Splenectomy Correlates With Increased Risk of Pyogenic Liver Abscess: A Nationwide Cohort Study in Taiwan

OBJECTIVES Little is known about the risk of pyogenic liver abscess in patients with splenectomy. We explored the relationship between splenectomy and pyogenic liver abscess in Taiwan. METHODS We conducted a nationwide cohort analysis using the hospitalization dataset of the Taiwan National Health Insurance Program. We included 17,779 subjects aged 20-84 years who underwent splenectomy in 1998 to 2010 (splenectomy group) and 70,855 randomly selected subjects without splenectomy (non-splenectomy group). Both groups were matched by sex, age, other comorbidities, and hospitalization year of receiving splenectomy. The incidence of pyogenic liver abscess at the end of 2011 was measured. The multivariable Cox proportional hazard regression model was used to estimate the hazard ratios and 95% confidence intervals for pyogenic liver abscess associated with splenectomy and other comorbidities. RESULTS The overall incidence rate was 3.75-fold higher in the splenectomy group than that in the non-splenectomy group (2.15 vs 0.57 per 1000 person-years; 95% confidence interval, 3.57-3.94). After controlling for potential confounding factors, the adjusted hazard ratio of pyogenic liver abscess was 3.89 in subjects with splenectomy (95% confidence interval, 3.20-4.72) when compared with subjects without splenectomy. In further analysis, the hazard ratio markedly increased to 14.34 for those with splenectomy and having any of the assessed comorbidities, including alcoholism, biliary stone, chronic kidney disease, chronic liver diseases, and diabetes mellitus (95% confidence interval, 10.61-19.39). CONCLUSIONS Patients with splenectomy are at an increased risk of developing pyogenic liver abscess, particularly when they have comorbid conditions.