tape carrier by braided silk thread.
Progressively larger sizes of rubber tubing are used as the laryngeal
lumen increases in size under the absorptive influence of the
continuous elastic pressure of the rubber. Several months of wearing
the tube are required until dilatation and epithelialization of the
open trough thus formed are completed. Painstaking after-care is
essential to success. When dilatation and healing have taken place,
the laryngostomy wound in the neck is closed by a plastic operation to
convert the trough into a trachea by supplying an anterior wall.

_Intubational treatment of chronic laryngeal stenosis_ may be tried in
certain forms of stenosis in which the cicatrices do not seem very
thick. The tube is a silver-plated brass one of large size (Fig. 110).
A post which screws into the anterior surface of the tube prevents its
expulsion. Over the post is slipped a block which serves to keep open
the tracheal fistula. Detailed discussion of these operative
treatments is outside the scope of this work, but mention is made for
the sake of completeness. Before undertaking any of the foregoing
procedures, a careful study of the complete descriptions in Peroral
Endoscopy is necessary, and a practical course of training is
advisable.

[FIG. 110.--The author's retaining intubation tube for treatment of
chronic laryngeal stenosis. The tube (A) is introduced through the
mouth, then the post (B) is screwed in through the tracheal wound.
Then the block (C) is slid into the wound, the square hole in the
block guarding the post against all possibility of unscrewing. If the
threads of the post are properly fitted and tightly screwed up with a
hemostat, however, there is no chance of unscrewing and gauze packing
is used instead of the block to maintain a large fistula. The shape of
the intubation tube has been arrived at after long clinical study and
trials, and cannot be altered without risk of falling into errors that
have been made and eliminated in the development of this shape.]

[309] CHAPTER XXXIX--DECANNULATION AFTER CURE OF LARYNGEAL STENOSIS

In order to train the patient to breathe again through the larynx it
is necessary to occlude the cannula. This is best done by inserting a
rubber cork in the inner cannula. At first it may be necessary to make
a slot in the cork so as to permit some air to enter through the tube
to supplement the insufficient supply obtainable through the
insufficiently patulous