Saphenous artery-based flap models in rats: new flap designs for experimental studies.

BACKGROUND: Experimental research using laboratory animals provides substantial data about reconstructive surgery. However, the literature does not include any experimental studies that have used flap models on the hind limbs of rats. To gain an understanding of the physiology of lower-extremity flaps and of flap failures, this study assessed the cutaneous perforators of the saphenous artery, and new flap models were designed for the hind limbs of rats.

MATERIALS AND METHODS: The experiment was designed to include three stages and used 35 rats. The first stage involved mapping the perforators of the saphenous artery. In the second stage, the contents and structures of McFarlane, epigastric, and anterior hind limb flap tissues were compared histologically. The third stage of the study involved designing and comparing different flaps for the hind limbs of the rats and included random flaps, perforator-based peninsular flaps, perforator-based island flaps, and perforator-based flaps with rotated pedicles. Postoperative necrosis ratios were evaluated using computer-based software.

RESULTS: Mapping of the saphenous artery perforators revealed an average of 2.2 septocutaneous arteries in each hind limb. Histologic studies showed thick dermis and panniculus carnosus in the McFarlane flaps, thick dermis, and thin panniculus carnosus layers in the epigastric flaps, and thin subcutaneous tissue with no panniculus carnosus tissue in the skin of the hind limbs. The results of the flap studies that used random flaps showed a 52.4% necrosis, while there was no necrosis when perforator-based peninsular flaps, island flaps, and flaps with rotated pedicles were used.

CONCLUSIONS: New flap models used on the saphenous artery perforators of the hind limbs of rats can provide valuable information about the physiology of lower-extremity flaps. New studies can also be designed based on these flap models to acquire more knowledge about pathologic conditions such as ischemia and venous insufficiency.