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

Centralized Static Ex Vivo Lung Perfusion in the United States

BACKGROUND

Ex vivo lung perfusion (EVLP) may improve donor lung utilization but requires significant infrastructure and expertise. Centralized EVLP facilities may mitigate these requirements.

METHODS

From the United Network for Organ Sharing database, we identified 345 adults undergoing isolated, first-time lung transplantation using donor lungs perfused by static EVLP (March 1, 2018-December 31, 2022). Recipients of lungs perfused at centralized EVLP facilities (n = 165) were compared with recipients of lungs perfused at individual transplant centers (n = 180). Propensity score matching was used to create balanced groups for comparison.

RESULTS

Centralized EVLP facilities were increasingly used from 2018 to 2022 (35.3% vs 55.8%, P = .04) and were more likely used when the annual center volume of EVLP lung transplants was low. Compared with allografts placed on EVLP at individual transplant centers, those placed on EVLP at centralized facilities had longer median ischemic time (11.3 vs 9.6 hours, P < .001) and were less likely to come from donation after circulatory death donors (25.4% vs 39.5%, P = .003) or be used for double-lung transplant (73.3% vs 83.9%, P = .02). In 102 well-matched recipient pairs, 2-year survival was equivalent between those receiving allografts perfused at centralized facilities (77.9%; 95% CI, 68.0%-85.1%) vs individual transplant centers (77.7%; 95% CI, 67.8%-84.9%; P = .90). Multivariable Cox regression analysis also showed equivalent 2-year survival (adjusted hazard ratio, 1.02; 95% CI, 0.57-1.84; P = .95).

CONCLUSIONS

Transplanting lung allografts that underwent static EVLP at centralized facilities had similar outcomes compared with transplanting lungs perfused at individual transplant centers. The centralized model of clinical EVLP can potentially improve access to EVLP.

Impact of Time of Day on Surgical Outcomes After Lung Transplantation (Nighttime Lung Transplant)

BACKGROUND

Surgical outcomes have been linked to the technical and cognitive abilities of an exhausted surgical team. In parallel, advancements in preservation have led to the proposal of daytime lung transplants. We sought to investigate whether time of day is associated with outcomes in lung transplants.

METHODS

Data on 30,404 lung transplants from 2005 to 2021 were obtained from the United Network for Organ Sharing database. Patients were categorized based on the time of surgery with early-hours defined as donor cross-clamp between 10 pm and 3 am, and Cox regression models for 90-day and long-term mortality were made to assess the risk according to time of transplant and covariates. Additionally, the Cox modeling was repeated with donor cross-clamp and the estimated reperfusion time of day as continuous functions.

RESULTS

Among 30,404 transplants, 20.7% (6295) were performed during early hours. No significant difference was found between the 2 groups in unadjusted 90-day and long-term mortality (log-rank, P = .176 and .363, respectively), and results were unchanged when adjusting for covariates (P = .233 and .738, respectively). However, when examining donor cross-clamp time and reperfusion time as continuous variables in separate multivariable analyses, we observed significant associations with 90-day mortality (P = .002 and .022, respectively). Notably, lower mortality rates were observed for donor clamp-times between 8 am and 1 pm and estimated reperfusion times between 1 pm and 6 pm.

CONCLUSIONS

Although binary categorizations of the time of day of lung transplants did not show a significant impact on short- or long-term survival, continuous-time analyses demonstrated that certain times during the day were associated with favorable short-term survival.

Prolonged Preservation of up to 24h at 10°C does not Impact Outcomes after Lung Transplantation

OBJECTIVE

To determine the impact of prolonged storage of donor lungs at 10°C of up to 24h on outcome after lung transplantation.

BACKGROUND

An increasing body of evidence suggests 10°C as the optimal storage temperature for donor lungs. A recent study showed that cold ischemic times can be safely expanded to >12h when lungs are stored at 10°C. However, it is currently unknown how long donor lungs can be preserved before they deteriorate in function.

