according to the number and combination of persistent tunics, and we
read of the mixed internal and the mixed external type. These points
have less clinical importance, however, than a proper appreciation of
the size and shape of a tumor, because all aneurisms are false after
they exceed a certain size. When an aneurism involves the entire
periphery of the aorta, it may be cylindrical, fusiform, or globular in
shape, and receive names accordingly. When it is a mere bulging on one
side of the artery it is saccular in shape. Obviously, the opening into
the fusiform aneurism is quite or nearly the entire length of the
tumor, whereas in the false saccular type the orifice may be reduced to
a mere puncture of the arterial wall. The size of the orifice is a
matter of great importance, particularly in connection with the
question of operative interference, and therefore it will be referred
to later. The sacciform and fusiform aneurisms are often combined
together, or, in other words, it is quite common to find a lateral
bulging superimposed upon a local dilatation of the artery; but such
grouping is not necessary, as either form appears {802} without the
other. It is not uncommon also to find one bulbous aneurism
superimposed upon another, the dependent aneurism in this case being of
the false or diffuse type. The second aneurism often lies outside the
chest-wall, and it is connected with the mother aneurism by a narrow
opening or channel.
Varicose aneurism is a false aneurism formed by communication between
the aorta and the vena cava, the pulmonary artery, the right auricle,
or the right ventricle. It is almost without exception rapidly fatal
and not amenable to treatment.
Occasionally the aorta will present alternate bulgings upon one side
and the other, so that the vessel appears to wind in its course. This
condition is called cirsoid aneurism, but it has nothing in common with
external aneurism of the same name.
The size of an aneurism is variable, like its shape, but in general the
true aneurism rarely exceeds the size of an egg (Jaccoud). Beyond this
size one or more of the coats give way, and the aneurism becomes false,
in which condition it may grow as large as an adult's head if the
patient lives long enough to allow such development. Balfour refers to
two rare forms of aneurism--the intravalvular, which is situated within
the aortic valves and above the ventricle, and the intervalvular, which
is still more rare, and is situated between the valves themselves. The
symptoms of these aneurisms are merely those of valvular lesion, and
therefore present no differential points for diagnosis.
ETIOLOGY.--Local weakness of the aorta submitted to sudden strain is
unquestionably the most frequent cause of aneurism. It is rare to find
an aneurism in an otherwise healthy aorta, and some authors go so far
as to assert that aneurism never occurs without preceding degenerative
changes in the arterial wall. Naturally, strain is the physiological
burden of the aorta, and this strain tends sooner or later to
degeneration of the arterial tunics. Then, given a weakened spot, the
ordinary occurrences of every-day life are sufficient to precipitate
disaster. A sneeze, a cough, some sudden exertion of the body in
lifting or moving, have been the starting-points of aneurism. All
accumulated testimony indicates that sudden strain is more dangerous
than prolonged uniform strain, and therefore some occupations are more
productive of aneurism than others. Inasmuch as age, sex, occupation,
and personal habits influence the development and nutrition of the
aorta, it is obvious that they must exert an important influence upon
the occurrence of aneurism.
All records agree that aneurism is pre-eminently a casualty of middle
life, and a glance at the accompanying table, which I have prepared
from an analysis of 69 reported cases, shows that the disease is most
common between thirty and fifty years of age:
From 20 to 30 years of age, 4 cases.
" 30 " 40 " " 21 "
" 40 " 50 " " 29 "
" 50 " 60 " " 14 "
" 60 " 70 " " 1 case.
Youngest case, 20 years of age.
Oldest " 72 " "
Crisp analyzed 551 cases, and reports 398 between the ages of thirty
and fifty.
Beneke has found in his records of arterial measurements that the
pulmonary artery greatly exceeds the aorta in circumference up to the
age of thirty. After that period the aorta begins to increase with
relatively greater rapidity, until in the forties it exceeds the
pulmonary artery in size, and it maintains its superiority from that
time forward. The aorta continues to increase in circumference
throughout life, but after the age of fifty this increase is considered
a senile dilatation rather than an actual growth. It is interesting to
{803} note that the era of greatest liability to aneurism coincides
with that of most rapid aortic development.
