Morphology of the pancreatic ductal epithelium after traumatization of the papilla of Vater or endoscopic retrograde pancreatography with various contrast media in cats.

The epithelium of the pancreatic duct in cats was examined histologically, in the scanning electron and in the transmission electron microscope, after traumatization of the papilla of Vater or after pancreatography (ERP) with various contrast media. Ten minutes after traumatizing the papilla by repeated cannulation, we found lesions of the surface membrane of the epithelial cells. After ERP with the contrast media metrizamide and sodium meglumine ioxaglate, in the acute experiments, the least damage was observed when the low-osmolar, non-ionic metrizamide was used. In our chronic experiments the epithelial changes did not correlate with the contrast medium used. The degree of papillary stenoses and, probably, the initial injection pressure are more important. A mixture of the antiseptic polyvinyl pyrrolidone iodine to the contrast medium, which would prevent a bacterial contamination of the pancreatic duct after ERP, is morphologically justifiable but entails a risk of latent hyperthyroidism. Parenchymography with this mixture damaged the epithelium more than pancreatography.