Intussuscepted partial-thickness ileal valve in continent urinary diversion

This study was undertaken to ascertain the feasibility of fashioning a nipple valve from partial-thickness ileum and to assess the competence and durability of that valve. The approach employed was designed to circumvent the necessity for considerable lengths of bowel to be committed to valve formation and to avoid the tendency for desusception, present with other forms of nipple valves.

A technique in which a subterminal segment of partial-thickness ileum was 'skinned' circumferentially of serosa and muscularis propria and then intussuscepted to form a continent nipple-valve mechanism was studied for up to 4 months in 10 dogs. The intussuscepted partial-thickness ileal valve was in continuity with a terminal ileal segment sutured flush with skin and, internally, with another segment laid open and anastomosed to the bladder.

All valves were competent, withstanding intravesical pressures up to 90 cm H2O. Six dogs were catheterized, without difficulty, twice daily up to 104 days. The valve mucosal surfaces were smooth due to a loss of plicae circulares, and, between 'back-to-back' submucosal layers, a fine stroma developed.

This simple technique, which is frugal in its use of bowel, provided a robust and effective ileal continence mechanism. Furthermore, because of denervation and interposing fibrous tissue, this nipple valve is considered most unlikely to desuscept subsequently. The intussuscepted partial-thickness ileal valve approach is recommended now for clinical evaluation.