Induction of carcinoma at ureterosigmoid anastomosis--with and without faecal stream.

The induction of tumours at the site of uretero-intestinal anastomosis was investigated in Hannover: WISTAR rats. The rats were divided into 3 groups. In one group (n = 70) the ureter of the left kidney was implanted into the colon, using microsurgical techniques developed for humans. In 13% of the rats in this group benign tumours developed; in 16% malignant tumours occurred. In a second group (n = 76) the ureter was implanted into a rectal bladder; the faeces were excluded from the anastomosis by a descending colon anus praeter. In this group benign tumours developed in 17% and malignant tumours in 8%, all of them being situated at the site of the anastomosis. In a control group (n = 80) no colonic tumour could be identified.