SKIN SUTURES. 107 



degree of tension, mobility, etc., of the wound, is apt to be followed 

 by tearing apart of the newly formed, tender tissues within the 

 succeeding twenty-four hours, necessitating a fresh operation. When 

 sutures threaten to cut out, either from being drawn too tight or 

 from local swelling, it is often advisable quickly to insert a few fresh 

 ones rather more distant from the edges, so as to avoid the need 

 for entirely resuturing the parts, which is not always successful. 

 Sutures of aseptic material may be left in position eight to fourteen 

 days or even longer without causing suppuration. 



Sutures may be divided into uniting or coaptative, which serve 

 to draw wounds together, and tension sutures or satures of relaxation, 

 which counteract the pull exercised by the tissues and thus relieve 

 tension on the uniting sutures. 



The greater number of special sutures described from time to 

 time have only an historical interest. 



Skin Sutures. The most important and the most commonly used is 

 the plain interrupted suture shown in Fig. 140, which can be 

 employed in almost all cases. It is made by passing a thread through 

 the opposing lips of the wound, drawing the free ends together, and 

 tying them firmly towards one side of the wound. The needle 

 carrying the suture is grasped in the right hand, the thumb on the 

 concave, the index and middle fingers on the convex side (Fig. 141), 

 or a needle-holder may be used (Fig. 137). The edges of the wound 

 are successively raised with forceps, and the needle passed through 

 them first from without inwards, then through the opposite lip from 

 within outwards (Fig. 141). Another method, however, is to raise 

 both lips together, producing a somewhat deep fold, through the 

 upper part of which the needle is passed with a single thrust (Fig. 142). 

 This secures a larger surface for union ; when only the extreme 

 edges of the skin are brought into contact, rapid union is much less 

 certain. The comparative poverty of blood-vessels in the skin of 

 animals as compared with that of man explains the difficulty with 

 which skin surfaces alone unite, or when united hold together under 

 tension. The appearance of a wound sutured in the above-described 

 manner is certainly somewhat unsatisfactory, but there need be no 

 fear of the fold remaining. As soon as the threads are absorbed 

 or removed the fold disappears, leaving only a narrow cicatrix. To 

 relieve tension in wounds so united it is generally desirable to insert 

 one or more " relaxation " sutures. 



Sutures may be tied successively as inserted, or tying may be 

 deferred until all are in place. In animals it is usually best to tie 

 them as one proceeds. The fear of them tearing out when the 



