The effects of hyperbaric oxygen on free flaps in rats.

The effects of hyperbaric oxygen on survival were investigated in free flaps and island flaps. Skin flaps transplanted following 18, 21, and 24 hours of preservation at 24 degrees C demonstrated survival rates of 20%, 10%, and 0%, respectively. Treatment with hyperbaric 100% oxygen improved the survival rates to 66%, 67%, and 40%. A preservation time of 21 to 24 hours at room temperature appears to be the threshold of irreversible ischemic damage. In acute island flaps, flap survival was improved significantly from 35% to 53% and 64% of the random flap area by preoperative or postoperative treatment, respectively. Prolonged preoperative and postoperative treatment improved survival to 66%.