Utility of sigmoid intramucosal pH in the early diagnosis of ischemic colitis after aorta surgery

A 62-year-old man with grade III ischemia of the legs and occlusion of an aortofemoral shunt underwent axillofemoral bypass and bilateral profundoplasty. During surgery, an aneurysm in the aortic origin of the right common iliac artery ruptured, requiring ligation of the inferior vena cava, the iliac veins and the right common iliac artery. Upon transfer of the patient to the recovery unit, the sigmoid intramucosal pH (pHi) was 6.83 (arterial pH 7.35), the regional CO2 pressure (PrCO2) was 100 mmHg (arterial PCO2 35.2 mmHg), and the lactic acid concentration was 3.6 mmol/L. Ischemic colitis was suspected and colonoscopy confirmed the presence of severe rectal and moderate sigmoid inflammation. An extended sigmoidectomy was performed with colostomy. The patient died from multiorgan failure 48 hours after surgery. Ischemic colitis is a severe complication of aortic surgery. Sigmoid pHi monitoring is non-invasive and highly useful for the early diagnosis of ischemic colitis.