Intestinal fistulae

An intestinal fistula is an abnormal track, usually lined by granulation tissue, between the gut and the skin. Fistulae are unusual but serious complications of abdominal surgery, and occasionally arise spontaneously as the result of disease. Beware of postoperative fistulae: (1) After you have divided adhesions for intestinal obstruction, especially if you have opened the gut by mistake, and closed it inadequately, or if it is obstructed distally. (2) When you have anastomosed it inaccurately, or in the presence of tension, a poor blood supply, or local disease. (3) If gut is caught in the sutures, especially tension sutures, when you close the abdomen. (4) After appendicectomy (a caecal fistula). (5) After crushing the spur of a double-barrelled colostomy.

Don't try to operate yourself. Even in good hands the mortality rate of a high output fistula ([mt]1500 ml/24 hours) is 70%, and a low output one 30%. The repair of a fistula is one of the most difficult operations in surgery.

SUDHA (25 years), a young housewife had an operation in a district hospital for ''appendicitis' through a McBurney incision. Five days after the operation the wound discharged large quantities of pus, and then liquid faeces and gas. She was fed on a low-residue diet, and the skin round the fistulous opening was painted and protected with zinc oxide paste. Absorbent dressings were changed 3 times a day and her distal colonic obstruction due to constipated faeces was treated with glycerine suppositories and a plain water enema. The fistula healed in 2 weeks and she went home. LESSON Some fistulae will close on nonoperative treatment. They are more likely to do so if there is no obstruction distal to the internal opening of the fistula.

INTESTINAL FISTULAE If pus or intestinal contents discharge from the main wound, or the site of a drain postoperatively, suspect that a fistula is forming. If the patient says that gas comes out, this confirms it; so does charcoal, given orally, appearing in the wound, or an X-ray with contrast medium (a fistulogram). If necessary, insert a plastic tube into the track and inject 10 to 20 ml of water-soluble contrast medium.

TREATMENT is supportive.

Replace fluid and electrolytes, orally, intravenously (15.5), or by jejunostomy (9.7). He may need large quantities of electrolytes.

Maintain his nutrition, orally, or by jejunostomy. You are unlikely to have the protein and energy-rich fluids to give him intravenously.

Care for his skin, by keeping the contents of his gut away from it, with adequate drainage, if necessary with a sump drain (4-11), by nursing him prone, as in Fig. 9-13, and by applying karaya gum or zinc oxide to his skin.

Control infection with antibiotics and drainage, when necessary.

Keep his distal colon empty, with saline enemas and glycerine suppositories on alternate days.

REFER HIM if: (1) His fistula discharges [mt]1500 ml/day for [mt]3 days. (2) It has not closed after 3 weeks of non- operative management. (4) He is very ill. (5) It is high[md]oral charcoal appears within 15 minutes. (6) A fistulogram shows communication with his duodenum or jejunum. (7) He does not pass faeces or flatus for 5 days.

THE INDICATIONS FOR OPERATION are: (1) A high output fistula [mt]1500 ml/24 hours. (2) Distal obstruction. (3) A drain abscess. (4) Failure to close after 3 weeks of non-operative treatment. (5) Disease of the fistula track, as with tuberculosis or a foreign body. (6) Intestinal mucosa pouting on to the skin.

Mr Printer. There are two ''not in series' figures ''That must be the new doctor' and ''Mr Y is asking to have his whole gut irrigation with beer' that can be taken in on the first double page spreads in this chapter or the next that would otherwise have no figures.

10 The acute abdomen: intestinal obstruction