Pylephlebitis

Acute abdominal pain, fever, and chills prompted a 51-year-old man to visit his local hospital twice in one week. On both visits, a clinical and laboratory workup was negative. He then presented to a tertiary care center with worsening symptoms. His history included hypertension and tobacco and alcohol use.

The patient was febrile and had right upper quadrant tenderness. The remainder of the physical findings were unremarkable. Results of a complete blood cell count, basic metabolic profile, and urinalysis were normal. The serum alkaline phosphatase level was mildly elevated; other liver enzyme levels were normal.

A CT scan of the abdomen showed portal and superior mesenteric vein thrombosis with no evidence of cirrhosis or intra-abdominal sepsis. This CT slice shows the thrombus in the superior mesenteric vein with surrounding venous collaterals. Systemic anticoagulation was initiated. Four days later, blood cultures grew Bacteroides fragilis.

Pylephlebitis usually results from infection in the region drained by the portal system (especially diverticulitis and appendicitis) or in the structure contiguous to the portal vein. However, a definite source of infection may be unknown, as in this patient. Bacteremia occurs frequently. The most common bloodstream isolate is B fragilis. There is a strong association between anaerobic infections and thrombotic diseases. One suggested mechanism for this is a cell-wall component in Bacteroides that can accelerate coagulation.¹

Abdominal pain and fever are the most common presenting symptoms. Clinical signs include right upper quadrant or generalized abdominal tenderness and hepatomegaly.

The diagnosis requires the demonstration of pylethrombosis usually accompanied by bacteremia in a febrile patient. Frequently, diagnosis is delayed because the condition is uncommon, the symptoms are nonspecific, and the primary focus of infection typically lacks clinical signs. In addition, the portal vein may be poorly visualized.

Prompt broad-spectrum antibiotic therapy is mandatory. Anticoagulation is not essential but is associated with a decrease in septic embolization to the liver. Untreated pylephlebitis may lead to bowel ischemia, hepatic abscess, and death.

This patient was given penicillin and metronidazole, and his symptoms resolved. A hypercoagulable workup for inherited thrombophilia was negative.

References:

REFERENCE:

1.

Kasper DL, Sahani D, Misdraji J. A 40-year-old man with prolonged fever and weight loss.

N Engl J Med

. 2005;353:713-722.