i66 



OPERATIVE TECHNIQUE. 



compressed either with the finger or with a tampon of cotton wool 

 (immediate compression). In the event of this faihng, the main vessel 

 supplying- the parts is compressed at the point nearest the w^ound, 

 where it can be brought directl}^ against a bone (mediate compression). 

 This plan rarely stops bleeding completely, however, and at the end 

 of the operation one is obliged to resort to some other method. In 

 dealing with hollow wounds long strips of antiseptic gauze, tarlatan, 

 or muslin ma}- be packed into the cavit}' under pressure, and the lips 

 of the wound provisionally united b}' a few sutures. This usually 

 checks bleedinc: from small vessels. 



J 



Fig. 191. — ^Greig-Smith's artery 

 forceps. 



Fig. 192. — Spencer Wells' artery forceps 

 (with separable limbs for cleaning). 



Ligation is effected with threads of silk or catgut ; chromic 

 gut is the best. \^'hen an arter}' crosses the field of operation, 

 and must be divided, it is isolated, ligatured in two places, and the 

 section made between the two ligatures. If a \'essel, whether 

 arter}' or vein, is accidentally divided, the ends are grasped with 

 forceps or a tenaculum and strongly ligatured as high up as possible, 

 using a surgical knot. In the case of an arter}-, the object is to di^•ide 

 the inner and middle coats, which retract, and become incurved 

 towards the axis of the vessel, whilst the external stretches slightly, 



