Oral administration of L-Arginine decreases necrosis of the epigastric skin flap in the rat

We investigated the effect of prolonged oral arginine administration on tissue necrosis and perfusion in the rat skin flap. Twenty-five Sprague-Dawley rats had an 8 x 8 - cm epigastric skin flap elevated and were divided in 2 groups, l-Arginine and Control, which respectively received oral 6% l-arginine solution or water for 8 days postoperatively. On postoperative day 8, area of flap necrosis was measured, and the animals were perfused systemically with 15-microm colored fluorescent microspheres before (blue) and after (yellow-green) ligation of the flap pedicle. l-Arginine reduced total flap necrosis (6.53 +/- 3.76 cm versus 11.91 +/- 4.12 cm; P < 0.01). After pedicle ligation, total flap perfusion remained unchanged in Control but diminished in the l-Arginine group (Control: 0.47 +/- 0.23 and 0.42 +/- 0.06; P = nonsignificant versus l-Arginine: 0.58 +/- 0.29 and 0.27 +/- 0.19; P < 0.01). Serum levels of l-arginine were higher in the l-arginine-treated animals (504 +/- 154 versus 152 +/- 34 micromol/l; P < 0.0001). Postoperative oral administration of l-arginine decreased flap necrosis in the rat epigastric skin flap. Flap perfusion following oral l-arginine was more dependent on the main vascular pedicle.