Calcareous Degeneration of Veins. The transformation of the walls of veins into earthy tubes, or calcareous deposition among their tissues, is infinitely less common than in arteries. It still however does occur, and apparently in the same manner, by the same progressive changes, and from the existence of the same constitutional tendency, only in cir cumstances of greater intensity.
Occasionally patches of atheromatous de posit consisting, as in arteries, of choles terine, oil, and phosphate of lime, are seen on the inner surface of veins, though they are always much smaller, and less general than those which are found in the arteries of the same individual. They present a white opaque appearance, and produce a slight elevation of the surface where they are situate. This de posit becomes converted by degrees into bony matter, as in arteries ; but instances where this has existed to any considerable extent, are very rare.
There are, however, some few on record. Bailie has described ossification of the inferior cava. Morgagni refers to a case observed by Bonazolius and Stancarius, in which the cava and emulgents were much dilated, and con verted partly into cartilage and partly into bone. Beclard mentions an instance where the femoral vein was calcified, and it was lying in contact with a still more ossified fe. moral artery. Horn noticed ossification of the femoral and uterine veins. Mr. Hodgson re lates an instance of ossification of the saphena, in which one calcareous patch measured an inch in length ; and Phcebus states that he saw in an anatomical museum an ossified sa phenous vein taken from a patient fifty-six years of age, who died of cancer of the stomach. By the calcareous deposit the vein was rendered thick and inflexible ; but at the points corresponding with the joints of the leg the vein could be bent. The deposition was between the coats of the vein, and was less regular than that which is found in the coats of arteries. The lining membrane was thick, opaque, and nowhere broken. Microscopi cally, the deposit presented irregular projec tions and excavations. Furst and Bonetus have found the coronary veins of the heart converted into bone. Otto enumerates in stances of this change as also having occurred in the splenic, portal, brachial, femoral, and coronary veins.
A concretion of phosphate of lime, the size of a nut, was found by Andral in the parietes of the external saphena. This might have been an attached phlebolite.
Fatty Tumours. Fatty tumours are occa sionally developed in the walls of veins around the areolar tissue. Andral mentions one,
" I once saw a case of this description, in which a tumour, presenting all the anatomical characters of adipose tissue, was developed between the coats of the vena ports;, near its entrance into the liver. This tumour, which was about the size of a walnut, projected into the interior of the vein, and almost entirely obliterated its cavity.* Entozoa in Veins. There is upon record a unique example of acephalocysts being deve loped in the pulmonary veins of the human subject, in which pouches were formed for their reception. The observation was made by Andral. I quote his description in extenso from the " Clinique " Several of these (acephalocysts) were lodged in pouches with a smooth surface, which at first seemed to be so many cysts. Others of them empty, and rolled several times on themselves, were contained in nar row canals, the elongated form of which they assumed. The inner surface of these canals was smooth, like that of the great pouches ; they ramified like vessels. We soon ascer tained that at each pouch a vessel terminated of small calibre, which, to form it, underwent greater or less dilatation. We then dissected the pulmonary veins, at their entrance into , the heart, and we traced them into the lungs : when we had to their almost capillary divisions, we began to perceive several of them present a considerable number of enlargements, which were filled with hydatids. After being thus dilated, the vein resumed its original ca libre then, a little further on, it was again dilated. The largest of the pouches might have contained a large nut, and the smallest would admit a pea. They existed equally in both lungs. The hydatids, which they contained, had all the characters of acephalocysts ; se veral presented small points of a dull white colour in their substance ; others presented on their inner surface a great number of miliary granulations. Most of them were , burst.' t Another entozoon, the Distonza hepatica?», has been found in the (hepatic) veins. Several examples have been recorded, but have again been questioned. The matter has, however, now been set at rest. In 1830, M. Duval, at Rennes, demonstrated to an anatomical class several of these parasites in the hepatic veins of a man. They were floating about in the fluid blood. The vessels themselves were free from any lesion.t be found the application of the subject in its practical bearings, in so far at least as the large venous trunks are concerned.