OPERATIONS ON AIR PASSAGES.
OPERATIONS ON THE LARYNX AND TRACHEA.--The great air passage may be
opened at three different situations, and to the operations at these
different places the following names have been given:--
_Laryngotomy_, when the opening is made in the interval between the
cricoid and thyroid cartilages, through the crico-thyroid membrane.
_Laryngo-tracheotomy_, when the cricoid cartilage and the upper ring of
the trachea are divided.
_Tracheotomy_, when the trachea itself is opened by the division of two,
three, or more rings.
Of these the last, _tracheotomy_, is by far the most frequent,
important, difficult, and dangerous, and requires a very detailed
description. Chassaignac[127] says "the only really rational operation
for the opening of the air passages by the surgeon is tracheotomy."
TRACHEOTOMY.--_Anatomy._--Between the cricoid cartilage and the level of
the upper border of the sternum, the middle line of the neck is occupied
by the upper portion of the trachea. Its depth from the surface varies,
gradually increasing as the trachea descends, and varying very much
according to the fatness, muscularity, and length of the neck. It is,
however, almost subcutaneous at the commencement below the cricoid, and
on the level of the sternum it is in most cases at least an inch from
the surface, in many much deeper. Again, its length varies, even in the
adult, from two and a half to three, or even four inches. This is
important, as affecting the simplicity of the operation, which, as a
rule, is easier the longer the neck is.
The trachea has most important and complicated anatomical
relations--some constant, others irregular.
1. The carotid arteries and jugular veins lie at either side, but, where
these are regular in their distribution, do not practically interfere in
a well-conducted operation.
2. The thyroid gland lies in close relation to the trachea, one lobe
being at each side (Fig. XXXI. B B), and the isthmus of the thyroid
crosses the trachea just over the second and third cartilaginous rings.
In fat vascular necks, or where the thyroid is enlarged it may occupy a
much larger portion of the trachea. The position of the isthmus
practically divides the trachea into two portions in which it is
possible to perform tracheotomy. Both have their advocates, but the
balance of authority tends to support the operation below the thyroid. A
separate notice of each will be required immediately.
[Illustration: FIG. XXXI.[128]]
3. The _muscles_ in relation to the trachea are the sterno-hyoid and
sterno-thyroid of each side. The latter are the broadest, are in close
contact across the trachea by the inner edges below, but gradually
diverge as they ascend the neck. In thick-set, muscular necks, however,
they are in close contact for a considerable distance, and require to
be separated to give access to the trachea.
The _arteries_ are in most cases unimportant; no named branch of any
size ought to be divided in the operation. However, occasionally very
free bleeding may result from the division of an abnormal _thyroidea
ima_ running up the trachea to the thyroid body from the innominate, or
even from the aorta itself.
The _veins_ are very numerous and irregularly distributed. There is
generally a large transverse communicating branch between the superior
thyroid veins just above the isthmus. The isthmus itself has a large
venous plexus over it. Below the isthmus the veins converge into one
trunk (or sometimes two parallel ones) lying right in front of the
trachea.
4. The last anatomical point which may give trouble in normal necks is
the thymus, which is present in children below the age of two, and
covers the lower end of the trachea just above the level of the sternum.
Where this is not only not diminished, but enlarged, as it sometimes is
in unhealthy children, it may give a very great deal of trouble, rolling
out at the wound and greatly embarrassing proceedings.
Abnormalities are very various and sometimes very dangerous: vessels
crossing the trachea, as the innominate did in Macilwain's case,[129] or
where two brachiocephalic trunks are present, as recorded by
Chassaignac.[130] One of the most frequent dangers to be guarded against
is a possible dilatation of the aorta or aneurism of the arch. This may
very possibly, as happened in one case to the author, give rise to
suffocative paroxysms from its pressure on the recurrent laryngeal
nerves. Tracheotomy may be deemed necessary, and there is a great risk,
unless proper precautions be taken, of wounding the aorta, where it
passes upwards in the jugular fossa. In the author's case the vessel had
actually to be pushed downwards by the pulp of the forefinger while the
trachea was opened, the knife being guided on the back of the nail of
the same finger.
THE OPERATION.--In a work of this kind it would be utterly impossible to
go at all into the subject of what diseases, injuries, etc., warrant or
require the operation. It is enough to describe the various methods of
operating, their dangers and difficulties.
1. _The operation above the isthmus of the thyroid._--A spot about a
quarter or half of an inch in vertical diameter between the cricoid
cartilage (Fig. XXXI.) and thyroid isthmus.
_Advantages._--It is near the surface, the vessels are few and
comparatively small. It is most suitable in cases of aneurism.