Sex furnishes a distinction in the frequency of aneurism. In 82 cases I
found that only a seventh were females; Crisp registers less than an
eighth. The radically different occupations and habits of women may
contribute somewhat to their relative immunity from aneurism, and their
physiological development also seems in their favor. Beneke states that
the blood-pressure during childhood is about the same for both sexes.
From puberty onward it is greater in the male. This is due to the fact
that after puberty the volume of the heart relative to the length of
the body is less in the female than in the male, and at the same time
the main arteries of the body relative to the length of the body are
only a trifle narrower in women than in men. The pulmonary artery,
indeed, is relatively a trifle wider in women than in men. It follows
from this that the blood-tension in both the large vessels emerging
from the heart is less in the female than in the male.
In general terms, it may be said that those people who are exposed to
heavy labor, as mechanics, laborers, soldiers, porters, cabmen, etc.,
are more liable to aneurism than those who are less exposed to such
straining efforts. Fixture of the chest during effort brings greater
strain upon the heart and aorta, and therefore men who wield heavy
hammers and sledges are especially liable to aortic disease.
Constriction of the neck or forcible extension of the same during
exertion is dangerous, because it thus happens that the arteries are
stretched in their long diameter at the same instant that the
blood-wave is expanding them laterally, and they are thereby subjected
to double strain. I knew of a trotting horse which was killed by this
very combination of strain upon the aorta. At the end of a trial of
speed the animal refused to stop; whereupon a groom sprang forward,
seized him by the bit, and threw his head strongly upward and backward.
His carotids and aorta were thus stretched to full length at the moment
when his heart was acting with great force. The horse dropped dead, and
the autopsy revealed a rupture of the aorta.
The frequency of aneurism among the soldiers of the English army was
long the subject of anxiety and thought to English surgeons. Finally,
some bright man recognized one cause in the dress of the soldiers. They
were obliged to wear a high stock, which constricted the neck and kept
it stretched, and their trappings were adjusted so as to keep the body
in a stiff and unnatural position. These objectionable details of the
dress have been removed, and it is now claimed that aneurism is much
less common in the army.
Syphilis and gout undoubtedly contribute to the formation of aneurism,
because they both dispose to degenerative processes in the arterial
tunics. Some writers, however, have laid too much stress upon syphilis.
It was claimed that this disease was the cause of the great frequency
of aneurism in the English army. Barwell, however, calls attention to
the fact that aneurism has been 13½ times more frequent per 1000 men in
the army than in the navy, and yet no one maintains that syphilis is
more common in the army than in the navy.
SYMPTOMS.--The diagnosis of aneurism of the aorta may be one of the
easiest problems of clinical medicine, or it may present difficulties
which defeat the most skilful diagnosticians. A large number of
aneurisms utter no sign of their existence, and are only revealed by
the manner of death or by an autopsy. Again, the so-called signs of
aneurism are so indefinite in character, and so associated with other
pathological conditions, that the greatest confusion often befogs their
interpretation. Mistakes therefore arise in two ways: either aneurism
is diagnosed as present when it is absent, or it is declared absent
when present. Robin reports the case of a vigorous young man upon whom
several of the most eminent clinicians of {804} Paris diagnosed
aneurism of the aorta, and yet a rest of a few days sufficed to remove
all symptoms of that disease. Three candidates for the diploma of the
Royal College of Physicians and Surgeons in England recently declared a
case of loculated pleurisy to be aneurism of the aorta, and B. W.
Richardson says he has "seen at least seven persons suffering severe
mental anxiety from the belief that they were fatally struck with
aneurism," and yet they were free of such disease. Balfour says: "There
is only one phenomenon positively characteristic of thoracic aneurism,
and that is the existence in some part of the thorax of a pulsating
tumor other than the heart, which beats isochronously with it, and at
least as forcibly, and which at each pulsation expands in every
direction." And yet simple dilatation of the aorta, combined with
mental excitement, will so increase the thoracic pulsations as to
simulate aneurism. It is necessary, therefore, that a patient during an
examination should be as quiet as possible, both in mind and body, and
if any doubt exist regarding the significance of the symptoms present,
the patient should be kept in bed for a few days in order to allay the
arterial excitement.
