Rectal Hesection in the Dog A New Surgical Approach and the Evaluation of Its Effect on Fecal Continence

Thirteen healthy mixed breed dogs (6 female and 7 male) underwent rectal transection and resection of 0 to 6 cm using a dorsal approach. Rectoanal sphincter pressure studies were performed preoperatively and 6 weeks after surgery using a double balloon manometer device. Sphincter pressure profiles were altered in the 6 cm resection dogs. Clinical observations of defecation and degree of continence were made over a 10 week period postoperatively. The transection only and 4 cm resection dogs defecated normally. All dogs in the 6 cm resection group involving the peritoneal reflection were incontinent but retained some normal posturing behavior. Surgical complications included minor infection in two dogs, rectocutaneous fecal leakage in four dogs, breakdown of the anastomotic site in four dogs, and incontinence in all of the dogs that underwent 6 cm resections. Barium enemas were performed on the rectums postmortem to ascertain the degree of stricturing induced by the surgery. The index of stenosis measured did not correlate well with the extent of straining in each group. Histopathologic findings on dogs in the transection only and 4 cm resection groups without dehiscence showed mild granulomatous proctitis with normal myenteric plexi seen. Dogs suffering dehiscence had suppurative proctitis, necrosis, and obliteration of the myenteric plexi.