[Management of anastomotic fistula following excision of rectal cancer].

The risk of anastomotic leak after resection of cancers of the mid or low rectum with mesorectal excision is about 10%--the lower the colo-rectal or colo-anal anastomosis, the higher the risk of leak. If the fistula is asymtomatic and the leak is walled off, it is best to defer the closure of the diverting ileostomy for 2-3 months and to proceed only when a radiologic contrast study shows the fistula to have disappeared. More commonly, the anastomotic fistula presents as a pelvic abscess. It is simple and logical to drain the abscess into the digestive tube by enlarging the orifice of the fistula; this can usually be done with a brief general anesthetic. Less commonly, the abscess may present at some distance from the anastomotic leak; this calls for percutaneous drainage. If abscess drainage fails, if pelvic sepsis persists, or if the leak presents from the start as generalized peritonitis, laparotomy is called for in order to lavage the abscess cavity, place effective drains, and perform, if necessary, a diverting stoma upstream. Two strategies are possible: 1) drain placement at the leak site with upstream loop diverting stoma, or 2) takedown of the anastomosis, closure of the distal stump as a Hartmann pouch, and proximal end colostomy in the left lower quadrant. In the first instance, one must be sure the fistula has healed before stoma closure. In the second, the problem is to obtain (at a second stage) sufficient length of well-vascularized proximal colon to make an anastomosis to a short Hartmann pouch or to the anus in a pelvis scarred and inflamed by infection and radiation. A Soave procedure may allow an anastomosis with less risk to peri-rectal innervation and with less blood loss. Two maneuvers which may help to gain length are the Toupet technique for freeing the transverse mesocolon or the Deloyer technique of mobilizing the hepatic flexure. In the face of post-operative pelvic sepsis, an early intervention adapted to the circumstances will increase the chances of healing and reestablishment of intestinal continuity, and may avoid multiple complex interventions with poor functional results including incontinence, urgency, and difficult evacuation.