METHODS

Patients who received a donor lung stored at 10°C between 11/2020 and 06/2023 at the lung transplant programs of Toronto, Vienna and Madrid were included in this retrospective analysis. After excluding EVLP-cases, recipients were grouped based on the total preservation times of their donor organs (<12h: n=48; 12-18h: n=109; ≥18h: n=24). 372 recipients who had received an organ stored on-ice during the study period served as a control group.

RESULTS

Length of lung preservation ranged from 2h 27min to 29h 33min (mean 14h 06min). Despite these prolonged preservation times, early postoperative outcomes were excellent. Median length of mechanical ventilation did not differ between the three study groups (<12h: 41h [IQR 24-109]; 12-18h: 56h [IQR 24-143] and ≥18h: 59h [IQR 28-108]; P=0.493). ICU length of stay (6 d [4-14]; 8 d [4-23]; 8 d [5-32]) and hospital length of stay (32 d [20-48]; 29 d [20-50]; 26 d [17-50]) were also similar. Furthermore, length of donor organ preservation had no impact on patient survival (log rank P=0.413).

CONCLUSIONS

Prolonged static preservation of donor lungs at 10°C for up to 24 hours is safe and does not impair short-intermediate outcomes after lung transplantation.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights from 2024

This special article is the 17th in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor in chief, Dr Kaplan, and the editorial board for the opportunity to continue this series, namely, the research highlights of the past year in the specialty of cardiothoracic and vascular anesthesiology.1 The major themes selected for 2024 are outlined in this introduction, and each highlight is reviewed in detail in the main article. The literature highlights in the specialty for 2024 begin with an update on perioperative rehabilitation and enhanced recovery in cardiothoracic surgery, with a focus on novel methods to best assess our patients in the preoperative period and the impact of implementing enhanced recovery care models on outcomes. The second major theme is focused on cardiac surgery, with the authors discussing new insights into anemia, transfusions, and coronary artery bypass grafting outcomes with a focus on gender disparities. The third theme is focused on cardiothoracic transplantation, with discussions focusing on techniques related to lung transplantation, including mechanical circulatory support. The 4th theme is focused on mechanical circulatory support, with discussions exploring advancements in left ventricular assist devices highlight the evolving landscape of mechanical circulatory support and discussion of anticoagulation practices. The fifth and final theme is an update on medical cardiology, with a focus on the outcomes of transcatheter management of regurgitant pathology, device management in heart failure, and new techniques in catheter ablation. The themes selected for this article are only a few of the diverse advances in the specialty during 2024. These highlights will inform the reader of key updates on a variety of topics, leading to improvement in perioperative outcomes for patients with cardiothoracic and vascular disease.

Donor Lungs' Procurement Implementation with Ex Vivo Lung Perfusion in a Low-Volume Lung Transplant Center

(1) Background: Ex Vivo Lung Perfusion (EVLP) is a technique designed to assess and recondition marginal lungs, potentially expanding the donor pool and improving transplant outcomes (2) Methods: This retrospective study evaluated lung transplantation outcomes after EVLP. Donor lungs were assessed using the Toronto protocol, with data on hemodynamics, gas exchange, and perfusion parameters collected and analyzed. Post-transplant complications and survival rates were also examined. (3) Results: Over five years, 17 EVLP procedures were performed. Despite an improvement in lung function, 47% of donor lungs were rejected after EVLP. EVLP-reconditioned lungs showed comparable survival rates to standard transplants, but complications like sepsis and primary graft dysfunction (PGD) occurred. (4) Conclusions: EVLP shows promise in expanding the donor organ availability and reducing PGD, but nearly half of the lungs assessed were rejected. Further research is necessary to optimize EVLP and address potential complications like lung injury and sepsis.

Extended ischemic times during ex vivo lung perfusion is not associated with increased mortality

BACKGROUND

The purpose of this study was to identify the association of increasing ischemic times in recipients who receive lungs evaluated by ex vivo lung perfusion (EVLP) and their association with outcomes following lung transplantation.

