Amyloid degeneration of the kidney is occasionally connected with uratic deposits in the organ. Ebstein and others have reported a few cases of this kind. The same authors have also observed numer ous instances in which extensive incrustation of the joints was unac companied by any trace of wage deposit in the kidneys. Only the lesions of chronic interstitial nephritis were present, indicating that chronic inflammation, rather than mineral infiltration, is the fact of prime importance in visceral gout.
The circulatory apparatus stands next to the kidney in the order of incidence of visceral gout. The heart is scarcely ever found, after death, in a perfectly healthy condition. It usually presents in milder forms of the disease the characteristic ventricular hypertrophy that is associated with the contracted kidney, chiefly involving the left side of the organ. The valves exhibit very little change. The mus cular substance of the heart frequently shows a sclerotic change; but sometimes it is absent even in cases of considerable hypertrophy.
But when gout has become inveterate, and the joints and kidneys have become infiltrated with urates, the heart exhibits dilatation of all its cavities. The muscular fibres present the appearance of gran ular degeneration with partial loss of striation. The entire organ. is soft and flaccid; its walls are covered with fat that often penetrates between the fibres of the ventricular wall. The valves rarely show any signs of disease; their discoloration is dependent upon post-mortem imbibition; and if diseased they are covered with vegetations, or have undergone calcification as in ordinary cases of endocarditis. Very seldom indeed is the discovery of true uratic deposit upon the cardiac valves, yet such an event has been occasionally noted. In like man ner, the arterial walls hardly ever fail to present extensive atheroma tous deposits, but are only in the most exceptional cases invaded by the true uratic infiltrations. The large vessels near the heart and the cerebral arteries are the favorite seats of degeneration. The inner coat and the muscular layer of the arterial wall become calcified, while the adjacent parts undergo fatty degeneration. By these pro cesses the vascular walls lose their elasticity, and the lumen of the vessels is diminished or wholly obliterated. Sometimes ulceration occurs around the atheromatous patch, and thrombosis may ensue, with consequent liberation of emboli and obstruction of distant regions of the circulatory apparatus. These facts are of prime im portance in explanation of the proclivity of gouty patients to diseases of the brain and to cardiac angina dependent upon interference with the vascular supply of those organs.
The veins present in a minor degree the same lesions that have been noted in the arteries. Sometimes they exhibit the clinical phe nomena of phlebitis, but as this usually terminates in recovery, little i known about its anatomical changes. Occasionally a deposit of orates has been found in the wall of a vein, even though the arterial walls were not correspondingly affected, but this is a very rare event. Varicosity of the veins, on the contrary, is one of the most common evidences of the arthritic diathesis. Few are its subjects who do not sooner or later display this proof of the morbid condition of their venous system. Hemorrhoids, varicocele, varices, phlebitis, or peri phlebitis, obstinate ulcerations dependent upon those conditions, and the chronic oedema so frequently involving the extremities of the gouty, are among the most common consequences of veno-vascular arthritism. The capillary network does not escape the general morbid tendency. Though not the seat, perhaps, of coarser infiltration, the frequent occurrence of capillary hemorrhages in different tissues of the body is sufficient to show that these minute vessels share in the universal deterioration of structure and function that characterizes the progress of gout.
In the respiratory organs, it is sometimes possible to discover uratic deposits in the bronchi, but this is an unusual incident. More frequently the fibrous structures and articulations of the larynx are thus invaded. The mucous membrane escapes, but the subjacent fibrous tissues are sometimes distinctly infiltrated with unites. Yet, though it be not liable to such deposits, the mucous membrane of the air-passages is exceedingly prone to infiltration that is modified if not directly caused by the arthritic predisposition of the subject. Such patients in early childhood are subject to long-continued attacks of severe bronchitis ; as infants they are wheezy; and as they advance in years their lungs become emphysematous. The bronchial mucous membrane is thickened and darkly congested; the bronchi are often dilated; the air cells of the lungs are greatly enlarged, and their walls have lost their elasticity. In old cases that have succumbed to failure of the heart, the lungs are engorged with blood and other liquids. Catarrhal or interstitial pneumonia is sometimes present; and this last affection is accompanied by thickening and adhesion of the pleural surfaces. The lymphatic vessels sometimes share in the in flammatory process—occasionally even to the extent of suppuration.