injury

Transplant centers around the world have been using extended criteria donors to remedy the ongoing demand for lung transplantation. With a rapidly aging population, older donors are increasingly considered. Donor age, at the same time has been linked to higher rates of lung ischemia reperfusion injury (IRI). This process of acute, sterile inflammation occurring upon reperfusion is a key driver of primary graft dysfunction (PGD) leading to inferior short- and long-term survival. Understanding and improving the condition of older lungs is thus critical to optimize outcomes. Notably, ex vivo lung perfusion (EVLP) seems to have the potential of reconditioning ischemic lungs through ex-vivo perfusing and ventilation. Here, we aim to delineate mechanisms driving lung IRI and review both experimental and clinical data on the effects of aging in augmenting the consequences of IRI and PGD in lung transplantation.

Outcomes after lung transplantation in recipients aged 70 years or older

BACKGROUND

The proportion of lung transplant (LTx) recipients older than 70 years is increasing, thus we assessed long-term survival after LTx in this cohort relative to younger counterparts.

PATIENTS AND METHODS

We retrospectively reviewed charts of patients who underwent LTx between 2012 and 2016 at our center and divided patients by age: group A (<65 years), B (65-69 years), and C (≥70 years). Survival statistics were evaluated using the Kaplan-Meier method and Cox regression.

RESULTS

The study included 375 LTx recipients: 221 (58.9%) in group A, 109 (29.1%) in group B, and 45 (12.0%) in group C. Group C was mostly men (37/45 [82.2%]; P = 0.003) and had the highest mean serum creatinine at listing (P = 0.02). Survival at 1, 3, and 5 years after transplant in group A (93.2%, 70.1%, 58.8%) was significantly higher than group B (83.5%, 59.6%, 44.0%; P = 0.005, 0.028, 0.006, log-rank test) and was similar to group C (86.7%, 64.4%, 57.8%), although trended higher at 1 year (P = 0.139, 0.274, 0.489, log-rank test). Groups B and C had comparable survival at all time points.

CONCLUSIONS

Although survival decreased after age 65, long-term survival was comparable between LTx recipients aged 65-69 years and recipients ≥70 years.

Donor factors and risk of primary graft dysfunction and mortality post lung transplantation: A proposed conceptual framework

Lung transplantation remains a therapeutic option in end-stage lung disease. However, despite advances in the field, early allograft function can be compromised by the development of primary graft dysfunction (PGD); this being the leading cause of morbidity and mortality immediately following the lung transplant procedure. Several recipient factors have been associated with increased risk of PGD, but less is known about donor factors. Aging, tobacco, and chronic alcohol use are donor factors implicated, but how these factors promote PGD remains unclear. Herein, we discuss the available clinical data that link these donor factors with outcomes after lung transplantation, and how they might render the recipient susceptible to PGD through a two-hit process.

The effects of donor age on organ transplants: A review and implications for aging research

Despite the considerable amount of data available on the effect of donor age upon the outcomes of organ transplantation, these still represent an underutilized resource in aging research. In this review, we have compiled relevant studies that analyze the effect of donor age in graft and patient survival following liver, kidney, pancreas, heart, lung and cornea transplantation, with the aim of deriving insights into possible differential aging rates between the different organs. Overall, older donor age is associated with worse outcomes for all the organs studied. Nonetheless, the donor age from which the negative effects upon graft or patient survival starts to be significant varies between organs. In kidney transplantation, this age is within the third decade of life while the data for heart transplantation suggest a significant effect starting from donors over age 40. This threshold was less defined in liver transplantation where it ranges between 30 and 50 years. The results for the pancreas are also suggestive of a detrimental effect starting at a donor age of around 40, although these are mainly derived from simultaneous pancreas-kidney transplantation data. In lung transplantation, a clear effect was only seen for donors over 65, with negative effects of donor age upon transplantation outcomes likely beginning after age 50. Corneal transplants appear to be less affected by donor age as the majority of studies were unable to find any effect of donor age during the first few years posttransplantation. Overall, patterns of the effect of donor age in patient and graft survival were observed for several organ types and placed in the context of knowledge on aging.

