SURGICAL ANATOMY OF THE INTESTINAL CANAL. 931 



the greater amount of circular muscular fibres. The small intestine, and most frequently the 

 iiuum. may become strangulated by internal bands, or through apertures, normal or abnormal. 

 The bands may be formed in several different ways : they may be old peritoneal adhesions from 

 previous attacks of peritonitis ; or an adherent omentutn from the same cause ; or the band 

 may be formed by Meckel's diverticulum, which has contracted adhesions at its distal extremity ; 

 or the band may be the result of the abnormal attachment of some normal structure, as the 

 adhesion of two appendices epiploicae, or an adherent vermiform appendix or Fallopian tube. 

 Intussusception or mvagination of the small intestine may take place in any part of the jejunum 

 and ileum, but the most frequent situation is at the ileo-caecal valve, the valve forming the apex 

 of the entering tube. This form may attain great size, and it is not uncommon in these cases to 

 find the valve projecting from the anus. Stricture, the impaction of foreign bodies, and twist- 

 ing of the gut (volvulus) may lead to intestinal obstruction. 



Resection of a portion of the intestine may be required in cases of gangrenous gut ; in cases 

 of intussusception ; for the removal of new growth in the bowel; in dealing with artificial 

 anus; and in cases of rupture. The operation is termed enterectomy, and is performed as 

 follows : the abdomen having been opened and the amount of bowel requiring removal having 

 been determined upon, the gut must be clamped on either side of this portion in order to 

 prevent the escape of any of the contents of the bowel during the operation. The portion of 

 bowel is then separated above and below by means of scissors. If the portion removed is 

 small, it may be simply removed from the mesentery at its attachment and the bleeding vessels 

 tied; but if it is large, it will be necessary to remove also a triangular piece of the mesentery, 

 and, having secured the vessels, suture the cut edges of this structure together. The surgeon 

 then proceeds to unite the cut ends of the bowel together by the operation of what is termed 

 end-to-end anastomosis. There are many ways of doing this, which may be divided into two 

 classes : one where the anastomosis is made by means of some mechanical appliance, such as 

 Murphy's button, or one of the ibrms of decalcified bone bobbins ; and the other, where the 

 operation is performed by suturing the ends of the bowel in such a manner that the peritoneum 

 covering the free divided ends of the bowel is brought into contact, 'so that speedy union may 

 ensue. 



The vermiform appendix is very liable to become inflamed. This condition may be set up 

 by the appendix becoming twisted, owing to the shortness of its mesentery, in consequence of 

 distention of the caecum. As the result of this its blood-supply, which is mainly through one 

 large artery running in the mesentery, becomes interfered with. Again, in rarer cases, the 

 inflammation is set up by the impaction of a solid mass of feces or a foreign body in it. The 

 inflammation may result in ulceration and perforation, or. if the torsion is very acute, in gangrene 

 of the appendix. These conditions may require operative interference, and in cases of recurrent 

 attacks of appendicitis it is generally advisable to remove this diverticulum of the bowel. In 

 external hernia the ileum is the portion of bowel most frequently herniated. When a part of 

 the large intestine is involved, it is usually the caecum, and this may occur even on the left side. 

 In some few cases the vermiform appendix has been the part implicated in cases of strangulated 

 hernia, and has given rise to serious symptoms of obstruction. Occasionally ulceration of the 

 duodenal glands may occur in cases of burns, but is not a very common complication. The 

 ulcer may perforate one of the large duodenal vessels, and may cause death from hemorrhage, 

 or it may perforate the coats of the intestine and produce fatal septic peritonitis. The diameter of 

 the large intestine gradually diminishes from the caecum, which has the greatest diameter of any 

 part of the bowel, to the point of junction of the sigrnoid flexure with the rectum, at or a little 

 below which point stricture most commonly occurs and diminishes in frequency as one proceeds 

 upward to the caecum. When distended by some obstruction low down, the outline of the large 

 intestine cau be defined throughout nearly the whole of its course all, in fact, except the 

 hepatic and splenic flexures, which are more deeply placed ; the distention is most obvious in 

 the two flanks and on the front of the abdomen just above the umbilicus. The caecum, how- 

 ever, is that portion of the bowel which is, of all, most distended. It sometimes assumes 

 enormous dimensions, and has been known to give way from the distention, causing fatal peri- 

 tonitis. The hepatic flexure and the right extremity of the transverse colon are in close rela- 

 tionship with the liver, and abscess of this viscus sometimes bursts into the gut in this situation. 

 The gall-bladder may become adherent to the colon, and gall-stones may find their way through 

 into the gut, where they may become impacted or may be discharged per anum. The mobility 

 of the sigmoid flexure renders it more liable to become the seat of a volvulus or twist than any 

 other part of the intestine. It generally occurs in patients who have been the subjects of 

 habitual constipation, and in whom, therefore, the meso-sigmoid flexure is elongated. The gut 

 at this part being loaded with feces, from its weight falls over the gut below, and so gives rise 

 to the twist. 



The surgical anatomy of the rectum is of considerable importance. There may be congeni- 

 tal malformation due to arrest or imperfect development. Thus, there may be no inflection of 

 the epiblast, and consequently a complete absence of the anus; or the hind-gut may be imper- 

 fectly developed, and there may be an absence of the rectum, though the anus is developed; 

 or the inflection of the epiblast may not communicate with the termination of the hind-gut 

 from want of solution of continuity in the septum which in early foetal life exists between the 

 two. The mucous membrane is thick and but loosely connected to the muscular coat beneath, 

 and thus favors prolapse, especially in children. The vessels of the rectum are arranged, 

 as mentioned above, longitudinally, and are contained in the loose cellular tissue between the 