Professor Spence[131] gives his sanction to the high operation in adults
with thick short necks when the operation is performed for ulceration or
papilloma of larynx or for spasm from aneurism, the low operation being
still best in cases of croup or diphtheria.
_Disadvantages._--The space is too small, requires very considerable
disturbance of the thyroid isthmus, or actual division of it. It is too
near the point where the disease is; so much so, that in most cases of
croup or diphtheria it would be perfectly useless. However, if required,
or if the operation lower down be contra-indicated, this may be
performed easily enough. A straight incision being made in the middle
line about one inch and a half in length, expose the upper ring by
careful dissection, if possible draw aside the veins, and depress the
thyroid isthmus, divide the rings thus exposed, and introduce the tube.
_The operation below the isthmus._--This, though more difficult in its
performance, is a much more scientific and satisfactory operation.
Considerable coolness and a thorough knowledge of the anatomy of the
part are absolutely required.
The patient being in the recumbent posture, the shoulders should be well
raised, and the head held back so as to extend the windpipe, and thus
bring it as near as possible to the surface. A pillow, or the arm of an
assistant, behind the neck will be of service.
_N.B._--Be careful lest too great extension by an anxious assistant,
accompanied by closure of the mouth, should choke the patient (whose
breathing is of course already much embarrassed) before the operation be
begun.
Chloroform may occasionally be given, and, if well borne, renders the
operation very much easier than it would otherwise be. An incision must
then be made exactly in the median line of the neck, from a little below
the cricoid cartilage, almost to the upper edge of the sternum; at first
it should be through skin only, then the veins will be seen, probably
turgid with dark blood; the larger ones should be drawn aside, if
necessary divided, the bleeding stopped by gentle pressure. The deep
fascia must then be cautiously divided, great care being taken to keep
exactly in the middle line, and the contiguous edges of sterno-thyroid
muscles separated from each other by the handle of the knife. A quantity
of loose connective tissue, containing numerous small veins, must now be
pushed aside, the thyroid isthmus pressed upwards, still with the handle
of the knife. The forefinger must then be used to distinguish the rings
of the trachea. If there is much convulsive movement of the larynx and
trachea, they should be fixed by the insertion of a small sharp hook
with a short curve, just below the cricoid cartilage, and this should be
confided to an assistant. The surgeon should then, with the forefinger
of his left hand, fix the trachea, and open it by a straight
sharp-pointed scalpel, boldly thrusting it through the rings with a jerk
or stab, the back of the knife being below, and divide two or three of
the rings from below upwards. Any attempt to enter the trachea slowly
with a blunt knife or trocar will probably be unsuccessful, as the
rings, especially in children, give way before the knife, which merely
approximates the sides of the trachea without opening it.
_Question of Hæmorrhage._--It is often a question of some importance,
and one which sometimes it is not easy to settle, how far attempts
should be made completely to arrest the venous hæmorrhage before opening
the trachea.
_On the one hand_, if not arrested, besides the risk of weakening the
patient, we have to dread the much more serious complication of the
admission of blood into the wound. And this is very serious in a patient
whose respiration has already been much impeded, whose lungs are
probably engorged, and who has certainly, by the mere existence of a
wound in his trachea, lost the power of coughing properly; it must never
be forgotten that a quantity of blood so trifling as to be at once
ejected by a single cough in the case of a healthy chest, may be a fatal
obstacle to respiration in one already weakened by disease. Thus any
well-marked arterial hæmorrhage from cut branches, or from the isthmus
of the thyroid, must certainly be arrested prior to opening the trachea.
Besides this, blood once having entered the bronchi is apt to extend
into their smaller ramifications and prove a cause of death, by acting
as a local irritation, and setting up intra-lobular suppurative
pneumonia. The author has found this to be the case both after
tracheotomy and still more frequently in suicide by cut throat.
But, _on the other hand_, it is equally true that there is almost always
a considerable amount of oozing from small venous radicles divided
during the operation, which depends simply on the great venous
engorgement resulting from the obstruction to the respiration, so that
while to attempt to tie every point would be simply endless, we may be
almost certain that the oozing will cease whenever the trachea is
opened, and respiration fairly improved. Slight pressure on the wound is
generally sufficient to stop the bleeding till the venous engorgement
has disappeared.
Of late years many tracheotomies have been done bloodlessly by use of
the thermo-cautery, for division of the soft parts, but the subsequent
sloughing of the wound is a great objection to this method.
