200 THE LARYNX, BRONCHI AND OESOPHAGUS
Tracheostomy> if done correctly, carries no morbidity. In the newborn or
infant, however, it is a difficult operation and is fraught with danger. The
diameter of an infant trachea is less than that of the adult's little finger.
During the procedure a high subclavian vein or the bulging of pleura into the
suprasternal area may force the surgeon to open the trachea at a higher level
than usual. Damage to the first tracheal ring or the cricoid is not uncommon
if an inexperienced operator performs a tracheostomy in an infant.
Laryngeal paralysis may be congenital and associated with other anomalies of
the central nervous system, the heart and great vessels, the trachea or the
oesophagus. Birth injury is not a common cause. The paralysis may be
unilateral or bilateral, the latter being twice as common as the former. In
unilateral paralysis the presenting feature is slight stridor and a weak cry.
The most severe stridor is seen in bilateral incomplete paralysis. A complete
account of the causes and management are given in Chapter 38. The only way
to diagnose this condition and to assess the effect of the paralysis is to do a
direct laryngoscopy under local anaesthesia, or with no anaesthesia, and to
watch the cords during crying.
Congenital cysts of the larynx occur as developmental anomalies in the
ventricle and saccule, as true retention cysts of the supraglottis and as
laryngoceles. They project into the laryngeal lumen and produce dysphonia
and stridor in proportion to their size. Small cysts can be uncapped and
drained at direct laryngoscopy but larger cysts will require to be dealt with
using suspension laryngoscopy and the techniques of microlaryngeal surgery.
Laryngoceles (Plate VIIIy 3) are very rare and usually require no treatment in
Congenital haemangioma and lymphangioma are usually found in the
subglottic area or on a vocal cord and are only distinguishable histologically.
A purplish subglottic swelling may either be a haemangioma of the subglottis
or an indentation and erosion of the subglottis by an abnormal vessel or
aneurysxn. Because of this no biopsy or removal should be attempted until the
situation has been more fully assessed by angiography. It is unusual to have to
remove subglottic lymphangiomas or haemangiomas surgically since they
usually regress on their own. If they cause stridor it is better to irradiate them
because surgery in the infant subglottis will almost certainly lead to laryngeal
stenosis. If the tumours are on the vocal cord the cry will be hoarse and they
can be removed with little difficulty at direct laryngoscopy.
Multiple papUhmata are the most common laryngeal tumours in children
but in the whole spectrum of laryngeal disease they are rare. They may be
present at or soon after birth but more commonly they arise about the age of
2 years. Their cause is unknown but it is probable that they are due to a virus,
not unlike tliat which causes warts elsewhere on the body. Strength is given
to this theory by tbe fact that they are implantable, especially down the
trachea after numerous intubations, and they are also transmissible since