Influence of lung donor agonal and warm ischemic times on early mortality: Analyses from the ISHLT DCD Lung Transplant Registry

Donation After Circulatory Death following Withdrawal of Life-Sustaining Treatments. Are We Ready to Break the Dead Donor Rule?

A fundamental criterion considered essential to deem the procedure of vital organ procurement for transplantation ethical is that the donor must be dead, as per the Dead Donor Rule (DDR). In the case of Donation after Circulatory Death (DCD), is the donor genuinely dead? The main aim of this article is to clarify this uncertainty, which primarily arises from the fact that in DCD, death is determined based on cardiac criteria (Circulatory Death, CD), rather than neurological criteria (Brain Death, BD), and that to allow the procurement procedure, physicians reperfuse the organs in an assisted manner. To ensure that the cessation of circulation leads to the irreversible loss of brain functions, DCD regulations require that physicians wait a certain period after CD before commencing vital organ procurement. However, during this "no-touch period," the organs are at risk of damage, potentially rendering them unsuitable for transplantation. When DCD is performed on patients whose CD follows a Withdrawal of Life-Sustaining Treatment (WLST) (DCD Maastricht III category), how long should the no-touch period last? Does its existence really make sense? Does beginning the procedure of vital organ procurement immediately after WLST constitute a violation of the DDR that can be ethically justified? The discussion aims to provide arguments in support of the non-absoluteness of the DDR.

Potential for organ donation after controlled circulatory death: a retrospective analysis

Objectives

Despite the discrepancy between demand and availability of organs for transplantation, controlled circulatory death donation has not been implemented in Portugal. This study aimed to estimate the potential increase in organ donation from implementing such a program.

Material and Methods

All deceased patients within the intensive care medicine department at Centro Hospitalar Universitário de São João, throughout the year 2019, were subjected to retrospective analysis. Potential gain was estimated comparing the results with the number of donors and organs collected during the same period at this hospital center. Differences in variables between groups were assessed using t tests for independent samples or Mann-Whitney U tests for continuous variables, and chi-squared tests were used for categorical variables.

Results

During 2019, 152 deaths occurred after withdrawal of life-sustaining therapies, 10 of which would have been potentially eligible for donation after controlled circulatory death. We can anticipate a potential increase of 10 prospective donors, a maximum 21% growth in yearly transplantation activity, with a greater impact on kidney transplantation. For most patients, the time between withdrawal of organ support and death surpassed 120 minutes, an outcome explained by variations in withdrawal of life-sustaining measures and insufficient clinical records, underestimating the potential for controlled circulatory arrest donation.

Conclusion

This study effectively highlights public health benefits of controlled circulatory arrest donation. Legislation allowing donation through this method represents a social gain and enables patients who will never meet brain death criteria to donate organs as part of the end-of-life process in intensive care medicine, within a framework of complete ethical alignment.

How do we expand the lung donor pool?

PURPOSE OF REVIEW

Lung transplantation activity continues to be limited by the availability of timely quality donor lungs. It is apparent though that progress has been made. The steady evolution of clinical practice, combined with painstaking scientific discovery and innovation are described.

RECENT FINDINGS

There have been successful studies reporting innovations in the wider use and broader consideration of donation after circulatory death donor lungs, including an increasing number of transplants from each of the controlled, uncontrolled and medically assisted dying donor descriptive categories. Donors beyond age 70 years are providing better than expected long-term outcomes. Hepatitis C PCR positive donor lungs can be safely used if treated postoperatively with appropriate antivirals. Donor lung perfusion at a constant 10 degrees appears capable of significantly improving donor logistics and ex-vivo lung perfusion offers the potential of an ever-increasing number of novel donor management roles. Bioartificial and xenografts remain distant possibilities only at present.

SUMMARY

Donor lungs have proved to be surprisingly robust and combined with clinical, scientific and engineering innovations, the realizable lung donor pool is proving to be larger than previously thought.

Advances in lung transplantation: 60 years on

Lung transplantation is a well-established treatment for advanced lung disease, improving survival and quality of life. Over the last 60 years all aspects of lung transplantation have evolved significantly and exponential growth in transplant volume. This has been particularly evident over the last decade with a substantial increase in lung transplant numbers as a result of innovations in donor utilization procurement, including the use donation after circulatory death and ex-vivo lung perfusion organs. Donor lungs have proved to be surprisingly robust, and therefore the donor pool is actually larger than previously thought. Parallel to this, lung transplant outcomes have continued to improve with improved acute management as well as microbiological and immunological insights and innovations. The management of lung transplant recipients continues to be complex and heavily dependent on a tertiary care multidisciplinary paradigm. Whilst long term outcomes continue to be limited by chronic lung allograft dysfunction improvements in diagnostics, mechanistic understanding and evolutions in treatment paradigms have all contributed to a median survival that in some centres approaches 10 years. As ongoing studies build on developing novel approaches to diagnosis and treatment of transplant complications and improvements in donor utilization more individuals will have the opportunity to benefit from lung transplantation. As has always been the case, early referral for transplant consideration is important to achieve best results.

Lung Transplantation in Controlled Donation after Circulatory-Determination-of-Death Using Normothermic Abdominal Perfusion

The main limitation to increased rates of lung transplantation (LT) continues to be the availability of suitable donors. At present, the largest source of lung allografts is still donation after the neurologic determination of death (brain-death donors, DBD). However, only 20% of these donors provide acceptable lung allografts for transplantation. One of the proposed strategies to increase the lung donor pool is the use of donors after circulatory-determination-of-death (DCD), which has the potential to significantly alleviate the shortage of transplantable lungs. According to the Maastricht classification, there are five types of DCD donors. The first two categories are uncontrolled DCD donors (uDCD); the other three are controlled DCD donors (cDCD). Clinical experience with uncontrolled DCD donors is scarce and remains limited to small case series. Controlled DCD donation, meanwhile, is the most accepted type of DCD donation for lungs. Although the DCD donor pool has significantly increased, it is still underutilized worldwide. To achieve a high retrieval rate, experience with DCD donation, adequate management of the potential DCD donor at the intensive care unit (ICU), and expertise in combined organ procurement are critical. This review presents a concise update of lung donation after circulatory-determination-of-death and includes a step-by-step protocol of lung procurement using abdominal normothermic regional perfusion.

Simultaneous Lung-abdominal Organ Procurement From Donation After Circulatory Death Donors Reduces Donor Hepatectomy Time

BACKGROUND

Prolonged organ procurement time impairs the outcome of donation after circulatory death (DCD) and liver transplantation (LiT). Our transplant team developed a simultaneous, rather than sequential, lung-abdominal organ explantation strategy for DCD donation to prioritize liver procurement. We evaluated whether this change in strategy effectively reduced donor hepatectomy time (dHT), without affecting donor pneumonectomy time (dPT), and influenced LiT and lung transplantation outcome.

