Sphincter of Oddi dysfunction: Sphincter of Oddi dysfunction or discordance? What is the state of the art in 2018?

Purpose of review To review important manuscripts published over the previous 2 years relative to sphincter of Oddi dysfunction (SOD). Recent findings The long-term outcomes of the Evaluating Predictors and Interventions of SOD (EPISOD) trial further substantiated results from the initial EPISOD study, reinforcing that neither endoscopic retrograde cholangiopancreatography-manometry nor endoscopic sphincterotomy are appropriate for SOD type III. Pain management in the latter patients has reverted to neuromodulating agents, and recent studies have suggested a role for duloxetine and potentially acupuncture. The functional role of the sphincter of Oddi has been reiterated with a report demonstrating a higher clinically significant pancreatic fistula rate in distal pancreatectomy patients treated with higher doses of postoperative narcotics. Moreover, the injection of periampullary botulinum toxin preoperatively has been shown to decrease these fistulas in a pilot trial. Additional studies have reinforced that eluxadoline can cause sphincter of Oddi spasm and pancreatitis. In contrast to approaching patients with acute relapsing pancreatitis using endoscopic retrograde cholangiopancreatography and manometry, previous and current studies suggest that endoscopic ultrasound should be done first and the role of SOD in idiopathic acute relapsing pancreatitis remains controversial. Finally, there remain widespread disparities in practice patterns in the approach to patients currently classified as SOD type II. Summary In contrast to historical manuscripts which stress the classical definitions of three types of SOD and their consequences, more recent manuscripts on this topic have focused on improving surgical outcomes based on the physiologic role of sphincter of Oddi, as well as the pharmacologic causes and treatments of SOD. The simplistic view that SOD, however it has been diagnosed, requires biliary or dual sphincterotomy is just that, simplistic and potentially misguided.