The Abdomen i8i 



Surgerv of the Intestines 



■ For all intestinal operations the animal should be secured in the 

 dorsal position with hopples and a general anesthetic administered, 

 the opening in the abdominal wall being made in the median line. 



ENTEBORRAPHY. 



The coats of the dog's bowel are composed of the following 

 layers : ( i ) Mucosa, consisting of the gland follicles and muscularis 

 mucosa, (2) Submucosa, which according to Clason is formed of 

 two relatively thin layers of inelastic connective tissue fibrils, which 

 cross at acute angles and run in a spiral manner around the intestine, 

 (3) Muscularis externa, a well-developed coat of thick inner cir- 

 cular fibers and of thinner outer longitudinal fibers, and (4) Serosa. 



The mucosa can easily be scraped away with the aid of some 

 blunt instrument, and the serosa and muscularis externa can also be 

 removed with a little trouble. There then remains the white fibrous 

 submucosa, which is a very important layer and may be regarded 

 as the framework of the canal, the other tissues forming adjuncts 

 for the performance of its functions. This submucosa constitutes 

 the so-called "sausage-skin", from which catgut is manufactured. 

 It is regarded by Halsted as most important in suture of the intes- 

 tine, because it affords a better hold for the stitches than does the 

 muscular coat. 



In applying sutures it is highly important to guard against 

 sepsis from the interior of the bowel. While experience has taught 

 that simple celiotomy on the dog rarely terminates unsuccessfully 

 through infection, it is a different matter when the continuity of 

 of the bowel-wall is interferred with. No stitch which passes to the 

 outside of the serosa must penetrate the mucosa. The reason for 

 this is obvious. A communicating channel would thereby be fonned 

 through which bacteria-laden intestinal contents would find egress 

 and rapidly infect the peritoneum. Septic peritonitis has often fol- 

 lowed experimental operations where such precautions have been 

 neglected. 



A strong point made by Halsted is that each stitch should pass 

 through part of the fibrous submucosa, which is far stronger than 

 the combined thickness of the serosa and muscularis, but must on no 