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Data on the effects of donor age upon the outcomes of organ transplantation are an underutilized resource in biogerontology

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We compiled data on the effect of donor age following liver, kidney, pancreas, heart, lung and cornea transplantation

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Older donor age is associated with worse outcomes for all the organs studied

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The donor age from which the negative effects upon survival starts to be significant varies between organs

Extracorporeal Respiratory Support With a Miniature Integrated Pediatric Pump-Lung Device in an Acute Ovine Respiratory Failure Model

Respiratory failure is one of the major causes of mortality and morbidity all over the world. Therapeutic options to treat respiratory failure remain limited. The objective of this study was to evaluate the gas transfer performance of a newly developed miniature portable integrated pediatric pump-lung device (PediPL) with small membrane surface for respiratory support in an acute ovine respiratory failure model. The respiratory failure was created in six adult sheep using intravenous anesthesia and reduced mechanical ventilation at 2 breaths/min. The PediPL device was surgically implanted and evaluated for respiratory support in a venovenous configuration between the right atrium and pulmonary artery. The hemodynamics and respiratory status of the animals during support with the device gas transfer performance of the PediPL were studied for 4 h. The animals exhibited respiratory failure 30 min after mechanical ventilation was reduced to 2 breaths/min, indicated by low oxygen partial pressure, low oxygen saturation, and elevated carbon dioxide in arterial blood. The failure was reversed by establishing respiratory support with the PediPL after 30 min. The rates of O₂ transfer and CO₂ removal of the PediPL were 86.8 and 139.1 mL/min, respectively. The results demonstrated that the PediPL (miniature integrated pump-oxygenator) has the potential to provide respiratory support as a novel treatment for both hypoxia and hypercarbia. The compact size of the PediPL could allow portability and potentially be used in many emergency settings to rescue patients suffering acute lung injury.

Lung transplantation with lungs from older donors: recipient and surgical factors affect outcomes

BACKGROUND

A shortage of donors has compelled the use of extended-criteria donor organs in lung transplantation. The purpose of this study was to evaluate the impact of using older donors on outcomes after lung transplantation using current protocols.

METHODS

From January 2003 to August 2009, 593 lung transplants were performed at our institution. We compared 87 patients (14.7%) who received lungs from donors aged 55 years or older with 506 patients who received lungs from donors less than 55 years old. We also examined risk factors for mortality in recipients of lungs from older donors.

RESULTS

The incidence of major complications including severe primary graft dysfunction and early mortality rates were similar between the groups. However, posttransplant peak FEV1 was lower in the patients who received lungs from older donors (71.7% vs. 80.7%, P<0.05). In multivariate analysis, recipient pulmonary hypertension (transpulmonary pressure gradient >20 mm Hg) and prolonged intraoperative cardiopulmonary bypass were significant risk factors for mortality in the recipients of lungs from older donors.

CONCLUSIONS

This large, single-center experience demonstrated that transplanting lungs from donors older than 55 years did not yield worse short- or long-term outcomes as compared with transplanting lungs from younger donors. However, transplanting lungs from older donors into recipients with pulmonary hypertension or recipients who required prolonged cardiopulmonary bypass increased the risk for mortality. Although lungs from older donors should not be excluded because of donor age alone, surgeons should carefully consider their patient selection criteria and surgical plans when transplanting lungs from older donors.

Lung donor selection criteria

The criteria that define acceptable physiologic and social parameters for lung donation have remained constant since their empiric determination in the 1980s. These criteria include a donor age between 25-40, a arterial partial pressure of oxygen (PaO2)/FiO2 ratio greater than 350, no smoking history, a clear chest X-ray, clean bronchoscopy, and a minimal ischemic time. Due to the paucity of organ donors, and the increasing number of patients requiring lung transplant, finding a donor that meets all of these criteria is quite rare. As such, many transplants have been performed where the donor does not meet these stringent criteria. Over the last decade, numerous reports have been published examining the effects of individual acceptance criteria on lung transplant survival and graft function. These studies suggest that there is little impact of the historical criteria on either short or long term outcomes. For age, donors should be within 18 to 64 years old. Gender may relay benefit to all female recipients especially in male to female transplants, although results are mixed in these studies. Race matched donor/recipients have improved outcomes and African American donors convey worse prognosis. Smoking donors may decrease recipient survival post transplant, but provide a life saving opportunity for recipients that may otherwise remain on the transplant waiting list. No specific gram stain or bronchoscopic findings are reflected in recipient outcomes. Chest radiographs are a poor indicator of lung donor function and should not adversely affect organ usage aside for concerns over malignancy. Ischemic time greater than six hours has no documented adverse effects on recipient mortality and should not limit donor retrieval distances. Brain dead donors and deceased donors have equivalent prognosis. Initial PaO2/FiO2 ratios less than 300 should not dissuade donor organ usage, although recruitment techniques should be implemented with intent to transplant.

