EPISOD puts an end to sphincter of Oddi dysfunction type III

The Rome III revision of the Milwaukee Biliary Group classification has long been utilized to diagnose, classify and drive intervention in patients with suspected sphincter of Oddi dysfunction (SOD). SOD Type III is defined as recurrent biliary-type pain in the absence of elevated liver enzymes and/or imaging abnormalities (common bile duct <8 mm) [1]. While patients with SOD Type II are more likely to have manometric evidence of SOD (55% of the time), studies have shown that only 28% of patients with SOD Type III have manometric evidence of biliary sphincter dysfunction [2]. In 1989, Geenan et al showed that 17 of 18 patients with verified SOD on manometry benefitted from endoscopic sphincterotomy [3]. Subsequent literature from the 1990’s revealed that patients with SOD Type I benefit from sphincterotomy without the need for manometry. These studies also showed a poor correlation between the results of manometry and response to sphincterotomy [4-6]. Based on the low rate of manometric changes in SOD Type III as well as the aforementioned poor correlation of sphincter manometry with response to sphincterotomy, the optimal management for these patients remains a therapeutic challenge. In the May issue of JAMA, Cotton et al [7] present a multi-center, prospective, sham-controlled randomized trial demonstrating that endoscopic sphincterotomy did not reduce disability due to pain in patients presenting with abdominal pain (suspected SOD Type III) after cholecystectomy. With over 700,000 patients undergoing cholecystectomy every year [8] and greater than 10% reporting pain afterwards [9], Cotton et al set out to identify if patients with SOD Type III respond to endoscopic sphincterotomy (biliary and/or pancreatic). In addition, the ability of sphincter manometry to predict outcomes was evaluated. The trial was conducted at 7 tertiary centers throughout the US. Between 2008 and 2012, 214 patients (predominantly female) post-cholecystectomy with suspected SOD Type III underwent randomization. All patients underwent ERCP, sphincter manometry and were then randomized, regardless of manometry results, to sphincterotomy (n=141) versus sham sphincterotomy (n=73). Within the sphincterotomy group, patients with pancreatic sphincter hypertension were randomized to biliary versus dual (biliary and pancreatic) sphincterotomy. Both groups received small caliber pancreatic stents but no rectal indomethacin. The treatment was considered successful if the patients had a low RAPID score (<6 days of lost productivity due to pain) at 9 and 12 months, did not require a repeat ERCP, and/or did not require narcotics. Overall, the investigators found that pain and disability were reduced in both groups during 12-month follow up, yet it was the sham sphincterotomy group (37%; 95%CI 25.9-48.1%) that experienced successful treatment more often than the sphincterotomy group (23%; 95%CI 15.8-29.6%). In patients with pancreatic sphincter hypertension, dual sphincterotomy (30%; 95% CI 16.7-42.9%) was equivalent to biliary sphincterotomy alone (20%; 95% CI 8.7-30.5%). No association was found between outcomes and manometry results. No specific subgroups appeared to benefit from sphincterotomy. Patients in an additional observational arm had the same success rates. Complication rates were reported with pancreatitis occurring in 11% and 15% of the sphincterotomy and sham groups respectively.