Pressure studies of the ileocolonic junctional zone of dogs

¹ Departments of Medicine, Radiology, and Surgery, University of Rochester School of Medicine and Dentistry, Rochester, New York

This investigation was undertaken to define the pressure profile of the canine ileocolonic junctional segment and to determine whether a zone of increased pressure exists between the ileum and colon. In four adult dogs, the area was made accessible by bringing ileal and colonic stomas to the abdominal wall. An open-tipped, water-filled polyethylene tube and miniature balloons, 5 x 10 and 7 x 7 mm, tied over identical tubes and connected to pressure transducers were withdrawn at 0.5-cm intervals from the colon into the ileum of the fasted, conscious animals. In many instances, a zone of elevated pressure was encountered. Mean pressures at the center of the junctional area by the open-tipped tube were 19.7 (sem ± 1.43) cm H₂O above ambient, 5 x 10 mm balloon 37.7 (sem ± 2.16) and 7 x 7 mm balloon 47 (sem ± 1.73). Similar pressures were recorded at this site when units were withdrawn from ileum to colon. Length of the zone was usually 1 cm. Simultaneous cinefluorographic pressure studies showed that the zone of increased pressure was located in the cone-shaped configuration indicating the ileocolonic junction.

Key Words: ileum • colon • pressures

Submitted on November 5, 1964