Ann. Medit. Burns Club - vol. VII - n. 3 - September 1994

TRACHEO-OESOPHAGEAL FISTULA AS A COMPLICATION IN EXTENSIVE BURNS WITH INHALATION INJURY

Padera L, Kenigova R, Hdjek M.

SUMMARY. Two patients with extensive bums and inhalation injury were treated in our Intensive Care Unit in 1992-93. The patients were artificially ventilated for three and two months respectively by means of tracheostomy. The long-term ventilation led to the developmerit of perforation of the trachea, complicated by a communication with the oesophagus.

Acquired tracheo-oesophageal fistulae are life-threatening conditions and represent a very difficult area of comprehensive therapy. The danger of fistulae is mainly represented by the risk of aspiration and subsequent infection, while at the same time the patient can become cachectic. The fact that some patients with a fistula can survive for a number of weeks or months does not decrease the risk of these conditions; on the contrary, prolonged survival worsens the prognosis of the operation.

The three most important local factors leading to a tracheal stenosis or a tracheo-oesophageal fistula are:

1. lesion of the tracheal mucosa due to inhalation injury;
2. tissue ischaemia due to pressure of an expanded endotracheal cuff;
3. repeated minor traumas during respiratory tract care.

However, much more important than local factors are the general aspects - mainly hypoxia, septic conditions affecting the respiratory tract, and the patient as a Whole. Most significant is the hypermetabolic state, with 4 low nutritional and protein index and continuing inummodeficiency related to a critical state.
The diagnosis of fistula is easily established, provided the possibility of its occurrence is considered. A prompt bronchoscopic and oesophagoscopic examination is indispensable.
Conservative treatment of acquired tracheo-oesophageal fistulae does not come into consideration at all. A palliative operation which we ourselves had previously tried in one patient (a gastrostomy) was disappointing because a gastro-oesophageal reflux led to flooding of the trachea and aspiration. Spontaneous closure of a fistula is unlikely.
An operation is indicated if the patient's prognosis is not hopeless as regards the basic diagnosis. All patients are at very high risk. The prognosis of recovery after reconstruction is more favourable in patients with controlled catabolism and without concomitant sepsis. Technically the operation is performed by preparation of the trachea and the oesophagus in the neck and chest region, using an auxiliary sternotomy. Both affected organs must be separated. Finally, a dermal graft is inserted between the two sutures.

We report on two patients with extensive burns (84% and 91% TBSA) and inhalation injury treated in our Intensive Care Unit.
Case 1. A 23-year-old female sustained burns involving the face, neck, trunk, upper and lower extremities, and the respiratory tract, with TBSA 91% (61% full-thickness burns). On day 6 post-burn (p.b.) tracheostomy was performed and necrectomies were started; raw areas were covered with xenografts and subsequently allografts from the patient's sisters, in combination with autografting. These procedures were successful. Because of positive bacteriological findings in the tracheostomic tube certain antibioties were applied (Tab. 1).

On day 26 p.b. a greenish fluid was aspirated from the tracheostomic tube which suggested a gastric content. During oesophagoscopie examination a large fistula was found in the upper part of the oesophagus.
On day 59 p.b. some of the allografts were rejected.
On day 66 p.b. surgical closure of the fistula was carried out.
On day 70 p.b. greenish fluid again appeared in the tracheostomic tube.
On day 74 p.b. a massive bleeding occurred in the respiratory tract owing to rupture of the necrotic wall of the external carotid artery. This haemorrhage was the immediate cause of death, eight days after the operation on the fistula, which was a pressure sore due to the long-term tracheostomic tube. This was confirmed on necroscopy.
Case 2. A 22-year-old male sustained burns involving the face, neck, trunk, upper and lower extremities, and the respiratory tract, with TBSA 84% (70% full-thickness burns). Partial pressure of oxygen at 10 to 15 kilopascals was reached only when the concentration of oxygen in the inspiratory air was maintained at 40 to 70%.
On day 2 p.b. fibrobronchoscopic examination of the respiratory tract was made, with the finding of whitish slime with soot covering the wall of the terminal subsegments of the airways. An important laboratory result was a significant decline of blood platelets (60,000).
On day 9 p.b. tracheostomy was required, followed by necrectomy with xenografting, allografting and autografting.
On day 30 p.b. a green fluid was aspirated from the tracheostomic tube. On oesophagoscopic examination a fistula at 10 to 15 mm was again discovered.
Two days later (day 32 p.b.) the fistula was sutured. After one week the patient developed pneumonia and ileus. Conservative treatment was not successful and gastrostomy according to Witzel was carried out. Hyperpyrexia (40 to 41'C) continued after the surgical procedures and on day 59 p.b. the patient died (27 days  after the fistula operation). Necropsy showed relapse of the tracheo-oesophageal fistula at 15 to 40 mm, inflammation of the oesophagus and trachea, bronchopneumonia, ileus, gastric ulcer, perforation of the right colic flexure and diffuse peritonitis. The general condition of this patient was very poor, for which reason we did not re-operate.

Burned patients with inhalation injury often develop decreased lung compliance due to the adult respiratory distress syndrome with a different pathophysiology. This results in upper airway pressure, and a higher intracuff pressure is needed to maintain the cuff's sealing effect. Prolonged intubation is necessary in these patients. The presence of a wide-bore gastric tube causes pressure on the sandwiched mucosa between the cuff of the tracheal tube and the gastric tube.

Excessive motion of the tracheal tube during frequent dressing changes and respiratory care is another predisposing factor. Local infection worsens the mucosal damage, resulting in perforation. The duration of artificial ventilation by means of a tracheal tube in these patients exerts a basic influence on the occurrence of this complication.

RESUME. Les auteurs décrivent deux patients atteints de brûlures étendues et de lésions aux voies respiratoires traités dans leur centre de réanimation en 1992-93. Les patients étaient maintenus en ventilation artificielle pour trois et deux mois respectivement, moyennant la trachéostomie. La ventilation à long terme a causé le développement de la perforation de la trachée, aggravée par la complication de la communication avec l'oesophage.

1. Tan K.K., Lee J.K., Tan L, Sarvesvaran R.: Acquired tracheo-oesophageal fistula following tracheal intuba,tion in a burned patient. Bums, 19:360,1993.