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

Background: We investigated the effect of prolonged oral arginine administration on tissue necrosis and perfusion in the rat skin flap.
Methods: 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.
Results: 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).
Conclusions: 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.