Role of perivenous areolar tissue in the viability of venous flaps: an experimental study on the inferior epigastric venous flap of the rat.

This study was performed to investigate how the perivenous areolar tissue affects survival of the rat inferior epigastric venous flap model designed by Yuen and Leung (1991). Five groups of flaps were studied; group A--flap based on an inferior epigastric vein and areolar tissue; group B--flap with a skeletonised vein; group C--control, nonvascularised flap; group D--flap based on perivascular areolar tissue alone; group E--flap with a skeletonised artery and vein. Each group included 40 flaps; 20 of them had a silicone sheet placed under the flap, the other 20 did not. All flaps of group E survived. The success rate of group A with and without a silicone sheet was 60% and 90% respectively. All flaps of the other groups (B, C, D) necrosed. Histological examination of the pedicle showed that many minute vascular channels (single-cell-layered capillaries) were present apart from the inferior epigastric vein. This result confirms the importance of the perivenous areolar tissue in perfusion of the skin island, at least, in the inferior epigastric venous flap in the rat.