Subzero nonfreezing preservation in a murine limb replantation model

Area of Science:

• Surgical Research
• Organ Preservation
• Transplantation Medicine

Background:

• Hypothermic storage is crucial for prolonging organ and tissue viability during ischemia.
• Current standard hypothermic preservation at 4°C has limitations in extending ischemia tolerance for complex tissues like limbs.

Purpose of the Study:

• To determine the optimal non-freezing temperature for hypothermic limb storage.
• To evaluate the efficacy of subzero non-freezing preservation (-1°C) versus standard hypothermia (4°C) in a murine hindlimb replantation model.

Main Methods:

• Amputated murine hindlimbs were preserved at -1°C and 4°C for varying durations (4-72 hours).
• Preserved limbs were replanted using microsurgical techniques.
• Vascular patency and histological viability of muscle and bone were assessed post-replantation.

Main Results:

• Preservation at -1°C for up to 72 hours demonstrated significantly superior anastomotic patency rates compared to 4°C preservation (P < 0.05).
• Histological analysis showed better muscle preservation and maintained osteoblastic activity in bone at -1°C compared to 4°C.
• Subzero preservation extended the maximum viable ischemia time for muscle-containing limbs to 8 hours, exceeding the 6-hour limit at 4°C.

Conclusions:

• Subzero non-freezing preservation at -1°C is more effective than 4°C hypothermia for prolonging ischemic tolerance in limb replantation.
• This approach offers a significant advantage for major limb replantations involving muscle tissue, potentially improving surgical outcomes.