Gastrointestinal Variant of Lemierre's Syndrome: A Systematic Review and Comprehensive Analysis of 36 Case Reports

A gastrointestinal (GI) variant of Lemierre's syndrome (LS) involving Fusobacterium species causing pylephlebitis and possibly liver abscesses was recently identified. This systematic review aims to summarize the literature on this variant. PubMed, Embase, Scopus, and Cochrane databases were searched up to November, 2nd, 2023 for case reports or case series detailing the GI variant of LS. Data regarding demographics, clinical features, and management were extracted. Descriptive statistics were used for analysis, including means, standard deviations, and percentages. The cohort included 36 patients (mean age 50.8 years; predominantly men 72%). Positive blood cultures were detected in 88.8% of cases, primarily growing Fusobacterium nucleatum (47.2%) and Fusobacterium necrophorum (33.3%). The GI tract was the primary infection source (58.3%), mostly related to diverticular disease (25%). Common manifestations were fever (86.1%), abdominal pain (72.2%), and leukocytosis (86.1%). Thrombosis involved the portal vein in 77.7%, with isolated portal vein thrombosis (PVT) (44.4%) and PVT extending to the superior mesenteric vein (30.5%). Liver abscesses were detected in 50% of cases, with positive aspirate cultures in 92.3%. Treatment included penicillin/penicillin-lactamase inhibitors alone (17%) and ertapenem alone (17%). Abscess drainage (13/18) resulted in complete/near-complete resolution in 83%. Long-term anticoagulation therapy was given in 75% of cases, commonly using vitamin K antagonists (59.2%). No deaths occurred. The GI variant of LS should be considered in patients with abdominal pain, fever, leukocytosis, and portal/superior mesenteric vein thrombosis. Identifying Fusobacterium species in blood cultures and liver abscesses further supports the diagnosis. Management involves antibiotic therapy, abscess drainage, and long-term anticoagulation. [Display omitted]