Normothermic Perfusion is Superior to Cold Perfusion in Porcine Ex Situ Lung Perfusion.

Cold ex situ lung perfusion (ESLP) has demonstrated improved preservation in small animal ESLP compared to normothermic ESLP and cold static preservation. We hypothesized that cold negative pressure ventilation (NPV)-ESLP would improve graft function in a porcine transplantation model. Four perfusate temperatures were examined with 12 hours NPV-ESLP in a large animal transplantation model. Pig lungs were allotted to four groups: (1) Normothermia (38°C, n = 6); (2) profound hypothermia (10°C, n = 6); (3) moderate hypothermia (20°C, n = 3); (4) subnormothermia (32°C, n = 3). A fifth group subnormothermic low-flow (SNLF) perfusion was examined to assess the effect of reduced cardiac output with cold perfusion (32°C, 10% cardiac output, n = 6). Only Normothermic and SNLF groups demonstrated acceptable oxygenation after 12 hours NPV-ESLP and were transplanted. All other groups failed prematurely. After 12 hours of ESLP, Normothermic lungs demonstrated significantly greater dynamic compliance compared to SNLF lungs (P = .03). Edema formation post-ESLP was significantly worse in the SNLF group (P = .01). There was no significant difference in pulmonary artery pressures after ESLP (P = .10); however, pulmonary vascular resistance was significantly greater in the SNLF (P = .04). Isolated left lung oxygenation 4-hours post-transplant and left lung edema formation was not significantly different between Normothermic and SNLF post-transplant (P = .09). Proinflammatory cytokines were significantly greater during SNLF-ESLP (tumor necrosis factor alpha, P < .05). Prolonged normothermic (38°C) NPV-ESLP is superior to 10, 20, and 32°C perfusion. Normothermic ESLP of porcine lungs results in superior graft function and reduced inflammation versus SNLF-ESLP.

Forgie K ，Fialka N ，Watkins A ，Du K ，Himmat S ，Hatami S ，Khan M ，Wang X ，Edgar R ，Buswell-Zuk KM ，Freed DH ，Nagendran J ... -  《-》

Moderate-Flow Perfusion is Superior to Low-Flow Perfusion in Ex Situ Lung Perfusion.

Forgie K ，Fialka N ，Watkins A ，Du K ，Himmat S ，Hatami S ，Khan M ，Wang X ，Edgar R ，Buswell-Zuk KM ，Freed D ，Nagendran J ... -  《-》

Perfusate Exchange Does Not Improve Outcomes in 24-hour Ex Situ Lung Perfusion.

Reliable 24-hour preservation is required to optimize the rehabilitation potential of Ex Situ Lung Perfusion (ESLP). Other ESLP protocols include fresh perfusate replacement to counteract an accumulation of deleterious by-products. We describe the results of our reliable 24-hour negative pressure ventilation (NPV)-ESLP protocol with satisfactory acute post-transplant outcomes and investigate perfusate exchange (PE) as a modification to enhance prolonged ESLP. Twelve pig lungs underwent 24 hours of NPV-ESLP using 1.5L of cellular perfusate (500 mL packed red blood cells and 1 L buffered perfusate). The Control (n = 6) had no PE; the PE (n = 6) had 500 mL replaced after 12 hours of NPV-ESLP with 1000 mL fresh perfusate. Three left lungs per group were transplanted. Results are reported as Control vs PE (mean ± SEM). Both groups demonstrated stable and acceptable oxygenation during 24 hours of ESLP with final PF ratios of 527.5 ± 42.19 and 488.4 ± 35.38 (P = .25). Final compliance measurements were 20.52 ± 3.59 and 18.55 ± 2.91 (P = .34). There were no significant differences in pulmonary artery pressure after 24 hours of ESLP (10.02 ± 2.69 vs 14.34 ± 1.64, P = .10), and pulmonary vascular resistance only differed significantly at T12 (417.6 ± 53.06 vs 685.4 ± 81.19, P = .02). Percentage weight gain between groups was similar (24.32 ± 8.4 and 45.33 ± 7.76, P = .07). Post-transplant left lung oxygenation was excellent (327.3 ± 14.62 and 313.3 ± 15.38, P = .28). There was no significant difference in % weight gain of lungs post-transplant (22.20 ± 7.22 vs 14.36 ± 9.96, P = .28). Acceptable lung function was maintained during 24-hour NPV-ESLP and post-transplant regardless of PE.

Forgie K ，Watkins A ，Du K ，Ribano A ，Fialka N ，Himmat S ，Hatami S ，Khan M ，Wang X ，Edgar R ，Buswell-Zuk KM ，Freed DH ，Nagendran J ... -  《-》

Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism.

Forgie KA ，Fialka N ，Buchko M ，Himmat S ，Hatami S ，Qi X ，Wang X ，Buswell KM ，Edgar R ，Freed DH ，Nagendran J ... -  《Jove-Journal of Visualized Experiments》

Subnormothermic ex vivo lung perfusion attenuates graft inflammation in a rat transplant model.

Ex vivo lung perfusion has emerged as a novel technique to safely preserve lungs before transplantation. Recent studies have demonstrated an accumulation of inflammatory molecules in the perfusate during ex vivo lung perfusion. These proinflammatory molecules, including damage-associated molecular patterns and inflammatory cytokines, may contribute to acute and chronic allograft dysfunction. At present, ex vivo lung perfusion is performed clinically at normothermic temperature (37°C). The effect of lowering temperature to the subnormothermic range during ex vivo lung perfusion has not been reported. In this study, we hypothesized that lower ex vivo lung perfusion temperature will lead to a reduction in allograft inflammation and result in improved post-transplant graft function. Lewis rat heart-lung blocs underwent 4 hours of ex vivo lung perfusion in 3 temperature groups: 37°C (MP37), 30°C (MP30), and 25°C (MP25). In the control group, lung grafts were preserved by static cold storage before transplantation. After ex vivo lung perfusion or static cold storage, the left lung was transplanted for 2 hours before the animal was killed. Sera and tissue were collected and analyzed. There were no differences in partial pressure of arterial oxygenation to fraction of inspired oxygen ratios during 4 hours of ex vivo lung perfusion between temperature groups. Tumor necrosis factor α significantly increased in the MP37 group during ex vivo lung perfusion, whereas this was not seen at lower temperatures. Extracellular DNA and high-mobility group box 1 perfusate concentrations increased significantly during ex vivo lung perfusion in all groups, but the rate of increase was diminished at lower temperature. Two hours post-transplant, there were no significant differences in partial pressure of arterial oxygenation to fraction of inspired oxygen ratios of the lung graft or serum damage-associated molecular pattern levels among groups. On histologic grading after transplantation, greater injury was observed in the MP30 and MP37 groups, but not MP25, when compared with static cold storage. Subnormothermic ex vivo lung perfusion at 25°C reduces the production of inflammatory mediators during ex vivo lung perfusion and is associated with reduced histologic graft injury after transplantation.

Gloria JN ，Yerxa J ，Kesseli SJ ，Davis RP ，Samoylova ML ，Barbas AS ，Hartwig MG ，Duke Ex Vivo Organ Laboratory ... -  《-》