The impact of ursodeoxycholic acid on gallstone disease after bariatric surgery: a meta-analysis of randomized control trials

Bariatric Surgery Is Associated with Lower Concentrations of Fecal Secondary Bile Acids and Their Metabolizing Microbial Enzymes: A Pilot Study

INTRODUCTION

Excess body fat elevates colorectal cancer risk. While bariatric surgery (BRS) induces significant weight loss, its effects on the fecal stream and colon biology are poorly understood. Specifically, limited data exist on the impact of bariatric surgery (BRS) on fecal secondary bile acids (BA), including lithocholic acid (LCA), a putative promotor of colorectal carcinogenesis.

METHODS

This cross-sectional case-control study included 44 patients with obesity; 15 pre-BRS (controls) vs. 29 at a median of 24.1 months post-BRS. We examined the fecal concentrations of 11 BA by liquid chromatography and gene abundance of BA-metabolizing bacterial enzymes through fecal metagenomic sequencing. Differences were quantified using non-parametric tests for BA levels and linear discriminant analysis (LDA) effect size (LEfSe) for genes encoding BA-metabolizing enzymes.

RESULTS

Total fecal secondary BA concentrations trended towards lower levels post- vs. pre-BRS controls (p = 0.07). Individually, fecal LCA concentrations were significantly lower post- vs. pre-BRS (8477.0 vs. 11,914.0 uM/mg, p < 0.008). Consistent with this finding, fecal bacterial genes encoding BA-metabolizing enzymes, specifically 3-betahydroxycholanate-3-dehydrogenase (EC 1.1.1.391) and 3-alpha-hydroxycholanate dehydrogenase (EC 1.1.1.52), were also lower post- vs. pre-BRS controls (LDA of - 3.32 and - 2.64, respectively, adjusted p < 0.0001). Post-BRS fecal BA concentrations showed significant inverse correlations with weight loss, a healthy diet quality, and increased physical activity.

CONCLUSIONS

Concentrations of LCA, a secondary BA, and bacterial genes needed for BA metabolism are lower post-BRS. These changes can impact health and modulate the colorectal cancer cascade. Further research is warranted to examine how surgical alterations and the associated dietary changes impact bile acid metabolism.

The Management of Biliary Disease in Patients with Severe Obesity Undergoing Metabolic and Bariatric Surgery-An International Expert Survey

OBJECTIVE

This study aimed to survey international experts in metabolic and bariatric surgery (MBS) to improve and consolidate the management of biliary disease in patients with severe obesity undergoing MBS.

BACKGROUND

Obesity and rapid weight loss after MBS are risk factors for the development of gallstones. Complications, such as cholecystitis, acute cholangitis, and biliary pancreatitis, are potentially life-threatening, and no guidelines for the proper management of gallstone disease exist.

METHODS

An international scientific team designed an online confidential questionnaire with 26 multiple-choice questions. The survey was answered by 86 invited experts (from 38 different countries), who participated from August 1, 2023, to September 9, 2023.

RESULTS

Two-thirds of experts (67.4%) perform concomitant cholecystectomy in symptomatic gallstones during MBS. Half of experts (50%) would wait 6-12 weeks between both surgeries with an interval approach. Approximately 57% of the experts prescribe ursodeoxycholic acid (UDCA) prophylactically after MBS, and most recommend a 6-month course. More than the half of the experts (59.3%/53.5%) preferred laparoscopic assisted transgastric ERCP as the approach for treating CBD stones in patients who previously had RYGB/OAGB.

CONCLUSION

Concomitant cholecystectomy is preferred by the experts, although evidence in the literature reports an increased complication rate. Prophylactic UDCA should be recommended to every MBS patient, even though the current survey demonstrated that not all experts are recommending it. The preferred approach for treating common bile duct stones is a laparoscopic assisted transgastric ERCP after gastric bypass. The conflicting responses will need more scientific work and clarity in the future.

The role of bacteria in gallstone formation

Gallstones are a prevalent biliary system disorder that is particularly common in women. They can lead to various complications, such as biliary colic, infection, cholecystitis, and even gallbladder cancer. However, the etiology of gallstones remains incompletely understood. The significant role of bacteria in gallstone formation has been demonstrated in recent studies. Certain bacteria not only influence bile composition and the gallbladder environment but also actively participate in stone formation by producing enzymes such as β-glucuronidase and mucus. Therefore, this review aimed to analyze the mechanisms involving the types and quantities of bacteria involved in gallstone formation, providing valuable references for understanding the etiology and clinical treatment of gallstones.

