Bladder carcinogenesis in portacaval shunt rats.

The induction of transitional cell bladder tumors following portacaval shunt (PCA) in rats was investigated. Thirty-five (29 males; 6 females) out of 86 animals developed a carcinoma. The highest incidence of tumors (73%) was seen in control animals without a PCA but with implantation of a bladder stone.