Ultrastructural changes in rat peripheral nerve following pneumatic tourniquet compression

Area of Science:

• Neuroscience
• Surgical Research

Background:

• Pneumatic tourniquets are widely used in extremity surgery to reduce blood loss.
• Potential nerve damage from tourniquet application can lead to complications and delayed recovery.

Purpose of the Study:

• To investigate the ultrastructural changes in rat sciatic nerves following pneumatic tourniquet compression.
• To determine the relationship between tourniquet application duration and the severity of nerve damage.

Main Methods:

• Sciatic nerves from 12 male rats were subjected to pneumatic tourniquet compression at 300 mmHg for durations ranging from 30 minutes to 3 hours.
• Nerve tissues were examined using electron microscopy 14 days post-compression.

Main Results:

• Mild myelin fissuring occurred after 30 minutes of compression, with no axonal degeneration.
• Nerves compressed for 1-3 hours showed progressive damage, including myelin lamellae splaying, axonal shrinkage, periaxonal edema, Schwann cell hypertrophy, and increased microtubules/mitochondria.
• Complete myelin sheath rupture was observed in nerves compressed for over 2 hours.
• Damage was more severe in larger diameter nerves and correlated with compression time.

Conclusions:

• Ultrastructural nerve damage from pneumatic tourniquets is time-dependent and affects larger nerves more significantly.
• These findings provide a basis for understanding delayed muscle rehabilitation after tourniquet use.
• The study suggests that tourniquet palsy may be more common than previously recognized.