Ursodeoxycholic Acid Prophylaxis and the Reduction of Gallstone Formation After Bariatric Surgery: An Updated Meta-Analysis of Randomized Controlled Trials

Gallstone formation following bariatric surgery poses a significant clinical concern, prompting various preventive strategies, including ursodeoxycholic acid (UDCA) prophylaxis. This systematic review and meta-analysis aimed to assess the efficacy of UDCA in preventing gallstone formation after bariatric surgery. A comprehensive literature search was conducted in major databases up to September 2023, identifying 12 randomized controlled trials (RCTs) meeting the inclusion criteria. The studies, spanning from 1993 to 2022, involved 2,767 patients who underwent diverse bariatric procedures. The primary outcome was the overall incidence of cholelithiasis, with secondary outcomes encompassing gallstone occurrences at three, six, and 12 months; symptomatic cholelithiasis; and rates of cholecystectomy. The Cochrane risk-of-bias tool was utilized for evaluating study quality, and statistical analyses were conducted using the RevMan software (Cochrane Collaboration, London, UK). Patients receiving UDCA demonstrated a significantly lower overall incidence of gallstones post-bariatric surgery (risk ratio [RR] 0.13; P < 0.0001). Subgroup analyses confirmed reduced gallstone incidence at three months (P = 0.04), six months (P < 0.00001), and one year (P < 0.00001) with UDCA prophylaxis. Symptomatic cholelithiasis incidence was also lower in the UDCA group (RR 5.70; P < 0.00001), and cholecystectomy rates were significantly reduced (RR 3.05; P = 0.002). This meta-analysis supports the efficacy of UDCA prophylaxis in preventing gallstone formation after bariatric surgery. The findings suggest that UDCA administration not only lowers overall gallstone incidence but also reduces the occurrence of symptomatic cholelithiasis and mitigates the need for cholecystectomy. However, caution is warranted due to heterogeneity, diverse surgical procedures, and limited long-term follow-up in the included studies. Further research with standardized protocols and extended observational periods is recommended to strengthen the evidence base and guide clinical practice.

Ursodiol Prescriptions Following Bariatric Surgery: National Prescribing Trends and Outcomes

BACKGROUND

Rapid weight loss after bariatric surgery is a risk factor for gallstone development. Numerous studies have shown that ursodiol after surgery decreases rates of gallstone formation and cholecystitis. Real-world prescribing practices are unknown. This study aimed to examine prescription patterns for ursodiol and reassess its impact on gallstone disease using a large administrative database.

METHODS

The Mariner database (PearlDiver, Inc.) was queried using Current Procedural Terminology codes for Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) between 2011 and 2020. Only patients with International Classification of Disease codes for obesity were included. Patients with pre-operative gallstone disease were excluded. The primary outcome was gallstone disease within 1 year, which was compared between patients who did and did not receive an ursodiol prescription. Prescription patterns were also analyzed.

RESULTS

Three hundred sixty-five thousand five hundred patients fulfilled inclusion criteria. Twenty-eight thousand seventy-five (7.7%) patients were prescribed ursodiol. There was a statistically significant difference in development of gallstones (p < 0.001), development of cholecystitis (p = .049), and undergoing cholecystectomy (p < 0.001). There was a statistically significant decrease in the adjusted odds ratio (aOR) for the development of gallstones (aOR 0.81, 95% CI: 0.74, 0.89), development of cholecystitis (aOR 0.59, 95% CI: 0.36, 0.91), and undergoing cholecystectomy (aOR 0.75, 95% CI: 0.69, 0.81).

CONCLUSION

Ursodiol significantly decreases the odds of development of gallstones, cholecystitis, or cholecystectomy within 1 year following bariatric surgery. These trends hold true when analyzing RYGB and SG separately. Despite the benefit of ursodiol, only 10% of patients received an ursodiol prescription postoperatively in 2020.

[Cholecystolithiasis and intestinal bypass procedures]

With the increasing number of surgical interventions for obesity, the numbers of associated complications, such as gallstones after bariatric surgery are also increasing. The incidence of postbariatric symptomatic cholecystolithiasis is 5-10%; however, the numbers of severe complications due to gallstones and the probability of a necessary extraction of gallstones are low. For this reason, a simultaneous or preoperative cholecystectomy should only be carried out in symptomatic patients. Treatment with ursodeoxycholic acid reduced the risk of gallstone formation in randomized trials but not the risk of complications related to gallstones in cases of pre-existing gallstones. The most frequently used access route to bile ducts after intestinal bypass procedures is the laparoscopic approach via the stomach remnants. Other possible access routes are the enteroscopic approach as well as the endosonography-guided puncture of the stomach remnants.

Incidence and risk factors for cholelithiasis after bariatric surgery: a systematic review and meta-analysis

BACKGROUND

Obesity has been identified as an independent risk factor for cholelithiasis. As a treatment for obesity, bariatric surgery may increase the incidence of cholelithiasis. The risk factors for cholelithiasis after bariatric surgery remain uncertain. The purpose of this study was to explore the risk factors for postoperative cholelithiasis after weight-loss surgery and propose suggestions for clinical decision making.

METHODS

Four databases, PubMed, EMBASE, Web of Science and Cochrane, were systematically searched for all reports about cholelithiasis after bariatric surgery, and literature screening was performed following prespecified inclusion criteria. The included studies were all evaluated for quality according to the NOS scale. Data extraction was followed by analysis using Reviewer Manager 5.4 and StataSE 15.

