Department of Orthopaedic Surgery, University of Michigan Health System, Ann Arbor, MI.
Department of Surgery, University of Michigan Health System, Ann Arbor, MI.
Transplantation. 2019 Oct;103(10):2105-2112. doi: 10.1097/TP.0000000000002800.
Hypothermic ex situ perfusion (HESP) systems are used to prolong allograft survival in solid organ transplantations and have been shown to be superior to static cold storage (SCS) methods. However, the effect of this preservation method on limb allograft survival and long-term function has not yet been tested. In this study, we investigated the long-term effects of the HESP on skeletal muscle metabolism, structure, and force generation and compared it with the current standard of preservation.
Forty male Lewis rats (250 ± 25 g) were divided into 5 groups, including naive control, sciatic nerve transection or repair, immediate transplantation, SCS, and HESP. For the SCS group, limbs were preserved at 4°C for 6 hours. In the HESP group, limbs were continuously perfused with oxygenated histidine-tryptophan-ketoglutarate (HTK) solution at 10-15°C for 6 hours. Hemodynamic and biochemical parameters of perfusion were recorded throughout the experiment. At 12 weeks, electromyography and muscle force measurements (maximum twitch and tetanic forces) were obtained along with muscle samples for histology and metabolomics analysis.
Histology demonstrated 48% myocyte injury in the HESP group compared with 49% in immediate transplantation (P = 0.96) and 74% in the SCS groups (P < 0.05). The maximum twitch force measurement revealed a significantly higher force in the HESP group compared with the SCS group (P = 0.029). Essential amino acid levels of the gastrocnemius muscle did not reach significance, with the exception of higher proline levels in the HESP group.
HESP using HTK protects viability of the limb but fails to restore muscle force in the long term.
低温离体灌流（HESP）系统用于延长实体器官移植中的同种异体移植物的存活时间，并且已被证明优于静态冷藏（SCS）方法。然而，这种保存方法对肢体同种异体移植物存活和长期功能的影响尚未得到检验。在这项研究中，我们研究了 HESP 对骨骼肌代谢、结构和力量产生的长期影响，并将其与当前的保存标准进行了比较。
40 只雄性 Lewis 大鼠（250±25g）分为 5 组，包括正常对照组、坐骨神经横断或修复组、即刻移植组、SCS 组和 HESP 组。对于 SCS 组，肢体在 4°C 下保存 6 小时。在 HESP 组中，肢体在 10-15°C 下用含氧组氨酸-色氨酸-酮戊二酸（HTK）溶液连续灌注 6 小时。在整个实验过程中记录血液动力学和生化灌注参数。在 12 周时，进行肌电图和肌肉力量测量（最大颤搐和强直力），并采集肌肉样本进行组织学和代谢组学分析。
组织学显示 HESP 组的肌细胞损伤为 48%，与即刻移植组（P=0.96）和 SCS 组（P<0.05）的 49%相似。最大颤搐力测量显示 HESP 组的力明显高于 SCS 组（P=0.029）。除 HESP 组脯氨酸水平较高外，比目鱼肌的必需氨基酸水平没有达到显著性差异。
使用 HTK 的 HESP 可以保护肢体的活力，但不能在长期内恢复肌肉力量。
