What is important for continent catheterizable stomas: angulations or extension?

We developed an experimental ex-vivo model to define factors that may influence continence of catheterizable channels by urinary and colonic stomas based on the principle of imbrication of the outlet tube.

From 20 pigs, colon specimens with 25 cm length were obtained and a transverse flap with 3.0 cm length x 1.5 cm width in the average point of the intestine was tubulated to create an efferent tube. With the tube configured, it was embedded by 3 seromuscular stitches far 0.5 cm each other. A pressure study of both intra-luminal surface and channel was then conducted during the filling of the submerse piece with environmental air in a water container, to define the efferent channel continence. The study was repeated after the progressive release of suture stitches until only one stitch remains.

Channel continence analyzed in each segment in three different valve length situations, making a total of 20 segments, revealed that with 3 stitches (1.5 cm valve) the maximum average pressure prior to overflow was 54 cm H2O; 53.65 cm H2O with 2 stitches (1.0 cm of valve), and 55.45 cm H2O with only one stitch (0.5 cm of valve), which are the same values. The record at the segment explosion pressure was 67.87 cm H20.

The study showed that angulation of channel with colon, maintained by only one stitch (0.5 cm imbrication) was more important than a larger extension of the valve, represented by 3 suture stitches (1.5 cm imbrication) in order to allow continence to the efferent channel.