Superior Mesenteric Vein Thrombosis

superior mesenteric vein thrombosis

This 83 year-old male presents 1yr post laparoscopic cholecystectomy with malaise, abdominal pain and abnormal liver function tests.
The CT coronal reformat demonstrates free fluid and a SMV filling defect (arrow), consistent with SMV thrombosis. Note that the scan is well into the portal venous phase, making flow artefact unlikely.

SMV Thrombosis

Epidemiology: 10% of bowel infarction, SMV > IMV1

Aetiology:
1. Infection
2. Hypercoagulable state
3. Trauma
4. Mechanical1

Presentation: Non specific, subacute (1-4 weeks) or may be acute, severe abdominal pain with rebound and guarding if bowel infarction has occurred. However, proximal SMV thrombosis rarely causes infarction. Distal thrombosis more likely to do so by causing congestion2.

Radiology: Ileus, Ascites, bowel wall thickening, dilated vein with filling defect, mesenteric congestion1.

Treatment: Anticoagulation, intraarterial thrombolytics via SMA or transhepatic or transjugular portal vein mechanical or chemical transcatheter thrombolysis3

References:
1. Dahnert W. Radiology Review Manual. 5th Ed. Lippincott Williams and Wilkins.
2. Okino Y et al. Root of the Small-Bowel Mesentery: Correlative Anatomy and CT Features of Pathologic Conditions. RadioGraphics 2001; 21: 1475
3. Bradbury MS, et al. Mesenteric Venous Thrombosis: Diagnosis and Noninvasive Imaging RadioGraphics 2002; 22: 527.

Credit: Dr Neha Singh