Long-term outcome of pyogenic liver abscess: factors related with abscess recurrence.

BACKGROUND/AIMS Long-term surveillance of pyogenic liver abscess remains unavailable. We thus aimed to identify the recurrence rates of pyogenic liver abscess among various etiologies and pathogens, and to elucidate the factors related with this recurrence. METHODS Six-hundred and one patients with pyogenic liver abscess were prospectively enrolled to observe abscess recurrence during a mean follow-up period of up to 6.06 years. On the basis of the etiology of the initial abscess, patients were divided into different subgroups as follows: there were 152 (25.3%) patients classified as cryptogenic, 229 (38.1%) with diabetes mellitus, 144 (24%) with underlying biliary tract disease, and 76 (12.6%) with other organic diseases or mixed subgroups. RESULTS The cumulative recurrence rates of pyogenic liver abscess were lower in both the cryptogenic (2.0%) and diabetic (4.4%) groups than in the underlying biliary tract disease (23.8%) group (log-rank test, P<0.001). The diabetic group had a higher rate of Klebsiella pneumoniae infection and a lower rate of Escherichia coli infection than the biliary tract group (P<0.001). For patients infected with K. pneumoniae, the recurrence rate of pyogenic liver abscess was as low as that of the diabetes and the cryptogenic groups (P>0.05). CONCLUSIONS Pyogenic liver abscess is more commonly recurrent in patients with underlying biliary tract disease. Irrespective of diabetic status or cryptogenic etiology, the recurrence of K. pneumoniae-infected liver abscess is low in the long-term.