Trauma
to the neck
In the majority of cases admitted to accident
and emergency centres the wound does not involve important neurovascular
structures but only skin, platysma and sternocleidomastoid or strap muscles. It
is, however, prudent to explore all of these wounds formally.
The cavity of the mouth or pharynx may have
been entered and the epiglottis may be divided via the pre-epiglottic space.
These wounds require repair with absorbable sutures on a formal basis under a
general anaesthetic. If there is any degree of associated oedema or bleeding,
particularly in relation to the tongue base or laryngeal inlet, it
is advisable to
perform a tracheostomy to avoid any subsequent respiratory distress.
Wounds
of the thyroid and cricoid cartilage
Blunt crushing injuries or severe laceration
injuries to the laryngeal skeleton can cause marked haematoma formation and
rapid loss of the airway. There may be significant disruption of the laryngeal
skeleton. These patients should not have an endotracheal intubation for any
length of time, even if this is the initial emergency way of protecting the
airway. The larynx is a delicate three-tiered
sphincter and the presence of a foreign body in its lumen after severe
disruption gives rise to major fibrosis and loss of laryngeal function. These
injuries are frequently an absolute indication for a low tracheostomy, following
which the larynx can be carefully explored and damaged cartilages repositioned
and sutured, and the paraglottic space drained. An indwelling stent of soft
sponge shaped to fit the
laryngeal lumen and held by a nylon retaining suture through the neck may be
left in place for approximately 5 days. This stent can be removed endoscopically after
cutting the retaining suture and as the laryngeal damage heals the patient may
then be decannulated.
Division
of the trachea
Wounds of the trachea are fortunately rare but
they should all be formally explored, and in order to obtain adequate exposure it
is usually
necessary to divide and ligate the thyroid isthmus. A small tracheostomy below
the wound and then repair of the trachea with a limited number of submucosal
sutures is appropriate. In self-inflicted wounds the recurrent laryngeal nerves,
which lie protected in the tracheo-oesophageal grooves, are rarely injured.
However, in stab wounds to the neck any nerve may be involved including the
vagus, recurrent laryngeal nerve or cervical sympathetic chain. Primary repair
is rarely possible but may be undertaken at the time of formal exploration of
a major neck wound.
Vascular
complications of cut throat
In contrast to nerve damage, vascular damage
can be severe. Major haemorrhagic shock may occur as a consequence of injury to
the common carotid, external or internal carotid, or a venous air embolism as a
result of damage to one of the major veins, most commonly the internal jugular.
Infection of large neck wounds is not uncommon, and cellulitis may supervene and
spread inferiorly to the mediastinum. Surgical emphysema may result if damage to
the trachea is not recognised and air escapes into the neck. Oesophageal and
pharyngeal fistula may occur but usually heal spontaneously. Aphonia or
dysphonia may follow injury to the vocal folds or division of the recurrent
laryngeal nerves. Stenosis of the trachea or larynx may be caused by scarring
from major injuries due to road traffic accident or attempted hanging.
Wounds
of the cervical portion of the thoracic duct
Wounds to the thoracic duct are fortunately
rare and most often occur in association with dissection of lymph nodes in the
left supraclavicular fossa. When damage to the duct is not recognised at the
time of operation, chyle may subsequently leak from wound in amounts up to 2
litres/day and, as a result, the patient may waste rapidly.
Treatment
Should the damage be recognised during an
operation, the proximal end of the duct must be ligated. Ligation of the duct is
not harmful because there is a number of anastomotic channels between the
lymphatic and venous system in the lower neck. If undetected, chyle usually
starts to discharge from the neck wound within 24 hours of the operation. On
occasions firm pressure by a pad and bandage to the lower neck may stop the
leakage but frequently this is unsuccessful and it is best to re-explore the wound and locate and ligate
the damaged duct. If the patient is given some cream to drink 2 hours before the
operation the cut end of the duct is more easily found just lateral to the lower
4 cm of the left internal jugular vein. If it proves impossible to find the duct, particularly in an
area of oedematous and fragile tissue, the wound can be packed firmly with a
Whitehead’s varnish pack and allowed to heal by granulation.