International Society for Heart and Lung Transplantation Donation After Circulatory Death Registry Report

Improving lung allograft function in the early post-operative period through the inhibition of pyroptosis

Lung transplantation is the only definitive therapy for end-stage pulmonary disease. Less than 20 % of offered lungs are successfully transplanted due to a limited ischemic time window and poor donor lung quality manifested by pulmonary edema, hypoxia, or trauma. Therefore, poor donor organ recovery and utilization are significant barriers to wider implementation of the life-saving therapy of transplantation. While ischemia reperfusion injury (IRI) is often identified as the underlying molecular insult leading to immediate poor lung function in the post-operative period, this injury encompasses several pathways of cellular injury in addition to the recruitment of the innate immune system to the site of injury to propagate this inflammatory cascade. Pyroptosis is a central molecular inflammatory pathway that is the most significant contributor to injury in this early post-operative phase. Pyroptosis is another form of programmed cell death and is often associated with IRI. The mitigation of pyroptosis in the early post-operative period following lung transplantation is a potential novel way to prevent poor allograft function and improve outcomes for all recipients. Here we detail the pyroptotic pathway, its importance in lung transplantation, and several therapeutic modalities that can mitigate this harmful inflammatory pathway.

Ex vivo lung perfusion in donation after circulatory death: A post hoc analysis of the Normothermic Ex Vivo Lung Perfusion as an Assessment of Extended/Marginal Donors Lungs trial

OBJECTIVE

Donation after circulatory death (DCD) donors offer the ability to expand the lung donor pool and ex vivo lung perfusion (EVLP) further contributes to this ability by allowing for additional evaluation and resuscitation of these extended criteria donors. We sought to determine the outcomes of recipients receiving organs from DCD EVLP donors in a multicenter setting.

METHODS

This was an unplanned post hoc analysis of a multicenter, prospective, nonrandomized trial that took place during 2011 to 2017 with 3 years of follow-up. Patients were placed into 3 groups based off procurement strategy: brain-dead donor (control), brain-dead donor evaluated by EVLP, and DCD donors evaluated by EVLP. The primary outcomes were severe primary graft dysfunction at 72 hours and survival. Secondary outcomes included select perioperative outcomes, and 1-year and 3-years allograft function and quality of life measures.

RESULTS

The DCD EVLP group had significantly higher incidence of severe primary graft dysfunction at 72 hours (P = .03), longer days on mechanical ventilation (P < .001) and in-hospital length of stay (P = .045). Survival at 3 years was 76.5% (95% CI, 69.2%-84.7%) for the control group, 68.3% (95% CI, 58.9%-79.1%) for the brain-dead donor group, and 60.7% (95% CI, 45.1%-81.8%) for the DCD group (P = .36). At 3-year follow-up, presence observed bronchiolitis obliterans syndrome or quality of life metrics did not differ among the groups.

CONCLUSIONS

Although DCD EVLP allografts might not be appropriate to transplant in every candidate recipient, the expansion of their use might afford recipients stagnant on the waitlist a viable therapy.

Use of a novel donor lung scoring system as a tool for increasing lung recovery for transplantation

BACKGROUND

There is a critical shortage of donor lungs for transplantation. We previously developed a parsimonious, highly discriminatory 9-variable Lung Donor (LUNDON) acceptability score. Here we assessed the utility of this score as a tool for improving lung recovery rates for transplantation.

METHODS

We examined all brain-dead donors between 2014 and 2020 from 3 US organ procurement organizations and validated the score's predictive performance. We examined the trajectory of donors with low (<40) and high (>60) initial LUNDON scores, their corresponding lung recovery rates, factors contributing to score improvement using multivariable regression models, and 1-year post-transplant recipient survival.

RESULTS

Overall lung recovery was 32.4% (1410 of 4351). Validation of the LUNDON score in our cohort revealed a C statistic of 0.904 and required intercept calibration. Low initial LUNDON donors that improved to a high final score had an increase in lung recovery rate from 29.3% (1100 of 3765) to 86.8% (441 of 508), associated with lower body mass index, management in a specialized donor care facility (SDCF), and more bronchoscopies. Donors with high initial and final LUNDON scores had a lung recovery rate of 85.2% (98 of 115), associated with shorter length of hospital stay. One-year survival was similar in recipients of low-to-high versus high-to-high LUNDON score donors (0.89 vs 0.84; P = .2).

