INTUSSUSCEPTED PARTIAL-THICKNESS ILEAL VALVE IN CONTINENT URINARY-DIVERSION

Objective: This study was undertaken to ascertain the feasibility of f ashioning a nipple valve from partial-thickness ileum and to assess th e competence and durability of that valve. The approach employed was d esigned to circumvent the necessity for considerable lengths of bowel to be committed to valve formation and to avoid the tendency for desus ception, present with other forms of nipple valves. Methods: A techniq ue in which a subterminal segment of partial-thickness ileum was 'skin ned' circumferentially of serosa and muscularis propria and then intus suscepted to form a continent nipple-valve mechanism was studied for u p to 4 months in 10 dogs. The intussuscepted partial-thickness ileal v alve was in continuity with a terminal ileal segment sutured flush wit h skin and, internally, with another segment laid open and anastomosed to the bladder. Results: All valves were competent, withstanding intr avesical pressures up to 90 cm H2O. Six dogs were catheterized, withou t difficulty, twice daily up to 104 days. The valve mucosal surfaces w ere smooth due to a loss of plicae circulares, and, between 'back-to-b ack' submucosal layers, a fine stroma developed. Couclusions: This sim ple technique, which is frugal in its use of bowel, provided a robust and effective ileal continence mechanism. Furthermore, because of dene rvation and interposing fibrous tissue, this nipple valve is considere d most unlikely to desuscept subsequently. The intussuscepted partial- thickness ileal valve approach is recommended now for clinical evaluat ion.