METHODS

Lung transplant recipients who received an allograft evaluated by EVLP were identified from the United Network for Organ Sharing (UNOS) Database from 2016-2023. Recipients were stratified into three groups based on total ischemic time (TOT): short TOT (STOT, 0 to <7 h), medium TOT (MTOT, 7> to <14 h), and long TOT (LTOT, +14 h). The groups were assessed with comparative statistics and Kaplan-Meier methods. A Cox regression was created to determine the association of ischemic time in EVLP donors and long-term mortality.

RESULTS

Recipients in the LTOT group had significantly longer length of stay and post-operative extracorporeal membrane use at 72 h (p < 0.05 for both). Additionally, they had nonsignificant increases in rate of stroke (4.7%, p = 0.05) and primary graft dysfunction grade 3 (PGD3, 27.5%, p = 0.082). However, there was no significant difference in hospital mortality or mid-term survival (p > 0.05 for both). On multivariable analysis, ischemic time was not associated with increased mortality whereas increasing recipient age, preoperative ECMO use and donation after circulatory death donors were (p < 0.05 for all).

CONCLUSIONS

If EVLP technology is available, under certain circumstances, surgeons should not be dissuaded from using an allograft with extended ischemic time.

Dynamic associations between adverse events after lung transplantation and allograft ischaemic time

OBJECTIVES

The effect of allograft ischaemic time (AIT) on postoperative events after lung transplantation remains unclear. This study aims to assess the feasibility of extending the duration of AIT.

METHODS

The United Network for Organ Sharing database was queried for adult lung transplantation from 4 May 2005 to 30 June 2020. Patients were divided as per AIT into standard ischaemic time (<6 h) and prolonged ischaemic time (≥6 h) groups using propensity score matching and evaluated on a continuous scale using restricted cubic splines. The primary outcome was overall 1-year and 5-year survival.

RESULTS

Among 11 438 propensity-matched recipients, standard ischaemic time and prolonged ischaemic time showed no differences in overall 1-year (P = 0.29) or 5-year (P = 0.29) survival. Prolonged ischaemic time independently predicted early postoperative ventilator support for >48 h (OR = 1.33, 95% CI 1.22-1.44), dialysis (OR = 1.55, 95% CI 1.30-1.84), primary graft dysfunction (PGD; OR = 1.28, 95% CI 1.09-1.50), acute rejection (OR = 1.42, 95% CI 1.24-1.62), and interestingly, decreased 5-year bronchiolitis obliterans syndrome (HR = 0.91, 95% CI 0.85-0.97). In relative risk curves, 1-year mortality, prolonged ventilation, dialysis and PGD steadily increased per hour as AIT extended. The risk of acute rejection and 5-year bronchiolitis obliterans syndrome also showed significant changes between 5 and 8 h of AIT. In contrast, 5-year mortality remained constant despite rising AIT.

CONCLUSIONS

Prolonged AIT worsened early outcomes such as PGD, but improved bronchiolitis obliterans syndrome freedom at later time points. Despite this, both short- and long-term survival were similar between prolonged ischaemic time and standard ischaemic time patients. Dynamic risk changes in post-transplant events should be noted for prolonged ischaemia lung use.

Utilization of the Liver-First Approach in Combined Lung-Liver Transplant Provides Comparable Outcomes to the Traditional Lung-First Approach: A UNOS Study

Multiorgan transplantation is offered to a selected group of patients every year. The sequence in which organs are transplanted depends on ischemic time graft tolerance and the sickest organ first strategy. In the case of Lung-Liver transplantation, lung allografts are usually implanted before the liver. There are some theoretical advantages to a liver-first strategy and a few centers have reported a series of cases that spark a growing interest in the feasibility and potential benefits of this approach. In this contemporary study of the United Network for Organ Sharing (UNOS) database, we evaluate and report outcomes using either strategy.

Lung transplantation following controlled hypothermic storage with a portable lung preservation device: first multicenter European experience

Introduction

Compared with traditional static ice storage, controlled hypothermic storage (CHS) at 4-10°C may attenuate cold-induced lung injury between procurement and implantation. In this study, we describe the first European lung transplant (LTx) experience with a portable CHS device.