CONCLUSIONS

The LUNDON score performs well as a predictor of lung recovery in a contemporary cohort but may require organ procurement organization-specific calibration. SDCF care, increasing use of bronchoscopy, and decreasing the time from brain death to organ procurement may improve lung utilization. The LUNDON score can be used to guide donor management to expand the donor pool.

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.

Ex vivo lung perfusion and the Organ Care System: a review

With the increasing prevalence of heart failure and end-stage lung disease, there is a sustained interest in expanding the donor pool to alleviate the thoracic organ shortage crisis. Efforts to extend the standard donor criteria and to include donation after circulatory death have been made to increase the availability of suitable organs. Studies have demonstrated that outcomes with extended-criteria donors are comparable to those with standard-criteria donors. Another promising approach to augment the donor pool is the improvement of organ preservation techniques. Both ex vivo lung perfusion (EVLP) for the lungs and the Organ Care System (OCS, TransMedics) for the heart have shown encouraging results in preserving organs and extending ischemia time through the application of normothermic regional perfusion. EVLP has been effective in improving marginal or borderline lungs by preserving and reconditioning them. The use of OCS is associated with excellent short-term outcomes for cardiac allografts and has improved utilization rates of hearts from extended-criteria donors. While both EVLP and OCS have successfully transitioned from research to clinical practice, the costs associated with commercially available systems and consumables must be considered. The ex vivo perfusion platform, which includes both EVLP and OCS, holds the potential for diverse and innovative therapies, thereby transforming the landscape of thoracic organ transplantation.

Outcomes after lung transplantation from selected donors older than 70 years in a single centre: time to close the debate?

OBJECTIVES

The aim of this study was to compare the outcomes of lung transplantations using grafts from donors aged over 70 years against those performed using younger donors.

METHODS

This retrospective single-centre analysis includes lung transplants conducted at our institution from January 2014 to June 2022. Lung recipients were classified into 2 groups based on donor age (group A <70 years; group B ≥70 years). Variables regarding demographics, peri and postoperative outcomes and survival were included. The statistical analysis approach included univariable analysis, propensity score matching to address imbalances in donor variables (smoking status), recipient characteristics (sex, age, diagnosis and lung allocation score) and calendar period and survival analysis.

RESULTS

A total of 353 lung transplants were performed in this period, 47 (13.3%) using grafts from donors aged over 70 years. Donors in group B were more frequently women (70.2% vs 51.6%, P = 0.017), with less smoking history (22% vs 43%, P = 0.002) and longer mechanical ventilation time (3 vs 2 days, P = 0.025). Recipients in group B had a higher lung allocation score (37.5 vs 35, P = 0.035). Postoperative variables were comparable between both groups, except for pulmonary function tests. Group B demonstrated lower forced expiratory volume 1 s levels (2070 vs 2580 ml, P = 0.001). The propensity score matching showed a lower chance of chronic lung allograft dysfunction by 12% for group B. One-, three- and five-year survival was equal between the groups.

CONCLUSIONS

The use of selected expanded-criteria donors aged over 70 years did not result in increased postoperative morbidity, early mortality or survival in this study.

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.

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.

Controlled donation after circulatory death lung transplantation: Results of the French protocol including in situ abdominal normothermic regional perfusion and ex vivo lung perfusion

BACKGROUND

The French national protocol for controlled donation after circulatory determination of death (cDCD) includes normothermic regional perfusion (NRP) in case of abdominal organ procurement and additional ex-vivo lung perfusion (EVLP) before considering lung transplantation (LT).

METHODS

We made a retrospective study of a prospective registry that included all donors considered for cDCD LT from the beginning of the program in May 2016 to November 2021.

