Under the name of hypovenosity has been described a condition of the saphenous system in which there is a deficiency in the number and size of the veins. The outlines of the limb (bone, muscle, etc.) are effaced, the skin is dusky, the limb brawny, and there are no veins visible. The motion of the limb is painful and difficult. There is degeneration of the superficial veins, collateral dilatation of the deep veins, and ultimately atrophy of the muscles.
Exercise, frictions, and hot applications are to be employed. Rest and bandaging as a mode of treatment aggravate the disease.13 The affection is of rare occurrence.
13 J. Gay, Lancet, Nov., 1871.
Occlusion of Veins.
Venous occlusion results very frequently from adhesive phlebitis. It is also brought about by the presence of cancerous or other tumors. The complete arrest of the current of blood through a vein rarely produces the serious results which may occur from a like obstruction of an artery. The aggregate diameter of the venous system is much greater than that of the arterial, and the venous walls are much thinner and more distensible. Hence an adequate collateral circulation is more readily established. In a healthy individual and in a healthy condition of the part simple occlusion of a vein produces only a moderate oedema of the tissues on the distal side of the obstruction. In unhealthy conditions, however, as already pointed out in discussing phlegmasia dolens, very serious results may follow.
Occlusion of either the superior or the inferior vena cava is of not very rare occurrence. It may be the result of pressure from a cancerous or other growth,14 which is the most frequent cause, or in the case of the inferior cava it may be brought about by a thrombus gradually extending upward in one of the iliac veins until it reaches the bifurcation, when a thrombus in the other iliac is occasioned by the partial obstruction of its entrance into the cava. These united thrombi then extend upward into the cava, producing complete occlusion. This is an occasional event in phlegmasia dolens.
14 Watson describes a case arising from pressure from hydatids of the liver.
Occlusion of the superior cava is less frequent than that of the ascending. It is nearly always the result of pressure from an intra-thoracic tumor, and its symptoms are more or less masked by those directly referable to the growth. There are, however, great dilatation of the veins and oedema of the tissues of the head and neck and of the upper part of the thorax. These symptoms in a case in which there are physical signs of a substernal growth would afford a strong presumption of obstruction of the cava.15
15 Stocks, Med. Times and Gaz., April 22, 1876; Williams, Tr. Dublin Path. Soc'y, July, 1878.
The glandulæ concatenatæ of the neck are apt to be enlarged from the chronic engorgement. Watson mentions a case in which this added so much to the volume of the neck as to give a superficial resemblance to goitre.