METHODS

All lung-abdominal and abdominal-only transplant procedures between 2010 and 2020 were analyzed in this retrospective cohort study. Relationships were assessed between the year of transplant and dHT and dPT (univariate linear regression), 1-y patient and graft survival, primary graft dysfunction, and nonanastomotic biliary strictures (univariate logistic regression).

RESULTS

Fifty-two lung-abdominal and 110 abdominal-only DCD procedures were analyzed. A significant decrease in dHT was noted in lung-abdominal (slope -1.14 [-2.14; -0.15], P = 0.026) but not in abdominal-only procedures; dPT did not increase. There were no significant associations between the year of transplant and nonanastomotic biliary strictures frequency, primary graft dysfunction incidence, 1-y patient, and graft survival.

CONCLUSIONS

Simultaneous organ procurement in multiorgan lung-abdominal DCD procedures is feasible, and effectively shortened dHT without affecting lung transplantation outcome. No impact on LiT outcome was observed; however, larger multicenter studies are needed.

Lung recovery utilizing thoracoabdominal normothermic regional perfusion during donation after circulatory death: The Colorado experience

Objective

Donation after circulatory death (DCD) procurement and transplantation after thoracoabdominal normothermic regional perfusion (TA-NRP) remains a novel technique to improve cardiac and hepatic allograft preservation but may be complicated by lung allograft pulmonary edema. We present a single-center series on early implementation of a lung-protective protocol with strategies to mitigate posttransplant pulmonary edema in DCD lung allografts after TA-NRP procurement.

Methods

Data from all lung transplantations performed using a TA-NRP procurement strategy from October 2022 to April 2023 are presented. Donor management consisted of key factors to reduce lung allograft pulmonary edema: aggressive predonation and early posttransplant diuresis, complete venous drainage at TA-NRP initiation, and early pulmonary artery venting upon initiation of systemic perfusion. Donor and recipient characteristics, procurement characteristics such as TA-NRP intervals, and 30-day postoperative outcomes were assessed.

Results

During the study period, 8 lung transplants were performed utilizing TA-NRP procurement from DCD donors. Donor ages ranged from 16 to 39 years and extubation time to declaration of death ranged from 10 to 90 minutes. Time from declaration to TA-NRP initiation was 7 to 17 minutes with TA-NRP perfusion times of 49 to 111 minutes. Median left and right allograft warm ischemia times were 55.5 minutes (interquartile range, 46.5-67.5 minutes) and 41.0 minutes (interquartile range, 39.0-53.0 minutes, respectively, with 2 recipients supported with cardiopulmonary bypass or venoarterial extracorporeal membrane oxygenation during implantation. No postoperative extracorporeal membrane oxygenation was required. There were no pulmonary-related deaths; however, 1 patient died from complications of severe necrotizing pancreatitis with a normal functioning allograft. All patients were extubated within 24 hours. Index intensive care unit length of stay ranged from 3 to 11 days with a hospital length of stay of 13 to 37 days.

Conclusions

Despite concern regarding quality of DCD lung allografts recovered using the TA-NRP technique, we report initial success using this procurement method. Implementation of strategies to mitigate pulmonary edema can result in acceptable outcomes following lung transplantation. Demonstration of short- and long-term safety and efficacy of this technique will become increasingly important as the use of TA-NRP for thoracic and abdominal allografts in DCD donors expands.

The effect of warm ischemia and donor ejection fraction on 30-day mortality after donation after circulatory death heart transplantation: A national database analysis

Donation after circulatory death (DCD) donor hearts recovered using the direct procurement and perfusion method experience variable durations of warm ischemia at the time of procurement (WIP). We used the Organ Procurement and Transplantation Network database to assess the effect of WIP on 30-day mortality after DCD heart transplantation. The analysis evaluated outcomes in 237 recipients of DCD heart transplantation, demonstrating an optimal WIP cut point of <36 minutes. Multivariable logistic regression modeling identified donor left ventricular ejection fraction (LVEF) <60% as an independent predictor of 30-day mortality. The area under the receiver operating characteristic curve for predicting 30-day mortality based on WIP ≥36 minutes and donor LVEF <60% was 0.90. Based on these findings, we do not recommend proceeding with DCD heart transplantation for patients with WIP ≥36 minutes, particularly in donors with LVEF <60%.

Bronchial Stenosis After Lung Transplantation From cDCD Donors Using Simultaneous Abdominal Normothermic Regional Perfusion: A Single-center Experience

BACKGROUND

Controlled donation after circulatory death (cDCD) has increased the number of lung donors significantly. The use of abdominal normothermic regional perfusion (A-NRP) during organ procurement is a common practice in some centers due to its benefits on abdominal grafts. This study aimed to assess whether the use of A-NRP in cDCD increases the frequency of bronchial stenosis in lung transplant (LT) recipients.

METHODS

A single-center, retrospective study including all LTs was performed between January 1, 2015, and August 30, 2022. Airway stenosis was defined as a stricture that leads to clinical/functional worsening requiring the use of invasive monitoring and therapeutic procedures.

RESULTS

A total of 308 LT recipients were included in the study. Seventy-six LT recipients (24.7%) received lungs from cDCD donors using A-NRP during organ procurement. Forty-seven LT recipients (15.3%) developed airway stenosis, with no differences between lung recipients with grafts from cDCD (17.2%) and donation after brain death donors (13.3%; P  = 0.278). A total of 48.9% of recipients showed signs of acute airway ischemia on control bronchoscopy at 2 to 3 wk posttransplant. Acute ischemia was an independent risk factor for airway stenosis development (odds ratio = 2.523 [1.311-4.855], P  = 0.006). The median number of bronchoscopies per patient was 5 (2-9), and 25% of patients needed >8 dilatations. Twenty-three patients underwent endobronchial stenting (50.0%) and each patient needed a median of 1 (1-2) stent.

CONCLUSIONS

Incidence of airway stenosis is not increased in LT recipients with grafts obtained from cDCD donors using A-NRP.

Waitlist and Transplant Outcomes in Organ Donation After Circulatory Death: Trends in the United States

OBJECTIVES

To summarize waitlist and transplant outcomes in kidney, liver, lung, and heart transplantation using organ donation after circulatory death (DCD).

BACKGROUND

DCD has expanded the donor pool for solid organ transplantation, most recently for heart transplantation.

METHODS

The United Network for Organ Sharing registry was used to identify adult transplant candidates and recipients in the most recent allocation policy eras for kidney, liver, lung, and heart transplantation. Transplant candidates and recipients were grouped by acceptance criteria for DCD versus brain-dead donors [donation after brain death (DBD)] only and DCD versus DBD transplant, respectively. Propensity matching and competing-risks regression was used to model waitlist outcomes. Survival was modeled using propensity matching and Kaplan-Meier and Cox regression analysis.

