Single and Multiple Pyogenic Liver Abscesses: Etiology, Clinical Course, and Outcome

<i>Background:</i> Pyogenic liver abscesses are uncommon but they still carry a high mortality rate when encountered. This study was undertaken to evaluate the differences in the clinical behaviour of patients with single and multiple abscesses. <i>Methods:</i> From January 1985 to December 1997, 133 patients with this disease were treated in the surgical departments of five hospitals, 97 had a single abscess and 36 had multiple abscesses. Clinical features, methods of treatment, and outcome were assessed and compared in both types of abscesses. <i>Results:</i> A biliary origin from ascending cholangitis was most frequently found in multiple abscesses (p = 0.007). Mean age and duration of symptoms were higher in multiple lesions (p = 0.03 and p = 0.001). High levels of alkaline phosphatase were more frequently seen in multiple abscesses than in solitary ones (p = 0.02). They were both most frequently located on the right side. Antibiotic therapy alone was most frequently used in multiple abscesses (p = 0.01). Mortality rate was also higher in this type of patients (p = 0.01). The abscess-related morbidity rate was higher in multiple lesions as well but the statistical difference was not significant. <i>Conclusions:</i> These results suggest that multiple liver abscesses comprise a disease of biliary origin, higher age, longer symptomatic periods, and also higher mortality rate than in single abscess.