The phenomena produced by an aneurism are naturally divided into two
groups: 1. The direct symptoms, which are confined to the limits of the
tumor itself, and which are termed the physical signs. 2. The indirect
symptoms, which are due to the influence of the tumor upon neighboring
organs, and which present themselves often at remote points as signals
of distress within. This influence of the tumor upon its environment is
purely mechanical and due to pressure, and the resulting symptoms vary
according to the particular organ or function involved. These symptoms
are therefore classified as the physiological signs.
Pain is one of the earliest and most troublesome of the pressure
symptoms of aneurism. It is due to a stretching of the nerve-filaments
in the aortic wall and to the pressure of the tumor upon neighboring
organs, especially the vertebral column and sternum. When due to
nerve-stretching, the pain is neuralgic in character, and is not
necessarily confined to the chest. It may appear in the back, and is
intensified by coughing or sneezing. It may be rheumatic in type, and
affect the arm and shoulders for several months before other aneurismal
signs develop. In such cases the right arm and shoulder appear to be
most often affected. Sometimes the pain cannot be located, but is
referred indefinitely to the chest, or it may accompany acts of
deglutition. As a rule--and this point is important--this form of pain
from an aneurism exhibits wide variations of intensity and is usually
intermittent. Exercise, coughing and sneezing, mental excitement, or
anything which increases the activity of the circulation or raises the
blood-tension, increases the pain. It may resemble angina pectoris in
location and radiation, but it differs essentially otherwise. It is
more continuous, and is associated with less anxiety, which is such a
conspicuous element of angina.
When the pain is due to erosion of the vertebræ or sternum, it is more
steady and gnawing. It is still liable to violent exacerbations, and
excitement of all kinds increases it. Oftentimes the pain is so
excessive that the sufferer cannot lie down or obtain relief in any
position. This is especially the case with aneurism of the abdominal
aorta. Bennet reports the case of a patient who poisoned himself to be
free from the terrible pain, and deaths by exhaustion from pain and
distress are not uncommon.
Numerous other accidents besides pain arise from pressure upon the
neighboring veins. Balfour says that severe dyspnoea, vomiting, and
flatulency are frequently caused by pressure of an aneurism upon the
pneumogastric nerves, and that these symptoms may be relieved by gently
rubbing the tumor. Hiccough and paralysis of one-half the diaphragm are
caused by pressure upon the phrenic nerve. Occasionally destructive
inflammations of {805} the lung and pleura occur with aneurism, and
these have been attributed to pressure upon the pneumogastric nerves
and the pulmonary plexus. Palpitation of the heart is likewise often
produced in a similar manner. Sometimes the patient is conscious of a
pulsation in the tumor itself. Pressure upon the intercostal nerves
will produce herpes zoster, and cicatricial records of such attacks are
found upon patients with aneurism. Implication of the sympathetic
nerves produces modifications of the pupils according as the nerves are
merely irritated or paralyzed. In the first case the radial muscles of
the iris become permanently contracted and the pupil is dilated. In the
second case the radial muscle becomes paralyzed and the pupil is
contracted. Jaccoud says that this succession of changes is not rare,
and he has watched cases progress through both pupillary stages. The
nerves affected are those which emerge from the cilio-spinal region,
which extends, according to Budge and Waller, from the sixth cervical
to the sixth dorsal, or, according to Brown-Séquard, as low as the
tenth dorsal vertebra. From the anterior roots of this region
nerve-filaments pass through the cervical sympathetic to the iris. The
difference in the pupils is often so slight that it requires very
careful measurement to detect it. The application of atropia will
assist in the examination, because that drug has very incomplete
influence upon the affected pupil. The pupil is also much less
sensitive to light, but it contracts more strongly than the normal eyes
in its accommodation for near objects. Robertson cautions against
conclusions based upon mere casual observance of the eyes, because 1
person in every 14 has one pupil naturally smaller than the other.
