EXUDATIVE PERICARDITIS DUE TO FOREIGN BODIES. 



387 



the hypochondrium becomes attached to the sternum. (3.) Point at which 

 the external mammary vein penetrates the abdominal wall (Fi^- 178). 



Lines uniting these three points enclose a right-angled triangle, which 

 the operator must imagine to be bisected by a third line. 



The iucision, which should be about 8 inches in length, follows this 

 bisecting line at an equal distance between the white line and the circle 

 of the hypochondrium, to a point within about 8 inches of the anterior 

 margin of the mamma. All these points are readily observable before 

 the animal is cast. 



The cutaneous incision affords exit to large quantities of fluid, and the 



VM.a. 



L.B. 



Fig. 178. — Seat of operation for puncturing the pericardium by way of the ensiform 

 cartilage. L B, White line; H, line of the hypochondrium; Y.M.a., anterior 

 mammary vein ; P, point where the pericardium is punctured through the incision. 



pectoral muscles attached to the neck of the ensiform cartilage can then 

 be divided with the bistoury. The area of operation is thus uncovered. 



Second stage. The second phase comprises incision of the tissues 

 opposite the neck of the ensiform cartilage, about 8 inches in front of 

 the base of the triangle and at equal distances from the points Nos. 1 

 and 2; incision through the skin for a distance of 8 inches, and dis- 

 section' of the muscles of the ensiform region exposed at the neck of the 



*^^' By^'means of the index finger or the index and middle fingers of the 



right hand the mediastinal space is explored, and the fatty masses round 



the base of the heart broken through. If the pericardium is greatly 



distended, the point of the sac can be felt with the tip of the finger, or 



its position can be recognised, even from a little distance, on account of 



the fluid contents transmitting the impulse of the heart. The sensation 



conveyed to the finger is very clear. 



c c .z 