RESULTS

One hundred grafts from 14 donor hospitals were accepted by 6 LT centers. The median duration of the agonal phase was 20 minutes [2-166]. The median duration from circulatory arrest to pulmonary flush was 62 minutes [20-90]. Ten lung grafts were not retrieved due to prolonged agonal phases (n = 3), failure of NRP insertion (n = 5), or poor in situ evaluation (n = 2). The remaining 90 lung grafts were all evaluated on EVLP, with a conversion rate of 84% and a cDCD transplantation rate of 76%. The median total preservation time was 707 minutes [543-1038]. Seventy-one bilateral LTs and 5 single LTs were performed for chronic obstructive pulmonary disease (n = 29), pulmonary fibrosis (n = 21), cystic fibrosis (n = 15), pulmonary hypertension (n = 8), graft-versus-host disease (n = 2), and adenosquamous carcinoma (n = 1). The rate of PGD3 was 9% (n = 5). The 1-year survival rate was 93.4%.

CONCLUSION

After initial acceptance, cDCD lung grafts led to LT in 76% of cases, with outcomes similar to those already reported in the literature. The relative impacts of NRP and EVLP on the outcome following cDCD LT should be assessed prospectively in the context of comparative studies.

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.

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.

Lung Transplantation From Controlled and Uncontrolled Donation After Circulatory Death (DCD) Donors With Long Ischemic Times Managed by Simple Normothermic Ventilation and Ex-Vivo Lung Perfusion Assessment

Donation after cardiac death (DCD) donors are still subject of studies. In this prospective cohort trial, we compared outcomes after lung transplantation (LT) of subjects receiving lungs from DCD donors with those of subjects receiving lungs from donation after brain death (DBD) donors (ClinicalTrial.gov: NCT02061462). Lungs from DCD donors were preserved in-vivo through normothermic ventilation, as per our protocol. We enrolled candidates for bilateral LT ≥14 years. Candidates for multi-organ or re-LT, donors aged ≥65 years, DCD category I or IV donors were excluded. We recorded clinical data on donors and recipients. Primary endpoint was 30-day mortality. Secondary endpoints were: duration of mechanical ventilation (MV), intensive care unit (ICU) length of stay, severe primary graft dysfunction (PGD3) and chronic lung allograft dysfunction (CLAD). 121 patients (110 DBD Group, 11 DCD Group) were enrolled. 30-day mortality and CLAD prevalence were nil in the DCD Group. DCD Group patients required longer MV (DCD Group: 2 days, DBD Group: 1 day, p = 0.011). ICU length of stay and PGD3 rate were higher in DCD Group but did not significantly differ. LT with DCD grafts procured with our protocols appears safe, despite prolonged ischemia times.

Textbook Outcome: Definition and Analysis of a Novel Quality Measure in Lung Transplantation

OBJECTIVE

To define textbook outcome (TO) for lung transplantation (LTx) using a contemporary cohort from a high-volume institution.

SUMMARY BACKGROUND DATA

TO is a standardized, composite quality measure based on multiple postoperative endpoints representing the ideal "textbook" hospitalization.

METHODS

Adult patients who underwent LTx at our institution between 2016 and 2019 were included. TO was defined as freedom from intraoperative complication, postoperative reintervention, 30-day intensive care unit or hospital readmission, length of stay >75th percentile of LTx patients, 90 day mortality, 30-day acute rejection, grade 3 primary graft dysfunction at 48 or 72 hours, postoperative extracorporeal membrane oxygenation, tracheostomy within 7 days, inpatient dialysis, reintubation, and extubation >48 hours post-transplant. Recipient, operative, financial characteristics, and post-transplant outcomes were recorded from institutional data and compared between TO and non-TO groups.

RESULTS

Of 401 LTx recipients, 97 (24.2%) achieved TO. The most common reason for TO failure was extubation >48 hours post-transplant (N = 119, 39.1%); the least common was mortality (N = 15, 4.9%). Patient and graft survival were improved among patients who achieved versus failed TO (patient survival: log-rank P < 0.01; graft survival: log-rank P < 0.01). Rejection-free and chronic lung allograft dysfunction-free survival were similar between TO and non-TO groups (rejection-free survival: log-rank P = 0.07; chronic lung allograft dysfunction-free survival: log-rank P = 0.3). On average, patients who achieved TO incurred approximately $638,000 less in total inpatient charges compared to those who failed TO.

CONCLUSIONS

TO in LTx was associated with favorable post-transplant outcomes and significant cost-savings. TO may offer providers and patients new insight into transplant center quality of care and highlight areas for improvement.