RESULTS

DCD transplant volumes have increased significantly across all organs. Liver candidates listed for DCD organs were more likely to undergo transplantation compared with propensity-matched candidates listed for DBD only, and heart and liver transplant candidates listed for DCD were less likely to experience death or clinical deterioration requiring waitlist inactivation. Propensity-matched DCD recipients demonstrated an increased mortality risk up to 5 years after liver and kidney transplantation and up to 3 years after lung transplantation compared with DBD. There was no difference in 1-year mortality between DCD and DBD heart transplantation.

CONCLUSIONS

DCD continues to expand access to transplantation and improves waitlist outcomes for liver and heart transplant candidates. Despite an increased risk for mortality with DCD kidney, liver, and lung transplantation, survival with DCD transplant remains acceptable.

Expanding Donor Options for Lung Transplant: Extended Criteria, Donation After Circulatory Death, ABO Incompatibility, and Evolution of Ex Vivo Lung Perfusion

Only using brain-dead donors with standard criteria, the existing donor shortage has never improved in lung transplantation. Currently, clinical efforts have sought the means to use cohorts of untapped donors, such as extended criteria donors, donation after circulatory death, and donors that are ABO blood group incompatible, and establish the evidence for their potential contribution to the lung transplant needs. Also, technical maturation for using those lungs may eliminate immediate concerns about the early posttransplant course, such as primary graft dysfunction or hyperacute rejection. In addition, recent clinical and preclinical advances in ex vivo lung perfusion techniques have allowed the safer use of lungs from high-risk donors and graft modification to match grafts to recipients and may improve posttransplant outcomes. This review summarizes recent trends and accomplishments and future applications for expanding the donor pool in lung transplantation.

Newly synthesized glycoprotein profiling to identify molecular signatures of warm ischemic injury in donor lungs

Despite recent technological advances such as ex vivo lung perfusion (EVLP), the outcome of lung transplantation remains unsatisfactory with ischemic injury being a common cause for primary graft dysfunction. New therapeutic developments are hampered by limited understanding of pathogenic mediators of ischemic injury to donor lung grafts. Here, to identify novel proteomic effectors underlying the development of lung graft dysfunction, using bioorthogonal protein engineering, we selectively captured and identified newly synthesized glycoproteins (NewS-glycoproteins) produced during EVLP with unprecedented temporal resolution of 4 h. Comparing the NewS-glycoproteomes in lungs with and without warm ischemic injury, we discovered highly specific proteomic signatures with altered synthesis in ischemic lungs, which exhibited close association to hypoxia response pathways. Inspired by the discovered protein signatures, pharmacological modulation of the calcineurin pathway during EVLP of ischemic lungs offered graft protection and improved posttransplantation outcome. In summary, the described EVLP-NewS-glycoproteomics strategy delivers an effective new means to reveal molecular mediators of donor lung pathophysiology and offers the potential to guide future therapeutic development.NEW & NOTEWORTHY This study developed and implemented a bioorthogonal strategy to chemoselectively label, enrich, and characterize newly synthesized (NewS-)glycoproteins during 4-h ex vivo lung perfusion (EVLP). Through this approach, the investigators uncovered specific proteomic signatures associated with warm ischemic injury in donor lung grafts. These signatures exhibit high biological relevance to ischemia-reperfusion injury, validating the robustness of the presented approach.

Lung preservation: from perfusion to temperature

PURPOSE OF REVIEW

This article will review the evidence behind elements of the lung preservation process that have remained relatively stable over the past decade as well as summarize recent developments in ex-vivo lung perfusion and new research challenging the standard temperature for static cold storage.

RECENT FINDINGS

Ex-vivo lung perfusion is becoming an increasingly well established means to facilitate greater travel distance and allow for continued reassessment of marginal donor lungs. Preliminary reports of the use of normothermic regional perfusion to allow utilization of lungs after DCD recovery exist, but further research is needed to determine its ability to improve upon the current method of DCD lung recovery. Also, research from the University of Toronto is re-assessing the optimal temperature for static cold storage; pilot studies suggest it is a feasible means to allow for storage of lungs overnight to allow for daytime transplantation, but ongoing research is awaited to determine if outcomes are superior to traditional static cold storage.

SUMMARY

It is crucial to understand the fundamental principles of organ preservation to ensure optimal lung function posttransplant. Recent advances in the past several years have the potential to challenge standards of the past decade and reshape how lung transplantation is performed.

Outcomes Of Lung And Liver Transplantation After Simultaneous Recovery Using Abdominal Normothermic Regional Perfusion In Donors After The Circulatory Determination Of Death Versus Donors After Brain Death

Normothermic regional perfusion (NRP) in controlled donation after the circulatory determination of death (cDCD) is a growing preservation technique for abdominal organs that coexists with the rapid recovery of lungs. We aim at describing the outcomes of lung transplants (LuTx) and liver transplants (LiTx) when both grafts are simultaneously recovered from cDCD donors using NRP, and compare them to donation after brain death (DBD). All LuTx and LiTx meeting these criteria during January-2015 to December-2020 in Spain were included in the study. Simultaneous recovery of lungs and livers was undertaken in 227 (17%) cDCD with NRP and 1,879 (21%) DBD donors (p<0.001). Primary graft dysfunction grade-3 within the first 72hours was similar in both LuTx groups (14.7% cDCD vs. 10.5% DBD;p=0.139). LuTx survival at 1 and 3years was 79.9% and 66.4% in cDCD, vs. 81.9% and 69.7% in DBD (p=0.403). The incidence of primary non-function and ischemic cholangiopathy was similar in both LiTx groups. Graft survival at 1 and 3years was 89.7% and 80.8% in cDCD vs. 88.2% and 82.1% in DBD LiTx (p=0.669). In conclusion, the simultaneous rapid recovery of lungs and preservation of abdominal organs with NRP in cDCD donors is feasible, and offers similar outcomes in both LuTx and LiTx recipients to transplants using DBD grafts.

Expanding the Lung Donor Pool: Donation After Circulatory Death, Ex-Vivo Lung Perfusion and Hepatitis C Donors

"Organ shortage remains a limiting factor in lung transplantation. Traditionally, donation after brain death has been the main source of lungs used for transplantation; however, to meet the demand of patients requiring lung transplantation it is crucial to find innovative methods for organ donation. The implementation of extended donors, lung donation after cardiac death (DCD), the use of ex-vivo lung perfusion (EVLP) systems, and more recently the acceptance of hepatitis C donors have started to close the gap between organ donors and recipients in need of lung transplantation. This article focuses on the expansion of donor lungs for transplantation after DCD, the use of EVLP in evaluating extended criteria lungs, and the use of lung grafts from donors with hepatitis C."

