Incidence and factors associated with de novo cholelithiasis formation following bariatric surgery: A multicentre, retrospective cohort study.

INTRODUCTION: Bariatric surgery is an approved method of weight loss, while the post-operative complications are still under the question. This study aimed to estimate the incidence of de novo cholelithiasis (CL) and factors associated with it. PATIENTS AND METHODS: In this study, 4618 patients who underwent one-anastomosis gastric bypass (OAGB), laparoscopic sleeve gastrectomy (LSG) or Roux-en-Y gastric bypass (RYGB) completed 12 months' follow-up. Ultrasound examination was performed at 12 months after surgery to detect CL formation. Multivariable analyses were performed to identify CL predictors using the SPSS software version 11.5. RESULTS: The incidence rate of gallstone formation was 9.42% (435 events; 95% confidence interval: 8.61%-10.30%). This rate differed among the surgical groups: 5.02% for RYGB, 16.0% for LSG and 6.55% for OAGB ( P < 0.001 for inter-group comparison). The frequency of dyslipidaemia ( P = 0.015) and total weight loss (TWL) ( P = 0.008) was different between patients with and without CL. In logistic regression, 12-month TWL (odds ratio [OR] =1.028, P = 0.004) and having dyslipidaemia before surgery (OR = 1.424, P = 0.011) were the significant factors. CONCLUSIONS: The significance of careful selection of the appropriate bariatric surgery for each patient, in addition to close monitoring and applying preventive measures in individuals with a high risk of CL formation. Further prospective research is required to confirm these findings while clarifying the underlying mechanisms linking bariatric surgery to CL formation.