Sa1534 The Best Moment to Use Mitomycin C in Caustic Esophagitis - Experimental Study

Abstract

48 Wistar rats were divided into 6 groups of 8 animals each: G1: infusion of 0.9% saline solution in the distal esophagus; G2: infusion of 0.9% saline solution in the distal esophagus, with temporary ligation of the organ; G3: induction of a caustic lesion without treatment; G4: MMC applied immediately after the induction of the caustic lesion; G5: MMC applied 14 days after induction of the caustic lesion; G6: esophageal dilation and application of MMC 14 days after caustic lesion. We performed contrast esophagograms of 4 animals from each group, 7 and 21 days after the caustic injury. On day 28 after the caustic injury, all animals were sacrificed, and morphological and histopathological analyses were performed on the esophageal specimens, besides the ultrastructural analysis using scanning electron microscopy. The contrast images of the esophagus showed no stenosis in G1 rats, mild stenosis with impaired motility in G2 animals, and total stenosis in G3 and G4 rats, progressing to partial stenosis in G4 rats. In G5 rats, 2 animals with partial stenosis showed improvement, while the other 2 animals maintained total stenosis. In G6 rats, 2 out of 4 animals with total stenosis progressed to partial stenosis. By histopathological analysis, the animals in groups G1 and G2 did not show any histopathological damage. In groups G3 and G5, damage was intermediate, while there was considerable histopathological damage in the rats in groups G4 and G6. Morphological analysis showed no differences in the area filled by collagen in the submucosa at any time in any of the groups, when compared to G2 rats. Ultrastructural analysis showed that the esophagus were normal in groups G1 and G2. In G3 there was marked retraction of the esophageal wall, as in the G6 group, where the dilation seemed to have damaged the tissue. Groups G4 and G5 showed an improvement in the retraction pattern, as evidenced by the presence of faint scars. The use of MMC had beneficial effects when applied immediately after the induction of esophageal lesions.