Functional classification of conduits for continent diversion.

To facilitate rational surgical application of conduits leading from intestinal reservoirs, the mechanisms that maintain continence are classified and illustrated with 4 hydrodynamic principles: 1) sphincteric compression, achieved by decreasing the caliber of the conduit, 2) peristalsis, which conducts urine toward the reservoir, 3) equilibration of inside and outside pressure as gained by nipple formation or construction of a chamber, and 4) the flap valve principle, with configurations similar to those of ureteroneocystostomy. An additional contribution to continence comes from the seal produced by the inner softness of the mucosa.