Phlebitis. 361 



The lesiojis 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. L,ater the changes implicate those, 

 thrombosis follows and one of various ulterior processes. 



In adhesive phlebitis which is most frequent as the result of 

 purely mechanical injury, the endothelium is disquamated and 

 granulations from the denuded surface extend into the clot and fi- 

 nally occlude the vein. A recovery takes place by the organiza- 

 tion 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 mor- 

 bid growths into or through the venous walls, producing inflam- 

 mation niDre 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 sympto7ns in localized cas;s 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 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 