Textbook outcome in lung transplantation: Planned venoarterial extracorporeal membrane oxygenation versus off-pump support for patients without pulmonary hypertension

BACKGROUND

Planned venoarterial extracorporeal membrane oxygenation (VA ECMO) is increasingly used during bilateral orthotopic lung transplantation (BOLT) and may be superior to off-pump support for patients without pulmonary hypertension. In this single-institution study, we compared rates of textbook outcome between BOLTs performed with planned VA ECMO or off-pump support for recipients with no or mild pulmonary hypertension.

METHODS

Patients with no or mild pulmonary hypertension who underwent isolated BOLT between 1/2017 and 2/2021 with planned off-pump or VA ECMO support were included. Textbook outcome was defined as freedom from intraoperative complication, 30-day reintervention, 30-day readmission, post-transplant length of stay >30 days, 90-day mortality, 30-day acute rejection, grade 3 primary graft dysfunction at 48 or 72 hours, post-transplant ECMO, tracheostomy within 7 days, inpatient dialysis, reintubation, and extubation >48 hours post-transplant. Textbook outcome achievement was compared between groups using multivariable logistic regression.

RESULTS

Two hundred thirty-seven BOLTs were included: 68 planned VA ECMO and 169 planned off-pump. 14 (20.6%) planned VA ECMO and 27 (16.0%) planned off-pump patients achieved textbook outcome. After adjustment for prior BOLT, lung allocation score, ischemic time, and intraoperative transfusions, planned VA ECMO was associated with higher odds of textbook outcome than planned off-pump support (odds ratio 3.89, 95% confidence interval 1.58-9.90, p = 0.004).

CONCLUSIONS

At our institution, planned VA ECMO for isolated BOLT was associated with higher odds of textbook outcome than planned off-pump support among patients without pulmonary hypertension. Further investigation in a multi-institutional cohort is warranted to better elucidate the utility of this strategy.

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.

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.

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.

An Intention-to-treat View of Lung Transplantation for Interstitial Lung Disease: Successful Strategies to Minimize Waiting List and Posttransplant Mortality

BACKGROUND

Access to lung transplantation (LTx) and rates of waiting list and posttransplant mortality for patients with interstitial lung disease (ILD) remain problematic. We evaluated the outcomes of ILD patients listed for LTx at our institution.

METHODS

Between 2012 and 2018, adult patients with ILD were listed and transplanted from a donor-pool that included extended criteria and donation after circulatory-determined death donors. Patients were categorized as experiencing 1 of 4 competing events: transplant, waitlist death, delisting, or alive on waitlist. Multivariable competing risk regression analysis was performed to determine predictors of waitlist death/delisting. Posttransplant survival was analyzed using Kaplan-Meier methods.

RESULTS

Among 187 patients listed, 82% (153 of 187) underwent LTx (median time-to-transplant, 2.0 mo), whereas 16% (30 of 187) died or were delisted (median time-to-event, 1.6 mo). At 90 d, 6 mo, and 12 mo after listing, 51%, 63%, and 78% of patients had been transplanted, whereas 10%, 14%, and 16% had died or were delisted. Multivariable predictors of waitlist death/delisting were: blood group O compared to A (subdistribution hazard ratio [SHR]: 6.43, P < 0.001), shorter height (per 1 cm, SHR: 1.11, P < 0.001), hospitalization at listing (SHR: 3.98, P = 0.002), and reduced 6-min-walk test distance (per 50 m, SHR: 1.28, P = 0.001). Among LTx recipients, 24% (36 of 153) underwent single LTx. Donor lungs were 58% (88 of 153) extended-criteria, inclusive of 24% (37 of 153) circulatory-determined death. Ninety-day and 1-, 3-, and 5-y retransplant free survival were 97% ± 1%, 92% ± 2%, 81% ± 4%, and 69% ± 6%.

CONCLUSIONS

Patients with ILD require a rapid transit to LTx after listing. Despite this, the vast majority of ILD patients in this study reached LTx with excellent early and midterm outcomes.

