Intraoral coverage of defects with the superficial epigastric fat flap in rats

The standard superficial epigastric artery flap has become a reliable model for flap research. The purpose of this study was to design a flap model in the rat, with the possibility of intraoral coverage of defects. A fat flap based only on the medial trunk of the superficial epigastric vessels was generated, raised to the neck, and used for the coverage of a created intraoral defect in 28 Sprague-Dawley rats. Twenty-five epigastric flaps were raised and anastomosed to the neck, and three flaps were sutured into the oral cavity as a control without anastomosing the vessels to the rat's neck. For histological examination, each of the five flaps was harvested after 7, 14, and 35 days. A total of five rats died perioperatively, and 23 rats survived. One epigastric fat flaps became necrotic, which attracted attention by dehiscence after 3 or 4 days postoperatively, consisting of one anastomosed and all nonvascularized flaps. A swollen cheek was noted in these cases after about 5 days. Although this model demands the control of basic microsurgical techniques, it is possible to use it as a training model for further refining microsurgical techniques in flap raising. It is planned to use this flap as a model for healing purposes in the oral cavity.