TRACHEO-LARYNGEAL OPER ATIONS.
Thyrotomy.—Thyrotomy is calculated to expose freely the interior of the larynx for the removal of foreign bodies and tumors. To admit air into the respira tory tract, however, in diphtheria, laryn geal cedema, etc., it is not satisfactory, as a rule, being too close to the lesion for the relief of which it is practiced. When a foreign body is impacted above the vocal cords and cannct be removed from above, it not only facilitates breathing, but also the removal of the offending mass. Tumors of the larynx, when situ ated within the larynx proper, are brought within easy access, and may be thoroughly scraped off.
The operation consists in a vertical in cision through the skin in the median line and splitting of the thyroid carti lage underneath. Care should be taken to open the latter at the junction of the two alm. A sharp and strong bistoury is required. In some cases the cartilage is ossified and a fine saw must be em ployed. The operation is comparatively bloodless.
There is always danger of impairing the voice, and it is advisable to close the wound as early as possible. Some oper ators, when the larynx has been cleared of tumors, and when air must be arti ficially admitted into the trachea, extend the incision, performing a laryngo tracheotomy in addition to the thy rotomy, close up the thyroid wound, and insert the tube below.
Laryngotomy.—In case of emergency —i.e., when through the presence of a foreign body, an injury, oedema, etc., air must artificially be admitted into the larynx—this operation is very satisfac tory. It consists in an incision through the cricothyroid membrane, in the me dian line from the thyroid cartilage down to the first tracheal ring. After incising the skin and on reaching the cricothyroid membrane beneath, an ar tery — the cricothyroid — is met with; this should be pushed aside and the membrane incised perpendicularly. In doing this care should be taken to pene trate the tracheal mucous membrane, which tends to become detached and sac culated, thus blocking the trachea. A small tracheotomy-tube should be used, and removed as early as practicable, ne crosis of the cricoid or thyroid cartilages being otherwise likely.
Laryngo-tracheotomy. — When in lar pagotomy the operation is extended so as to include the cricoid cartilage and the first ring of the trachea—not lower, lest the isthmus of the thyroid body be encountered—the procedure becomes a laryngo-tracheolomy. When the patient is on the verge of asphyxia, technical nicety must sometimes be sacrificed to the urgency of the case. The trachea must immediately be opened whether hmmorrhage be feared or not, by a per pendicular incision in the skin and one a little shorter through the walls of the trachea. If nothing but a pen-knife is at hand, this may be used when cleansed, and two hair-pins bent flatwise into let ters S may be employed as hooks to keep the wound gaping while the patient's respiration becomes normal. Before in cising the skin, however, it is always well to trace lightly, with a soft pencil, the site of the incision: i.e., the middle line. Tf this precaution is neglected, the in cision is almost always irregular; indeed, the knife may not enter the trachea at all, but suddenly plunge to one side of it. When the outline of the incision is drawn, the skin should be held firmly down in its proper place with the thumb and middle finger of the left hand, while the right does the cutting. The isthmus of the thyroid should be avoided if pos sible, but this is often difficult. owing to the short distance between it and the cricoid cartilage above.
Tracheotomy.—The various conditions in which this operation is indicated may be divided into three classes: 1. Those in which a morbid process suddenly or gradually reduces the laryngeal lumen and involves the probability of asphyxia, such as diphtheria, croup, oedema, pa ralysis, malignant disease, etc. 2. Those in which physiological rest tends to re duce the activity of the morbid process and delay its progress, such as laryngeal tuberculosis and syphilis. 3. Those in which an impacted foreign body cannot be removed through the glottis.