Superior mesenteric vein thrombosis induced by influenza infection: A case report

BACKGROUND: Among the various types and causes of mesenteric ischemia, superior mesenteric vein (SMV) thrombosis is a rare and ambiguous disease. If a patient presents with SMV thrombosis, past medical history should be reviewed, and the patient should be screened for underlying disease. SMV thrombosis may also occur due to systemic infection. In this report, we describe a case of SMV thrombosis complicated by influenza B infection. CASE SUMMARY: A 64-year-old male visited the hospital with general weakness, muscle aches, fever, and abdominal pain. The patient underwent computed tomography (CT) and was diagnosed with SMV thrombosis. Since the patient’s muscle pain and fever could not be explained by the SMV thrombosis, the clinician performed a test for influenza, which produced a positive result for influenza B. The patient had a thrombus in the SMV only, with no invasion of the portal or splenic veins, and was clinically stable. Anticoagulation treatment was prescribed without surgery or other procedures. The follow-up CT scan showed improvement, and the patient was subsequently discharged with continued oral anticoagulant treatment. CONCLUSION: This case provides evidence that influenza may be a possible risk factor for SMV thrombosis. If unexplained abdominal pain is accompanied by an influenza infection, examination of an abdominal CT scan may be necessary to screen for possible SMV thrombosis.