Mesenteric venous thrombosis in a young adult: A case report and review of the literature.

Background: Acute mesenteric vein thrombosis (MVT) accounts for only 2%-10% of all cases of acute mesenteric ischaemia, with an incidence rate of ~0.1% in Europe and the United States. It represents < 10% of mesenteric infarction cases and is seen predominantly in older adults. In younger individuals, MVT is uncommon, with 36% of cases having unidentified mechanisms and causes.

Case summary: A 27-year-old man presented to the emergency department on February 29, 2024, with a chief complaint of intermittent abdominal pain for 3 day. He was previously in good health. As the abdominal pain was not alleviated by conventional treatment, an abdominal computed tomography (CT) scan was performed, which showed increased density in the portal and mesenteric veins. Further imaging, including portal vein ultrasound, mesenteric CT angiography, and enhanced abdominal CT, revealed widespread thrombosis of the portal vein system (including the main portal vein, left and right branches, proximal mesenteric vein, and splenic vein). After 10 day of thrombectomy and anticoagulation therapy, the patient's abdominal pain had improved significantly. Follow-up assessments indicated that portal venous blood flow had largely returned to normal. He was discharged on March 9, 2024. During a follow-up exam 2 months later, repeat abdominal enhanced CT showed that the previously detected thrombi were no longer visible.

Conclusion: Clinicians should remain vigilant for acute MVT in young patients presenting with abdominal pain, to prevent misdiagnosis of this fatal condition.