PROGNOSIS AND TREATMENT OF ATRESIA ANI. 595 



munication between the upper vaginal wall and rectum can usually 

 be discovered with the finger or probe. 



In the latter case the animal may live, provided the ano-vaginal 

 opening is large enough to allow discharge of bowel contents. 

 Burmeister saw an ano-vaginal fistula of the size of a straw in a six 

 weeks pig. Pieperbrok found recto-vaginal fistula and imperforate 

 anus in a pregnant sow. 



In atresia ani or recti the animals sooner or later die, if provision 

 be not made by operation for discharge of excrement, though, as 

 the milk forms comparatively little faeces, the animals may continue 

 to live for several weeks. Atresia ani was seen by Waltrup in a twenty- 

 six days sucking pig, and by Moller in a puppy of the same age. 

 Ruminants seldom live so long ; in them severe disturbance results 

 from suppressed defalcation after four to eight days ; in a case 

 described by Bull, a calf lived five days : the post-mortem showed 

 the walls of the rectum adherent for a distance of 5 to 6 inches. 



Prognosis is in general favourable, provided operation is not 

 too long deferred. It depends principally on whether the anus alone 

 or both anus and a considerable length of rectum are simultaneously 

 closed ; in the latter case there is always great difficulty in laying 

 open the bowel and in keeping it patent. The artificial anus tends 

 strongly to contract and interfere with defalcation, whilst the rectum 

 becomes paralysed on account of severe distension, and may even 

 be ruptured ; in such case operation gives no relief. 



Treatment. Operation is the sole resource. Some recommend 

 delaying it for a day or two after birth, because moderate distension 

 of the rectum is rather advantageous, but as a rule the surgeon's 

 attention is not demanded at this time, often not till much later, 

 when death is unavoidable. In atresia ani the anus is only closed 

 by a layer of skin which is simply grasped with forceps and cut 

 through with the scissors. Faeces are usually discharged at once ; 

 if not, the subcutaneous tissue, which sometimes contributes to the 

 obstruction, must be thrust on one side. Reunion of the edges may 

 generally be prevented by smearing the parts with some mild ointment. 

 For a similar purpose the mucous membrane of the rectum is in man 

 united with the outer skin by incising the skin from above downwards 

 right over the anus, dividing the subcutis on either side of the pro- 

 jecting end of the rectum, cutting through the mucous membrane 

 in the same direction, and uniting it with the outer skin by several 

 interrupted sutures. Stenosis is thus prevented. 



The operation for atresia recti is more difficult, particularly if 

 the rectum is extensively adherent to neighbouring parts. The less 



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