314 EXPERIMENTAL PHARMACOLOGY 



holds the heart over in the right side of the thorax and 

 thus gives a freer field for the operation. With a probe 

 (blunt point] carefully dissect loose the pleural (fascia) 

 covering over the area between the arch of the aorta and 

 the adjacent pulmonary vein. Beneath this fascial cover- 

 ing you will find the pulmonary artery. 



Consult Fig. 274 and carefullly pass a large aneurism 

 needle beneath the artery. Free as long a space of the ar- 

 tery as you can readily isolate. This will average about 

 three-fourths of an inch. Pass a twine ligature around the 

 vessel and tie it loosely (Fig. 274). Now with large for- 

 ceps (using one finger to help hold the twine) slip the liga- 

 ture outward into the edge of the left lung as far as you 

 can and then tie tightly. Take hold of the ligature and lift 

 up the lung as far as you can safely raise it, pass the 

 ligature out over the chest wall and clamp it with a hemo- 

 stat to the chest wall. With the aneurism needle still un- 

 der the vessel pass a second ligature around the artery and 

 tie it loosely. A iveak-springed, rounded-edged bull-dog 

 clamp is now placed on the artery as near to the heart as 

 possible. The loose ligature is placed just peripheral to 

 the bull-dog. 



With the aneurism needle now lift the outer end of the 

 vessel and cut it about one-half across (Fig. 276) with the 

 scissors. With his right hand the operator now passes 

 one of the points of the large sharp-pointed forceps into 

 the lumen of the vessel and holds it open (the aneurism 

 needle is held under the vessel with the operator's left 

 hand) while the assistant inserts the short, wide tip of the 

 cannula (Figs. 278 and 279) into the vessel. The operator 

 and assistant (each using one hand) now tie the loose 

 ligature around the vessel thus fastening the cannula 

 in securely. It is advisable to leave the washout tube on 

 the cannula while it is being placed in the vessel but the 

 manometer tube is best left off until the cannula is securely 

 fastened in the vessel. This is done on account of the dif- 



