EXUDATIVE PERICARDITIS DUK TO FOREIGN BODIES. 



383 



In very exceptional cases the sinuous tract is ramified, possibly as a 

 result of displacements of the foreign body. 



The orifices of the tract are to be found, one in the reticulum, the 

 other in the pericardium. On the side of the reticulum there is never 

 more than one opening, and in many instances the tract is already closed 

 on that side, either by exuberant granulations or Ly a cicatrix. 



On the contrary, the fistula is more frequently open in the pericardial 

 cavity. Its walls are of very varying appearance, depending on their age : 



Fig. 176.— Appearance of the lesions in a case of fatal pericarditis. P, inflamed peri- 

 cardium, distended with exudate and adherent to the neighbouring pulmonary lobes ; 

 1, posterior lobe ; 2, cardiac lobe ; 3, anterior lobe ; Fp, pleural false membranes. 



they may be red, greyish, soft or hard, and when the lesion is of old 

 standing they may have been converted into a sclerotic tissue. 



The pericardium appears distended with a considerable quantity of 

 liquid of a special character— sometimes sero-sanguinolent, sometimes 

 almost or entirely purulent ; sometimes yellowish, or greenish-grey ; 

 sometimes frothy, inodorous, or very fcetid. 



These characters depend on the nature and number of the germs 

 which have invaded the pericardial cavity. They also vary with the 

 gravity and number of the hasmorrhages produced l)y the action of the 

 foreign body on the myocardium. 



