ILEOCECAL VALVE RESISTANCE AUGMENTATION USING GLUTARALDEHYDE CROSS-LINKED COLLAGEN: A CANINE MODEL FOR ENDOSCOPIC SALVAGE OF THE LEAKING INDIANA RESERVOIR

Abstract

Periurethral injection of glutaraldehyde cross-linked collagen is a well-established modality for the treatment of patients with incontinence caused by structural defects at the bladder outlet. Little is known about the potential usefulness of this approach to the nonfunctioning continence mechanism of a leaking continent urinary reservoir. An animal model of an incontinent Indiana reservoir was created using the naturally incompetent canine ileocecal valve. The effectiveness and feasibility of endoscopic submucosal injection of glutaraldehyde cross-linked collagen into the ileocecal valve to increase resistance were examined. Seven beagle dogs underwent isolation of the ileocecal segment. The right colon and ileum were brought to the skin as 2 stomas. Baseline leak point pressures of the ileocecal valve were determined while infusing contrast material into the right colon. The leak point was observed fluoroscopically, and the pressure at which contrast material crossed the valve was measured. Glutaraldehyde cross-linked collagen, 4 to 10 ml., was injected endoscopically into the valve in a circumferential pattern. Leak point pressures were measured immediately, 1 month after injection and 3 months after injection. An average of 7.1 gm. (range, 4.1 to 10.1 gm.) was required to create an endoscopically "closed" ileocecal valve. Leak point pressure increased from a mean 3.8 mm. water (range, 2.5 to 6.0 mm. water) at baseline to mean 35.7 mm. water after injection (range, 22.0 to 57.0 mm. water). At 1 month, mean leak point pressure decreased slightly to 26.7 mm. water. This pressure stabilized at 3 months at 29.5 mm. water. Endoscopic delivery of glutaraldehyde cross-linked collagen into the ileocecal valve consistently enhanced resistance as measured by leak point pressure. This effect was durable over a 3-month period of observation. Admittedly, this period of observation is relatively short. Longer followup may have demonstrated significant diminution of collagen migration or resorption. However, this feasibility study demonstrates that collagen injections may provide a minimally invasive means of treating the incontinent continent urinary reservoir.