Editing Intestinal Segments and Urinary Diversion (section)

== Neuromechanical Aspects of Intestinal Segments ==

* '''2 aspects of neuromechanical properties are important to urinary intestinal diversion: volume-pressure relationships and motor activity:'''

=== Volume-pressure considerations ===
* '''By splitting most segments, the volume increases by ≈50%.''' The goal in reconfiguring the bowel is to achieve a spheric storage vessel. This configuration has the most volume for the least surface area.
* '''Over time, the volume capacity of segments increases'''. This occurs only if they are frequently filled. Their volume decreases with time if they are nonfunctional

=== Motor activity ===
* It has been suggested that splitting the bowel on its antimesenteric border discoordinates motor activity and thereby causes a lesser intraluminal pressure. However, the literature is contradictory with respect to the effect of detubularization on segments of ileum and colon used to construct storage vessels for continent diversions.
* Thus, '''reconfiguring bowel usually increases the volume, but its long-term effect on motor activity and wall tension is unclear at this time'''. Some patients with orthotopic bladders after a number of years of spontaneous voiding require intermittent catheterization. In these patients the bowel segment has become flaccid, and the ability of the patient to generate intraluminal pressure by a Valsalva maneuver is limited.