The effect of acute hyperbaric oxygen therapy on axial pattern skin flap survival when administered during and after total ischemia.

The effect of hyperbaric oxygen (HBO) on axial pattern skin flap survival in male Wistar rats, when administered during and immediately following prolonged total flap ischemia, was evaluated. Eighty-one 3 x 6 cm rectangular epigastric skin flaps were elevated, and the inferior epigastric pedicle of each flap occluded for 8 hr. The animals were divided into a control and three other experimental groups: Control (n = 27) -8 hr flap ischemia, no HBO; Group (n = 21) - HBO therapy (100 percent O2--three 1.75 hr dives at 2.5 atm) during ischemia; Group 2 (n = 21) - HBO therapy (two 1.75 hr dives) following ischemia; Group 3 (n = 12) - HBO treatment during ischemia but with the flap contained in a metal-coated Mylar bag to prevent oxygen diffusion. The percentage of flap necrosis was calculated on postoperative day 6. Mean flap necrosis for controls was 28 percent (+/- 21 S.D.), while HBO treatment during ischemia or during reperfusion significantly reduced this necrosis to 9 percent (+/- 11) and 12 percent (+/- 14), respectively (p less than 0.01). The percentage of necrosis for Group 3, with the local with the local effect of HBO on the flap blocked by the diffusion barrier, was 5 percent (+/- 7), also significantly better than the controls (p less than 0.0005) but no different from the other two experimental groups. HBO treatment increases the percentage of axial pattern skin flap survival when administered during or immediately following total flap ischemia. The improved flap survival appears to be a systemic and not a local effect.