On the varying degrees of cancerogenicity of modified gastroentero-anastomoses.

In our serial investigations we checked the incidence of carcinomas in different cases of anastomoses and resections on the rat stomach. Moreover we supervised the regenerative behaviour of the gastric mucosa by means of in vivo autoradiography using 3H-thymidine. The experimental animals were divided into 5 treatment groups. We carried out gastroenterostomy on 9 animals (group I), Billroth's second operation on 7 animals (group II), a duodenal ligature, pyloroplasty and gastro-enterostomy with Braun's anastomosis on 10 animals (group III), a pylorectomy as well as Roux's gastro-enterostomy on 10 animals (group IV) and a laparotomy on 11 control animals (group V). The greatest tumour onset rates with 4 adenocarcinomas each were observed in the groups I and III, and with 5 carcinomas in group II 7 months after the operations. The labelling indices obtained autoradiographically are such that glandular hyperplasias with indices of over 13.3 p.c. and carcinomas with values of about 24.7 p.c. enable an unambiguous distinction from the values of the sound glandular gastric mucosa. Entero-gastric reflux is discussed in this paper as the most important cause of carcinogenesis.