PRELIMINARY OPERATIONS 



313 



veins. The left pulmonary artery lies just posteriorly and 

 cephalad to the vein which is nearest the apex of the chest. 

 Keep to the left of the anterior mediastinum if possible. 



Cut close to outer 

 ligature 



Bull-dog on pulmonary 

 artery close to heart 



Fig. 276. A special bull-dog is placed on the vessel near the heart and a notch is 

 cut in the artery close to the outer ligature with the scissors. 



Disconnected tube 



to manometer 



Cannula in position to be 

 inserted into 



pulmonary artery 



rfrtery held open 



with forceps 



Fig. 277. Method of inserting the special cannula into the artery. (For discussion 



see text.) 



This keeps the heart on the right side. It is usually ad- 

 visable to pick up the mediastinum and clamp it to the tis- 

 sues at the right sawed edge of the sternum. This securely 



