402 Obstruction of the Mesenteric Arteries. 



ly into the blood, or not at all, they rapidly bloat the affected 

 bowel (circumscribed, local meteorism), and this occurs easily 

 since the irregular contractions taking place here and there in 

 the intestinal tract are not favorable to a regular passage of 

 the intestinal contents towards the anus. 



The conditions for an active development of gases are, how- 

 ever, not given in mild forms of hemorrhagic infarction, hence 

 no cessation of the erstwhile marked peristalsis occurs, if, after 

 a certain interval, which is usually not long, the equilibrium of 

 circulation is reestablished. On the other hand, grave forms of 

 circulatory disturbances produce, in their further course, a 

 gradual diminution of peristalsis which leads to complete ces- 

 sation within several, occasionally within one to two, hours. 



With the onset of circumscribed intestinal paralysis, per- 

 istalsis also ceases in the parts situated posteriorly, usually be- 

 fore the feces from the diseased portion have reached the rec- 

 tum. The paralytic portion has the same effect as a portion 

 ol)structed from some cause or other, and as soon as its per- 

 istalsis has completely ceased, portions of the intestines anterior 

 to it are stimulated to convulsive contractions by their accu- 

 mulating contents; these are usually not very intense and not 

 very prolonged. Finally the increasing contents produce grad- 

 ual cessation of contractility, wiiicli progresses towards the 

 stomach. 



The effect upon intestinal peristalsis of circulatory disturbances due to throm- 

 bosis of the mesenteric arteries has been explained in various ways. Panum, Cohn 

 and Bollinger assumed that the thrombotic territory was paralyzed from the start. 

 However, this claim was not borne out by observations made in man. Bloody stools 

 have been observed not infrequently in man during the whole course of the affec- 

 tion, and similar observations have been made by Litten and Marek on experimental 

 dogs. However, if there was at once a circumscribed intestinal paralysis, such occur- 

 rences would be impossible. Indeed, animal experiments have shown beyond doubt 

 that the immediate effect of the circulatory disturbances is not at all an intestinal 

 paralysis, but intermittent convulsive contractions, producing colicky pains. Kader 

 states that after ligation of the mesenteric arteries in dogs and cats peristalsis 

 ceases after four or five hours. In his experiments, where external influences inhib- 

 iting intestinal movements were excluded, Marek found that immediately, or one or 

 two minutes after ligation of the artery, the whole length of the affected bowel per- 

 formed energetic convulsive movements simultaneously in several places. These 

 active contractions continued until the death of the animal occurred (the animals 

 were not kept alive longer than eight hours) ; and they even continued for an hour 

 and a quarter if the caclaver was kept in a warm box. If the intestinal loops were 

 so placed that some wei-e hanging down and soon became filled with intestinal con- 

 tents, their movements ceased sooner. If the arteria mesent. ant., some of its 

 branches and all of its anastomoses had been ligated, and hemorrhagic infarction 

 and in some part anemia had been produced, the movements in the anemic portion 

 ceased after one and one-half hours, while they were still going on in the infarcted 

 territory 



The intestinal wall which is damaged in its nutrition, or 

 eventually necrotic through grave circulatory disturbances, 

 early permits intestinal bacteria to enter into the peritoneal 

 cavity; these then multiply rapidly in a serous exudate and pro- 

 duce circumscribed, later general peritonitis, which causes con- 

 tinuous inflammatory pain; the bacteria and their toxins are 

 also absorbed into the blood, general infection or intoxication 



