Abstract
Clinical cases of tracheal stenosis were investigated to study the cause of it. One hundred and eighty-two cases of tracheal stenosis were experienced (according to the data from the division of otorhinolaryngology of 37 universities) between January 1974 and July 1978. Of these cases, about 50% was caused by tracheotomy and about 20% was caused by wounds, of which 60% was caused by traffic accidents.
In order to examine the vessels in the tracheas of rabbits, latex was injected into the aortasof 11 rabbits, and the following results were obtained. The tracheoesophageal arteries of rabbits are branched from right and left longitudinal tracheoesophageal arteries (tentatively named). The right one is branched from the right subclavian artery and the left one from the left common carotid artery. There were some variations at the bifurcation of the left longitudinal tracheoesophageal artery. The branches of the longitudinal tracheoesophageal arteries were ligated at 2 to 4 sites on each side of the right and left, but there was no change in the trachea. There were many vessels in the tracheal mucosa, and the anastomoses were very complicated. It was considered that there was no problem in hemodynamics in the cases of end-to-end anastomosis.
Curettage of tracheal mucosa, tracheotomy, intubation and crushing of trachea were conducted in rabbits and rats. Curettage of the whole circumference of tracheal mucosa did not result in stenosis. Regarding a cannula used for tracheotomy, its shape and size rather than its material are important factors for tracheal stenosis under the consideration of its fitness to the tracheal lumen. Using a tube with cuffs, inflammation of the trachea reaching to the perichondrium was already observed 10 hours after the intubation. When the cannula used was too large, necrosis and desquamation of the whole layers of mucosa, formation of pseudomembrane and respiratory obstruction were observed, even though the application time was short. When tracheal cartilages of more than 3 annuli were crushed, severe stenosis occurred. However, deformation and stenosis will be protected against to some degree if a T-tube, for example, is inserted in time into the crushed site.
