136 OPERATIVE TECHNIQUE. 



sometimes obliged to seek primary union of the skin, leaving union 

 of the depths to follow by granulation. A drain'^age-tube may then be 

 inserted to facilitate discharge, care being taken to select the most 

 dependent point for its exit ; but considerable doubt has been thrown 

 on the efficacy of drainage-tubes, and after being replaced by gauze, 

 plaited horsehair, etc., they have been finalh' abandoned by a good 

 many operators. They are, however, useful in properly selected cases. 

 Retention of discharge must be carefully prevented, because not only 

 would such discharge thrust apart the deeper surfaces of the wound, 

 but it would greatl}' favour the multiplication of micro-organisms. 



When rapid healing of deep wounds is of great importance, the 

 deeper seated structures should be united with aseptic material, and 

 the threads cut short before the skin wound is closed. These " buried 

 sutures," if aseptic, cause neither irritation nor suppuration. In pene- 

 trating wounds involving the peritoneum the serous surfaces must first 

 be brought together, then the muscles, and finalh' the skin ; similarly in 

 extensive wounds of tendon sheaths and joints, the tendon sheath or 

 capsule of the joint is first to be united and afterwards the skin. 



To avoid displacing the margins sutures should be inserted at right 

 angles to the long axis of the wound. They should merely bring the 

 surfaces into contact and hold them together ; the most frequent error 

 in this respect is to draw them too tight, causing them to cut out or even 

 to produce local necrosis of the lips of the wound. They should be left 

 in position until the new tissue has become sufficiently firm. Primary 

 union occurs ^\■ithin three to five days or not at all ; the changes in 

 the wound after this time onh' inlluence the firmness of the cicatrix. 

 The usual direction, to remo^•e sutures between the fourth and sixth 

 da3-s, without reference to the size, degree of tension, mobility, etc., of 

 the wouiid, is apt to be followed by tearing apart of the newly formed, 

 tender tissues within the succeeding twenty-four hours, necessitating 

 a fresh operation. Some practitioners seem to dread a trifling amount 

 of cutting, but it is of no particular consequence. When sutures 

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

 swelling, it is often ad^'isable quickly to insert a few fresh ones rather 

 more distant from the edges, so as to avoid the need for entire!}' 

 resuturing the parts, which is not always successful. Sutures of 

 aseptic material may be left eight or even fourteen days in position 

 without causing suppuration. 



Sutures may be divided into uniting or coaptative, which serve to 

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

 which counteract the pull exercised b}- the tissues and thus relieve 

 tension on the uniting sutures. 