[Organ donation-Not only a responsibility of intensive care medicine]

Im Jahr 2019 starben in Deutschland 756 Menschen, während sie auf der Warteliste für ein Spenderorgan standen. Sowohl im Eurotransplant-Verbund als auch weltweit gehört Deutschland mit 10,8 Organspendern/Mio. Einwohner im Jahr 2019 zur Schlussgruppe. Sämtliche politischen Versuche, die Spenderzahlen zu steigern, scheinen bislang ohne Effekt geblieben zu sein. Darüber hinaus hat die durch das „severe acute respiratory syndrome coronavirus 2“ (SARS-CoV-2) ausgelöste Pandemie zum weiteren Rückgang der Spenderzahlen geführt. Der Intensivmedizinerin kommt im Prozess der Erkennung möglicher Spender sowie als erste Ansprechpartnerin für die Angehörigen eine zentrale Rolle zu. Jedoch existieren nicht nur in den gesellschaftlichen und medialen Diskussionen um das Thema Organspende viele Unklarheiten, sondern auch bei den intensivmedizinisch tätigen Ärzten. Viele Annahmen und Hypothesen, die mit den niedrigen Spenderzahlen in einen Zusammenhang gebracht werden, lassen sich wissenschaftlich jedoch nicht belegen und sollen in diesem Beitrag diskutiert werden.

The Future Direction of the Organ Donation System After Legislation of the Life-Sustaining Treatment Decision Act

Background

The transplant community is seeking ways to encourage organ donation after cardiac arrest to solve the problem of the insufficiency of organs available for the increasing number of people awaiting transplantation. This study aimed to determine whether the life-sustaining treatment (LST) decision system, implemented in Korea on February 4, 2018, can address the shortage of organ donations.

Material/Methods

We retrospectively analyzed the medical records of the 442 patients who had filled out forms for the LST decision at Ewha Womans University Mokdong Hospital from April 2018 to December 2019, and classified the eligibility of organ and tissue donation according to the Korean Organ Donation Agency criteria.

Results

We included 442 patients in this study. Among them, 238 (53.8%) were men, and 204 (46.2%) were women. The average age of the patients was 71.8 years (the youngest and oldest were aged 23 years and 103 years, respectively). Of these, 110 patients (24.9%) decided on their own to discontinue LST, whereas 332 (75.1%) decided to discontinue with their family’s consent. This study demonstrated that 50% of patients who were not brain-dead and discontinued LST were eligible for organ donation. However, the patients and caregivers were not aware of this option because the current law does not allow the discussion of such donations.

Conclusions

A discussion regarding donation after circulatory death is recommended to solve the problem of insufficient organ donation.

Role of normothermic perfusion with ECMO in donation after controlled cardiac death in Spain

Spain has become one of the most active countries in donation after controlled cardiac death, using normothermic abdominal perfusion with ECMO in more than 50% of all donors - a situation contributed to by the creation of mobile teams to support hospitals lacking this technology. The donation process must be respectful of the wishes and values of the patients and their relatives, especially if there is pre mortem manipulation, and the absence of cerebral perfusion should be guaranteed. The liver is the most benefited organ by reducing biliary complications as well as the loss of grafts. In renal transplantation, the technique could contribute to reduce the incidence of delayed graft function. In addition, the procedure is compatible with surgical rapid recovery in hypothermia when there is also lung donation. The future lies in the consolidation of cardiac donation by extending normothermic perfusion to the thoracic cavity.

Donor Aorta as Conduit for Ex Vivo Lung Perfusion

For ex vivo lung perfusion (EVLP), there is often inadequate pulmonary artery for effective EVLP. Creation of a neopulmonary artery conduit with donor aorta alleviates this shortcoming. This technique will become of more importance and need as there are more donation after circulatory death donor (DCD) heart procurements as this is a common source of EVLP. With the time constraints associated with the DCD recovery approach, there is a high likelihood of having a short native pulmonary artery with the lung block necessitating this approach.

Lung transplantation using allografts with more than 8 hours of ischemic time: A single-institution experience

BACKGROUND

Six hours was historically regarded as the limit of acceptable ischemic time for lung allografts. However, broader sharing of donor lungs often necessitates use of allografts with ischemic time >6 hours. We characterized the association between ischemic time ≥8 hours and outcomes after lung transplantation using a contemporary cohort from a high-volume institution.