RESULTS

A total of 19 articles were included in this meta-analysis, and all studies were of high quality. A total of 20,553 patients were included in this study. Sex [OR = 0.62, 95% CI (0.55, 0.71), P < 0.00001] and race [OR = 1.62, 95% CI (1.19, 2.19), P = 0.002] were risk factors for cholelithiasis after bariatric surgery. Surgical procedure, preoperative BMI, weight-loss ratio, smoking, hypertension, diabetes mellitus, and dyslipidemia were neither protective nor risk factors for cholelithiasis after bariatric surgery.

CONCLUSION

Caucasian race and female sex are risk factors for developing cholelithiasis after bariatric surgery; surgical procedure, BMI, weight loss ratio, hypertension, diabetes mellitus, dyslipidemia, and smoking are not risk factors for cholelithiasis after bariatric surgery.

Frequency of cholelithiasis in need of surgical or endoscopic treatment a decade or more after Roux-en-Y gastric bypass

BACKGROUND

Symptomatic cholelithiasis requiring treatment is a known side effect after Roux-en-Y gastric bypass (RYGB), but reported rates vary greatly. The objectives for this study were to evaluate the long-term frequency of surgical or endoscopic treatment for symptomatic cholelithiasis 10-15 years after RYGB and its relation to self-reported abdominal pain.

METHODS

Observational data from 546 patients who underwent RYGB at public hospitals in Central Norway between March 2003 and December 2009 were analyzed.

RESULTS

Median follow-up was 11.5 (range 9.1-16.8) years. Sixty-five (11.9%) patients had undergone cholecystectomy prior to RYGB. Out of the 481 patients with intact gallbladder, 77 (16.0%) patients underwent cholecystectomy and six (1.2%) patients had treatment for choledocholithiasis during the observation period. Median time from RYGB to cholecystectomy or treatment of choledocholithiasis was 51 (range 1-160) and 109 (range 10-151) months, respectively. Female sex was associated with an increased risk of subsequent cholecystectomy [OR (95% CI) 2.88 (1.31-7.15)], p < 0.05. There was a higher frequency of self-reported abdominal pain at follow-up [OR (95% CI) 1.92 (1.25-2.93)] among patients who underwent cholecystectomy before or after RYGB.

CONCLUSION

With a median follow-up of more than 11 years after RYGB, one in six patients with an intact gallbladder at time of RYGB underwent cholecystectomy, and 1.1% of the patients needed surgical or endoscopic treatment for choledocholithiasis. Patients with a history of cholecystectomy reported a higher frequency of abdominal pain.

Prevention of Gallstones After Bariatric Surgery using Ursodeoxycholic Acid: A Narrative Review of Literatures

Obesity by itself is a factor in the development of gallstone disease, and periods of weight loss after bariatric surgery further increase the risk of gallstone formation. In patients with obesity, hypersecretion of cholesterol may increase the risk of gallstone formation, which is approximately five-fold higher than that in the general population. The incidence of gallstone formation after bariatric surgery is 10-38% and often associated with a proportional increase in the risk of developing biliary complications. Routine postoperative administration of ursodeoxycholic acid (UDCA) is recommended to prevent gallstone formation. Several randomized trials have indicated that UDCA can effectively prevent gallstones and reduce the risk of cholecystectomy after bariatric procedures. The effective daily dose of UDCA in each study ranged from 500 to 1,200 mg, and it may be considered at least during the period of rapid weight loss (first 3-6 months postoperatively) to decrease the incidence of symptomatic gallstones.

Ursodeoxycholic acid for the prevention of gallstones and subsequent cholecystectomy after bariatric surgery: a meta-analysis of randomized controlled trials

BACKGROUND

This meta-analysis aimed to compare the incidence of gallstone formation, subsequent biliary disease and the need for cholecystectomy in untreated patients and patients treated with ursodeoxycholic acid (UDCA) following bariatric surgery.

METHODS

Randomized controlled trials (RCTs) comparing UDCA and controls for the prevention of gallstone formation after bariatric surgery published until February 2022 were selected and subjected to a systematic review and meta-analysis. Articles were searched in the MEDLINE, Web of Science and Cochrane Trials Register databases. Meta-analysis was performed with Review Manager 5.0.

RESULTS

Eleven randomized controlled studies were included, with a total of 2363 randomized patients and 2217 patients analysed in the UDCA group versus 1415 randomized patients and 1257 patients analysed in the control group. Considering analysed patients, prophylactic use of UDCA was significantly associated with decreased (i) gallstone formation (OR = 0.25, 95% CI = 0.21-0.31), (ii) symptomatic gallstone disease (GD) (OR = 0.29, 95% CI = 0.20-0.42) and consequently (iii) cholecystectomy rate (OR = 0.33, 95% CI = 0.20-0.55). The results were similar in ITT analysis, in the subgroup of patients undergoing sleeve gastrectomy or considering only randomized versus placebo studies.

CONCLUSIONS

Prophylactic use of UDCA after bariatric surgery prevents both gallstone formation and symptomatic GD and reduces the need for cholecystectomy.