Splenectomy and risk of renal and perinephric abscesses: A population-based cohort study in Taiwan

Little epidemiological research is available on the relationship between splenectomy and renal and perinephric abscesses. The purpose of the study was to examine this issue in Taiwan. We conducted a population-based retrospective cohort study using the hospitalization dataset of the Taiwan National Health Insurance Program. A total of 16,426 participants aged 20 and older who were newly diagnosed with splenectomy from 1998 to 2010 were assigned to the splenectomy group, whereas 65,653 sex-matched, age-matched, and comorbidity-matched, randomly selected participants without splenectomy were assigned to the nonsplenectomy group. The incidence of renal and perinephric abscesses at the end of 2011 was measured in both groups. The multivariable Cox proportional hazards regression model was used to measure the hazard ratio (HR) and 95% confidence interval (CI) for risk of renal and perinephric abscesses associated with splenectomy and other comorbidities including cystic kidney disease, diabetes mellitus, urinary tract infection, and urolithiasis. The overall incidence rate of renal and perinephric abscesses was 2.14-fold greater in the splenectomy group than that in the nonsplenectomy group (2.24 per 10,000 person-years vs 1.05 per 10,000 person-years, 95% CI 2.02, 2.28). After controlling for sex, age, cystic kidney disease, diabetes mellitus, urinary tract infection, and urolithiasis, the multivariable regression analysis demonstrated that the adjusted HR of renal and perinephric abscesses was 2.24 for the splenectomy group (95 % CI 1.30, 3.88), when compared with the nonsplenectomy group. In further analysis, the adjusted HR markedly increased to 7.69 for those comorbid with splenectomy and diabetes mellitus (95% CI 3.31, 17.9). Splenectomy is associated with renal and perinephric abscesses, particularly comorbid with diabetes mellitus. In view of its potential morbidity and mortality, clinicians should consider the possibility of renal and perinephric abscesses when patients with splenectomy present with fever of unknown origin.