Lung transplantation from donation after circulatory death, evolution, and current status in the United States

BACKGROUND

The number of lung transplants from donors after circulatory death has increased over the last decade. This study aimed to describe the evolution and outcomes following lung transplantation donation after circulatory death (DCD) and report the practices and outcomes of ex vivo lung perfusion (EVLP) in this donor population.

METHODS

This was a retrospective study using a prospectively collected national registry. The United Network for Organ Sharing (UNOS) database was queried to identify adult patients who underwent lung transplantation between May 1, 2005, and December 31, 2021. Kaplan-Meier analysis and Weibull regression were used to compare survival in four cohorts (donation after brain death [DBD] with or without EVLP, and DCD with or without EVLP). The primary outcome of interest was patient survival.

RESULTS

Of the 21 356 recipients who underwent lung transplantation, 20 380 (95.4%) were from brain death donors and 976 (4.6%) from donors after circulatory death. Kaplan-Meier analysis showed no difference in the survival time between the two groups. In a multivariable analysis that controlled for baseline differences in donor and recipient characteristics, recipients who received lungs from cardiac death donors after EVLP had 28% shorter survival time relative to donor lungs after brain death without EVLP (hazard ratio [HR] 1.53, 95% confidence interval [CI] 1.10-2.15, p = .01).

CONCLUSIONS

The early survival differences observed after lung transplants from donors after circulatory death in lungs evaluated with EVLP deserves further investigation.

Machine learning-based techniques to improve lung transplantation outcomes and complications: a systematic review

BACKGROUND

Machine learning has been used to develop predictive models to support clinicians in making better and more reliable decisions. The high volume of collected data in the lung transplant process makes it possible to extract hidden patterns by applying machine learning methods. Our study aims to investigate the application of machine learning methods in lung transplantation.

METHOD

A systematic search was conducted in five electronic databases from January 2000 to June 2022. Then, the title, abstracts, and full text of extracted articles were screened based on the PRISMA checklist. Then, eligible articles were selected according to inclusion criteria. The information regarding developed models was extracted from reviewed articles using a data extraction sheet.

RESULTS

Searches yielded 414 citations. Of them, 136 studies were excluded after the title and abstract screening. Finally, 16 articles were determined as eligible studies that met our inclusion criteria. The objectives of eligible articles are classified into eight main categories. The applied machine learning methods include the Support vector machine (SVM) (n = 5, 31.25%) technique, logistic regression (n = 4, 25%), Random Forests (RF) (n = 4, 25%), Bayesian network (BN) (n = 3, 18.75%), linear regression (LR) (n = 3, 18.75%), Decision Tree (DT) (n = 3, 18.75%), neural networks (n = 3, 18.75%), Markov Model (n = 1, 6.25%), KNN (n = 1, 6.25%), K-means (n = 1, 6.25%), Gradient Boosting trees (XGBoost) (n = 1, 6.25%), and Convolutional Neural Network (CNN) (n = 1, 6.25%). Most studies (n = 11) employed more than one machine learning technique or combination of different techniques to make their models. The data obtained from pulmonary function tests were the most used as input variables in predictive model development. Most studies (n = 10) used only post-transplant patient information to develop their models. Also, UNOS was recognized as the most desirable data source in the reviewed articles. In most cases, clinicians succeeded to predict acute diseases incidence after lung transplantation (n = 4) or estimate survival rate (n = 4) by developing machine learning models.

CONCLUSION

The outcomes of these developed prediction models could aid clinicians to make better and more reliable decisions by extracting new knowledge from the huge volume of lung transplantation data.

Prioritizing direct heart procurement in organ donors after circulatory death does not jeopardize lung transplant outcomes

Background

Controlled donation after circulatory death (cDCD) has become a standard in liver, kidney, and lung transplantation (LTx). Based on recent innovations in ex vivo heart preservation, heart transplant centers have started to accept cDCD heart allografts. Because the heart has very limited tolerance to warm ischemia, changes to the cDCD organ procurement procedures are needed. These changes entail delayed ventilation and prolonged warm ischemia for the lungs. Whether this negatively impacts lung allograft function is unclear.

Methods

A retrospective analysis of cDCD lungs transplanted between 2012 and February 2022 at the Medical University of Vienna was performed. The heart + lung group consisted of cases in which the heart was procured by a cardiac team for subsequent normothermic ex vivo perfusion. A control group (lung group) was formed by cases where only the lungs were explanted. In heart + lung group cases, the heart procurement team placed cannulas after circulatory death and a hands-off time, collected donor blood for ex vivo perfusion, and performed rapid organ perfusion with Custodiol solution, after which the heart was explanted. Up to this point, the lung procurement team did not interfere. No concurrent lung ventilation or pulmonary artery perfusion was performed. After the cardiac procurement team left the table, ventilation was initiated, and lung perfusion was performed directly through both stumps of the pulmonary arteries using 2 large-bore Foley catheters. This study analyzed procedural explant times, postoperative outcomes, primary graft dysfunction (PGD), duration of mechanical ventilation, length of intensive care unit (ICU) stay, and early survival after LTx.

Results

A total of 56 cDCD lungs were transplanted during the study period. In 7 cases (12.5%), the heart was also procured (heart + lung group); in 49 cases (87.5%), only the lungs were explanted (lung group). Basic donor parameters were comparable in the 2 groups. The median times from circulatory arrest to lung perfusion (24 minutes vs 13.5 minutes; P = .002) and from skin incision to lung perfusion (14 minutes vs 5 minutes; P = .005) were significantly longer for the heart + lung procedures. However, this did not affect post-transplantation PGD grade at 0 hours (P = .851), 24 hours (P = .856), 48 hours (P = .929), and 72 hours (P = .874). At 72 hours after transplantation, none of the lungs in the heart + lung group but 1 lung (2.2%) in lung group was in PGD 3. The median duration of mechanical ventilation (50 hours vs 41 hours; P = .801), length of ICU stay (8 days vs 6 days; P = .951), and total length of hospital stay (27 days vs 25 days; P = .814) were also comparable in the 2 groups. In-hospital mortality occurred in only 1 patient of the lung group (2.2%).

Conclusions

Although prioritized cDCD heart explantation is associated with delayed ventilation and significantly longer warm ischemic time to the lungs, post-LTx outcomes within the first year are unchanged. Prioritizing heart perfusion and explantation in the setting of cDCD procurement can be considered acceptable.

Experimental Models of Ischemic Lung Damage for the Study of Therapeutic Reconditioning During Ex Vivo Lung Perfusion

Background.

Ex vivo lung perfusion (EVLP) may allow therapeutic reconditioning of damaged lung grafts before transplantation. This study aimed to develop relevant rat models of lung damage to study EVLP therapeutic reconditioning for possible translational applications.

