Abstract

Acute mesenteric ischemia occurs in 1 of 1000 hospital admissions, and a nonocclusive mechanism makes up about 20% of these cases.¹Nonocclusive mesenteric ischemia (NOMI) is a condition where the macrovasculature is patent, but the microvascular blood flow is inadequate to meet intestinal tissue demands leading to gangrene and disastrous consequences. The pathophysiology of NOMI involves low blood flow states such as shock, heart failure, hemodialysis and direct splanchnic arteriolar vasoconstriction by drugs, eg, digoxin.^2,3Angiography is the gold standard for diagnosis; however, its invasive nature, potential for contrast nephropathy and limited availability makes it a less than optimal screening tool. Use of Doppler ultrasonography in the early detection of NOMI has not been reported. A 68-year-old man with congestive heart failure was admitted for recurrent ventricular tachycardia. His medications included digoxin, amiodarone, furosemide, metoprolol succinate, and warfarin. On physical examination, he was mildly hypotensive. Laboratory investigations showed a creatinine of 1.7 mg/dL, with normal electrolytes. The digoxin concentration was in the normal range. His medications, including digoxin, were continued in the hospital. On the third hospital day, he developed cramping abdominal pain with nausea starting 30 minutes after eating, which improved intermittently between meals. Abdominal examination was benign and x-rays were normal. Mesenteric ischemia was suspected and a Doppler ultrasound of the mesenteric arteries was obtained. There was normal peak systolic velocity with severely decreased diastolic flow both pre and postprandially in the superior mesenteric artery. This was suggestive of elevated resistance in the distal mesenteric arterioles consistent with NOMI. The digoxin was stopped. In the setting of renal insufficiency, it was decided to optimize hemodynamic status before angiography. The patient's symptoms started to resolve after 24 hours. Daily follow-up Doppler ultrasounds showed progressive improvement in diastolic flow. Angiogram of the mesenteric arteries four days after discontinuation of digoxin was normal. Doppler study performed at this time also showed normal diastolic flow with resolution of the vasospasm. The patient was discharged home without digoxin. On follow up one month later, the patient had no abdominal symptoms.