Methods

A prospective observational study was conducted of all consecutively performed LTx following CHS (11 November 2022 and 31 January 2024) at two European high-volume centers. The LUNGguard device was used for CHS. The preservation details, total ischemic time, and early postoperative outcomes are described. The data are presented as median (range: minimum-maximum) values.

Results

A total of 36 patients underwent LTx (i.e., 33 bilateral, 2 single LTx, and 1 lobar). The median age was 61 (15-68) years; 58% of the patients were male; 28% of the transplantations had high-urgency status; and 22% were indicated as donation after circulatory death. In 47% of the patients, extracorporeal membrane oxygenation (ECMO) was used for perioperative support. The indications for using the CHS device were overnight bridging (n = 26), remote procurement (n = 4), rescue allocation (n = 2), logistics (n = 2), feasibility (n = 1), and extended-criteria donor (n = 1). The CHS temperature was 6.5°C (3.7°C-9.3°C). The preservation times were 11 h 18 (2 h 42-17 h 9) and 13 h 40 (4 h 5-19 h 36) for the first and second implanted lungs, respectively, whereas the total ischemic times were 13 h 38 (4 h 51-19 h 44) and 15 h 41 (5 h 54-22 h 48), respectively. The primary graft dysfunction grade 3 (PGD3) incidence rates were 33.3% within 72 h and 2.8% at 72 h. Intensive care unit stay was 8 (4-62) days, and the hospital stay was 28 (13-87) days. At the last follow-up [139 (7-446) days], three patients were still hospitalized. One patient died on postoperative day 7 due to ECMO failure. In-hospital Clavien-Dindo complications of 3b were observed in six (17%) patients, and 4a in seven (19%).

Conclusion

CHS seems safe and feasible despite the high-risk recipient and donor profiles, as well as extended preservation times. PGD3 at 72 h was observed in 2.8% of the patients. This technology could postpone LTx to daytime working hours. Larger cohorts and longer-term outcomes are required to confirm these observations.

Extended ischemic time (>15 hours) using controlled hypothermic storage in lung transplantation: A multicenter experience

Static ice storage has long been the standard-of-care for lung preservation, although freezing injury limits ischemic time (IT). Controlled hypothermic storage (CHS) at elevated temperature could safely extend IT. This retrospective analysis assesses feasibility and safety of CHS with IT > 15 hours. Three lung transplant (LuTx) centers (April-October 2023) included demographics, storage details, IT, and short-term outcome from 13 LuTx recipients (8 male, 59 years old). Donor lungs were preserved in a portable CHS device at 7 (5-9.3)°C. Indication was overnight bridging and/or long-distance transport. IT of second-implanted lung was 17.3 (15.1-22) hours. LuTx were successful, 4/13 exhibited primary graft dysfunction grade 3 within 72 hours and 0/13 at 72 hours. Post-LuTx mechanical ventilation was 29 (7-442) hours. Intensive care unit stay was 9 (5-28) and hospital stay 30 (16-90) days. Four patients needed postoperative extracorporeal membrane oxygenation (ECMO). One patient died (day 7) following malpositioning of an ECMO cannula. This multicenter experience demonstrates the possibility of safely extending IT > 15 hours by CHS.

Donor Lung Preservation at 10°C: Clinical and Logistical Impact

INTRODUCTION

Cold static donor lung preservation at 10°C appears to be a promising method to safely extend the cold ischemic time (CIT) and improve lung transplant (LTx) logistics.

METHODS

LTx from November 2021 to February 2023 were included in this single institution, prospective, non-randomized study comparing prolonged preservation at 10°C versus standard preservation on ice. The inclusion criteria for 10°C preservation were suitable grafts for LTx without any donor retrieval concerns.

PRIMARY ENDPOINT

primary graft dysfunction (PGD) grade-3 at 72-h. Secondary endpoints: clinical outcomes, cytokine profile and logistical impact.

