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-mum 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(2) versus 11.91 +/- 4.12 cm(2); p <. 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 mumol/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.