Case Presentation: A 55-year-old patient with history of Crohn s disease complicated by small bowel obstruction s/p resection and ileocolonic anastomosis, and transition to Upadacitinib from infliximab, a month prior to the admission, presented with a three-day duration of worsening abdominal pain, non-bloody diarrhea, and intermittent fevers. Vital signs notable for temperature of 102.2F and heart rate at 116/minute. The physical exam was only significant for diffuse abdominal guarding. Labs revealed leukocytosis of 15.4k and Lactic acid of 3. CT abdomen and pelvis (AP) with contrast showed terminal ileitis secondary to acute Crohn’s disease. Blood, urine, and stool cultures were drawn. The patient was initiated on bowel rest, intravenous(IV) fluids, vancomycin, and Zosyn. Upadacitinib was held due to concern for bacteremia and thrombotic risk (3). The Blood cultures from admission grew Klebsiella pneumoniae, Citrobacter freundii, Clostridium perfringens, and Fusobacterium species. The patient’s antibiotics were transitioned to Meropenem based on the microbiological data and persistent bacteremia on repeat blood cultures. The transthoracic echocardiogram showed no vegetation. Urine and stool cultures reported no growth. The patient continued to report intractable abdominal pain. Repeat CT AP with contrast demonstrated portal vein thrombosis and multiple new thrombi in distal ileal superior mesenteric vein branches. Hematology recommended hypercoagulable panel and heparin initiation. The Colorectal team suggested medical management due to the absence of peritoneal signs. Surveillance blood cultures were negative. Endoscopy with biopsy showed multiple nonbleeding clean base duodenal ulcers with no Helicobacter pylori. Thrombophilia workup was positive for Lupus anticoagulant, IgM anticardiolipin, and beta2 glycoprotein. The patient’s symptoms were improved. He was discharged with six weeks of IV antibiotics, budesonide, lifelong anticoagulation.

Discussion: Mesenteric venous thrombosis is one of the rare diagnoses, with an incidence of 1 in 5000-15, 0000. About 60-75% percent of cases are associated with hypercoagulable conditions (6). Inflammatory bowel diseases can predispose patients to venous thrombosis. Patients with Crohn s disease were found to have high prevalence for Anticardiolipin (23.4%), anti-phosphatidyl serine, and prothrombin antibodies (20.4%) (5). High levels of factors II, V, VIII von Willebrand factor, antithrombin, protein C, anticardiolipin (15.9%), and antiphosphatidylinositol (14.6% ) antibodies were also reported in Crohn s disease (4). Portal venous phase CT plays a key role in the diagnosis of mesenteric venous thrombosis. Once the diagnosis is made, anticoagulation treatment is initiated in patients without peritoneal signs. In patients with peritoneal signs, urgent surgical consultation is recommended (1). Patients with known reversible conditions will need anticoagulation for approximately 6 months and those with hypercoagulable states will require lifelong anticoagulation (7).

Conclusions: Diagnosis of Mesenteric vein thrombosis needs high index of suspicion in patients with Crohn s disease on Upadacitinib. Prompt anticoagulation and surgical consultation are recommended. Delay in diagnosis can lead to bowel ischemia and high mortality. The 5-year survival rate is about 70-82% and 30-day mortality can be up to 20-32% (2).

IMAGE 1: Thrombi in distal ileal superior mesenteric vein

IMAGE 2: Thrombi in distal ileal superior mesenteric vein- Venous filling defects or absence of mesenteric venous flow during the venous phase are characteristic findings on CT.