RESULTS

Thirty-three out of fifty-seven cases were preserved at 10°C. Donor and recipient characteristics were similar across the groups. Total preservation times (h:min) were longer (p<0.001) in the 10°C group [1st lung: median 12:09 (IQR 9:23-13:29); 2nd: 14:24 (12:00-16:20)] vs. standard group [1st lung: median 5:47 (IQR 5:18-6:40); 2nd: 7:15 (6:33-7:40)]. PGD grade-3 at 72-h was 9.4% in 10°C group vs. 12.5% in standard group (p=0.440). Length of mechanical ventilation (MV), ICU and hospital stays were similar in both groups. Thirty and ninety-day mortality rates were 0% in 10°C group (vs. 4.2% in standard group). IL-8 concentration was significantly higher 6-h post-LTx in the standard group (p=0.025) and IL-10 concentration was increased 72-h post-LTx in the 10°C group (p=0.045).

CONCLUSIONS

Preservation at 10°C may represent a safe and feasible strategy to intentionally prolong the CIT. In our center, extending the CIT at 10°C may allow for semi-elective LTx and improve logistics with similar outcomes compared to the current standard preservation on ice.

Impact of Prolonged Cold Ischemia Time on Long-Term Survival in Lung Transplant Recipients

BACKGROUND

Cold ischemia time (CIT) influences short- and long-term outcomes in lung transplant recipients. Most studies proved that prolonged CIT causes increased mortality. This study aimed to investigate the impact of prolonged CIT on patient survival time after lung transplantation (LTx).

METHODS

The retrospective study group consisted of 139 patients who underwent double LTx in a single center between January 2018 and August 2022. Prolonged ischemic time (PIT) was defined as total ischemic time >6 hours and divided into smaller time intervals according to increasing PIT (6-8, 8-10, 10-12, >12 hours). The assessed outcomes were 1- and 4-year survival.

RESULTS

Among the study group, PIT was observed in 98% (n = 137), and its average value was 10.33 hours. The prolonged CIT of 6 to 8 hours occurred in 10% (n = 14), 8 to 10 hours in 34% (n = 47), 10 to 12 hours in 36% (n = 49), and >12 hours in 20% (n = 27). In a comparison of 1-year survival between the PIT 6- to 10-hour group and the >10-hour arm (88% vs 78%), the difference was not statistically significant (P > .05).

CONCLUSION

PIT is a risk factor for reduced long-term survival in LTx recipients. Increasing PIT may be associated with higher mortality at 1 and 4 years. All efforts to reduce the duration of ischemic time can benefit patient survival after LTx.

Controlled Hypothermic Storage for Lung Preservation: Leaving the Ice Age Behind

Controlled hypothermic storage (CHS) is a recent advance in lung transplantation (LTx) allowing preservation at temperatures higher than those achieved with traditional ice storage. The mechanisms explaining the benefits of CHS compared to conventional static ice storage (SIS) remain unclear and clinical data on safety and feasibility of lung CHS are limited. Therefore, we aimed to provide a focus review on animal experiments, molecular mechanisms, CHS devices, current clinical experience, and potential future benefits of CHS. Rabbit, canine and porcine experiments showed superior lung physiology after prolonged storage at 10°C vs. ≤4°C. In recent molecular analyses of lung CHS, better protection of mitochondrial health and higher levels of antioxidative metabolites were observed. The acquired insights into the underlying mechanisms and development of CHS devices allowed clinical application and research using CHS for lung preservation. The initial findings are promising; however, further data collection and analysis are required to draw more robust conclusions. Extended lung preservation with CHS may provide benefits to both recipients and healthcare personnel. Reduced time pressure between procurement and transplantation introduces flexibility allowing better decision-making and overnight bridging by delaying transplantation to daytime without compromising outcome.

