681 DISEASES OF THE LIVER. 



thickened, infiltrated with serum, and shows a cloudiness of the mucous 

 coat, and an injection of the fibrous. In thrombosis, the wall of the 

 vein is at first normal, but it is soon changed in the manner above de- 

 scribed. The coagulation of the contents may be limited to some twigs 

 of the portal vein, but in other cases it extends to the trunk, roots, 

 and branches. The teiminations of pylephlebitis vary, and, according 

 to the difference of its termination, it is called adhesive or suppurative. 



In adhesive pylephlebitis, while the thrombus gradually shrinks, 

 undergoes fatty degeneration, and is partly or entirely absorbed, there 

 is inflammatory proliferation of the wall of the vein, which terminates 

 in its obliteration, although we cannot follow the different phases of 

 the process. If we examine a liver that has been the seat of adhesive 

 pylephlebitis, we find on its surface cicatricial retractions, and within 

 it, corresponding to these retracted places, we find a hard tissue, in 

 which may still be recognized the atrophied branches of the portal 

 vein. Occasionally these contain remains of the thromboses, colored 

 more or less yellow by haematin. 



In suppurative pylephlebitis, instead of atrophying gradually, the 

 thrombus dissolves into a puruloid fluid. This is, for the most part, a 

 finely-granular detritus, containing only a few roundish cells, which may 

 be either white blood-corpuscles or newly-formed pus-corpuscles. The 

 whole thrombus rarely breaks down at the same time. In the trunk 

 of the vein there is often a firm coagulum, while there is a puruloid 

 fluid in the branches and roots. But more frequently there is no dis- 

 integration in the finer branches of the portal vein, so that the coagula 

 there prevent the disintegrated masses entering the hepatic vein, and 

 reaching the pulmonary circulation. I have had the opportunity of 

 carefully observing this " sequestration " in two cases of suppurative 

 pylephlebitis. It readily explains the frequent escape of the lungs 

 from secondary disease, which could scarcely fail to occur if the termi- 

 nations of the portal vein were not closed. 



But, in phlebitis of the peripheral veins, the inflammation not un- 

 frequently extends from the adventitia to the surrounding parts, in- 

 ducing suppuration and formation of abscesses, so that inflammation 

 of the parenchyma of the liver, which terminates in the formation of 

 abscesses, often accompanies suppurative pylephlebitis. Then we often 

 find in the liver numerous deposits of pus, which surround the portal 

 vein, and often communicate with it. 4 



SYMPTOMS AND COURSE. When adhesive pylephlebitis is limited 

 to individual twigs of the portal vein, it runs its course without show- 

 ing any symptoms during life. The pervious branches suffice to trans- 

 fer the blood from the abdominal organs to the hepatic vein. If the 

 trunk of the portal vein, or all or most of its br-nches, be obliterated, 



