3209 Mesenteric Vein Thrombosis: An Unusual Cause of Small Bowel Obstruction

Abstract

INTRODUCTION: Mesenteric venous thrombosis (MVT) is an uncommon cause of acute to sub-acute abdominal pain. Early recognition and treatment have survival implications. CASE DESCRIPTION/METHODS: A 42 year-old male with past medical history of hypertension and obstructive sleep apnea presented with 3 weeks of worsening abdominal pain, nausea and vomiting. Physical exam revealed diffusely tender abdomen with mild guarding, no rebound tenderness and normoactive bowel sounds. Pertinent labs on admission included an elevated white count of 13.5 K/mm3 and lactate of 2 mmol/L. A non-contrast CT abdomen demonstrated small bowel loops with abnormal wall thickening and associated inflammatory changes. He was started on broad spectrum antibiotics for enteritis, however he had worsening abdominal pain and an abdominal x-ray revealed small bowel obstruction. Patient was made NPO and conservatively managed with IV fluids. His hospital course was complicated by fever of 100.8 F and leukocytosis of 26.3 K/mm3 Infectious work up was unremarkable and a CT abdomen with contrast revealed thrombosis of main portal, superior mesenteric and splenic vein. Hypercoagulable workup resulted in decreased Protein S activity (1779X) and Factor II heterozygosity (prothrombin G20210A mutation). DISCUSSION: MVT accounts for 6%–9% of all the cases of acute mesenteric ischemia. Most common presenting symptom is abdominal pain which occurs in 91–100% of the cases followed by nausea, vomiting and melena. Associated portal venous thrombosis can be seen if the disease originates in the major veins instead of the small vena rectae. Young patients without known risk factors for venous thromboembolic (VTE) and thrombosis in unusual sites such as portal, mesenteric and cerebral veins should be evaluated for thrombophilias. Approximately 20-40% of patients have previous history of deep vein thrombosis or may have a pre-existing hereditary hypercoagulable state such as protein C deficiency, protein S deficiency, anti thrombin III deficiency, factor V Leiden deficiency, or antiphospholipid syndrome. In general, outcomes in MVT are better when compared to arterial thrombosis with mortality of 44% as compared to 66–89% respectively. Studies have shown that early use of heparin has been associated with improved survival. Early recognition of MVT and treatment with anti coagulation has led to non-surgical treatment and improved outcomes.