Donor age and early graft failure after lung transplantation: a cohort study

Lungs from older adult organ donors are often unused because of concerns for increased mortality. We examined associations between donor age and transplant outcomes among 8860 adult lung transplant recipients using Organ Procurement and Transplantation Network and Lung Transplant Outcomes Group data. We used stratified Cox proportional hazard models and generalized linear mixed models to examine associations between donor age and both 1-year graft failure and primary graft dysfunction (PGD). The rate of 1-year graft failure was similar among recipients of lungs from donors age 18-64 years, but severely ill recipients (Lung Allocation Score [LAS] >47.7 or use of mechanical ventilation) of lungs from donors age 56-64 years had increased rates of 1-year graft failure (p-values for interaction = 0.04 and 0.02, respectively). Recipients of lungs from donors <18 and ≥65 years had increased rates of 1-year graft failure (adjusted hazard ratio [HR] 1.23, 95% CI 1.01-1.50 and adjusted HR 2.15, 95% CI 1.47-3.15, respectively). Donor age was not associated with the risk of PGD. In summary, the use of lungs from donors age 56 to 64 years may be safe for adult candidates without a high LAS and the use of lungs from pediatric donors is associated with a small increase in early graft failure.

The use of lung donors older than 55 years: a review of the United Network of Organ Sharing database

BACKGROUND

Current lung transplantation guidelines stipulate that the ideal donor is aged younger than 55 years, but several institutions have reported that outcomes using donors aged 55 years and older are comparable with those of younger donors.

METHODS

We retrospectively reviewed the United Network for Organ Sharing (UNOS) database to identify all adult lung transplants between 2000 and 2010 in the United States. Patients were stratified by donor age 18 to 34 (reference), 35 to 54, 55 to 64, and ≥ 65 years. Primary outcomes included survival at 30 days and at 1, 3, and 5 years and rates of bronchiolitis obliterans syndrome (BOS). Survival was assessed using the Kaplan-Meier method. Risk factors for mortality were identified by multivariable Cox and logistic regression.

RESULTS

We identified 10,666 recipients with median follow-up of 3 years (range, 0-10 years). Older donors were more likely to have died of cardiovascular or cerebrovascular causes, but there were no differences in recipient diagnosis, lung allocation score, or incidence of BOS as a function of donor age. The use of donors aged 55 to 64 years was not a risk factor for mortality at 1 year (odds ratio, 1.1; p = 0.304) or 3 years (odds ratio, 0.923; p = 0.571) compared with the reference group; however, use of donors aged > 65 years was associated with increased mortality at both time points (odds ratio, 2.8 and 2.4, p < 0.02).

CONCLUSIONS

Outcomes after lung transplantation using donors aged 55 to 64 years were similar to those observed with donors meeting conventional age criteria. Donors aged ≥ 65 years, however, were associated with decreased intermediate-term survival, although there was no increased risk of BOS for this group.

Donor evaluation for lung transplantation in Korea

Lung transplantation for end-stage lung disease results in prolonged survival and improved pulmonary function. However, the shortage of donor lungs has been a major limiting factor in Korea. We sought to investigate the number and utilization of donor lungs by the five institutions performing LTx in Korea, retrospectively reviewing outcomes of organs registered in the Korean Network for Organ Sharing from January to December, 2010. Lungs were offered from 270 brain-dead patients (189 males and 81 females) of mean age of 45.2 ± 14.2 years (range, 12 to 77 years). The most common cause of brain death was hemorrhage (n = 219, 81%). Only 18 (6.7%) donor lungs were used, which was low compared with kidney (93.3%), liver (86.3%), heart (26.7%), and pancreas (11.1%) use. The mean age of donors of transplanted lungs was 35.7 years (range, 14 to 51 years) compared with 45.9 years for other organs (P = .003). The characteristics of utilized donor lungs were: mean partial pressure of oxygen (PaO(2)), 300.9 mm Hg; mean smoking history, as 2.7 pack-years; and mean body mass index, 21.2 kg/m(2). The causes of refusal were medical ineligibility (n = 129) including poor PaO(2), abnormal chest x-ray, long smoking history, older age (n = 46), no properly matched recipient (n = 46), unknown (n = 17), and family withdrawal (n = 14). Only 8 (33.3%) were transplanted from standard criteria and 10 from the lungs that did not satisfy these criteria. An efficient utilization system is needed to improve lung transplantations.

