- Internal hernia: Secondary sign of a mesenteric tear (difficult to detect on CT). Closed loop bowel obstruction, volvulus, and strangulation can occur.
- Increased mesenteric attenuation: Can be a manifestation of isolated mesenteric injury.
- Mesenteric hematoma: When seen in the portal venous-phase, should be evaluated on delayed images: Enlargement or increased attenuation is a sign of active bleeding (see below). Small isolated mesenteric hematomas can be managed conservatively with observation. Large hematomas indicated injury to major mesenteric vessels, and are managed surgically to avoid the risk of delayed bowel ischemia.
- Beading or abrupt termination of mesenteric vessels: In the setting of trauma, these are signs of significant venous or arterial injury.
- Active extravasation: Uncommon, but ~100% specific for a significant vascular injury. Requires operative repair. Endovascular coil embolization is sometimes attempted with injury to smaller vessels; however, patients should be closely monitored for signs of bowel ischemia.
When specific signs of mesenteric trauma are encountered, a careful search for associated bowel injury should be initiated.
The image above is from a trauma patient. There is active extravasation of contrast in the right lower quadrant (blue arrows) from injury to iliocolic branch of the superior mesenteric artery (pink arrows). Delayed images show expansion of the extravasated pool of contrast (green arrows). The patient also had a jejunal hematoma (not shown).