Methods.

Lungs from 31 rats were exposed to cold ischemia (CI) or warm ischemia (WI), inflated at various oxygen fractions (FiO₂), followed by 3 h EVLP. Five groups were studied as follow: (1) C21 (control): 3 h CI (FiO₂ 0.21); (2) C50: 3 h CI (FiO₂ 0.5); (3) W21: 1 h WI, followed by 2 h CI (FiO₂ 0.21); (4) W50: 1 h WI, followed by 2 h CI (FiO₂ 0.5); and (5) W2h: 2 h WI, followed by 1 h CI (FiO₂ 0.21). Following 3 h EVLP, we measured static pulmonary compliance (SPC), pulmonary vascular resistance, lung weight gain (edema), oxygenation capacity (differential partial pressure of oxygen), and protein carbonyls in lung tissue (oxidative stress), as well as lactate dehydrogenase (LDH, lung injury), nitrotyrosine (nitro-oxidative stress), interleukin-6 (IL-6, inflammation), and proteins (permeability edema) in bronchoalveolar lavage (BAL). Perivascular edema was quantified by histology.

Results.

No significant alterations were noted in C21 and C50 groups. W21 and W50 groups had reduced SPC and disclosed increased weight gain, BAL proteins, nitrotyrosine, and LDH. These changes were more severe in the W50 group, which also displayed greater oxidative stress. In contrast, both W21 and W50 showed comparable perivascular edema and BAL IL-6. In comparison with the other WI groups, W2h showed major weight gain, perivascular edema, SPC reduction, drop of differential partial pressure of oxygen, and massive increases of BAL LDH and proteins but comparable increase of IL-6 and biomarkers of oxidative stress.

Conclusions.

These models of lung damage of increasing severity might be helpful to evaluate new strategies for EVLP therapeutic reconditioning. A model combining 1 h WI and inflation at FiO₂ of 0.5 seems best suited for this purpose by reproducing major alterations of clinical lung ischemia-reperfusion injury.

Lung transplantation from controlled donation after circulatory death using simultaneous abdominal normothermic regional perfusion: A single center experience

Despite the benefits of abdominal normothermic regional perfusion (A-NRP) for abdominal grafts in controlled donation after circulatory death (cDCD), there is limited information on the effect of A-NRP on the quality of the cDCD lungs. We aimed to study the effect of A-NRP in lungs obtained from cDCD and its impact on recipients´ outcomes. This is a study comparing outcomes of lung transplants (LT) from cDCD donors (September 2014 to December 2021) obtained using A-NRP as the abdominal preservation method. As controls, all lung recipients transplanted from donors after brain death (DBD) were considered. The primary outcomes were lung recipient 3-month, 1-year, and 5-year survival. A total of 269 LT were performed (60 cDCD and 209 DBD). There was no difference in survival at 3 months (98.3% cDCD vs. 93.7% DBD), 1 year (90.9% vs. 87.2%), and 5 years (68.7% vs. 69%). LT from the cDCD group had a higher rate of primary graft dysfunction grade 3 at 72 h (10% vs. 3.4%; p <  .001). This is the largest experience ever reported with the use of A-NRP combined with lung retrieval in cDCD donors. This combined method is safe for lung grafts presenting short-term survival outcomes equivalent to those transplanted through DBD.

A prediction model to determine the untapped lung donor pool outside of the DonateLife network in Victoria

Lung transplantation is limited by a lack of suitable lung donors. In Australia, the national donation organisation (DonateLife) has taken a major role in optimising organ donor identification. However, the potential outside the DonateLife network hospitals remains uncertain. We aimed to create a prediction model for lung donation within the DonateLife network and estimate the untapped lung donors outside of the DonateLife network. We reviewed all deaths in the state of Victoria's intensive care units using a prospectively collected population-based intensive care unit database linked to organ donation records. A logistic regression model derived using patient-level data was developed to characterise the lung donors within DonateLife network hospitals. Consequently, we estimated the expected number of lung donors in Victorian hospitals outside the DonateLife network and compared the actual number. Between 2014 and 2018, 291 lung donations occurred from 8043 intensive care unit deaths in DonateLife hospitals, while only three lung donations occurred from 1373 ICU deaths in non-DonateLife hospitals. Age, sex, postoperative admission, sepsis, neurological disease, trauma, chronic respiratory disease, lung oxygenation and serum creatinine were factors independently associated with lung donation. A highly discriminatory prediction model with area under the receiver operator characteristic curve of 0.91 was developed and accurately estimated the number of lung donors. Applying the model to non-DonateLife hospital data predicted only an additional five lung donors. This prediction model revealed few additional lung donor opportunities outside the DonateLife network, and the necessity of alternative and novel strategies for lung donation. A donor prediction model could provide a useful benchmarking tool to explore organ donation potential across different jurisdictions, hospitals and transplanting centres.

Lung Biomolecular Profile and Function of Grafts from Donors after Cardiocirculatory Death with Prolonged Donor Warm Ischemia Time

The acceptable duration of donor warm ischemia time (DWIT) after cardiocirculatory death (DCD) is still debated. We analyzed the biomolecular profile and function during ex vivo lung perfusion (EVLP) of DCD lungs and their correlation with lung transplantation (LuTx) outcomes. Donor data, procurement times, recipient outcomes, and graft function up to 1 year after LuTx were collected. During EVLP, the parameters of graft function and metabolism, perfusate samples to quantify inflammation, glycocalyx breakdown products, coagulation, and endothelial activation markers were obtained. Data were compared to a cohort of extended-criteria donors after brain death (EC-DBD). Eight DBD and seven DCD grafts transplanted after EVLP were analyzed. DCD’s DWIT was 201 [188;247] minutes. Donors differed only regarding the duration of mechanical ventilation that was longer in the EC-DBD group. No difference was observed in lung graft function during EVLP. At reperfusion, “wash-out” of inflammatory cells and microthrombi was predominant in DCD grafts. Perfusate biomolecular profile demonstrated marked endothelial activation, characterized by the presence of inflammatory mediators and glycocalyx breakdown products both in DCD and EC-DBD grafts. Early graft function after LuTx was similar between DCD and EC-DBD. DCD lungs exposed to prolonged DWIT represent a potential resource for donation if properly preserved and evaluated.

Donation After Circulatory Death in lung transplantation

The continuing shortage of pulmonary grafts from donors after brain death has led to a resurgence of interest in lung transplantation from donors after circulatory death (DCD). Most lungs from donors after withdrawal from life-sustaining therapy can be recovered rapidly and transplanted directly without ex-vivo assessment in case functional warm ischemic time is limited to 30 to 60 min. The potential of the DCD lung pool is still underutilized and should be maximized in countries with existing legislation. Countries lacking a DCD pathway should be encouraged to develop national ethical, professional, and legal frameworks to address public and professional concerns.

