The incidence and pathogenesis of tracheal injury following tracheostomy with cuffed tube and assisted ventilation. Analysis of a 3-year prospective study.

Observations are reported from a 3-year prospective study of tracheal injury occurring in patients managed by cuffed-tube tracheostomy and assisted ventilation in the Respiratory Failure Unit at Toronto General Hospital. When the cuffed tracheostomy tube was finally removed an initial bronchoscopic examination of the trachea was performed. Further clinical and radiological assessments were made 3 weeks and 3 months later, using bronchoscopy when indicated. The incidence of symptomatic tracheal stenosis in 153 patients studied was 21 per cent. Of these strictures, 18 occurred at the level of the tracheostome and 14 at the level of the inflatable cuff. Disability due to airway obstruction was severe in 18 and mild in 14 patients. These mild lesions might easily have remained undetected. Two patients with severe strictures died of airway obstruction before treatment could be instituted, a mortality of 6·2 per cent in patients developing strictures. The remaining 30 strictures required treatment either by dialtation alone or by dilatation and resection of the stricture with tracheal reanastomosis. Two of the 153 patients studied developed chronic tracheo-oesophageal fistulas. The observations indicate that stenosis can be anticipated before the lesion has developed by the finding of circumferential mucosal ulceration or segmental collapse at the initial per stomal bronchoscopy. Observations from the study prompted the following changes in technique:- 1 1. A modification of the connexions between the tracheostomy tube and the respirator, with a subsequent reduction in symptomatic stenosis at the stomal level. 2 2. A reduction in the diameter of tracheostomy tubes. 3 3. A search for a less injurious inflatable cuff. The conclusions reached by this study were as follows:– 1 1. Tracheostomy tubes of large diameter predispose to the development of strictures at the level of the tracheostome in male patients. 2 2. The presence of airway infection predisposes to stomal stenosis, and probably to cuff stenosis. 3 3. Cuff strictures are commoner in female patients than in male patients. 4 4. Age and pre-existing lung disease may be important in the production of stomal stenosis. 5 5. The use of a deliberate routine follow-up examination to evaluate tracheal injury following tracheostomy and assisted ventilation is a necessary undertaking.