Urinary diversion to the augmented and valved rectum. An experimental study in dogs.

A new model for diverting urine to the rectum was tried in dogs. An intussusception valve was constructed at the junction of the sigmoid colon and the rectum allowing passage only in aboral direction. The rectum was augmented by patching it with an opened and folded ileal segment. The ureters were implanted into the rectum by a new anti-reflux method. All three dogs survived the operation. The volume of the augmented rectum increased from 80-150 ml at operation to a maximum of 750 ml six months after the operation. The pressure in the rectum did not exceed 18 cm of water during maximal filling. No reflux to the bowel proximal to the intussusception valve or to the ureters could be observed even during maximal filling of the augmented rectum. No signs of obstruction of the fecal stream by the intussusception valve were seen. In three out of five implanted renal units strictures developed at the implantation sites and resulted in impaired renal function. In the two renal units without strictures, no impairment of kidney function was found. Involuntary leak from the anus was not observed and no masceration was found around the anus. These experiments are regarded as very encouraging an a clinical trial is now under way.