Management of the Potential Lung Donor

The use of donor management protocols has significantly improved recovery rates; however, the inherent instability of lungs after death results in low utilization rates of potential donor lungs. Donor lungs are susceptible to direct trauma, aspiration, neurogenic edema, ventilator-associated barotrauma, and ventilator-associated pneumonia. After irreversible brain injury and determination of futility of care, the goal of medical management of the donor shifts to maintaining hemodynamic stability and maximizing the likelihood of successful organ recovery.

Impact of anastomosis time during lung transplantation on primary graft dysfunction

Primary graft dysfunction (PGD) is a major obstacle after lung transplantation (LTx), associated with increased early morbidity and mortality. Studies in liver and kidney transplantation revealed prolonged anastomosis time (AT) as an independent risk factor for impaired short- and long-term outcomes. We investigated if AT during LTx is a risk factor for PGD. In this retrospective single-center cohort study, we included all first double lung transplantations between 2008 and 2016. The association of AT with any PGD grade 3 (PGD3) within the first 72 h post-transplant was analyzed by univariable and multivariable logistic regression analysis. Data on AT and PGD was available for 427 patients of which 130 (30.2%) developed PGD3. AT was independently associated with the development of any PGD3 ≤72 h in uni- (odds ratio [OR] per 10 min 1.293, 95% confidence interval [CI 1.136-1.471], p < .0001) and multivariable (OR 1.205, 95% CI [1.022-1.421], p = .03) logistic regression analysis. There was no evidence that the relation between AT and PGD3 differed between lung recipients from donation after brain death versus donation after circulatory death donors. This study identified AT as an independent risk factor for the development of PGD3 post-LTx. We suggest that the implantation time should be kept short and the lung cooled to decrease PGD-related morbidity and mortality post-LTx.

Donation after circulatory death and lung transplantation

Lung transplantation is the most effective modality for the treatment of patients with end-stage lung diseases. Unfortunately, many people cannot benefit from this therapy due to insufficient donor availability. In this review and update article, we discuss donation after circulatory death (DCD), which is undoubtedly essential among the strategies developed to increase the donor pool. However, there are ethical and legislative considerations in the DCD process that are different from those of donation after brain death (DBD). Among others, the critical aspects of DCD are the concept of the end of life, cessation of futile treatments, and withdrawal of life-sustaining therapy. In addition, this review describes a rationale for using lungs from DCD donors and provides some important definitions, highlighting the key differences between DCD and DBD, including physiological aspects pertinent to each category. The unique ability of lungs to maintain cell viability without circulation, assuming that oxygen is supplied to the alveoli-an essential aspect of DCD-is also discussed. Furthermore, an updated review of the clinical experience with DCD for lung transplantation across international centers, recent advances in DCD, and some ethical dilemmas that deserve attention are also reported.

Trends in Donation After Circulatory Death in Lung Transplantation in the United States: Impact Of Era

Background: Use of lungs donated after circulatory death (DCD) has expanded, but changes in donor/recipient characteristics and comparison to brain dead donors (DBD) has not been studied. We examined the evolution of the use of DCD lungs for transplantation and compare outcomes to DBD lungs.

Methods: The SRTR database was used to construct three 5-year intervals. Perioperative variables and survival were compared by era and for DCD vs. DBD. Geographic variation was estimated using recipient permanent address.

Results: 728 DCD and 27,205 DBD lung transplants were identified. DCD volume increased from Era 1 (n = 73) to Era 3 (n = 528), representing 1.1% and 4.2% of lung transplants. Proportionally more DCD recipients were in ICU or on ECMO pre-transplant, and had shorter waitlist times. DCD donors were older, had lower PaO2/FiO2 ratios compared to DBD, more likely to be bilateral, had longer ischemic time, length of stay, post-op dialysis, and increased use of lung perfusion. There was no difference in overall survival. Geographically, use was heterogeneous.

Conclusion: DCD utilization is low but increasing. Despite increasing ischemic time and transplantation into sicker patients, survival is similar, which supports further DCD use in lung transplantation. DCD lung transplantation presents an opportunity to continue to expand the donor pool.

Physiotherapy in Patients on the Organ Donation Pathway: A Survey of Current Practice

BACKGROUND

The purpose of the survey was to identify the current practices of physiotherapists in the management of patients on the organ donation pathway.

METHODS

The author conducted a cross-sectional telephone survey. Participants were 16 physiotherapists working in intensive care units (ICU) in Queensland, who were involved in the care of patients on the organ donation pathway.

RESULTS

In Queensland ICUs, only 57% of hospitals have formal guidelines for physiotherapy management of patients on the organ donation pathway. When comparing the frequency of interventions with organ donation status, 86% of physiotherapists reported increasing the frequency of interventions once a patient was considered for organ donation. Clinical reasoning was reported as the primary factor affecting intervention choice for 67% of physiotherapists, with no difference in frequency, or choice of intervention in patients for donation after circulatory death, compared with donation after brain death. In hospitals with a level I ICU (with infrequent exposure to organ donation), the use of protocols was supported by 100% of participants, whereas in hospitals with a level II and III ICU (and greater exposure), only 31% of participants supported the use of protocols.

CONCLUSIONS

There are wide variations and a lack of formal guidelines for physiotherapy management of patients on the organ donation pathway; however, clinical reasoning appears to be favored above protocolized management in hospitals with level II and level III ICUs.

Unassisted Return of Spontaneous Circulation Following Withdrawal of Life-Sustaining Therapy During Donation After Circulatory Determination of Death in a Child

OBJECTIVES

To describe the unassisted return of spontaneous circulation following withdrawal of life-sustaining treatment in a child.

DESIGN

Case report based on clinical observation and medical record review.

SETTING

Community Children's Hospital.

PATIENT

Two-year old child.

INTERVENTIONS

Following hypoxic-ischemic brain injury, the child was taken to the operating room for withdrawal of life-sustaining treatment during controlled donation after circulatory determination of death.

MEASUREMENTS AND MAIN RESULTS

In addition to direct observation by experienced pediatric critical care providers, the child was monitored with electrocardiography, pulse oximetry, and invasive blood pressure via femoral arterial catheter in addition to direct observation by experienced pediatric critical care providers. Unassisted return of spontaneous circulation occurred greater than 2 minutes following circulatory arrest and was accompanied by return of respiration.

CONCLUSIONS

We provide the first report of unassisted return of spontaneous circulation following withdrawal of life-sustaining treatment in a child. In our case, return of spontaneous circulation occurred in the setting of controlled donation after circulatory determination of death and was accompanied by return of respiration. Return of spontaneous circulation greater than 2 minutes following circulatory arrest in our patient indicates that 2 minutes of observation is insufficient to ensure that cessation of circulation is permanent after withdrawal of life-sustaining treatment in a child.

