Nerve and muscle vulnerability to ischemia.

Nerve and muscle vulnerability to structural damage during ischemia was examined in the hind legs of 50 cats after transient simultaneous clamping of the aorta and femoral artery for 1 to 10 h. Not until 5 h of ischemia were mild necrotic changes noted in nerves. Moderate to severe changes occurred after 8 h of ischemia. Contrariwise, mild muscle necrotic changes developed after 2-3 h, and moderate to severe changes after 5-7 h. The anterior tibialis muscle was usually more severely damaged than the gastrocnemius and soleus muscles. These studies demonstrate that: Longer periods of ischemia are required to produce nerve damage than suggested by previous tourniquet compression experiments. Longer periods of ischemia are necessary to produce necrosis in the posterior than anterior and lateral compartment muscles of the leg. Muscle is more vulnerable than nerve to ischemia.