168 



or by strangulation of an intestinal loop by fibrous bands resulting 

 from chronic jjeritonitis, etc. Of these various causes, the three prin- 

 cipal may here be described : — 



(1.) Tearing of the mesentery. As a result of mechanical violence 

 the ej)iploon or mesentery becomes fissured, and the peristaltic move- 

 ments cause a loop of intestine to pass through and become fixed in 

 the fissure. If the opening is narrow, as is usually the case, the base 

 of the intestinal loop, riding on the lower lip of the slit, becomes con- 

 stricted by the margins of the ojjening through which it has passed. 



(2.) In pelvic hernia a loop of intestine passes between the spermatic 

 cord and the walls of the pelvis. The fissure in this case is in the 

 serous fold which supports the large testicular arteries and the vas 

 deferens. The fold is often ruptured during castration, especially during 



the practice of " bistournage," in conse- 

 quence of traction exercised on the cord. 



(3.) Pseudo - ligaments and fibrous 

 bands due to chronic i^eritonitis. — In 

 local, sul.)acute or chronic peritonitis false 

 membranes may become organised, form- 

 ing fibrous cords or folds connecting the 

 parieto-visceral.or inter-visceral surfaces. 

 If by accident a loop of intestine insinu- 

 ates itself beneath one of these fibrous 

 bands, the passage of digestive material 

 is first impeded and then stopped. The 

 intestine becomes engorged, and symp- 

 toms of strangulation soon folloM'. 

 The symptoms appear suddenly, and are similar to those of inva- 

 gination. They consist of very acute colic, which disappears after ten 

 to twelve hours. 



The peristaltic movements drive the semi-digested food, whether liquid 

 or gaseous, towards the lower (strangulated) end, from which it cannot 

 escape. It therefore distends the herniated loop and sets up intestinal 

 engorgement. This constitutes the first stage of strangulation, and is 

 accompanied by severe disturbance in the local circulation. The nuicous 

 membrane of the intestine becomes swollen and infiltrated, so that it 

 alone soon fills the entire neck of the hernia. Necrosis of the loop of 

 intestine is then only a matter of time. 



The diagnosis of colic l)y strangulation is difficult. The condition 

 cannot often l)e recognised at an early stage, and may easily and 

 excusably be confused with invagination. Only in rare cases will rectal 

 and abdominal examination enable one to detect a pelvic or mesenteric 

 hernia. 



Fig. 69. — Schema of hernial 

 strangulation. 