Recommendations for the use of extended criteria donors in lung transplantation

Selection criteria for lung donation were based on initial experiences with lung transplantation without further studies to improve them, thereby guaranteeing the best use of donated organs. A definition of an extended criteria donor is therefore required to obtain more lungs to meet the demands of patients awaiting transplantation. Studies have been reviewed for the impact on survival and morbidity of age ranges, oxygen fraction, cause of death, smoking habits, x-ray findings, infection, hepatitis serology and non-heart-beating status, seeking to support physicians to make decisions regarding the use of marginal organs.

Special issues in the management and selection of the donor for lung transplantation

Lung transplantation is a viable treatment option for select patients with end-stage lung disease. Two issues hamper progress in transplantation: first, donor shortage is a major limitation to increasing the number of transplants performed. Secondly, recipient outcomes remain disappointing when compared with other solid organ transplant results. Outcomes are limited by primary graft dysfunction (PGD), the posttransplant acute lung injury that increases both short-and long-term mortality. Attempts to overcome donor shortage have included aggressively managing solid organ donors to increase the number of donor lungs suitable for transplantation. Yet, the quality of the lung donor is likely to be related to the probability of the recipient experiencing PGD. PGD is the culmination of a series of insults, hemodynamic, metabolic, and inflammatory, that begin with the brain dead donor and result in poor recipient outcomes. Understanding the mechanism of donor lung injury resulting from brain death and the possible treatment strategies for its inhibition could help to increase the number of usable lungs and decrease the rate of PGD in the recipient. Here we present a review of the key pathways which result in donor lung injury, and follow this with a brief review of recent biomarkers that are proving to be instrumental to our ability to predict truly unsuitable lungs, and our ability to predict and hopefully prevent or treat recipients with subsequent lung injury.

Donor factors are associated with bronchiolitis obliterans syndrome after lung transplantation

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) is the major hurdle preventing long-term success in lung transplantation, and is the primary reason for the 50% 5-year survival. Recipient and perioperative risk factors have been investigated in BOS, but less is known about donor factors. Therefore, we investigated what donor factors are important in the development of BOS.

METHODS

We performed a retrospective review of the United Network for Organ Sharing lung transplant database from 1987 to 2008. Lung transplant recipients had yearly follow-up. Donor factors were evaluated for their influence on BOS development. Kaplan-Meier plots of BOS-free survival were compared for each donor factor and a multivariate Cox proportional hazard model for BOS was created with donor factors.

RESULTS

A total of 17,222 lung transplant recipients were identified; 6,991 recipients had sufficient follow-up BOS data. Of these recipients 57% (n = 3,984) developed BOS within 5 years. Recipients who received lungs from donors who were younger, without an active pulmonary infection, or those without current tobacco use had longer BOS-free survival. Recipients who received lungs with higher partial pressures of oxygen in arterial blood (Pao(2)) developed more BOS (p < 0.0001). Donor high Pao(2), older age, and current tobacco use were independent predictors of BOS in lung transplant recipients.

CONCLUSIONS

Donor factors and donor management strategies are important contributors to development of recipient BOS. Identification of these factors may help limit BOS and may identify recipients at high risk. Surprisingly, high Pao(2) in the donor is an independent predictor of BOS development.

Extended donor criteria in lung transplantation

PURPOSE OF REVIEW

Despite improvements in respiratory care and lung transplant organ allocation algorithms, waiting lists continue to grow worldwide. Attempts at improving organ donation rates have generally had little impact on the increase in the number of transplants performed. Improved use of the available pool of cadaveric organ donors, therefore, represents one of few immediately available strategies to alleviate organ shortages.

RECENT FINDINGS

The once-strict lung donor selection criteria have, of necessity, been relaxed and, in many instances, this situation has been to no apparent detrimental effect on posttransplant outcome. There is, however, some evidence that extension of donor acceptability in some respects leads to poorer early outcomes, mainly by increasing the rate of early graft dysfunction. The extension of selection criteria to allow the maximum number of safe lung transplants, coupled with aggressive and appropriate donor management is, therefore, of particular current relevance to the lung transplantation community.

