Mesenteric vein thrombosis

Background

A rare (< 5% of all cases) subset of mesenteric ischemia that has a high rate of mortality approaching 50%. Risk factors include intrabdominal inflammation and hypercoaguability.

Clinical Features

Depends on subtype and disease can exist along a continuum.

• acute-expect typical features such as severe abdominal pain that is out of proportion to exam findings. Rebound and guarding may occur. Time course usually over days.
• subacute- abdominal pain can be vague and symptoms may be insidious over a period of days to weeks.
• chronic- patients usually are asymptomatic and thrombosis is usually found on imaging incidentally. Some patients may have post prandial colicky abdominal pain that resolves.

Differential Diagnosis

• Abdominal aortic aneurysm
  • Aortocaval fistula
• Acute gastroenteritis
• Aortoenteric fisulta
• Appendicitis (early)
• Bowel obstruction
  • Large bowel obstruction
    • Ogilvie's syndrome
  • Small bowel obstruction
  • Malignant bowel obstruction
• Bowel perforation
• Gastroparesis
• Diabetic ketoacidosis
• Hernia
• Inflammatory bowel disease
• Mesenteric ischemia
• Pancreatitis
• Peritonitis
• Sickle cell crisis
• Spontaneous bacterial peritonitis
• Volvulus

Evaluation

CT scan showing acute superior mesenteric vein thrombosis (black arrow) with bowel wall thickening (white arrowhead), mesenteric edema (black arrowhead) and ascites. Note the normal SMA enhancement (white arrow) and ratio of SMV to SMA diameters > 2.

Contrast enhanced CT (axial and coronal views) of the abdomen demonstrated a filling defect in the superior mesenteric vein (arrow), suggesting thrombus.

Workup

• Labs- CBC, CMP, Lipase, UA, HCG(when applicable), Lactate, Coags.
• imaging
  • from the ED stand point a multiphase contrast CT is the most accurate and timely.(Non-contrast, arterial phase, and venous phase).
  • oral contrast can help dilineate bowel thickness.
  • Magnetic resonance venography is another option if testing is non-diagnostic.