Phlebitis. 501 



The lesions in the'vein are often primarily of the nature of exu- 

 dation and cell growth in the coat, without at first any change in 

 the serosa or endothelium. I,ater the changes implicate these, 

 and thrombosis follows with one of various ulterior processes. 



In adhesive phlebitis, which is most frequent as the result of 

 purely mechanical injury, the endothelium is desquamated and 

 granulations from the denuded surface extend into the clot and 

 finally occlude the vein. A recovery takes place by the organi- 

 zation of this new product and the contraction of the vessel into 

 a simple fibrous cord. 



In suppurative phlebitis, which occurs especially in connec- 

 tion with infection (erysipelas, metritis), the inflammation, 

 though starting in the same way in the vascular coats, advances 

 rapidly to suppuration, and the intima, lying in contact with the 

 resulting thrombus, may become itself the seat of the suppurating 

 process. Cases of this kind are almost of necessity in the nature 

 of an infection and the danger is greatly enhanced. Small ab- 

 scesses formed in the vascular coats may burst into the vein and 

 passing on with the blood produce general infection (pyaemia) . 

 Even when the pus enters the vein at a point covered by the 

 thrombus, it may escape by the partial loosening of the clot from 

 the serosa, or through the interior of a honey-combed coagulum 

 and thus lead to general infection. This is especially liable to 

 follow in erysipelas and metritis, in which the tendency, as in the 

 solid tissues, is to diffuse suppuration without any investing limit- 

 ing membrane. There are other forms of bacterial colonization 

 of the vascular walls, of ulceration, and of the extension of 

 morbid growths into or through the venous walls, producing in- 

 flammation more or less localized, and leading or not to general 

 infection. The presence of phlebolites in the vein is a conceiva- 

 ble source of phlebitis, though no such case has been so far 

 recorded. 



The symptoms in localized cases of simple adhesive phlebitis 

 may be purely local. The vein if within reach may be felt like . 

 a firm, rounded cord, which extends in a direction away from the 

 heart. If there are no free anastomosis with neighboring veins on 

 the distal side of the thrombus, venous congestion and dropsy of 

 the tissues ensue, and in some cases moist gangrene. When, how- 

 ever, such anastomosis is abundant these peripheral symptoms 



