CT findings in isolated ischemic proctosigmoiditis

Abstract

The purpose of our study was to describe the CT features of ischemic proctosigmoiditis in correlation with clinical, laboratory, endoscopic, and histopathologic findings. Our study included seven patients with isolated ischemic proctosigmoiditis. Patients were identified by a retrospective review of all histopathologic records of colonoscopic biopsies performed during a time period of 4 years. All patients presented with left lower abdominal quadrant pain, bloody stools, and leukocytosis, and four patients had fever at the time of presentation. Four of seven patients suffered from diarrhea, one of seven was constipated and two of seven had normal stool consistency. The CT examinations were reviewed by two authors by consensus and compared with clinical and histopathologic results as well as with the initial CT diagnosis. The CT showed a wall thickening confined to the rectum and sigmoid colon in seven of seven patients, stranding of the pararectal fat in four of seven, and stranding of the perisigmoidal fat in one of seven patients. There were no enlarged lymph nodes, but five of seven patients showed coexistent diverticulosis and in three of these patients CT findings were initially misinterpreted as sigmoid diverticulitis. Endoscopies and histopathologic analyses of endoscopic biopsies confirmed non-transmural ischemic proctosigmoiditis in all patients. Isolated ischemic proctosigmoiditis often presents with unspecific CT features and potentially misleading clinical and laboratory findings. In an elderly patient or a patient with known cardiovascular risk factors the diagnosis of ischemic proctosigmoiditis should be considered when wall thickening confined to the rectum and sigmoid colon is seen that is associated with perirectal fat stranding.

CT Imaging of Colitis

“…Ischemic changes in the rectum are rare because of the excellent collateral blood supply. However, in elderly patients with atherosclerosis and precipitating factors such as a major illness or hemodynamic disturbance, the diagnosis of ischemic proctosigmoiditis should be considered when wall thickening confined to the rectum and sigmoid colon is seen in association with perirectal fat stranding (52,53). Ischemic changes in the colon may also be seen in cocaine users, including crack users, and may manifest in the right colon or in the rectosigmoid colon (54).…”

Accuracy of multidetector row computed tomography for the diagnosis of acute bowel ischemia in a non-selected study population

“…However, this seems to be well compensated by the fact that-in contrast to angiography-CT is able to show the pathologic changes at the intestine as well as possible complications of bowel ischemia directly and that CT is additionally able to diagnose various non-occlusive types of bowel ischemia as, for example, transient ischemic colitis and distension colitis with a similarly high accuracy as, for example, more rare types of bowel ischemia such as ischemic proctosigmoiditis or isolated cecal infarction [19,20]. Nevertheless, false negative or false positive diagnoses are certainly possible using CT, and here one should differentiate between cases that are missed and cases that are primarily misinterpreted.…”

An Unusual Case of Hematochezia: Acute Ischemic Proctosigmoiditis

“…4,6 CT findings in ischemic proctosigmoiditis are nonspecific 8,9 and may include increased mural thickness and perirectal fat stranding confined to the recto-sigmoid portion of the colon. 10 Arteriography is of limited utility unless acute mesenteric ischemia is suspected or active bleeding continues. The underlying mechanism leading to ischemic proctosigmoiditis is not completely understood.…”