Pylephlebitis complicating silent diverticulitis

Abstract

In December, 2005, a 70-year-old, previously healthy, man was admitted with a 1-week history of fever and pain in the upper abdomen without nausea or vomiting. On physical examination, he was febrile (39·5°C) and had rigors; blood pressure was 90/60 mmHg, pulse was 90 bpm, and he had epigastric and right upper quadrant tenderness. Laboratory test results showed leucocytosis of 11·2×10/L (neutrophils 89%), normochromic normocytic anaemia (Hb 112 g/L), high erythrocyte sedimentation rate (124 mm/h) and C-reactive protein (277 mg/L), and a total bilirubin of 27·7 μmol/L with a conjugated value of 15·7 μmol/L. Other laboratory tests for liver function were normal. An urgent contrastenhanced CT of the abdomen was unremarkable. We treated the patient with broad-spectrum intravenous antibiotics (imipenem and vancomycin). On the second day of admission, MRI showed thrombosis of the left branch of the portal vein (fi gure A), and several diverticulae and signs of diverticulitis in the left colon (fi gure B); no biliary dilatation was seen. On further questioning, the patient denied any symptoms of constipation, low abdominal pain, or bloody stools. Two blood cultures grew Clostridium tertium. Doppler ultrasonography confi rmed the occlusion of the left portal vein branch. No evidence of varices were found on oesophagogastroduodenoscopy. Colonoscopy confi rmed the presence of multiple diverticulae as well as mucosal oedema in the sigmoid colon. His fever and abdominal pain subsided on days 5 and 6 of admission, respectively. He was started on low molecular weight heparin and then switched to oral warfarin. Further laboratory tests for a hypercoagulable state were negative. He completed a 4-week course of intravenous antibiotics (imipenem and vancomycin) and a 3-month course of oral anticoagulation. Out-patient doppler ultrasonography 1 month after the initiation of anticoagulation therapy showed complete resolution of the clot. When seen for follow-up in June, 2006, the patient was in excellent health. Pylephlebitis, or septic thrombophlebitis, of the portal vein represents a previously under-diagnosed condition with a uniform mortality in the pre-antibiotic era. It is usually secondary to infections in the region drained by the portal system, and is most commonly associated with appendicitis and diverticulitis, but it has also been described in necrotising pancreatitis, infl ammatory bowel disease, haemorrhoidal disease, foreign body perforation, acute cholecystitis, Behcet’s disease, and amoebic colitis. The usual clinical fi ndings include fever and right upper quadrant pain without jaundice. Doppler ultrasonography, MRI, and contrast CT are all considered sensitive imaging techniques for diagnosis, although no comparative evidence exists. Multiple liver abscesses may complicate the course of the disease. An interaction between the infectious agent and the endothelium may precipitate the clotting cascade and result in portal vein thrombosis. Anaerobic infections are usually associated with thrombotic diseases because certain bacterial components may enhance fi brin clotting and heparin degradation. The role of anticoagulation is controversial, because no randomised studies addressing this issue exist. In a retrospective study of 44 cases, patients who received anticoagulation therapy had a better outcome than those who did not. However, it was reported that in patients with normal clotting function and isolated thrombosis of the portal vein, anticoagulation may be unnecessary. In the absence of consensus, anticoagulation treatment was empirically administered in our patient. A high index of suspicion for pylephlebitis is required in patients with any septic abdominal event and right upper quadrant pain without jaundice—even in the absence of clinical signs from the primary site of infection. Modern imaging techniques facilitate early diagnosis in cases that probably remained undiagnosed in the past due to poor visualisation of the portal vein. Prompt administration of antibiotics in this situation should be considered life saving.