METHODS

Patients who underwent primary isolated bilateral lung transplantation between 1/2016 and 5/2020 were included. Patients bridged to transplant with extracorporeal membrane oxygenation or mechanical ventilation, and ex-vivo perfusion cases were excluded. Recipients were stratified by total allograft ischemic time <8 hours (standard) vs ≥8 hours (long). Perioperative outcomes and post-transplant survival were compared between groups.

RESULTS

Of 358 patients, 95 (26.5%) received long ischemic time (≥8 hours) lungs. Long ischemic time recipients were more likely to be male and have donation after circulatory death donors than standard ischemic time recipients. On unadjusted analysis, long and standard ischemic time recipients had similar survival, and similar rates of grade 3 primary graft dysfunction at 72 hours, extracorporeal membrane oxygenation post-transplant, acute rejection within 30 days, reintubation, and post-transplant length of stay. After adjustment, long and standard ischemic time recipients had comparable risks of mortality or graft failure.

CONCLUSIONS

In a modern cohort, use of lung allografts with "long" ischemic time ≥8 hours were associated with acceptable perioperative outcomes and post-transplant survival. Further investigation is required to better understand how broader use impacts post-lung transplant outcomes and the implications for smarter sharing under an evolving national allocation policy.

Lung transplantation from uncontrolled and controlled donation after circulatory death: similar outcomes to brain death donors

Controlled donation after circulatory death donors (cDCD) are becoming a frequent source of lungs grafts worldwide. Conversely, lung transplantations (LTx) from uncontrolled donors (uDCD) are sporadically reported. We aimed to review our institutional experience using both uDCD and cDCD and compare to LTx from brain death donors (DBD). This is a retrospective analysis of all LTx performed between January 2013 and December 2019 in our institution. Donor and recipient characteristics were collected and univariate, multivariate and survival analyses were carried out comparing the three cohorts of donors. A total of 239 (84.7%) LTx were performed from DBD, 29 (10.3%) from cDCD and 14 (5%) from uDCD. There were no statistically significant differences in primary graft dysfunction grade 3 at 72 h, 30- and 90-day mortality, need for extracorporeal membrane oxygenation after procedure, ICU and hospital length of stay, airway complications, CLAD incidence or survival at 1 and 3 years after transplant (DBD: 87.1% and 78.1%; cDCD: 89.7% and 89.7%; uDCD: 85.7% and 85.7% respectively; P = 0.42). Short- and mid-term outcomes are comparable between the three types of donors. These findings may encourage and reinforce all types of donation after circulatory death programmes as a valid and growing source of suitable organs for transplantation.

Donor quality assessment and size match in lung transplantation

Careful donor quality assessment and size match can impact long-term survival in lung transplantation. With this article, we review the conceptual and practical aspects of the preoperative donor lung quality assessment and size matching.

Pushing the Envelope for Donor Lungs

The shortage of organ donors remains the major limiting factor in lung transplant, with the number of patients on the waiting list largely exceeding the number of available organ donors. Another issue is the low utilization rate seen in some types of donors. Therefore, novel strategies are continuously being explored to increase the donor pool. Advanced age, smoking history, positive serologies, and size mismatch are common criteria that decrease the rate of use when it comes to organ utilization. Questioning these limitations is one of the purposes of this review. Challenging these limitations by adapting novel donor management strategies could help to increase the rate of suitable lungs for transplantation while still maintaining good outcomes. A second goal is to present the latest advances in organ donation after controlled and uncontrolled cardiac death, and also on how to improve these lungs on ex vivo platforms for assessment and future specific therapies. Finally, pushing the limit of the donor envelope also means reviewing some of the recent improvements made in lung preservation itself, as well as upcoming experimental research fields. In summary, donor lung optimization refers to a global care strategy to increase the total numbers of available allografts, and preserve or improve organ quality without paying the price of early-, mid-, or long-term negative outcomes after transplantation.

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.

