Pathogenesis. 



431 



one case (Berlin report 1901-1902) ; it is, therefore, a great 

 rarity. The place of torsion is also rarely found in the left 

 divisions (fig. 46). 



Wall gives the following figures for twenty-six collected cases : Fifteen times 

 place of torsion right at the cecum, seven times in the transverse colon, three times 

 in the left divisions, once at the basis of the cecum, so that the latter had also been 

 twisted; it is possible that the place of torsion is more frequently at the cecum than 

 is usually supposed to be the case, since the finding of the place of torsion in this 

 region is coupled with great difficulties and hence the place may easily be over- 

 looked. In torsion at this place it may appear that only the upper division sinks 

 beside or below the ventral division to become strangulated at its junction with 

 the small colon, without elianging its position (authors' observation). In spite 

 of this, venous congestion develops because tlie vein is compressed either by the 

 prolapsed upper division or in torsion to the left by the tense mesocolon. 



In kinking of the large 

 intestine the himen (just 

 like in kinking of any 

 other tubular organ) be- 

 comes narrowed or oblit- 

 erated by the inward pro- 

 jection of the wall, and 

 the parts beyond the kink 

 show signs of intense con- 

 gestion. In kinking of the 

 apex of the cecum the 

 shut off portion usually 

 becomes anemic and ne- 

 crotic. 



In torsion of the mes- 

 entery of other portions 

 of the intestine, the mes- 

 entery itself is twisted 

 into a cord or there is a 

 volvulus when one por- 

 tion of the intestines has 

 wound around another 

 portion, and strangulated 

 it like a ring (fig. 47). 

 Parts of intestines stran- 

 gulated in this manner ap- 

 pear enormously distend- 

 ed and are dark red in 

 color. 



The peritoneal cavity contains, in any form of volvulus or 

 torsion, a bloody serous fluid; sometimes circumscribed or dif- 

 fuse peritonitis is present, occasionally intestinal rupture. 



The differential diagnosis of torsion or volvulus must consider hemorrhagic in- 

 farction of the intestinal wall in thrombosis or embolism of the mesenteric arteries 

 in those rare cases when on postmortem examination the displacements are not very 

 noticeable or are overlooked entirely. However, a careful examination of the blood 

 vessels, as to the size and position of any thrombi or emboli present, and careful 

 inspection will prevent errors. The sharp demarcation of hemorrhagic infiltration 



Fig. 46. Torsion of the left divisions of the 

 colon towards the right in a horse also suffer- 

 ing from volvulus of the small intestine. (As 

 a rule torsion occurs more anteriorly. ) 



