Experimental production of rectal stenosis and atresia in the rabbit.

Clinical reviews have suggested that there are different causes for the various types of anorectal atresia and stenosis. Such inferences have primarily been based upon the presence or absence of associated fistulas and other anogenital, urinary, and more remote congenital defects. Rectal stenosis and atresia of the middle and/or upper third of the rectum were produced in 27 of 38 rabbit feti subjected to partial to complete interruption of the blood supply to the rectosigmoid colon between the 24th and 26th day of gestation. Such experimental feti were located in the right tube, while a sham laparotomy was performed during the same maternal operation on 26 feti located in the left tube. An additional undisturbed 28 feti were available in both tubes to serve as controls. No other anomalies were produced in any group. These findings suggest that local ischemia, occurring late during fetal life, may well be the mechanism responsible for the creation of rectal stenosis and atresia of the middle and/or upper rectum.