Predictors of early mortality after lung transplantation for idiopathic pulmonary arterial hypertension

Lung transplantation remains an important therapeutic option for idiopathic pulmonary arterial hypertension (IPAH), yet short-term survival is the poorest among the major diagnostic categories. We sought to develop a prediction model for 90-day mortality using the United Network for Organ Sharing database for adults with IPAH transplanted between 2005 and 2021. Variables with a p value ≤ 0.1 on univariate testing were included in multivariable analysis to derive the best subset model. The cohort comprised 693 subjects, of whom 71 died (10.2%) within 90 days of transplant. Significant independent predictors of early mortality were: extracorporeal circulatory support and/or mechanical ventilation at transplant (OR: 3; CI: 1.4-5), pulmonary artery diastolic pressure (OR: 1.3 per 10 mmHg; CI: 1.07-1.56), forced expiratory volume in the first second percent predicted (OR: 0.8 per 10%; CI: 0.7-0.94), recipient total bilirubin >2 mg/dL (OR: 3; CI: 1.4-7.2) and ischemic time >6 h (OR: 1.7, CI: 1.01-2.86). The predictive model was able to distinguish 25% of the cohort with a mortality of ≥20% from 49% with a mortality of ≤5%. We conclude that recipient variables associated with increasing severity of pulmonary vascular disease, including pretransplant advanced life support, and prolonged ischemic time are important risk factors for 90-day mortality after lung transplant for IPAH.

The effect of allograft ischemic time on outcomes following bilateral, single, and reoperative lung transplantation

OBJECTIVE

To determine whether allograft ischemic times affect outcomes following bilateral, single, and redo lung transplantation.

METHODS

A nationwide cohort of lung transplant recipients from 2005 through 2020 was examined using the Organ Procurement and Transplantation Network registry. The effects of standard (<6 hours) and extended (≥6 hours) ischemic times on outcomes following primary bilateral (n = 19,624), primary single (n = 688), redo bilateral (n = 8461), and redo single (n = 449) lung transplantation were analyzed. A priori subgroup analysis was performed in the primary and redo bilateral-lung transplant cohorts by further stratifying the extended ischemic time group into mild (≥6 and <8 hours), moderate (≥8 and <10 hours), and long (≥10 hours) subgroups. Primary outcomes included 30-day mortality, 1-year mortality, intubation at 72 hours' posttransplant, extracorporeal membrane oxygenation (ECMO) support at 72 hours' posttransplant, and a composite variable of intubation or ECMO at 72 hours' posttransplant. Secondary outcomes included acute rejection, postoperative dialysis, and hospital length of stay.

RESULTS

Recipients of allografts with ischemic times ≥6 hours experienced increased 30-day and 1-year mortality following primary bilateral-lung transplantation, but increased mortality was not observed following primary single, redo bilateral, or redo single-lung transplants. Extended ischemic times correlated with prolonged intubation or increased postoperative ECMO support in the primary bilateral, primary single, and redo bilateral-lung transplant cohorts but did not affect these outcomes following redo single-lung transplantation.

CONCLUSIONS

Since prolonged allograft ischemia correlates with worse transplant outcomes, the decision to use donor lungs with extended ischemic times must consider the specific benefits and risks associated with individual recipient factors and institutional expertise.

Safety and efficacy of delaying lung transplant surgery to a morning start

Objective

We aimed to evaluate the safety and efficacy of delaying lung transplantation until morning for donors with cross-clamp times occurring after 1:30 am.

Methods

All consented adult lung transplant recipients between March 2018 and May 2022 with donor cross-clamp times between 1:30 am and 5 am were enrolled prospectively in this study. Skin incision for enrolled recipients was delayed until 6:30 am (Night group). The control group was identified using a 1:2 logistic propensity score method and included recipients of donors with cross-clamp times occurring at any other time of day (Day group). Short- and medium-term outcomes were examined between groups. The primary endpoint was early mortality (30-day and in-hospital).

Results

Thirty-four patients were enrolled in the Night group, along with 68 well-matched patients in the Day group. As expected, donors in the Night group had longer cold ischemia times compared to the Day group (344 minutes vs 285 minutes; P < .01). Thirty-day mortality (3% vs 3%; P = .99), grade 3 primary graft dysfunction at 72 hours (8% vs 4%; P = .40), postoperative complications (26% vs 38%; P = .28), and hospital length of stay (15 days vs 14 days; P = .91) were similar in the 2 groups. No significant differences were noted between groups in 3-year survival (70% vs 77%; P = .30) or freedom from chronic lung allograft dysfunction (91% vs 95%; P = .75) at 3 years post-transplantation. The median follow-up was 752.5 days (interquartile range, 487-1048 days).