Implications for Extracellular Matrix Interactions With Human Lung Basal Stem Cells in Lung Development, Disease, and Airway Modeling

The extracellular matrix (ECM) is not simply a quiescent scaffold. This three-dimensional network of extracellular macromolecules provides structural, mechanical, and biochemical support for the cells of the lung. Throughout life, the ECM forms a critical component of the pulmonary stem cell niche. Basal cells (BCs), the primary stem cells of the airways capable of differentiating to all luminal cell types, reside in close proximity to the basolateral ECM. Studying BC-ECM interactions is important for the development of therapies for chronic lung diseases in which ECM alterations are accompanied by an apparent loss of the lung's regenerative capacity. The complexity and importance of the native ECM in the regulation of BCs is highlighted as we have yet to create an in vitro culture model that is capable of supporting the long-term expansion of multipotent BCs. The interactions between the pulmonary ECM and BCs are, therefore, a vital component for understanding the mechanisms regulating BC stemness during health and disease. If we are able to replicate these interactions in airway models, we could significantly improve our ability to maintain basal cell stemness ex vivo for use in in vitro models and with prospects for cellular therapies. Furthermore, successful, and sustained airway regeneration in an aged or diseased lung by small molecules, novel compounds or via cellular therapy will rely upon both manipulation of the airway stem cells and their immediate niche within the lung. This review will focus on the current understanding of how the pulmonary ECM regulates the basal stem cell function, how this relationship changes in chronic disease, and how replicating native conditions poses challenges for ex vivo cell culture.

Transcriptomic investigation reveals donor-specific gene signatures in human lung transplants

INTRODUCTION

Transplantation of lungs from donation after circulatory death (DCD) in addition to donation after brain death (DBD) became routine worldwide to address the global organ shortage. The development of ex vivo lung perfusion (EVLP) for donor lung assessment and repair contributed to the increased use of DCD lungs. We hypothesise that a better understanding of the differences between lungs from DBD and DCD donors, and between EVLP and directly transplanted (non-EVLP) lungs, will lead to the discovery of the injury-specific targets for donor lung repair and reconditioning.

METHODS

Tissue biopsies from human DBD (n=177) and DCD (n=65) donor lungs, assessed with or without EVLP, were collected at the end of cold ischaemic time. All samples were processed with microarray assays. Gene expression, network and pathway analyses were performed using R, Ingenuity Pathway Analysis and STRING. Results were validated with protein assays, multiple logistic regression and 10-fold cross-validation.

RESULTS

Our analyses showed that lungs from DBD donors have upregulation of inflammatory cytokines and pathways. In contrast, DCD lungs display a transcriptome signature of pathways associated with cell death, apoptosis and necrosis. Network centrality revealed specific drug targets to rehabilitate DBD lungs. Moreover, in DBD lungs, tumour necrosis factor receptor-1/2 signalling pathways and macrophage migration inhibitory factor-associated pathways were activated in the EVLP group. A panel of genes that differentiate the EVLP from the non-EVLP group in DBD lungs was identified.

CONCLUSION

The examination of gene expression profiling indicates that DBD and DCD lungs have distinguishable biological transcriptome signatures.

Geographic Differences in Lung Transplant Volume and Donor Availability During the COVID-19 Pandemic

BACKGROUND

Regional variation in lung transplantation practices due to local coronavirus disease 2019 (COVID-19) prevalence may cause geographic disparities in access to lung transplantation.

METHODS

Using the United Network for Organ Sharing registry, we conducted a descriptive analysis of lung transplant volume, donor lung volume, new waitlist activations, and waiting list deaths at high-volume lung transplant centers during the first 3 months of the pandemic (March 1. 2020, to May 30, 2020) and we compared it to the same period in the preceding 5 years.

RESULTS

Lung transplant volume decreased by 10% nationally and by a median of 50% in high COVID-19 prevalence centers (range -87% to 80%) compared with a median increase of 10% (range -87% to 80%) in low prevalence centers (P-for-trend 0.006). Donation services areas with high COVID-19 prevalence experienced a greater decrease in organ availability (-28% range, -72% to -11%) compared with low prevalence areas (+7%, range -20% to + 55%, P-for-trend 0.001). Waiting list activations decreased at 18 of 22 centers. Waiting list deaths were similar to the preceding 5 years and independent of local COVID-19 prevalence (P-for-trend 0.36).

