The early diagnosis of acute mesenteric occlusion presents a difficult problem in abdominal surgery. In a study on rats the relation between graded small bowel
ischemia and the concentration of
heme compounds in the plasma was investigated. The
ischemia was produced by
ligation of terminal vessels at the mesenteric margin of the intestine (mesenteric end arcades) or the superior mesenteric artery.
Heme compounds were assayed by a
benzidine method developed by Crossby et al. The concentration of
heme compounds in the plasma was higher in animals with various grades of intestinal
ischemia than in animals subjected to
laparotomy alone. This increase was noted as early as 4 hours after induction of moderate and severe grade of
ischemia. The results indicate that an increase in plasma concentration of
heme compounds takes place at an early stage of moderate and severe small bowel
ischemia following
mesenteric vascular occlusion but not until after 48 hours in mild
ischemia. The clinical value of this method has to be tested in a clinical study.