Conclusions

Lung transplant recipients with donor cross-clamp times scheduled after 1:30 am may safely have their operations delayed until 6:30 am with acceptable outcomes. Adoption of such a policy in clinically appropriate settings may lead to an alternative workflow and improved team well-being.

S100A8/A9 as a prognostic biomarker in lung transplantation

OBJECTIVES

S100A8/A9 is a damage-associated molecule that augments systemic inflammation. However, its role in the acute phase after lung transplantation (LTx) remains elusive. This study aimed to determine S100A8/A9 levels after lung transplantation (LTx) and evaluate their impact on overall survival (OS) and chronic lung allograft dysfunction (CLAD)-free survival.

METHODS

Sixty patients were enrolled in this study, and their plasma S100A8/A9 levels were measured on days 0, 1, 2, and 3 after LTx. The association of S100A8/A9 levels with OS and CLAD-free survival was assessed using univariate and multivariate Cox regression analyses.

RESULTS

S100A8/A9 levels were elevated in a time-dependent manner until 3 days after LTx. Ischemic time was significantly longer in the high S100A8/9 group than in the low S100A8/A9 group (p = .017). Patients with high S100A8/A9 levels (> 2844 ng/mL) had worse prognosis (p = .031) and shorter CLAD-free survival (p = .045) in the Kaplan-Meier survival analysis than those with low levels. Furthermore, multivariate Cox regression analysis showed that high S100A8/A9 levels were a determinant of poor OS (hazard ratio [HR]: 3.7; 95% confidence interval [CI]: 1.2-12; p = .028) and poor CLAD-free survival (HR: 4.1; 95% CI: 1.1-15; p = .03). In patients with a low primary graft dysfunction grade (0-2), a high level of S100A8/A9 was also a poor prognostic factor.

CONCLUSIONS

Our study provided novel insights into the role of S100A8/A9 as a prognostic biomarker and a potential therapeutic target for LTx.

Extension of Cold Static Donor Lung Preservation at 10°C

BACKGROUND: Lung transplantation is performed on a 24/7 schedule to minimize organ ischemic time. Recent preclinical studies demonstrated superior graft preservation at 10°C compared with storage in an ice cooler (gold standard). METHODS: In this prospective, multicenter, nonrandomized clinical trial, we studied transplants from donors with overnight cross-clamp times (6:00 p.m. to 4:00 a.m.) that had an earliest allowed starting time of 6:00 a.m. Lungs meeting criteria for transplantation were retrieved, transported, and immediately transferred to a 10°C temperature-controlled incubator until implantation; 70 patients and 140 matched controls were included in this study. RESULTS: Total preservation times for lungs in the study group were 12 hours, 28 minutes (interquartile range, 10 hours, 14 minutes to 14 hours, 12 minutes) and 14 hours, 9 minutes (interquartile range, 12 hours, 3 minutes to 15 hours, 45 minutes) for the first and second lung implanted, respectively. Primary graft dysfunction grade 3 at 72 hours (primary outcome) was 5.7% in the study group versus 9.3% in matched controls (difference, −3.6; 95% confidence interval [CI], −10.5 to 5.3). No meaningful differences were observed in the need for postoperative extracorporeal membrane oxygenation (5.7 vs. 9.3%), median intensive care unit stay (5 vs. 5 days), or median hospital stay (25 vs. 30 days) between the two groups. One-year Kaplan–Meier survival was similar between the two groups (94 vs. 87%; hazard ratio, 0.65; 95% CI, 0.26 to 1.6). CONCLUSIONS: Extension of cold static preservation times at 10°C appears to be safe and has the potential to improve transplantation logistics and performance. (Funded by the UHN Foundation; Clinicaltrials.gov number, NCT04616365).

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.