DISEASES OF THE ARTERIES.

INFILTRATIONS AND DEGENERATIONS.

Calcareous Infiltration.-Calcareous infiltration frequently affects the arteries, either in the course of atheromatous changes, or the artery may simply be impregnated with limesalts without any foregoing pathologic change, being converted into a stone-like tube. This infiltration also occurs in the final organization of thrombi.

Amyloid Disease.-Amyloid infiltration of the arteries results from syphilis, chronic malaria, tuberculosis, suppuration-especially that of bone-and chronic lead-poisoning. The smaller (medium sized) arteries are almost without exception the ones which are affected by this infiltration. This may lead to a weakening of the arterial wall, and aneurysm may result. Amyloid infiltration in the internal organs usually accompanies this condition.

Fatty Degeneration.-Simple fatty degeneration of the intima usually occurs in individuals beyond middle life, and Virchow has described a similar condition occurring in chlorotic girls. Fatty degeneration, however, is usually one of the stages in atheroma.

Hyaline Degeneration.-Hyaline degeneration may also attack the arteries, commonly involving the intima.

ARTERITIS, OR INFLAMMATION OF THE
ARTERIES.

ACUTE ARTERITIS.

This condition usually results from some infective process. It is frequently encountered in pyemia, sometimes in ulcerative endocarditis and enteric fever. It may affect any of the arteries. The changes noted are distention of the vasa vasorum, the intima becomes roughened, and there is an inflammatory infiltration into one or more coats of the arteries which may go on to the formation of pus, or in some instances an aneurysm develops. Acute aortitis is rare, being a condition similar to ulcerative endocarditis. Thrombosis may result from roughening of the intima.

Micro-organisms may be found upon the surface of the projection or vegetation, and in the inflammatory area in the coats of the arteries.

Symptoms.-Acute arteritis may occur during the process of a primary lesion or during convalescence. The important symptom is spontaneous, localized pain in the region affected, most frequently a limb, exaggerated by movement and by pressure. Upon the occurrence of thrombosis a painful cord may be felt in the affected area. The pulse is obliterated, there is numbness and tingling with anesthesia, coldness of the skin, and swelling. The local temperature is lowered, and gangrene may follow.

ARTERIOSCLEROSIS.

Synonyms.-Arteriocapillary fibrosis; Gull and Sutton's

disease.

Definition. A sclerosis of the arteries, affecting usually the intima, but the adventitia and media may be involved. This may be local or general.

Etiology.-Arteriosclerosis is more common in the male than in the female sex.

This condition usually results from advancing age, but the rule has many exceptions, as the young are frequently attacked. It is a well-known saying that, "A man is as old as his arteries."

Heredity seems to play an important part in the causation, as some families show a distinct tendency to arteriosclerosis early in life. Improper living, sedentary occupations, overeating, overwork, occupations which give rise to severe muscular exertion, and syphilis are all important factors in the causation of this disease. Persons suffering from gout show a marked tendency to arteriosclerosis. Alcohol and chronic

lead-poisoning are also important causes.

Chronic interstitial nephritis gives rise to this condition; however, kidney disease may be secondary to arteriosclerosis, and again, both conditions, no doubt, often occur simultaneously from a common cause.

Pathology.-Arteriosclerosis may be diffuse, affecting many of the small arteries of the body, those of the brain, of the heart, and of the extremities. The arteries of the lungs are less commonly involved. Again, the sclerosis may be confined to the larger arteries, such as the aorta.

1. Atheromatous Arteritis.

This disease is primarily one of the intima. Early there is a milky opacity of this coat, and a thickening takes place in this membrane. A yellowish spot may next appear in the thickened area, which is the result of fatty degeneration. This fat may be carried away by the blood stream, leaving an ulceration, or the fatty patch may be converted into a calcareous plate. If the former result, the artery is predisposed to aneurysmal dilatation. In the latter event, emboli may be thrown into the circulation, providing the atheromatous plates are dislodged. This atheromatous change most frequently involves the aorta, but the iliacs, femorals, and arteries of the limbs and the cerebrals are often involved.

Microscopically, the thickening simply consists in the formation of fibrous connective tissue. As a result of this, the elasticity of the vessel becomes impaired and may dilate and form an aneurysm.

2. Arteritis Obliterans.

This condition, as a rule, occurs from syphilis. Occasionally, this change has been found in the cirrhotic kidney, fibroid lung, and in blood-vessels after ligation. The intima shows great thickening as a result of fibrous connective-tissue formation. The elastic coat and the muscular coat show little change, and the adventitia may in some instances be thickened. In consequence of this, the lumen of the artery becomes diminished, and in some instances completely obliterated, often leading to gangrene of the parts supplied. The intima does not show a tendency to fatty degeneration, so that it does not predispose to aneurysm, and the condition is usually associated with other signs of constitutional syphilis, and affects most frequently the small arteries.