Rapid postmortem ventilation improves donor lung viability by extending the tolerable warm ischemic time after cardiac death in mice

Uncontrolled donation after cardiac death (uDCD) contributes little to ameliorating donor lung shortage due to rapidly progressive warm ischemia after circulatory arrest. Here, we demonstrated non-hypoxia improves donor lung viability in a novel uDCD lung transplant model undergoing rapid ventilation after cardiac death and compared the evolution of ischemia-reperfusion injury in mice that underwent pulmonary artery ligation (PAL). The tolerable warm ischemia time at 37ºC was initially determined in mice using a modified PAL model. The donor lung following PAL was also transplanted into syngeneic mice and compared to those that underwent rapid ventilation or no ventilation at 37ºC prior to transplantation. Twenty-four hours following reperfusion, lung histology, PaO2/FIO2 ratio, and inflammatory mediators were measured. Four hours of PAL had little impact on PaO2/FIO2 ratio and acute lung injury score in contrast to significant injury induced by 5 hours of PAL. Four-hour PAL lungs showed an early myeloid-dominant inflammatory signature when compared to naïve lungs and substantially injured five-hour PAL lungs. In the context of transplantation, unventilated donor lungs showed severe injury after reperfusion, whereas ventilated donor lungs showed minimal changes in PaO2/FIO2 ratio, histologic score, and expression of inflammatory markers. Taken together, the tolerable warm ischemia time of murine lungs at 37^oC can be extended by maintaining alveolar ventilation for up to 4 hours. Non-hypoxic lung warm ischemia-reperfusion injury shows an early transcriptional signature of myeloid cell recruitment and extracellular matrix proteolysis prior to blood-gas barrier dysfunction and significant tissue damage.

An Audit of Lung Donor Pool: Optimal Current Donation Strategies and the Potential of Novel Time-Extended Donation After Circulatory Death Donation

BACKGROUND

In Australia, increased organ donation and subsequent lung transplantation (LTx) rates have followed enhanced donor identification, referral and management, as well as the introduction of a donation after circulatory death (DCD) pathway. However, the number of patients waiting for LTx still continues to exceed the number of lung donors and the search for further suitable donors is critical.

METHODS

All 2014-2018 Victorian DonateLife hospital deaths after intensive care unit (ICU) admission were analysed retrospectively to quantify unrecognised lung donors using current criteria, as well as novel time-extended (90 mins-24 hrs post-withdrawal) DCD lung donors.

RESULTS

Using standard lung donor eligibility criteria, we identified 473 potential lung donors and a further 122 time-extended DCD potential lung donors among 3,538 patients meeting general eligibility criteria. Detailed review of end-of-life discussions with patient families and the reasons why they were not offered donation revealed several categories of additional lung donors-traditional lung donors missed in current practice (n=2); hepatitis C infected lung donors potentially treatable with direct-acting antivirals (n=14), time-extended DCD lung donors (n=60); donor lungs potentially suitable for transplant with use of ex-vivo lung perfusion (EVLP) (n=7).

CONCLUSION

While the number of lung donor opportunities missed under existing DonateLife donor identification and management processes was limited, a time-extended DCD lung donation pathway could substantially expand the lung donor pool. The use of hepatitis C infected donors, and the possibility of EVLP to solve donor graft assessment or logistic issues, could also provide small additional lung donor opportunities.

Current status and further potential of lung donation after circulatory death

Chronic organ shortage remains the most limiting factor in lung transplantation. To overcome this shortage, a minority of centers have started with efforts to reintroduce donation after circulatory death (DCD). This review aims to evaluate the experimental background, the current international clinical experience, and the further potential and challenges of the different DCD categories. Successful strategies have been implemented to reduce the problems of warm ischemic time, thrombosis after circulatory arrest, and difficulties in organ assessment, which come with DCD donation. From the currently reported results, controlled-DCD lungs are an effective and safe method with good mid-term and even long-term survival outcomes comparable to donation after brain death (DBD). Primary graft dysfunction and onset of chronic allograft dysfunction seem also comparable. Thus, controlled-DCD lungs should be ceased to be treated as marginal and instead be promoted as an equivalent alternative to DBD. A wide implementation of controlled-DCD-lung donation would significantly decrease the mortality on the waiting list. Therefore, further efforts in establishment of legislation and logistics are crucial. With regard to uncontrolled DCD, more data are needed analyzing long-term outcomes. To help with the detailed assessment and improvement of uncontrolled or otherwise questionable grafts after retrieval, ex-vivo lung perfusion is promising.

A novel lung autotransplantation technique for treating central lung cancer: a case report

Lung autotransplantation is an alternative technique in treating central non-small cell lung cancer (NSCLC) for patients who are not suitable to undergo pneumonectomy. We hereby report a novel lung autotransplantation technique for treating central lung cancer. Two cases of central NSCLC involving right main bronchus underwent right basal segment and right lower lobe autotransplantation after resection. The inferior pulmonary vein of graft was anastomosed to superior pulmonary venous stump in both cases to reduce the bronchial and pulmonary arterial gap created after extensive resection. One case had anastomosis of basal segment artery to the right upper lobe anterior segment artery stump while the other case had pulmonary artery angioplasty only without segmental arterial resection. Both procedures were performed in situ without graft perfusion. The airway reconstructions were completed using parachute principle via end-to-side anastomosis of graft bronchus and lateral wall of trachea instead of end-to-end anastomosis with main bronchial stump. Both patients received ICU care postoperatively for 4 days. Chest tubes were successfully removed within 7 days. They were discharged within 11 days postoperatively. No major complication, such as severe infection, anastomotic dehiscence, anastomotic stenosis, atelectasis, or pulmonary embolism was observed. There was no evidence of recurrence at 9-month follow-up.

Donation after circulatory death (DCD)-lung procurement

The number of lungs available for lung transplantation is far lower than the number of patients awaiting them. Consequently, there is a significant attrition rate while awaiting transplantation. Lung procurement rates are lower than those of other solid organs. Lungs are procured from only 15–20% of donors compared with 30% of decreased donors for hearts. The reason for this low retrieval rate is related to a number of factors. Brain death is associated with neurogenic pulmonary edema. Additionally, injury to the lung itself may occur before or after brain death. Aspiration of gastric contents, pneumonia, previous thoracic trauma, ventilator-associated injury, atelectasis, and pulmonary thrombosis/embolism may all contribute to lung injury before consideration for harvest. Donation after circulatory death (DCD) is one category of nontraditional organ donation now being performed in increasing numbers as a way to increase the number of lungs available for transplantation. In some studies, estimates show that utilization of DCD lung procurement could increase the number of lungs available by up to 50%.

