Morphologic aspects of experimental esophageal lye strictures. II. Effect of steroid hormones, bougienage, and induced lathyrism on acute lye burns.

Among 77 dogs surviving standardized transmural esophageal lye injury for at least 2 weeks and as long as 12 weeks, 24 were untreated, 26 received corticosteroids and bougienage (S&B), and 27 received only the lathyrogen beta-aminoproprionitrile (BAPN). Stricture frequency was reduced markedly and significantly in the S&B and BAPN groups when compared to the controls (p less than 0,01). Strictures resulted from inward circumferential remodeling of all mural layers, not proliferating bulky scar tissue, and persistent ulceration was apparently not an influential factor in any group. The S&B dogs invariably showed reduction of the internal or mucosal length of the injured segment as compared to the outer length; these relations were quite variable in the other two groups so that mean internal shortening was significantly greater (p less than 0.01) in the S&B group. Marked mural thinning in the injured zone was present in all three groups but was most frequent in the BAPN-treated animals. The major conclusion is that BAPN-induced changes in the physical properties of reparative tissue can increase the ultimate caliber of an injured hollow viscus without resort to mechanical bougienage. In addition, the data suggest that wound contraction may play a role in stricture formation in this model.