Gallstone formation after weight loss following gastric banding in morbidly obese Dutch patients

Background: Obesity is a risk factor for the development of gallstones. Rapid weight loss may be an even stronger risk factor. We retrospectively assessed the prevalence and risk factors of gallstone formation after adjustable gastric banding (AGB) in a Dutch population. Methods: All patients who underwent AGB between Jan 1992 and Dec 2000 for morbid obesity were invited to take part in this study. Transabdominal ultrasonography of the gallbladder was performed in those patients without a prior history of cholecystectomy (Group A). Additionally, 45 morbidly obese patients underwent ultrasonography of the gallbladder before weight reduction surgery (Group B). Results: 120 patients were enrolled in the study (Group A). Prior history of cholecystectomy was present in 21 patients: 16 before and 5 after AGB. Ultrasonography was performed in 98 patients: gallstones were present in 26 (26.5%). On multivariate analysis, neither preoperative weight, nor maximum weight loss, nor the interval between operation and the postoperative ultrasonography were determinants of the risk for developing gallstone disease. Prevalence of gallstones was significantly lower in the morbidly obese patients who had not yet undergone weight reduction surgery (Group B). Conclusions: Rapid weight loss induced by AGB, is an important risk factor for the development of gallstones. No additional determinants were found. Every morbidly obese patient undergoing bariatric surgery must be considered at risk for developing gallstone disease.