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A woman in her early 50s with a history of polycystic ovarian syndrome, diabetes, stroke, and coronary artery disease that required coronary artery bypass graft 6 years earlier presented to the emergency department with 12 hours of sudden-onset, constant, right lower quadrant abdominal pain associated with vomiting and melena. She denied any hematochezia or history of peptic ulcer disease. She had no other surgical history and denied alcohol use or smoking. On examination, she was hypertensive (blood pressure, 185/85 mm Hg) although not tachycardic and was afebrile. She was locally tender to palpation in the right lower quadrant with rebound and voluntary guarding. Her abdomen was not tympanitic. The patient had no abdominal scars, hernias, or palpable masses. Laboratory results were significant for the following: leukocyte count, 23 600/µL (to convert to ×109/L, multiply by 0.001) with neutrophilia (94%); blood urea nitrogen level, 28 mg/dL (to convert to millimoles per liter, multiply by 0.357); creatinine concentration, 0.01 mg/dL (to convert to micromoles per liter, multiply by 88.4); lipase concentration, 195 U/L (to convert to microkatals per liter, multiply by 0.0167); and lactate concentration, 2.02 mg/dL (to convert to millimoles per liter, multiply by 0.111). Electrolyte levels and liver function test results were within normal limits. An electrocardiogram showed normal sinus rhythm. Computed tomography of the abdomen and pelvis with oral and intravenous contrast enhancement was performed (Figure).
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B. Colonic ischemia
Computed tomography revealed cecal wall hypoenhancement with pneumatosis, sparing of the remaining colon and appendix, and bilateral renal infarcts. Given the patient’s abdominal pain, imaging findings, and history of early-onset stroke and cardiovascular disease, she was diagnosed with isolated cecal ischemia, an extremely rare presentation of acute colonic ischemia.
Although the exact cause remains unclear, most cases are of nonocclusive origin,1,2 a variant of nonocclusive mesenteric ischemia, in which a low-flow state results in splanchnic vasoconstriction as blood flow is preferentially diverted to essential organs. It is associated with critical illness and cardiovascular disease. Occlusive causes are rarer and predominantly attributable to large arterial atherosclerotic disease with distal thromboembolism (spontaneous or after vascular procedures), cardiac arrhythmias with embolism of atrial thrombus, small arterial disease in patients with diabetes, or venous outflow obstruction from hypercoagulable states.3 Resultant segmental ischemia often occurs at watershed areas. The cecum may also represent a watershed area4 owing to its end arterial supply from the anterior and posterior cecal arteries. In most patients, there is dual arterial inflow from a vascular arcade that bridges the ileal and colic branches of the ileocolic artery5; however, the rare anatomical variant of a singular inflow off the colic branch may predispose these patients to ischemia.6 The appendix, terminal ileum, and ascending colon have multiple arterial sources, which may explain why these are at lesser risk of ischemia.
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Corresponding Author: Natasha DeNicola, MD, Department of Surgery, Mount Sinai St Luke’s Roosevelt Hospital, 1000 10th Ave, New York, NY 10019 (firstname.lastname@example.org).
Published Online: June 27, 2018. doi:10.1001/jamasurg.2018.1062
Conflict of Interest Disclosures: None reported.
Additional Contributions: We thank the patient for granting permission to publish this information.
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