Presentation
Acute onset of severe epigastric pain, vomiting and absence of bowel motion.
Patient Data
The abdominal supine radiograph showed mildly dilated small bowel loops with relatively normal wall thickness. No pneumoperitoneum or thumbprinting sign.
Small bowel loops (both jejunum and ileum) are mildly dilated (largest diameter ~3.2cm) with marked reduction of bowel wall enhancement, especially at the jejunum. No significant small bowel wall thickening. Small bowel feces sign within the distal jejunum at the left iliac fossa without downstream transition point to suggest mechanical obstruction, where this small bowel feces sign is likely secondary due to ileus/non-peristalsis. Pneumatosis intestinalis is noted for the dilated small bowel loops. The terminal ileum and large colon as well as the rectum are mostly collapsed.
Diffuse air pockets are seen within the small bowel mesentery veins, superior mesenteric vein and further into the peripheral branches of portal veins in both liver lobes in keeping with portal venous gas.
No pneumoperitoneum.
A large low attenuating thrombus seen at the origin of the superio mesenteric artery extending into the proximal SMA. Poor contrast opacification of the distal SMA, especially the jejunal and ileal arterial branches.
Part of its thrombus occludes the origin of the right renal artery, which has led to multiple wedge shaped hypodense areas within all poles of the right kidney, in keeping with acute renal infarctions.
A suspicious wedge shaped hypodense area is also noted at liver segment III which may represent a liver infarction. The origin of celiac trunk is narrowed without obvious thrombosis. However, the common hepatic artery is hypoplastic/small in caliber. This suggests that there is hepatic artery variant.
Large soft tissue mass at uterine fundus which can represent uterine fibroid.
No ascites.
Annotated images show gangrenous small bowel loops, occluded proximal SMA, porto-mesenteric gas as well as renal and hepatic infarctions.
Case Discussion
CT features are suggestive of acute small bowel mesenteric ischemia (bowel dilatation, pneumatosis intestinalis, ileus, poor bowel wall enhancement) secondary due to arterial occlusive thrombus/embolus at the proximal superior mesenteric artery. SMV and portal venous gas (pneumatosis portalis) are poor/grave prognostic factors of bowel ischemia. No pneumoperitoneum. The bowel wall can be normal or thinned in complete arterial occlusion
Multi-focal right renal infarctions, secondary due to occlusion at its origin of the right renal artery.
Liver segment III infarction with hepatomegaly due to hepatic artery variant.
The patient went on to have emergency laparotomy surgery.
Intraoperative finding:
Upon entering the peritoneal cavity, about 100cc turbid ascitic fluid drained from the peritoneum. No bowel perforation. Small bowel appeared ischemic (aperistalsis, pale/dusky, no pulse), 100cm from duodenojejunal flexure until 60cm from the terminal ileum.
Ischemic small bowel loops resected, double barrel ileostomy brought up to the right lumbar region.
Cecum, ascending colon, transverse, sigmoid & descending colon normal.
Radiology Pearls:
Bowel ischemia secondary to arterial mesenteric ischemia usually has no thickened bowel wall but can even have thin wall. Minimal intramural gas and unlikely to have mesenteric fluid/fat stranding. This is so different from venous mesenteric ischemia.