SYMPTOMS.—When the inner coat alone is affected, there are no symptoms of this disease. According as the degeneration extends deeper and involves the middle and outer tunics, the aorta begins to dilate, and the symptoms may vary from the slightest feelings of discomfort upon exertion to the most violent attacks of palpitation and pain.
Usually, at the beginning the symptoms are very obscure. A slight dyspnoea on exertion, or palpitation, or dyspeptic troubles are the chief complaint. The presence of these troubles in a man of fifty years or over, whose heart and kidneys present nothing abnormal, and in whom the smaller arteries of the extremities feel hard and calcareous, may excite the suspicion of atheroma of the aorta. There are no distinctive physical signs. Some writers speak of a short post-systolic murmur over the aorta beyond the valves, which may be audible only when the heart is acting strongly.
The aorta is almost invariably dilated, and Peter says that this dilatation may be traced by percussion. According to him, the normal aortic dull area measures from two to five centimeters transversely in the male, and from two to four centimeters in the female. He says that he has seen cases of atheroma where he was able to determine a dull aortic area of eight centimeters in diameter. If the inflammation extend from the aorta to the neighboring nerves, the patient may suffer from the ordinary symptoms of angina pectoris.
TREATMENT.—This disease cannot be cured by drugs. The physician's task is to regulate the habits of the patient, to remove so far as possible all conditions which tend to aggravate and increase the trouble, and to alleviate incidental symptoms of distress.
Thoracic Aneurism.
DEFINITION.—The origin of the term aneurism is buried in obscurity, and the theories which have been advanced regarding it are not very satisfactory. Montanus thought it was derived from a privative, and neuron, a nerve. Oetius declares it is from aneurisma, an enlargement, from eurumo, I dilate. Coale thinks a ready origin is offered in the words aneu, without, rusmos, a series, course, or succession, from ruo, I flow.
Aneurism of the aorta is a local dilatation of that vessel. When all the arterial tunics persist unruptured in the tumor, it is a true aneurism. When one or more of the tunics are torn in the process of expansion, it becomes a false aneurism. When all the tunics of the artery rupture and the blood escapes into the neighboring cellular tissue, it becomes a diffuse false aneurism. The internal and middle coats of an artery may burst, and the blood escape into and coagulate in the space between the middle and external tunics, and this is termed a dissecting aneurism. In rare instances of this type of aneurism the blood finds a second opening, and returns into the artery again, thus forming a double tube for a short distance.
In former times great stress was laid upon the distinction of aneurism 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 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.