Myosis is not pathognomonic of aneurism. It denotes merely some trouble
with the cilio-spinal nerves. The nature of that trouble must of course
be determined by the other associated symptoms of the case. The
contraction of the pupil is sometimes accompanied by paleness of the
corresponding side of the face and neck, while at other times the same
region may be swollen, oedematous, and perspiring. These symptoms are
due to local vascular changes from interference with, and
disorganization of, the vaso-motor nerves which govern these regions.
Remote local paralysis sometimes utters the first warning of aneurism,
and such cases are usually very striking. Paralysis of the recurrent
laryngeal is the most frequent of this group of signs. Urquhart reports
a case where for some months the chief symptom was a falling of the
head on the breast, as if it had been forcibly drawn down by the
sterno-cleido-mastoids. Another patient was supposed to have
rheumatism, but he soon became paralyzed on the right side and lost his
speech. He recovered somewhat, but died subsequently from bursting of
the tumor into a pulmonary cavity. Tufnell says if an amaurosis occur
suddenly look for valvular disease of the heart or for aneurism of the
aorta.
Dyspnoea.--The dyspnoea produced by an aneurism may vary from a slight
difficulty of breathing on exertion to the most marked orthopnoea. It
is produced by--_a_, direct pressure upon the trachea or bronchi; _b_,
pressure upon the recurrent laryngeal or the vagus. The two forms of
trouble are easily discriminated by physical examination. In cases of
pressure upon the respiratory tubes auscultation reveals very
characteristic signs. The constriction of the tube causes a peculiar
harsh sound, which, heard only in inspiration at first, becomes audible
later in expiration as well. If the pressure is upon the trachea, the
sounds will be heard equally in both lungs; whereas if only one
bronchus is involved, the sounds will be confined to the corresponding
side. If a bronchus be completely occluded by pressure, then the
peculiar breath-signs will disappear, and complete respiratory silence
reign instead. The dyspnoea of this origin is greatly relieved by
motion and by certain positions of the body. In capillary bronchitis,
pneumonia, asthma, etc. the patient sits with the head thrown back and
the shoulders raised, whereas a patient with tracheal compression finds
greater relief in leaning across the {806} back of a chair, with his
head resting upon his arms folded on a table, and the nights are passed
in this position. Again, the pressure dyspnoea is subject to sudden and
excessive variations. Any excitement which increases the cardiac
activity and the blood-tension will excite dyspnoea, whereas rest and
repose diminish it. This form of dyspnoea is likewise accompanied by
loud stridulous breathing, and by harshness and a metallic quality of
the voice. The stridor and dyspnoea bear no direct relation to the size
of the tumor, because a small tumor pressing upon the side of the
trachea, where the cartilaginous rings are thinner and less resistant,
will produce more discomfort than a larger tumor directly in front.
Where the compression of an air-tube is considerable, it usually
provokes inflammation of the mucous membrane, and the secretions
thereby engendered are liable to collect behind the obstruction and
increase the distress for breath. Cases are reported where, tracheotomy
having been performed, a catheter was pushed by the obstruction and the
backed-up secretion allowed to escape, to the great relief of the
sufferer. One case is recorded where the examining physician was able
to see by the aid of a laryngoscope an inward projection of the wall of
the trachea, which pulsated with each heart-beat.
The dyspnoea arising from pressure upon the recurrent laryngeal and
vagus may begin in two ways--either by a sudden paralysis of both vocal
cords, or by a preliminary spasm of the cords due to nerve-irritation.
When both cords are paralyzed, which is very rare, the voice is
entirely obliterated and the dyspnoea is intense and continuous. The
complete paralysis may be associated with choking at meals. When only
one cord is paralyzed, the breathing is not materially affected, though
the voice is altered in a characteristic manner.
If the compression of the nerves mentioned simply irritates them, then
the phenomenon of laryngeal spasm occurs. The voice becomes high,
squeaking, and false or whispering, with a muffled falsetto. Jaccoud
describes a condition where the nerves of the two sides are not
uniformly affected, and therefore the cords are not equally tense in
their spasm. The result of this difference of tension and vibration is
a peculiar commingling of high and low tones, which produces a very
discordant and unpleasant sound to the ear. Jaccoud terms this la voix
bitonale. The dyspnoea from spasm persists through both inspiration and
expiration, whereas with paralysis of the cords the inspiration is
alone or mainly affected. The cough in these cases is phenomenal in its
character, being very loud and metallic, often barking, and it is very
distressing to the patient and to all who hear it.
