340 THE ABDOMEN AND PELVIS 



colic ligament. Superiorly, the flexure is in contact with the 

 lower end of the spleen, and, posteriorly, it rests on the lateral 

 part of the anterior surface of the left kidney. 



The left colic artery, which is a branch of the inferior 

 mesenteric, runs upwards and to the left, behind the peritoneum 

 of the left infra-colic compartment and in front of the internal 

 spermatic vessels, ureter, and kidney. Before it reaches the 

 left colic flexure, the artery divides into a descending branch, 

 which runs downwards along the medial border of the descending 

 colon, and an ascending branch, which supplies the flexure and 

 then enters the transverse meso-colon to supply the transverse 

 colon and anastomose with the left branch of the middle colic. 



The lymph vessels of the left flexure pass through the epi- and 

 para-colic lymph glands to reach the intermediate group on 

 the left colic artery. Jamieson and Dobson state that a few 

 lymph vessels from the flexure enter the splenic lymph glands, 

 and that, on this account, complete removal of the lymphatic 

 area in malignant disease of the flexure is impossible. 



Resection of the left colic flexure involves the removal 

 of the left third of the transverse colon and the upper part of 

 the descending colon. This necessitates the division of (i) the 

 peritoneum in the left para-colic gutter, (2) the phrenico-colic 

 ligament, (3) the left part of the greater omentum, and (4) the 

 left part of the transverse meso-colon. In this way the flexure 

 is mobilised, and it can then be stripped downwards and medially 

 by the fingers. During this process care must be exercised 

 not to injure the kidney or ureter (cf. resection of right flexure, 

 p. 339). The ascending branch of the left colic artery is ligated 

 on the posterior surface of the peritoneum, and the left branch 

 of the middle colic is caught before the transverse colon and 

 meso-colon are divided. 



The Descending Colon is about four inches long and 

 extends from the left flexure down to the iliac crest. Above, 

 it lies in the angle between the left kidney and the transversus 

 abdominis ; below, it lies on the quadra tus lumborum. It 

 separates the left infra-colic compartment from the left para-colic 

 gutter, and, anteriorly, it is in relation to the terminal part of 

 the transverse colon above, and to coils of small intestine below. 

 The peritoneum covers the descending colon in front and on 

 each side, but this part of the gut rarely possesses a mesentery. 

 The descending colon is in direct contact with the extra-peritoneal 

 fat (p. 275). 



