An animal model for the assessment of microvascular patency

A tubed superficial epigastric flap (TSEF), based on a single vascular pedicle, was designed in a rat. Forty TSEFs were created in three control groups: in 20 TSEFs both the femoral artery and vein were ligated proximal to the take-off of the superficial epigastric vessels, in 10 TSEFs the femoral artery and in the other 10 the femoral vein were ligated and transected at the same location. All TSEFs in the control groups sloughed, reflecting the dependence on the axial vasculature. A further 232 TSEFs were made with a survival rate of 84.5% (196/232). Delayed arterial or venous ligation was then performed up to 42 days after the initial surgery. The patency of the axial vein was crucial for survival for only the first postoperative week. The axial arterial patency was needed for survival of the TSEF for 6 weeks. The creation of this TSEF fulfills the need for a simple model that is as readily constructed as other models, is reproducible, has a high success rate and most importantly, reflects the patency of its nutrient vessels for a prolonged period of time.