378 CLINICAL APPLIED ANATOMY. 



In most cases the appendix lies internal to the long axis of the 

 caecum, but sometimes it is behind or to the outer side of it. 

 When it is to the inner side of the caecum it may lie under cover 

 of the lower end of the ileum and mesentery of the small 

 intestine, or be coiled up on the pelvic brim, or hang over into 

 the cavity of the true pelvis. If it is behind the ileum and its 

 mesentery, which is not an uncommon position for it to occupy, 

 these structures will have to be raised in order to expose it, and 

 the peritonitis which results from its inflammation is very apt 

 to spread widely amongst the coils of the small intestine. In such 

 cases the local swelling and tenderness will be felt in the right 

 iliac fossa internal to the position of the caecum. Inflammation 

 of an appendix which lies coiled on the pelvic brim is in a 

 favourable position to infect both the pelvis and the right iliac 

 fossa ; the inflammatory mass should be felt superficially just 

 above Poupart's ligament. If the appendix hangs down over 

 the brim of the true pelvis, the peritonitis which results from its 

 inflammation involves the structures in the pelvis, and the 

 inflammatory mass may only be detected by rectal or vaginal 

 examination. 



When the appendix is not internal to the long axis of the 

 caecum, it may be found in a retrocaecal pouch, or may extend 

 upwards behind the ascending colon or lie in the sulcus between 

 the caecum and the right flank. An appendix in a retrocaecal 

 pouch may give rise to a localised and deep-seated abscess which 

 is difficult to find. The difficulty is even greater when the 

 appendix is actually bound down behind the ascending colon. 

 In such cases it has probably become entangled during the 

 descent of the caecum, and imprisoned by the normal adhesion 

 of the mesocaecum to the abdominal wall. The fact that all the 

 longitudinal bands of the colon converge to the root of the 

 appendix may afford considerable assistance to the surgeon in 

 his search for an abnormally placed appendix. When the 

 appendix lies behind the caecum or colon, tenderness on deep 

 pressure may often be found, not on the front of the abdomen, 

 but immediately above the iliac crest posteriorly. In such cases 