3. Diffuse Arteriosclerosis.

This condition is wide-spread, occurring frequently during middle life. The intima shows marked thickening, and the disease affects, more or less, the aorta and its branches.

As a consequence of sclerosis, the vessel-walls become inelastic, the onward flow of the blood is somewhat prevented, as the resistance is increased, and sooner or later the left ventricle becomes hypertrophied. This is especially so when it is associated with chronic interstitial nephritis. The arterial tension becomes high, and the diseased arteries are liable to aneurysmal dilatation. As a result of roughening of the intima, thrombosis not infrequently occurs.

Many degenerative changes may appear from narrowing of the blood-vessels, such as softening of the brain, fatty degeneration of the heart, etc.

Symptoms. Great changes may take place in the arteries without giving rise to symptoms. The condition is easily recognizable if the external arteries are the ones affected; thus, the hardening in the radial and temporal arteries may be felt, but the internal arteries are not open to scrutiny. The principal symptoms depend upon the high-tension pulse, which is full and strong and difficult to obliterate. Next in importance are changes which relate to hypertrophy of the heart, particularly the left ventricle. The apex-beat is dislocated downward and to the left, the impulse being forcible and heaving; the second aortic sound is clear, ringing, and accentuated. The involvement of the coronary arteries may develop symptoms of angina pectoris. If there be changes in the cerebral vessels, paralysis of various kinds may result. The ophthalmoscope may reveal changes in the retinal

vessels.

Vertigo is a prominent and frequent symptom. Urinary symptoms occur in a majority of the cases. The urine is increased in amount, of low specific gravity, rarely containing casts or albumin, pointing strongly to contracted kidney, which often is associated. If dilatation follow hypertrophy of the heart, relative insufficiency develops. This may be difficult to diagnosticate from actual organic valvular defects. The urine under such a condition will have changed, being lessened in amount, and of high specific gravity, containing albumin and casts (due to congestion of the kidney). Edema may result, as in failing compensation from valvular disease. Respiratory symptoms occasionally appear, such as relate to bronchitis and allied conditions.

Diagnosis. This depends upon the tortuous temporal arteries, hard, whip-like radials, high-tension pulse, accentuated second aortic sound, and hypertrophy of the left ventricle.

When the atheromatous condition involves the internal arteries, the diagnosis is more difficult, and the accentuation of the second aortic sound and hypertrophy of the left ventricle are less distinct.

Prognosis. The prognosis varies in individual cases. The patient may live for some time but the changes in the arteries are never amenable to cure.

Treatment. The patient's life should be carefully regulated, excesses avoided in food and drink, and there should be no exertion of any description, mental quietude being insisted upon. Alcohol should be absolutely prohibited.

If the history of syphilis occur in the case, a prolonged treatment by iodid of potassium is of use. In other cases, the best results are obtained by giving the nitrites, such as the nitrite of sodium or nitroglycerin. The bowels should be carefully regulated.

ANEURYSM.

Definition." An aneurysm is a circumscribed tumor, containing fluid or solid blood, communicating directly with a canal of an artery, and limited by a tunic which is called the sac" (Hilton Fagge).

Etiology.-Trauma is an important etiologic factor. Any condition which weakens the wall of a blood-vessel may give rise to aneurysm; thus, arteriosclerosis is an important cause. Any condition which raises local blood pressure may be causative, such as muscular effort, heavy lifting, wrestling, sudden fright, straining at stool, parturition, etc. Syphilis is important; many authors estimate as high as eighty per cent. of all cases due to this cause. Alcohol, in giving rise to arteriosclerosis, may be mentioned as a causative factor. Gout and lead-poisoning act in the same manner. The greatest number of cases occur between the ages of thirty and forty, and aneurysm is more frequent in the male than in the female.

General Considerations.-Dilatation may occur in any artery in the body, so that an aneurysm may vary in size from the so-called miliary aneurysm to an immense tumor. The condition is more frequent in some countries than in others; thus, it is comparatively rare in Germany, France, and Italy, but more frequent in England. The greater number of aneurysms in this country occur in foreigners. The majority of aneurysms appear in the thoracic aorta, next in the abdominal aorta, the subclavian artery, and the innominate artery. In the aorta itself, the arch seems to be affected in the greatest proportion of cases.

External aneurysms belong particularly to the domain of surgery, internal medicine having to do chiefly with aneurysm as it occurs in the aorta and its main divisions in the chest and abdomen, and the miliary aneurysm, particularly of the brain.