Tissue changes at different periods of ischemia

Area of Science:

• Reconstructive Surgery
• Ischemia-Reperfusion Injury
• Tissue Preservation

Background:

• Understanding the pathophysiological effects of ischemia on tissues is crucial for limb replantation.
• Normothermic and cold ischemia have distinct impacts on cellular integrity and biochemical markers.
• Histological changes in vessels, nerves, and muscles under ischemic conditions require detailed examination.

Purpose of the Study:

• To investigate pathophysiological and histological changes in muscle and nerve response to normothermic and cold ischemia.
• To analyze alterations in enzyme (potassium, lactate dehydrogenase) and lactate release during ischemia.
• To determine optimal timeframes for limb replantation based on ischemia duration and temperature.

Main Methods:

• Multidisciplinary study involving assessment of muscle and nerve responses.
• Measurement of enzyme (K, LDH) and lactate levels.
• Histological examination of vessels, nerves, and muscles.

Main Results:

• Hypothermic ischemia significantly reduced enzyme leakage, cellular damage, and pathological responses compared to normothermic ischemia.
• Muscle-containing parts have a replantation window of 4-5 hours at room temperature.
• Cooling extends the viable ischemia time for muscle parts to 8-10 hours and non-muscular parts to over 24 hours.

Conclusions:

• Cold ischemia is superior to normothermic ischemia in preserving tissue viability for limb replantation.
• Reduced temperature significantly extends the time window for successful limb replantation.
• These findings provide critical data for optimizing surgical protocols in limb salvage and replantation.