SURGICAL HEMOSTASIA. 



535 



it between vessels which are perfectly intact and those which 

 have been partially cut through or otherwise injured. 



The immediate ligating of an artery entirely e?««it?ec? includes 

 but two steps : the prehension of the artery and the adjustment 

 of the Ugature. 



"When drawn out of its position with the proper forceps the 

 artery must be carefully examined for possible adhesions, and 

 especially any nervous threads which may be attached to its sur- 

 face—all of which must be dissected. 



In placing the Ugature many operators carry the thread, form- 

 ing a loop, with the forceps, and on seizing the artery and seeing 

 that it is clear from the surrounding tissues, they slip the loop 

 down over the instrument upon the vessel, to be tied by an assist- 

 ant. The apparent simplicity of this movement is deceptive ; too 

 often the loop of the ligature adheres to the wound, the ends roU 

 over themselves and one another, the ligature cannot be properly 

 placed over the vessel, and the knot is tied over the forceps before 

 the thread has reached the artery. To avoid this it is better, when 

 the vessel has been weU secured and isolated, to have the assistant 

 apply the ligature by its middle upon the jaws of the forceps, be- 

 hind the hand of the surgeon holding them, in order to be free in 

 his movements. Then making first a simple knot, without twist- 

 ing the thread, and tying it close to the forceps, he then, with the 



Fia. 458.— Applying the Ligature. 



thumbs, pushes the thread further along the artery, and ties it by 

 pressing the thumbs together with sufficient firmness to rupture 

 the internal membrane of the vessel. If the wound be deep, in- 

 stead of the thumbs both indexes are used to carry the thread 

 along the artery and tie it. The forceps is then removed and 



