Colitis, Ischemic

• • Most common form of GI ischemia

  • May occur following low-flow states: shock, myocardial infarction, abdominal aortic aneurysm (AAA) repair

  • Reversible or irreversible

  • Vascular compromise by occlusive or nonocclusive mechanisms

  • May affect any portion of colon

  • Watershed areas (splenic flexure, rectosigmoid junction) especially vulnerable

  • No pathognomonic findings or signs; requires high index of suspicion

Epidemiology

• • Ischemia of the right colon seen in patients with coronary artery disease (CAD), aortic stenosis

  • Affects elderly most often (> 60 years)

  • May occur in association with diabetes, lupus, sickle cell crisis, pancreatitis

  • Left-sided ischemic colitis 1-2% following aortic reconstruction, higher incidence with ruptured AAA

Symptoms and Signs

• • Abrupt onset of abdominal pain

  • Diarrhea (may be bloody)

  • Nausea

  • Vomiting

  • Tenesmus

  • Fever

  • Physical exam may be unremarkable

  • Pain out of proportion to exam findings

Laboratory Findings

• • Nonspecific, no pathognomonic abnormalities

  • May have leukocytosis

Imaging Findings

• • Abdominal x-rays: Nonspecific Abdominal catastrophe: free air, pneumatosis intestinalis, portal vein air

  •Barium enema: May feature thumbprints

  • CT: May show thicken bowel wall

  • Angiography: May reveal major mesenteric vascular occlusion, stenosis, spasm

  • Colonoscopy

  • -May reveal edematous, hemorrhagic mucosa with or without ulcerations

    -Advanced ischemia appears as blue-black discoloration, patchy areas of black, nonviable mucosa

  • Grayish membrane resembles pseudomembranous colitis

• • Colorectal cancer

  • Diverticulitis

  • Inflammatory bowel disease

  • Pseudomembranous colitis

  • Infectious colitis

Rule Out

• • Neoplasm

  • Ulcerative colitis

  • Diverticulitis

• • Comprehensive history and physical exam

  • Is there recent history of low-flow state (AAA repair, cardiac event), pancreatitis

  • Colonoscopy

  • CT scan

  • Diagnosis requires high index of suspicion

  • Consider work-up for hypercoaguable state, embolic source (transesophageal echocardiography, aortography)

When to Admit

• • Patients with suspicion of ischemic colitis should be admitted for work-up, hydration, IV antibiotics, and observation to be certain that the problem is reversible

• • IV hydration

  • Broad-spectrum antibiotics

  • Inpatient hospitalization

  • Bowel rest

  • NG decompression

Surgery

Indications

• • Irreversible disease, failure of conservative measures (hydration, antibiotics, bowel rest) with persistence of symptoms

  • Full thickness necrosis (gangrenous ischemic colitis)

  • Development of stricture/obstruction

  • Worsening clinical course (fever, tachycardia, leukocytosis, acidosis, hypotension)

Medications

• • IV broad-spectrum antibiotics

Treatment Monitoring

• • Serial abdominal exam

  • Serial WBC count

  • Follow-up endoscopy

Complications

• • Severe ischemic disease often associated with other medical comorbidities

  • Overall mortality rate ~ 50%

  • Ischemic stricture

  • Peritonitis

  • Perforation

Prognosis