From an observed study, researchers examined a 68-year-old African American man presented to the emergency department with 72 hours of progressively worsening diffuse abdominal pain, distension, nausea, and nonbilious emesis. He was previously healthy and had no prior abdominal operations.

The patient noted pencil-thin stools that occurred during the past several months but had not had a colonoscopy in more than a decade. The rest of his history was non-contributory. He was mildly tachycardia but normotensive and afebrile. Physical examination revealed a lethargic patient with a distended abdomen, diffuse rebound tenderness, and involuntary guarding. No surgical scars or inguinal hernias were apparent on examination.

The only abnormal laboratory values were as follows: sodium concentration, 126 mEq/L (to convert to ×109 /L, multiply by 0.001). He was resuscitated with 2 L of lactated Ringer solution and underwent computed tomography of the abdomen and pelvis with intravenous contrast. Computed tomography revealed diffuse free fluid but without free air and several loops of dilated small bowel with thickened, hypo enhancing bowel walls.

The mesentery was markedly oedematous. The rest of the small bowel were dilated and air and fluid filled but had normal bowel wall enhancement. The colon was normal.

Acute mesenteric venous thrombosis has an estimated incidence of 2.7 per 100 000 population.

Its origin is multifactorial and can be divided into acquired vs inherited conditions. Localized inflammatory processes, such as infection, trauma, pancreatitis, or tumor leading to compression or invasion into surrounding structures, may increase the risk of mesenteric venous thrombosis that affects predominantly the larger veins.

If cirrhosis and solid organ neoplasms, the most common underlying causes, have been ruled out, diagnostic studies for thrombophilia and myeloproliferative disorders should performed. Polycythaemia Vera With Mesenteric Vein Thrombosis Patients with mesenteric venous thrombosis may also be diagnosed with a myeloproliferative neoplasm 8% to 18% of the time, although a previous study found rates as high as 40%.

Among patients with myeloproliferative neoplasm and mesenteric venous thrombosis, polycythaemia vera (PV) is the most common cause (27.5%), followed by essential thrombocytosis (26.2%) and primary myelofibrosis (12.8%).

Polycythemia vera is an acquired stem cell disorder characterized by erythroid proliferation independent of erythropoietin-mediated growth factor signaling. The JAK2 (OMIM 147796) V617F mutation is found in 96% of patients with PV and is a major criterion in the World Health Organization criteria for the diagnosis of PV.

Arterial or venous thrombotic events are potentially devastating clinical features in patients with PV. The hypercoagulability associated with PV is mediated by increased blood viscosity and complex platelet-leukocyte interactions, manifesting in multiple vascular beds as mesenteric thrombosis, deep vein thrombosis, pulmonary embolism, coronary events, and cerebral vascular accidents.

Finally, an intravenous heparin infusion should begin as soon as postoperative hemostasis is determined. Transition to long-term oral anticoagulation is indicated to reduce the likelihood of recurrent thrombosis.