Plastic Surgery Department, Cleveland Clinic, Cleveland, OH.
Transplantation. 2022 Aug 1;106(8):1638-1646. doi: 10.1097/TP.0000000000004045. Epub 2022 Feb 7.
Ischemia-reperfusion injury remains a primary concern in upper extremity transplantation. Ex vivo normothermic perfusion (EVNP) enables near-physiological organ preservation, avoiding the deleterious effects of hypoxia and cooling. We investigated the effectiveness of human limb EVNP compared with static cold storage (SCS).
Twenty human upper extremities were procured. Ten were perfused at 38 °C with an oxygenated red blood cell-based solution, and contralateral limbs served as SCS control (4 °C). EVNP was terminated with systolic arterial pressure ≥115 mm Hg, compartment fullness, or a 20% decline in oxygen saturation. Weight, contractility, compartment pressure, tissue oxygen saturation, and uptake rates were assessed. Perfusate fluid dynamics, gases, electrolytes, and metabolites were measured. Myocyte injury scores and liquid chromatography-mass spectrometry analysis were performed.
EVNP duration was 41.6 ± 9.4 h. Vascular resistance averaged 173.0 ± 29.4 mm Hg × min/L. Weight change and compartment pressures were 0.4 ± 12.2% ( P = 0.21) and 21.7 ± 15.58 mm Hg ( P = 0.003), respectively. Arterial and venous carbon dioxide partial pressure, oxygen saturation, and pH were 509.5 ± 91.4 mm Hg, 15.7 ± 30.2 mm Hg, 87.4 ± 11.4%, and 7.3 ± 0.2, respectively. Oxygen uptake rates averaged 5.7 ± 2.8 mL/min/g. Lactate reached 20 mmol/L after 15 (interquartile range = 6) h. Limb contractility was preserved for 30.5 (interquartile range = 15.8) h ( P < 0.001) and negatively correlated with perfusate potassium (ρ = -0.7, P < 0.001). Endpoint myocyte injury scores were 28.9 ± 11.5% (EVNP) and 90.2 ± 11.8% (SCS) ( P < 0.001). A significant increase in taurine ( P = 0.002) and decrease in tryptophan ( P = 0.002) were detected. Infrared thermography and indocyanine green angiography confirmed the presence of peripheral perfusion.
EVNP can overcome the limitations of cold preservation by extending preservation times, enabling limb quality assessment, and allowing limb reconditioning before transplantation.
缺血再灌注损伤仍然是上肢移植的主要关注点。体外常温灌注（EVNP）可实现接近生理的器官保存，避免缺氧和冷却的有害影响。我们研究了与人肢 EVNP 相比，静态低温保存（SCS）的效果。
采集 20 个人类上肢。其中 10 个在 38°C 下用含氧红细胞为基础的溶液进行灌注，对侧肢体作为 SCS 对照（4°C）。EVNP 以收缩压≥115mmHg、腔室饱满或氧饱和度下降 20%为终点。评估重量、收缩性、腔室压力、组织氧饱和度和摄取率。测量灌流液动力学、气体、电解质和代谢物。进行肌细胞损伤评分和液相色谱-质谱分析。
EVNP 持续时间为 41.6±9.4 小时。血管阻力平均为 173.0±29.4mmHg×min/L。体重变化和腔室压力分别为 0.4±12.2%（P=0.21）和 21.7±15.58mmHg（P=0.003）。动脉和静脉二氧化碳分压、氧饱和度和 pH 值分别为 509.5±91.4mmHg、15.7±30.2mmHg、87.4±11.4%和 7.3±0.2。氧摄取率平均为 5.7±2.8mL/min/g。乳酸在 15 小时（中位数=6）后达到 20mmol/L。肢体收缩性保存 30.5（中位数=15.8）小时（P<0.001），与灌流液钾呈负相关（ρ=-0.7，P<0.001）。终点肌细胞损伤评分分别为 28.9±11.5%（EVNP）和 90.2±11.8%（SCS）（P<0.001）。检测到牛磺酸显著增加（P=0.002）和色氨酸减少（P=0.002）。红外热成像和吲哚菁绿血管造影证实存在外周灌注。
EVNP 通过延长保存时间、实现肢体质量评估以及在移植前对肢体进行再调理，克服了低温保存的局限性。
