EXPANSION OF VENOUS FLAPS - AN EXPERIMENTAL-STUDY IN RATS

In this study, the effects of controlled tissue expansion on the survi val of unipedicled venous flaps were investigated in rats. In three gr oups of Lewis rats, a 3 x 6 cm unipedicled Lateral thoracic venous fla p was studied with group 1 as control group (n = 30) without ally mani pulation, group 2 (n = 30) where an expander was introduced under the flap area but was not expanded and group 3 (n = 30) in which a 40 ml e xpander was introduced under the flap area and was expanded over a per iod of 10 days. Observations included gross and histological examinati on, reverse microangiography, reverse flow resistance and percentage o f survival of flaps. Group 3 (expanded) showed more angiogenesis, a be tter delineation on microangiography, lower reverse flow resistance an d higher survival rates as compared to group 2 (non-expanded). In the control group the survival rate of flaps was the poorest and the flaps showed higher rates of reverse flow resistance. Microangiography was not successful in the control group. In a pilot project prior to this experiment microscopic examination of the Lateral thoracic vein in 10 Lewis rats had confirmed the presence of two or three valves in this v ein.