SUMMARY

Although the available evidence for and against the commonly used lung donor selection criteria leaves many questions unanswered, it can help decrease the large number of uncertainties that be falls the practice of lung donor selection and recipient matching.

[Lung transplantation: supply and demand in France]

INTRODUCTION

For a decade lung transplantation has suffered from a lack of donor organs which aroused a national debate and led to planned action in collaboration with The French National Agency for Transplantation.

BACKGROUND

Analysis of the stages of the process from potential donor to lung transplantation identified lung procurement as the main priority. An increase in the number of potential lung donors and revision of the acceptance criteria led to a doubling of the annual rate of lung transplantation in less than two years.

VIEWPOINTS

In the near future we may solve the problem of donor family refusals and establish scientifically based criteria for lung acceptance to increase the rate of lung transplantation. Transplantation from non heart-beating donors and the reconditioning of ex vivo non acceptable lungs might supply additional organs to fulfill demand in the long term.

CONCLUSIONS

The rate of lung transplantation activity in France doubled as the result of a dramatic increase of donor lung proposals. The current improvement in the results of lung transplantation might create new demands and generate future difficulties in the supply of donor lungs. New approaches, such as transplantation from non heart-beating donors and reconditioning ex vivo non acceptable lungs, should be examined in the near future.

Anesthetic Considerations for Lung Transplantation

Lung transplantation is the definitive treatment for end-stage lung disease. The number of lung transplantations performed is limited by the number of donors available and is far outnumbered by the potential recipients on the waiting list. Advances in surgical methods, organ preservation, and immunosuppression have decreased the morbidity and mortality associated with this procedure during the last few decades. Specific anesthetic concerns are associated with lung transplantation, including careful preoperative assessment of pulmonary and cardiac function, adequate venous access and monitors, and ventilation techniques, such as 1-lung ventilation and lung-protective strategies to decrease the risks of reperfusion injury, barotrauma, and re-expansion pulmonary edema. Intraoperative transesophageal echocardiography, cardiopulmonary bypass, and inhaled nitric oxide can also be important tools for the anesthesiologist to optimize patient care during this challenging procedure.

Impact of donor and recipient factors on allograft survival in lung transplantation: A single-center analysis

BACKGROUND

It remains unclear which donor and recipient factors influence long-term allograft function in lung transplantation (LTx).

METHODS

From October 1988 to February 2005, a total of 280 recipients underwent LTx at our center. Donor data and cause of death (CoD) were analyzed. The CoD was categorized according to rate of increase in intracranial pressure at the time of death. Each donor and recipient factor was correlated with long-term graft function. Recipient details, type of transplant, indication for transplant, and time on waiting list were analyzed. Recipients were stratified based on allograft ischemia time (AIT): 0 to 6, 6 to 8, 8 to 10, and >10 hours.

RESULTS

Mean donor age was 30.9 years (36.7% male); 49.8% were cytomegalovirus (CMV) positive. Donor CoD was characterized by a slow rise in intracranial pressure (ICP) in 34.4%, rapid ICP in 18.7%, an intermediate ICP in 44.3%, and with no rise in 2.6%. A graft survival benefit was seen with female donors (P = .048); 34.4% of recipients ultimately developed graft failure at long term follow-up. Mean recipient age was 48 years; 63% were male and mean body-mass index (BMI) was 23.6; 60.2% had single lung transplantation, and mean wait list time was 323 days. Mean AIT totaled 421 minutes. Graft survival was longer with AIT of 8 to 10 hours compared to 6 to 8 hours (P = .03).

CONCLUSIONS

Donor factor analysis implied only female donor status conferred a long-term graft survival advantage. Intracranial pressure rise differences appear clinically unimportant. Prolonged cold ischemic time (>10 hours) or low recipient BMI did not adversely affect allograft function in our review.