CONCLUSIONS

Regional variation in transplantation and donor availability in the early months of the pandemic varied by local COVID-19 activity.

Methylprednisolone Treatment in Brain Death-Induced Lung Inflammation-A Dose Comparative Study in Rats

Background: The process of brain death (BD) leads to a pro-inflammatory state of the donor lung, which deteriorates its quality. In an attempt to preserve lung quality, methylprednisolone is widely recommended in donor lung management. However, clinical treatment doses vary and the dose-effect relation of methylprednisolone on BD-induced lung inflammation remains unknown. The aim of this study was to investigate the effect of three different doses methylprednisolone on the BD-induced inflammatory response.

Methods: BD was induced in rats by inflation of a Fogarty balloon catheter in the epidural space. After 60 min of BD, saline or methylprednisolone (low dose (5 mg/kg), intermediate dose (12.5 mg/kg) or high dose (22.5 mg/kg)) was administered intravenously. The lungs were procured and processed after 4 h of BD. Inflammatory gene expressions were analyzed by RT-qPCR and influx of neutrophils and macrophages were quantified with immunohistochemical staining.

Results: Methylprednisolone treatment reduced neutrophil chemotaxis as demonstrated by lower IL-8-like CINC-1 and E-selectin levels, which was most evident in rats treated with intermediate and high doses methylprednisolone. Macrophage chemotaxis was attenuated in all methylprednisolone treated rats, as corroborated by lower MCP-1 levels compared to saline treated rats. Thereby, all doses methylprednisolone reduced TNF-α, IL-6 and IL-1β tissue levels. In addition, intermediate and high doses methylprednisolone induced a protective anti-inflammatory response, as reflected by upregulated IL-10 expression when compared to saline treated brain-dead rats.

Conclusion: We showed that intermediate and high doses methylprednisolone share most potential to target BD-induced lung inflammation in rats. Considering possible side effects of high doses methylprednisolone, we conclude from this study that an intermediate dose of 12.5 mg/kg methylprednisolone is the optimal treatment dose for BD-induced lung inflammation in rats, which reduces the pro-inflammatory state and additionally promotes a protective, anti-inflammatory response.

Safe Lung Flush Technique During Recovery From Donors After Circulatory Death

Donation after circulatory death is defined as donation after cardiac arrest and circulatory cessation. The number of circulatory death donors is growing and significantly increases the organ donor pool. Shortening the warm ischemia time is pivotal in the outcomes and survival after transplant. We describe simplified and safe technique for lung flush during lung recovery from donors after circulatory 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.

Developments in lung transplantation over the past decade

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

Expression of Claudin-4 in Lung Ischemia-Reperfusion Injury in Experimental Lung Transplantation

OBJECTIVE

To assess the presence of CLDN4 in bronchoalveolar lavage fluid (BALF) and pulmonary tissue as an early indicator of LIRI and its relationship with changes in pulmonary physiology, edema formation and histology in an experimental porcine model of LTx with CIT of 50 min or 6 h.

METHODS

In 12 pigs, LIRI was produced by: group I (n = 6) LTx with 50 min of CIT (LTx-50 min-CIT); and group II (n = 6) LTx with 6 h of CIT (LTx-6h-CIT). The lung function, edema formation, macroscopic and microscopic changes were assessed. CLDN4 expression in BALF and pulmonary tissue were determined.

RESULTS

Both groups presented similar clinical, edema, and histological damage, as well as similar expression of CLDN4 in BALF and tissue (p > 0.05, RM-ANOVA).

CONCLUSION

CLDN4 expressed in BALF and the pulmonary tissue during the first 5 h within 72 h of the PGD window are not associated by the deterioration of lung function, edema and lung histological injury, in LTx with CIT 50 min or 6 h, CLDN4 does not seem to be a valuable indicator of LIRI.

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.

The Year in Cardiothoracic Transplantation Anesthesia: Selected Highlights from 2019

The highlights in cardiothoracic transplantation focus on the recent research pertaining to heart and lung transplantation, including expansion of the donor pool, the optimization of donors and recipients, the use of mechanical support, the perioperative and long-term outcomes in these patient populations, and the use of transthoracic echocardiography to diagnose rejection.