Three experiments utilizing an isolated open ileal patch were performed in sequence on dogs. A segment of ileum, the length depending on the proposed use, was prepared and the blood supply carefully preserved. The main bowel tract was anastomosed, the ileal segment opened along the antimesenteric border (Fig 1), and the mucosa removed by scraping. After this had been done, a seromuscular "patch" was then placed in line with the muscular surface in apposition to the colon, duodenum, and bladder.
Colon.—The mid-transverse colon was severed and loosely anastomosed by a one-layer everting suture to insure anastomotic leakage. A prepared open patch, sufficient in length to fit the circumference of the colon, was then sutured about the anastomotic site. Killing of the animal in four months revealed, grossly, a firm, smooth union of the patch with the colon (Fig 2), preservation of the patch's vascular pedicle, and no evidence of