In cases of extreme urgency, all such minor considerations as
suppression of venous oozing must be ignored, and the trachea simply
opened as rapidly as possible. I had once to perform the operation after
respiration had entirely ceased, and no pulse could be felt at the
wrist, with no assistance except that of a female attendant. Merely
feeling that no large arterial branch was in the way, I cut straight
through all the tissues, opened the trachea, and commenced artificial
respiration. The patient eventually recovered.
_Question of Tubes, etc._--Once the trachea is opened, the next question
is, How is the opening to be kept pervious? For the moment the handle of
the scalpel is to be inserted in the wound, so as to stretch it
transversely; this will probably suffice to allow of the escape of any
foreign body. But where, to admit air, the wound is to be _kept_ open,
how is this to be done? It used to be advised that an elliptical portion
of the wall of the trachea be removed; this, though succeeding well
enough for a time, was unscientific, as the wound always tended to
cicatrise, and ended of course in permanent narrowing of the canal of
the trachea. It may be necessary thus to excise a portion of the
trachea, in cases where it is very intolerant of the presence of a
tube. Such a case is recorded by Sir J. Fayrer of Calcutta.[132] Not
much better is the proposal to insert a silk ligature in each side of
the wound, and by pulling these apart thus mechanically to open the
wound. This also is evidently a merely temporary expedient.
Various canulæ and tubes have been proposed. The ones recommended by the
older surgeons had all one great fault; they were much too small, and
were many of them straight, and thus liable to displacement. The
smallness of their bore was their greatest objection, and Mr. Liston
conferred a great benefit on surgery by his insisting upon the
introduction of tubes with a larger bore, and with a proper curve, so as
thoroughly to enter the trachea. The tube ought to be large enough to
admit all the air required by the lungs, without hurrying the
respiration in the least.
There is a mistake made in the construction of many of the tubes even of
the present day; the outer opening is large and full, while for
convenience of insertion the tube tapers down to an inner opening,
admitting perhaps not one-half as much air as the outer one does.
It must be remembered that for some days there is great risk of the tube
becoming occluded, by frothy blood or mucus, especially in cases of
croup, and in children. To prevent this a double canula will be found of
great service, providing only that it be remembered that the inner
canula, not the outer merely, is to be made large enough to breathe
through, and that the inner should project slightly beyond the outer
one.
The inner one can thus be removed at intervals and cleansed, by the
nurse, without any risk of exciting spasm or dyspnoea by its absence
and reintroduction.
_After-treatment._--The after-treatment of a case in which tracheotomy
has been performed demands great care and many precautions. For the
first day or two the constant presence of an experienced nurse or
student is always necessary to insure the patency of the tube. The
temperature of the room should be equable and high, and it seems of
importance that the air should be kept moist as well as warm by the use
of abundance of steam.
A piece of thin gauze, or other light protective material, should be
placed over the mouth of the tube, to prevent the entrance of foreign
bodies.
In cases where the operation has been performed for some temporary
inflammatory closure of the air passage, retention of the tube for a few
days may suffice. It may then be removed, but it must be remembered that
the wound will generally close with great rapidity, so that it is as
well to be quite sure of the patency of the natural passage before the
artificial one is allowed to close by the removal of the tube.
In cases where from long-standing disease or severe accident the larynx
is rendered totally unfit for work, and the tube has to be worn during
the rest of the patient's life, care must be taken (1.) lest the tube do
not fit accurately, in which case it may ulcerate in various directions,
even into the great vessels;[133] (2.) lest the tube become worn, and
lest the part within the windpipe fall into the trachea and suffocate
the patient.[134]
LARYNGOTOMY.--As a temporary expedient in cases of great urgency, where
proper instruments and assistants are not at hand, laryngotomy is
occasionally useful, though from the want of space without encroaching
on the cartilages of the larynx, and from its close proximity to the
disease, laryngotomy is by no means a suitable or permanently successful
operation.
In the adult, especially in males with long spare necks, the operation
itself is exceedingly easy to perform. The crico-thyroid space (Fig.
XXXI. A) is so distinctly shown by the prominence of the thyroid
cartilage, and is so superficial that it is quite easy to open it in the
middle line with a common penknife, there being merely the skin and the
crico-thyroid membrane to be cut through, with very rarely any vessel of
any size. The opening can then be kept patent by a quill or a small
piece of flat wood. This simple operation has in many cases, where a
foreign body has filled up the box of the larynx, succeeded in saving
life, and even in cases of disease I have known it useful in giving time
for the subsequent performance of tracheotomy.
Easy as it appears and really is, cases are on record in which the
thyro-hyoid space has been opened instead of the crico-thyroid, such
operations being of course perfectly useless.
The incision is best made transversely.