Improving the predictability of time to death in controlled donation after circulatory death lung donors

Although the use of donation after circulatory death (DCD) donors has increased lung transplant activity, 25-40% of intended DCD donors do not convert to actual donation because of no progression to asystole in the required time frame after withdrawal of cardiorespiratory support (WCRS). No studies have specifically focussed on DCD lung donor progression. This retrospective study reviewed intended DCD lung donors to make a prediction model of the likelihood of progression to death using logistic regression and classification and regression tree (CART). Between 2014 and 2018, 159 of 334 referred DCD donors were accepted, with 100 progressing to transplant, while 59 (37%) did not progress. In logistic regression, a length of ICU stay ≤ 5 days, severe infra-tentorial brain damage on imaging and use of vasopressin were related with the progression to actual donation. CART modelling of the likelihood of death within 90-minute post-WCRS provided prediction with a sensitivity of 1.00 and positive predictive value of 0.56 in the validation data set. In the nonprogressed DCD group, 26 died within 6 h post-WCRS. Referral received early after ICU admission, with nonspontaneous ventilatory mode, deep coma and severe infra-tentorial damage were relevant predictors. The CART model is useful to exclude DCD donor candidates with low probability of progression.

Expanding controlled donation after the circulatory determination of death: statement from an international collaborative

A decision to withdraw life-sustaining treatment (WLST) is derived by a conclusion that further treatment will not enable a patient to survive or will not produce a functional outcome with acceptable quality of life that the patient and the treating team regard as beneficial. Although many hospitalized patients die under such circumstances, controlled donation after the circulatory determination of death (cDCDD) programs have been developed only in a reduced number of countries. This International Collaborative Statement aims at expanding cDCDD in the world to help countries progress towards self-sufficiency in transplantation and offer more patients the opportunity of organ donation. The Statement addresses three fundamental aspects of the cDCDD pathway. First, it describes the process of determining a prognosis that justifies the WLST, a decision that should be prior to and independent of any consideration of organ donation and in which transplant professionals must not participate. Second, the Statement establishes the permanent cessation of circulation to the brain as the standard to determine death by circulatory criteria. Death may be declared after an elapsed observation period of 5 min without circulation to the brain, which confirms that the absence of circulation to the brain is permanent. Finally, the Statement highlights the value of perfusion repair for increasing the success of cDCDD organ transplantation. cDCDD protocols may utilize either in situ or ex situ perfusion consistent with the practice of each country. Methods to accomplish the in situ normothermic reperfusion of organs must preclude the restoration of brain perfusion to not invalidate the determination of death.

Utilization of extracorporeal membrane oxygenation in DCD and DBD lung transplants: a 2-year single-center experience

Donation after circulatory death (DCD) has the potential to expand the lung donor pool. We aimed to assess whether DCD affected the need for perioperative extracorporeal membrane oxygenation (ECMO) and perioperative outcomes in lung transplantation (LTx) as compared to donation after brain death (DBD). All consecutive LTxs performed between April 2017 and March 2019 at our tertiary center were analyzed. Donor and recipient preoperative characteristics, utilization of ECMO, and perioperative clinical outcomes were compared between DCD and DBD LTx. Multivariate models (frequentist and Bayes) were fitted to evaluate an independent effect of DCD on the intra- and postoperative need for ECMO. Out of 105 enrolled patients, 25 (23.8%) were DCD LTx. Donors' and preoperative recipients' characteristics were comparable between the groups. Intraoperatively, mechanical circulatory support (MCS) was more common in DCD LTx (56.0% vs. 36.2%), but the adjusted difference was minor (RR = 1.16, 95% CI 0.64-2.12; P = 0.613). MCS duration, and first and second lung ischemia time were longer in the DCD group. Postoperatively, DCD recipients more commonly required ECMO (32.0% vs. 7.5%) and the difference remained considerable after adjustment for the pre- and intraoperative covariates: RR = 4.11 (95% CI 0.95-17.7), P = 0.058, Bayes RR = 4.15 (95% CrI 1.28-13.0). Sensitivity analyses (two DCD-DBD matching procedures) supported a higher risk of postoperative ECMO need in DCD patients. Incidence of delayed chest closure, postoperative chest drainage, and renal replacement therapy was higher in the DCD group. Early postoperative outcomes after DCD LTx appeared generally comparable to those after DBD LTx. DCD was associated with a higher need for postoperative ECMO which could influence clinical outcomes. However, as the DCD group had a significantly higher use of EVLP with more common ECMO preoperatively, this might have contributed to worse outcomes in the DCD group.

Common Criteria for Ex Vivo Lung Perfusion Have No Significant Impact on Posttransplant Outcomes

BACKGROUND

Although it is intense in health care resources, by facilitating assessment and reconditioning, ex vivo lung perfusion (EVLP) has the potential to expand the donor pool and improve lung transplant outcomes. However, inclusion criteria used in EVLP trials have not been validated.

METHODS

This retrospective study from 2014 to 2018 reviewed our local state-based donation organization donor records as well as subsequent recipient outcomes to explore the relation between EVLP indications used in clinical trials and recipient outcomes. The primary outcome was primary graft dysfunction grade 3 at 24 hours, with 30-day mortality and posttransplant survival time as secondary outcomes, compared with univariate and multivariate analysis.

RESULTS

From 705 lung donor referrals, 304 lung transplantations were performed (use rate of 42%); 212 of recipients (70%) met at least 1 of the commonly cited EVLP initiation criteria. There was no significant difference in primary graft dysfunction grade 3 or 30-day mortality between recipients with or without an EVLP indication (10.2% versus 7.8%, P = .51; and 2.4% versus 0%, P = .14, respectively). Multivariate analyses showed no significant relationship between commonly cited EVLP criteria and primary graft dysfunction grade 3 or survival time. Recipient outcomes were significantly associated with recipient diagnosis.

CONCLUSIONS

At least 1 commonly cited criterion for EVLP initiation was present in 70% of the transplanted donors, and yet it did not predict clinical results; acceptable outcomes were seen in both subgroups. To discover the true utility of EVLP beyond good clinical management and focus EVLP on otherwise unacceptable lungs, a reconsideration of EVLP inclusion criteria is required.

Review 1: Lung transplant-from donor selection to graft preparation

For various end-stage lung diseases, lung transplantation remains one of the only viable treatment options. While the demand for lung transplantation has steadily risen over the last few decades, the availability of donor grafts is limited, which have resulted in progressively longer waiting lists. In the early years of lung transplantation, only the 'ideal' donor grafts are considered for transplantation. Due to the donor shortages, there is ongoing discussion about the safe use of 'suboptimal' grafts to expand the donor pool. In this review, we will discuss the considerations around donor selection, donor-recipient matching, graft preparation and graft optimisation.