82 VETERINARY SURGICAL OPERATIONS 



Ligation. 



DEFINITION. — Ligation is the application of a ligature, 

 or, in other words, the operation of tying either normal or 

 abnormal structures with a cord that encircles them. 



INDICATIONS.- — Ligation in surgery has two distinct 

 objects: — (i) The arrest of haemorrhage when applied to 

 blood vessels; and (2) The strangulation of neoplasms. 



The arrest of haemorrhage by ligation is an important sur- 

 gical process, made necessary by the profuseness of bleeding 

 that occurs when large vessels are divided, and when such 

 vessels can not be safely occluded by the more simple meth- 

 ods. In the course of surgical operations, or in the treat- 

 ment of a bleeding accidental wound, the demands for liga- 

 tion must be cautiously judged. Large vessels, especially 

 arteries, require ligation to prevent fatal bleeding, serious 

 anaemia, and shock, as well as to overcome the masking effect 

 of blood. Large vessels, although apparently safely twisted 

 with the haemostatic forceps, may yield a secondary haemor- 

 rhage, whenever the cut vessel is large enough to endanger 

 life by loss of blood, or to discharge enough blood into the 

 traumatic cavity to disturb the opposition of the mended 

 breach. It is contra-indicated when the vessels are small, 

 easily managed by twisting and unlikely to yield a secondary 

 bleeding; or, when buried in a trauma, the ligature might 

 act as a foreign body to the detriment of neat healing. 



The strangulation of neoplasms by ligating the base or 

 peduncle, is indicated as a method of ablation when the 

 growth is small, has a more or less constricted base and 

 where for various reasons surgical ablation is deemed inad- 

 visable. Warts and other growths on animals that run at 

 large, or .that are too wild to submit to daily- treatment of 

 their wounds, may be disposed of at one stroke by simply 

 strangulating them with a ligature and then leaving them to 

 slough off without any further attention. The operation has 

 the advantage of not exposing the underlying tissues to infec- 

 tion, as occurs when a growth is dissected out and the wound 

 is sutured. Sutured wounds require a certain amount of . 

 after-care that may be difficult or even impossible to execute 

 under some circumstances. Hygroma of the elbow (Shoe- 

 boil), located at a movable part that often heals badly when 

 wounded, is sometimes submitted to this form of treatment. 

 In fact many practitioners, owing to the bad behavior of the 

 surgfcal wound, have a decided aversion against total abla- 