LARYNGO-TRACHEOTOMY.--This modification consists in opening the air
passage by the division of the cricoid cartilage vertically in the
middle line, along with one or two of the upper rings of the trachea.
It seems to combine all the dangers with none of the advantages of the
other methods of operating. It is close to the disease, involves cutting
a cartilage of the larynx, and almost certain wounding of the isthmus of
the thyroid; and it is not easy to see what corresponding advantages it
has over tracheotomy in the usual position.
THYROTOMY is an operation by which the larynx is opened in the middle
line by a vertical incision, and its halves separated, while any morbid
growths are excised from the cords or ventricles. The merits and dangers
of this operation have been discussed at length by Mr. Durham[135] and
Dr. Morell Mackenzie.[136]
LARYNGECTOMY OR EXCISION OF THE LARYNX, first performed by Dr. Heron
Watson in 1866, has been lately frequently performed for carcinoma and
sarcoma. Each case presents its own difficulties, which vary according
to the amount and extent of the disease for which it is done.
The trachea must be divided and tamponed by a Trendelenburg canula,
after which the larynx must be carefully dissected out. The immediate
mortality, _i.e._ in first ten days, is fifty per cent., and Dr. Gross
holds that life has not been prolonged by the operation.[137]
OESOPHAGOTOMY.--This operation is very rarely required, and has as yet
been performed only for the removal of foreign bodies impacted in the
oesophagus, and interfering with respiration and deglutition. To cut
upon the flaccid empty oesophagus in the living body would be an
extremely difficult and dangerous operation, from the manner in which it
lies concealed behind the larynx, and in close contact with the great
vessels. When it is distended by a foreign body, and specially if the
foreign body has well-marked angles, the operation is not nearly so
difficult. It has now been performed in forty-three cases at least, of
which eight or nine have proved fatal. Seven, along with another in
which he himself performed it with success, were recorded by Mr. Cock of
Guy's Hospital.[138] Three others were performed by Mr. Syme, with a
successful result. Of the seven cases collected by Mr. Cock only two
died, one of pneumonia, the other of gangrene of the pharynx.
_Operation._--Unless there is a very decided projection of the foreign
body on the right, the left side of the neck should be chosen, as the
oesophagus normally lies rather on the left of the middle line. An
incision similar to that required for ligature of the carotid above the
omohyoid should be made over the inner edge of the sterno-mastoid
muscle; with it as a guide, the omohyoid may be sought and drawn
downwards and inwards, the sheath of the vessels exposed and drawn
outwards, the larynx slightly pushed across to the right, the thyroid
gland drawn out of the way by a blunt hook, the superior thyroid either
avoided or tied. The oesophagus is then exposed, and if the foreign
body is large, it is easily recognised; if the foreign body be small, a
large probang with a globular ivory head should then be passed from the
fauces down to the obstruction; this will distend the walls of the
oesophagus, and make it a much more easy and safe business to divide
them to the required extent. The wound in the oesophagus should be
longitudinal, and at first not larger than is required to admit the
finger, on which as a guide the forceps may be introduced to remove the
foreign body, or, if necessary, a probe-pointed bistoury still further
to dilate the wound.
For some days or even weeks the patient must be fed through an elastic
catheter introduced through the nose and retained, or by an ordinary
stomach-tube through the mouth. In introducing the latter there is
always a risk of opening the wound. No special sutures for the wound in
the oesophagus are required, nor is it advisable too closely to sew up
the external wound.
FOOTNOTES:
[127] _Leçons sur la Trachéotomie_, p. 10.
[128] Rough diagram of larynx and trachea:--A, crico-thyroid space,
_laryngotomy_; B B, dotted outline of thyroid isthmus and lobes, defines
the upper and lower positions for _tracheotomy_; C, thyroid--D, cricoid
cartilages; E, dotted outline of thymus gland in child of two years; F
F, outline of clavicles and jugular fossa.
[129] _Surgical Observations_, p. 335. See also Harrison _On the
Arteries_, vol. i. p. 16.
[130] _Leçons sur la Trachéotomie_, p. 9.
[131] _Lectures on Surgery_, 3d ed., vol. ii. p. 900.
[132] _Clinical Surgery in India_ (1866), p. 143.
[133] Mr. John Wood, _Path. Soc. Trans._, vol. xi. p. 20.
[134] South's _Chelius_, vol. ii. p. 400; and case recorded by Spence,
in _Ed. Med. Journal_, for August 1862.
[135] _Med. Chir. Transactions of London_, 1872.
[136] _British Med. Journal_ (Nos. 643, 644), 1873.
[137] Gross's _Surgery_, 6th ed., vol. ii. p. 342.
[138] _Guy's Hospital Reports_ for 1858.