UNLABELLED: Duodenal injuries, though rare, carry high rates of morbidity and mortality. The aim of the study was to evaluate the healing of the duodenal wall with the use of a Small Intestinal Submucosa (SIS) patch.MATERIAL AND METHODS: We studied 40 Wistar-Albino rats divided into two groups. In group A, we created a small defect in the duodenal wall, which was immediately covered with a SIS patch. In group B, the SIS patch was sutured over the defect after 6-8 hours, in order to induce peritonitis. The animals of both groups were sacrificed after 2, 6, 12 and 16 weeks respectively. In addition, we studied the immunohistochemical expression of TGF-β, which is a major constituent of SIS, and plays a central role in the healing process.RESULTS: Histology showed progressive development of the layers of the duodenal wall over the patch as early as the 2nd week in some of the animals of group A. Mucosa developed later on in the animals of group B, presumably due to the more intense inflammation elicited by peritonitis. Expression of TGF-β was initially more pronounced in the epithelial cells of the regenerating mucosa of animals of group A, but it was maintained in higher levels in the animals of group B, which showed delayed mucosa degeneration.CONCLUSIONS: SIS appears to be both efficient and safe for the management of duodenal trauma. TGF-β seems to play an important role in the healing process, inducing regeneration of the stroma, and controlling epithelial growth.