Association of Coloproctology of Great Britain and Ireland

The Association of Coloproctology of Great Britain and Ireland has been approached by the Royal College of Surgeons on behalf of a Coroner to remind colorectal and general surgeons about the risk of large bowel obstruction caused by inadvertent delivery of the wrong end of divided bowel when fashioning an end colostomy. Risks may be increased when the trephine method is employed, especially trephine sigmoid colostomy (1,2,3). The sigmoid colon is normally identified by the presence of appendices epiploicae and absence of omentum, but errors may occur with: Trephine stoma [1, 2] Trephine sigmoid colostomy, normally identified by appendices epiploicae and absence of omentum, risks: • delivery of transverse colon in error; • difficulty in identifying the ideal segment for the stoma; • closure of the proximal segment and maturation of the distal defunctioned segment, resulting in complete colonic obstruction. It is surprising that there are few publications describing this problem, which can potentially lead to perforation and fatal peritonitis. Yet no doubt there are some colorectal surgeons, including myself, who will be anecdotally aware of such cases. So what precautions should be taken? 1 Be aware of the possibility. 2 For a sigmoid colostomy, set up in the Lloyd Davis position. It is essential to have access to the anus to allow insufflation of air to identify the proximal and distal ends of the sigmoid before dividing the bowel. With this manoeuvre, the correct end will always be brought out. 3 Consider a loop stoma, if clinically appropriate, but bear in mind that redundant bowel might still twist and obstruct. 4 After construction of an end colostomy with laparotomy, check the underside of the trephine to ensure that the ‘proximal’ end has been delivered through the trephine, and consider marking the proximal end with an identifiable suture before delivery. 5 With a trephine sigmoid colostomy consider the following alternatives: • Combining flexible sigmoidoscopy and air insufflation with either laparoscopy, or a short midline laparotomy [1]; • Insufflating air via an enterotomy in the sigmoid loop toward the rectum to confirm the distal end [3]. • Occluding the bowel with a soft clamp and inflating air from the anus. However, this may be inadequate, as inflation of a redundant divided distal segment may increase intra-abdominal pressure sufficient to cause flatus to emerge from the proximal colon [2]. • an intra-operative water soluble contrast enema [5]. 6 Orientation of a trephine ileostomy is facilitated by identification of the antimesenteric fat in the distal few centimeters of terminal ileum and ⁄ or caecum. Before delivery through the trephine, the proximal loop is ideally orientated inferiorly to achieve an optimal spout. After delivery, the distal loop should be marked to ensure that the proximal and not the distal loop is spouted. 7 Laparoscopically assisted stoma formation aids identification of the terminal ileum or sigmoid and facilitates orientation, and is probably associated with less bleeding than the trephine method [6]. 8 If the stoma fails to function after 5–7 days, arrange a CT abdominal scan and, if necessary, a water-soluble contrast enema. Evolving large bowel obstructionmay be difficult to differentiate clinically from postoperative ileus.