Enhanced Peripheral Neovascularization of Musculocutaneous Flaps Following Pedicle Ligation in the Pig

Abstract

HM Clarke, G Chen. Enhanced peripheral neovascularization of musculocutaneous flaps following pedicle ligation in the pig. Can J Plast Surg 1994:2(4): 159-163. The augmentation of blood flow from the periphery following dominant pedicle ligation was studied in island latissimus dorsi muscle and musculocutaneous flaps in the pig. In the first study, a musculocutaneous flap and a muscle flap covered with a skin graft were raised on two sides of the same pig (n=25). Silicone rubber sheeting inhibited revascularization from the base. From one to seven days later the dominant vascular pedicles were ligated and blood flow from neovascularization to the flap was assessed immediately using radiolabelled 15 μm microspheres. The peripheral neovascularization of muscle and musculocutaneous flaps was not different when assessed at the time of pedicle ligation. Comparison with a previous study of flap survival, however, revealed that increased blood flow was seen in flaps in which the pedicle had been ligated two days prior to rather than at the time of assessment. Therefore, in a second study, musculocutaneous flaps were raised bilaterally and from one to eight days later the pedicle was ligated on one side only (n=29). After two days of further neovascularization the blood flow to the components of the flaps was assessed using 15 μm microspheres. Significant enhancement of peripheral neovascularization was seen in all animals in which two days had elapsed between pedicle ligation and the assessment of neovascularization (P<0.05). In addition, the flows seen in the skin component of the flaps were substantially greater than normal, suggesting a delay-like phenomenon.