INSERTING SUTURES. 105 



the result of releasing still disunited portions of the wound and 

 allowing the lips to open. To overcome this difficulty, chromicized 

 catgut, which only softens very slowly, is employed, but silk is pre- 

 ferable for all skin wounds, and can even be used for abdominal 

 operations, as if properly sterilised it does not irritate and becomes 

 encysted or disappears. A number of different sizes must be pro- 

 vided of each of these materials. Silkworm gut is very smooth, 

 non-absorbent, and non-irritant ; it is largely employed for suturing 

 skin wounds where immediate union is of much importance. Soft 

 metallic wire, kangaroo tendon, and prepared horsehair are also 

 used. To preserve silk and catgut in an aseptic condition the special 

 holders shown in Figs. 84 and 85 are very practical. 



General Directions for inserting Sutures. Before inserting sutures 

 bleeding must have completely ceased. Capillary haemorrhage is 

 sometimes stopped by the sutures themselves, the bleeding surfaces 

 being pressed together ; but any large vessels should be ligatured 

 or twisted, otherwise the object of suturing will be defeated. 

 All foreign bodies, and not merely those of a macroscopic character 

 like fragments of dirt from the wounding body, or of crushed tissues, 

 clots of blood, etc., but also organisms which would set up inflam- 

 mation and suppuration, must be removed. This can be effected by 

 shaving the hair from around the wound and carefully disinfecting 

 the parts. Wounds are in the most favourable condition for 

 union when all bleeding has ceased and the surfaces are covered 

 with a thin film of clear serum. Although in human surgery only 

 sterilised, that is, aseptic, dressings and sterilised water are used, 

 it is much better in animals to use some disinfectant, because in their 

 case wounds are much oftener infected from the beginning, and have 

 usually been inflicted a considerable time before coming under the 

 surgeon's notice. 



The preceding measures having been carried out, the lips of the 

 wound are approximated, and a decision arrived at as to the number, 

 kind, and arrangement of the sutures to be used. The number, 

 of course, depends on the size of the wound, and the kind on the 

 tissue to be united — whether it be skin, bowel, muscle, etc. In 

 wounds of the external ear with division of the conchal cartilage, and 

 wounds of the eyelid involving the tarsal plate, the divided cartilage 

 should be separately sutured and not included in the cutaneous 

 sutures. The first suture is best inserted where the parts are most 

 out of line. In very long wounds a series may first be placed at 

 somewhat long intervals, so as to ensure the approximately correct 

 apposition of the edges before proceeding to final closure. 



