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.

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.

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.