RESUMO
The evolution and phenotypic expression of mucosal lesions of the gastric stump were investigated in male rats submitted to gastric resection with reconstruction by the Bilroth II technique (biliopancreatic reflux - BPR) and by the Roux-en-Y procedure (without BPR). The animals were studied at 24, 36, 54 and 64 weeks after surgery. the phenotypic expression of the lesions was analyzed by immunohistochemical staining for pepsinogen isoenzyme 1 and by histochemical procedures for mucins. BPR was found to be responsible for the formation of adenomatous hyperplasia (AH) whose incidence and size increased with time. AH mainly consisted of gastric cells and always occurred in the transition of the gastrojejunal junction, and this site offers special conditions for the promoting effect of BPR to occur in full. In 101 rats submitted to BII procedures, 6 mucinous adenocarcinomas were diagnosed and this neoplasia expressed the phenotype of cells of the small intestine. The roux-en-Y procedure protects the gastric stump aginst the lesions observed in BII reconstruction