Are We Over-Blaming Metabolic and Bariatric Surgery for Gallbladder Diseases It Did Not Cause? The Impact of Preoperative Ultrasound Practices

Divergent Guidelines and Practices in MBS

The international consensus regarding the necessity of routine preoperative abdominal ultrasonography in metabolic and bariatric surgery (MBS) remains elusive. Some guidelines advise imaging only for patients with biliary symptoms or abnormal liver tests, citing limited impact on surgical planning. For instance, the updated 2019 ASMBS/AACE/TOS guidelines recommend ultrasonography in symptomatic patients, noting a weak evidence base for routine screening. This conservative approach is rooted in concerns about its utilization being time-consuming and having limited effectiveness due to excessive soft tissue in patients with severe obesity.
Conversely, some practitioners support universal preoperative US screening to detect occult gallstones, especially considering the high risk of gallstone diseases in patients undergoing MBS. Notably, obesity itself is a well-recognized risk factor for gallstone formation. Studies show that about 20.7% of patients develop de novo gallstones after MBS, with 8.2% becoming symptomatic. Rapid weight loss significantly increases the risk of cholelithiasis, particularly after gastric bypass, complicating endoscopic access to the biliary tree. Interestingly, post-MBS patients who have had cholecystectomy demonstrate high rates of weight loss.