Incidence of postoperative gallstone disease after antiobesity surgery: population-based study from Sweden.

BACKGROUND: Patients who have undergone antiobesity surgery are at risk of developing gallstones postoperatively. The aim of the present study was to assess the incidence of symptomatic gallstone disease in patients who have undergone antiobesity surgery compared with that of the general population. METHODS: We performed a population-based cohort study of antiobesity surgery in Sweden from 1980 to 2006. A total of 8901 patients who had undergone antiobesity surgery and had not previously been treated for gallstone disease were identified from the Inpatient Care Register. For each subject, 10 controls matched for age and gender, were identified in the register of the total population (89,010). Censoring occurred at the end of the study (December 31, 2006), date of emigration, or date of death (9.1 +/- 6.6 years of follow-up). RESULTS: The incidence of gallstone disease was 122.2/10,000 person-years in the surgical group compared with 22.2/10,000 person-years in the controls. The incidence of cholecystectomy was greater in the surgical group than in the controls (106.1 versus 19.5/10,000 person-years). The incidence ratio for gallstone disease was 5.5 (range 5.05.9) and for cholecystectomy was 5.4 (range 5.0-5.9). CONCLUSION: A fivefold increased risk of symptomatic gallstone disease was found after antiobesity surgery compared with that in the general population.