Image Diagnosis: Inferior Mesenteric Vein Thrombosis

Avin Aggarwal, MBBS; Shashank Garg, MBBS

Perm J 2015 Summer; 19(3):e120-e121 [Full Citation]

https://doi.org/10.7812/TPP/14-239

Case Study

A 59-year-old man presented to the gastroenterology clinic with 2 weeks of worsening lower back pain. There was associated poor appetite, fatigue, night sweats, and chills. The patient's medical history was significant for well-controlled hypertension and sigmoid diverticulosis. He had been smoking half a pack of cigarettes per day for 30 years. Physical examination was remarkable for fever (100.7°F), periumbilical tenderness, and a soft epigastric bruit. Laboratory evaluation, including complete blood count, lipase, liver and renal function, electrolytes, and lactate, were within normal limits. Ultrasound of the abdomen with venous duplex was performed to evaluate the epigastric bruit. The ultrasound revealed a nonocclusive thrombus in the splenic vein (Figure 1). A computed tomography (CT) scan with intravenous contrast confirmed a thrombus in the inferior mesenteric vein (IMV) (Figure 2) extending to the confluence of the IMV with the splenic vein (Figure 3). Inflammatory changes around the sigmoid colon with a hyperdense diverticulum were also noted on CT scan (Figure 4), suggestive of diverticulitis. No evidence of intestinal obstruction or infarction was seen on imaging, which indicated only partial vein occlusion and/or early IMV thrombosis. The thrombosis probably resulted from inflammation in the adjacent diverticulum. The patient was given ciprofloxacin and metronidazole for 10 days and was started on warfarin therapy, initially bridged with heparin.

A CT scan of the patient's abdomen was performed 15 weeks after his initial visit and treatment. The CT scan showed a smaller IMV without any collateral vein formation, indicating resolution of the thrombus (Figure 5). At 30 weeks, ultrasound of the patient's abdomen showed a patent splenic vein with normal flow (Figure 6). The patient had a comprehensive workup for thrombophilia, which was unremarkable. Warfarin therapy was stopped after resolution of the thrombus.

Image Diagnosis: Inferior Mesenteric Vein Thrombosis

Discussion

Acute mesenteric vein thrombosis is responsible for 6% to 9% of cases of acute mesenteric ischemia.¹ IMV thrombosis is relatively uncommon and constitutes 4% to 11% of cases of acute mesenteric vein thrombosis.^2,3 However, IMV thrombosis carries a 15% to 23% risk of mortality.^4-6 It is usually seen in the setting of thrombophilia or local inflammation, and IMV thrombosis on abdominal imaging should prompt workup for these conditions.⁷ Initial management involves bowel rest, pain control, intravenous hydration, and therapeutic anticoagulation with bridging from heparin to warfarin.⁷ Surgical resection is reserved for patients with progressive intestinal dilatation or peritoneal signs.

IMV thrombosis is an uncommon but potentially life-threatening complication of sigmoid diverticulitis. Prompt diagnosis and management of IMV thrombosis can prevent mesenteric infarction or surgical intervention.