An 87 y.o. woman presents after a bout of SVT converted with adenosine by EMS. She now has abdominal bloating

What do you notice on her CT?

Our patient had an episode of SVT and developed bowel ischemia in the watershed areas of the colon.

bowel wall thickening noted at the splenic flexure

Watershed regions are the regions between the two major arteries supplying the colon. The superior mesenteric artery supplies the bowel from the lower part of the duodenum to two-thirds of the transverse colon.  The inferior mesenteric artery supplies the  large intestine from the distal  one-third of the transverse colon to the rectum. The splenic flexure is the area between the SMA and IMA arteries which is prone to ischemic insults.

There are two types of bowel ischemia:  colonic ischemia as described in our patient and small bowel ischemia(mesenteric ischemia). The characteristics of acute small bowel ischemia differ from colonic ischemia.   Age of 60 years, not appearing severely ill, mild abdominal pain, or bloody diarrhea are more common in acute colonic ischemia. This is in contrast to small bowel ischemia which usually presents acutely with periumbilical pain.  Since bowel ischemia is the result of poor perfusion of the bowel, it can occur either due to arterial obstruction(atherosclerosis or embolus) or venous obstruction( mesenteric venous thrombosis).

Mesenteric venous thrombosis is often associated with malignancy and prothrombotic states  or myeloproliferative diseases which are JAK2 positive.

Amini A, Nagalli S. Bowel Ischemia.  In: Statpearls . StatPearls Publishing: 2022 Jan. 2021. Nov 25, PMID:32119414

Hmoud B, Singal A, Kamath P.  Mesenteric venous thrombosis. J Clin Exp Hepatol 2014 Sep;4(3):257-263.

Wasnik A, Liu P, Platt J.  Imaging findings in diagnosis of mesenteric aschemia: how can we be sure?

Clinical Practice 2014 11(3)