Is surface cooling effective for tissue preservation in free-flap surgery?

Area of Science:

• Biomedical Engineering
• Surgical Research

Background:

• Effective tissue cooling is crucial for extending safe ischemia periods during surgery.
• Maintaining low core temperatures can prevent tissue damage and improve outcomes.

Purpose of the Study:

• To evaluate the efficacy of surface cooling in achieving low core temperatures (4°C–10°C) in bovine muscle/subcutaneous fat flaps.
• To determine the time required for surface cooling to reach target temperatures in flaps of varying weights.

Main Methods:

• Bovine muscle/subcutaneous fat flaps (400g, 800g, 2000g) were initially warmed to 37°C.
• Flaps were then subjected to surface cooling, with core temperatures recorded every 5 minutes.

Main Results:

• All tested flaps successfully reached a core temperature of 4°C.
• Average times to reach 4°C were 136 min (400g), 153 min (800g), and 194 min (2000g).
• A notable inverse relationship was observed between flap weight and cooling efficiency, though even large flaps reached safe temperatures within tolerable ischemia limits.

Conclusions:

• Surface cooling is an effective method for rapidly lowering core temperatures in surgical flaps.
• The technique is viable even for larger flaps, achieving temperatures within safe ischemia timeframes.
• Concerns regarding ischemia time should not impede the use of surface cooling in free-flap surgery.