Physiological and biochemical markers of alveolar epithelial barrier dysfunction in perfused human lungs

To study air space fluid clearance (AFC) under conditions that resemble the clinical setting of pulmonary edema in patients, we developed a new perfused human lung preparation. We measured AFC in 20 human lungs rejected for transplantation and determined the contribution of AFC to lung fluid balance. AFC was then compared with air space and perfusate levels of a biological marker of epithelial injury. The majority of human lungs rejected for transplant had intact basal (75%) and beta(2)-adrenergic agonist-stimulated (70%) AFC. For lungs with both basal and stimulated AFC, the basal AFC rate was 19 +/- 10%/h, and the beta(2)-adrenergic-stimulated AFC rate was 43 +/- 13%/h. Higher rates of AFC were associated with less lung weight gain (Pearson coefficient -0.90, P < 0.0001). Air space and perfusate levels of the type I pneumocyte marker receptor for advanced glycation end products (RAGE) were threefold and sixfold higher, respectively, in lungs without basal AFC compared with lungs with AFC (P < 0.05). These data show that preserved AFC is a critical determinant of favorable lung fluid balance in the perfused human lung, raising the possibility that beta(2)-agonist therapy to increase edema fluid clearance may be of value for patients with acute lung injury and pulmonary edema. Also, although additional studies are needed, a biological marker of alveolar epithelial injury may be useful clinically in predicting preserved AFC.

Marginal Lung Donors: A Diminishing Margin of Safety?

Lung donor shortages have resulted in the critical appraisal of cadaveric donor acceptability criteria and the gradual relaxation of once strict guidelines. Many centers have reported their results with these "extended criteria" donors and an increasing number of multicenter registry studies have also been published. The results have been contradictory and leave many questions unanswered. Important new data has however come to light since the last review of the subject by the International Society for Heart and Lung Transplantation Pulmonary Council. We review the current literature focusing on recent developments in the pursuit of an expanded lung donor pool with acceptable outcomes.

Glutathione improves the function of porcine pulmonary grafts stored for twenty-four hours in low-potassium dextran solution

BACKGROUND

Flush perfusion with low-potassium dextran is the standard strategy in clinical lung preservation. Despite improved outcome, endothelial cell injury and surfactant dysfunction remain a significant problem after lung transplantation. The radical scavenger glutathione has been shown to be responsible for the efficacy of Celsior solution in lung preservation. We tested the hypothesis that the addition of glutathione to low-potassium dextran might further improve graft function by ameliorating ischemia-reperfusion injury.

METHODS

In 12 domestic pigs, lungs were flush preserved with either low-potassium dextran (n = 6) or low-potassium dextran supplemented by 5 mmol glutathione (n = 6). Left single lung transplantation was performed after 24-hour storage in low-potassium dextran at 8 degrees C. After 15 minutes of reperfusion the right main bronchus and pulmonary artery were crossclamped. Hemodynamic and respiratory measures were recorded in 30-minute intervals for a total observation period of 7 hours. Bronchoalveolar lavage fluid was obtained from the native lung and 2 hours after reperfusion from the graft. Bronchoalveolar lavage fluid and surfactant composition, and surfactant function analyses were performed. Neutrophil sequestration was assessed by myeloperoxidase activity assay. Tissue water content was calculated from wet/dry weight ratios at the end of the experiment.

RESULTS

In the low-potassium dextran group, 2 animals died during reperfusion. After reperfusion, pulmonary vascular resistance (P = .01) and pulmonary artery pressure remained lower in the glutathione/low-potassium dextran group, which was associated with a higher cardiac output (P = .05) in this group. Also, the oxygenation index at the end of the observation period was higher in the glutathione/low-potassium dextran group compared with the low-potassium dextran group (430 +/- 130 vs 338 +/- 184, respectively; P < .05). The graft water content representing postreperfusion lung edema was not different between the 2 study groups. Alteration of surfactant was less in the glutathione/low-potassium dextran group with a significantly decreased small to large aggregate ratio (P = .03) versus low-potassium dextran group. Myeloperoxidase activity was twice as high in the low-potassium dextran group when compared with the glutathione/low-potassium dextran group (glutathione/low-potassium dextran: 134 +/- 110 mU/g vs low-potassium dextran: 274 +/- 168 mU/g, P = .07).

CONCLUSION

The addition of glutathione to low-potassium dextran preservation solution reveals beneficial effects on vascular function and surfactant composition in transplanted lungs. Therefore, glutathione ameliorates ischemia-reperfusion injury in a preclinical model of lung transplantation. Future studies are needed to evaluate this promising modification in clinical lung transplantation.