S11 Endoscopic Sphincterotomy in Sphincter of Oddi Dysfunction: A Systematic Review of Prospective and Randomized Controlled Trials

Introduction: Sphincter of Oddi Dysfunction (SOD) is characterized by abnormal flow of bile and pancreatic secretions due to abnormal pressure at the sphincter. There has been a proposed role for endoscopic sphincterotomy (ES) in the management of SOD, however existing data appears to have conflicting outcomes. This systematic review aims to look at the impact of biliary endoscopic sphincterotomy for suspected SOD disorder to evaluate response to ES. Methods: A search analysis was conducted with the following terms: Search: Database with search terms: “Sphincter of Oddi,” “Endoscopic biliary sphincterotomy” on PubMed, Google Scholar, Cochrane Library. Inclusion criteria: Full- test, English, prospective studies, or randomized controlled trials on the role of sphincterotomy in patients with SOD. Exclusion criteria: Non-interventional, non-primary, and animal studies. Results: This systematic review evaluates the effectiveness of ES in patients with SOD. The pooled success across all studies was found to be 42%. The median follow-up period was 12 months, with follow-up durations ranging from 3 to 46 months. Roly et al. found that patients with Type 1 SOD experienced pain relief after procedure. Geenen et al. focused on patients with Type 2 SOD and observed that patients had improved pain following ES, particularly those with elevated basal pressures and was supported by Toouli et al. In contrast, Cotton et al., found no significant difference in outcomes between ES and a sham procedure. A multicenter prospective study by Coté et al., found a 60% improvement in abdominal pain following ES. This study also included patients who had not undergone cholecystectomy, which contrasts with the other studies reviewed and introduces a potential limitation in comparing findings. Conclusion: Our analysis has a few limitations. Not all of the studies included a placebo group. Additionally, there was concern about Type 2 error in 1 study that found statistical significance with ES. The overall sample size of patients with SOD undergoing ES was relatively small across all 3 types of SOD. This raises questions about the effectiveness of sphincterotomy for each type of SOD. Median follow-up period was 12 months, however 1 study reported the redevelopment of symptoms after 24 months and is possible long term follow up may be needed. Further studies are needed to better define the role of ES in each type of SOD, particularly with longer-term follow-up.