Straight ileoanal anastomosis after longitudinal strip myectomy in the swine model.

In an attempt to improve the function of the straight ileoanal anastomosis, an experimental study was performed using the swine model. The terminal ileum was altered by completely removing two longitudinal strips of muscle prior to performing a straight ileoanal anastomosis. The intent of the study was to determine whether muscle stripping was technically possible and whether bowel thus treated would remain viable to passively form a pelvic reservoir. The length of time required for formation of the reservoir was noted. All animals survived the procedure to allow evaluation. The muscle stripping was not difficult to perform. Viability was not a problem since the myectomy animals thrived well and demonstrated continence, weight gain, and reservoir formation. The results are encouraging. It appears that strips of muscularis propria can be removed from the terminal ileum without jeopardizing its viability. This seems to disrupt sufficiently the tonus of the bowel to allow better function of the straight ileoanal anastomosis through formation of a passive pelvic reservoir within a month's time in the swine model, and it may have application in the human.