When a bronchus is compressed the percussion note on the corresponding
lung is higher in pitch and tympanitic. The inspiratory murmur is
ordinarily diminished, but bronchial breathing may (rarely) occur. The
coincidence of bronchial breathing with tympanitic resonance is an
eccentric combination of a very paradoxical character. The cough is
almost pathognomonic, with a loud barking, distressing metallic clang.
Such a cough is still more suggestive when combined with the high,
shrill, whistling vox anserina. The amount of expectoration is at first
small, consisting of glairy, frothy mucus. Later it becomes more
copious and muco-purulent, and may even be rusty and red. The presence
of bloody sputa with an aneurism is always grave, because it raises
suspicion of a so-called weeping aneurism which is approaching rupture.
Dysphagia.--This is a common symptom with aneurism, but it is not so
constant in appearance as it is with other mediastinal tumors. It
appears more often when the aneurism is situated upon the transverse
portion of the aorta. It is frequently painful, but always variable in
severity, and may disappear for long intervals at a time. Lying upon
the face usually relieves the difficulty, while it is aggravated by
reclining upon the back. Fluids are usually {807} swallowed more easily
than solids. Hayden says that a feeling of sharp pain in a particular
part of the gullet in swallowing when aneurism is present indicates
erosion of the mucous membrane and early perforation.
Pressure upon Veins.--Localized oedema and cyanosis are two common
symptoms of aneurism of the aorta. The sudden eruption, the limited
distribution, and the terrifying effect of these symptoms render them
especially interesting. They are due to pressure of the tumor upon the
veins near the heart, and particularly upon the superior vena cava.
Dujardin-Beaumetz says that, thanks to the vena azygos, compression of
the superior vena cava produces simply a varicosity of the neck and
upper part of trunk. Should the vena azygos be simultaneously blocked,
then the oedema and cyanosis will spread over the entire head, neck,
arms, shoulders, and upper trunk--_i.e._ over all parts drained by the
superior vena cava. Only two such cases have been reported, however.
One case was seen by Piorry and one by Dujardin-Beaumetz. In the latter
case the oedema and cyanosis of parts named above came on suddenly
without apparent cause. The face was swollen, blue, and covered with
red patches, and the eyes were injected. The ears were cold; the
abdomen and lower limbs retained their normal color. The contrast
between the upper and lower portions of the body under these conditions
is very striking.
Balfour says that "a thick oedematous collar covered with large veins
surrounding the root of the neck" is indicative of compression of the
superior vena cava.
Pressure upon the brachio-cephalic veins produces oedema and cyanosis
of the head and upper extremities; oedema of the glottis has occurred
under such conditions. Sudden swelling of one arm, unaccompanied by
inflammation, is suspicious of aneurismal compression of the
corresponding vein, especially if it comes on suddenly after exertion.
Compression of the descending vena cava or right auricle may give rise
to congestion and dropsy of the lower part of the body, but these are
later symptoms.
Pressure upon the thoracic duct is relatively rare. It may cause
emaciation, but loss of flesh with aneurism is more often due to
obstruction of the oesophagus or to dyspepsia and the exhaustion from
pain and sleeplessness.
Pressure upon Bones.--Pressure of a tumor on neighboring bones causes
absorption and dislocation of the same. The clavicles, sternum, and
ribs are rapidly eroded by the aneurism, and are pushed forward and
disarticulated. Pressure upon the spinal column causes absorption of
the vertebræ and of the cartilages, until oftentimes the cord is laid
bare and even subjected to direct pressure.
Inspection.--Inspecting a person suspected of aneurism, one should
examine the pupils, the color of the skin, the condition of the veins
of the head, neck, and arms, all movements of the neck and chest, and
especially the contour of the front part of the chest.