Experimental cooling-induced preconditioning attenuates skin flap failure.

Area of Science:

• Regenerative Medicine
• Surgical Innovation
• Tissue Engineering

Background:

• Microvascular perfusion failure is a primary cause of tissue necrosis in reconstructive surgery.
• Investigating preconditioning strategies to enhance flap survival is critical.

Purpose of the Study:

• To evaluate local hypothermia as a preconditioning method for inducing stress proteins like heat-shock protein (HSP) 70 and haem oxygenase-1 (HO-1).
• To assess the impact of hypothermia on flap microcirculation and survival.

Main Methods:

• Hairless mice ears were subjected to local hypothermia (4°C for 30 min) 24 hours before flap elevation.
• Microcirculation and tissue necrosis were quantified using intravital fluorescence microscopy over 5 days.
• HO-1 and HSP-70 protein expression were analyzed via Western blot and immunohistochemistry.

Main Results:

• Local cooling significantly upregulated HO-1 expression but not HSP-70.
• A marked improvement in microvascular perfusion, primarily through capillary dilation, was observed (P < 0.050).
• Cooling led to a significant reduction in flap necrosis (P < 0.050).

Conclusions:

• Preoperative cooling effectively conditions flaps by inducing HO-1 expression.
• Local hypothermia is a promising preconditioning strategy to improve microcirculation and reduce tissue necrosis in reconstructive surgery.