Oddity of an Opiated Oddi: A Case of Sphincter of Oddi Dysfunction

Introduction: We present a case of recurrent right upper quadrant (RUQ) pain resulting from Sphincter of Oddi Dysfunction (SOD) in the setting of chronic opioid use. SOD is a functional gastrointestinal disorder that presents similarly to other disorders of the biliary tree. Understanding features of this disorder and its etiologies can streamline evaluation and treatment. Case Description/Methods: Our patient is a 77-year-old male, chronic opioid user, who had multiple Emergency Department (ED) visits and hospital admissions for RUQ pain in the setting of significantly elevated liver associated enzymes (LAEs). However, repeated imaging of the RUQ with CT, Ultrasound, and MRCP remained largely unremarkable. On a subsequent presentation, the patient experienced severe increase in pain after administration of morphine. Lab investigation showed an abrupt increase in LAEs and lipase after administration of morphine. Imaging was obtained, and was again inconsistent with cholecystitis. Interestingly, he attained analgesia with meperidine on admission. During a following ED visit, RUQ imaging showed non-specific gallbladder inflammation, and a Hepatobiliary Iminodiacetic Acid (HIDA) scan showed low gallbladder ejection fraction (GBEF). These findings suggested Functional Gallbladder Disorder and laparoscopic cholecystectomy was performed. Unfortunately, ten days later the patient had worsening RUQ pain with no signs of obstruction. With diagnostic criteria for SOD met and other etiologies ruled out, our patient was referred for sphincterotomy. Discussion: Opiate-induced SOD is theoretically well known, but there have been only few reported cases in literature. Furthermore, SOD is difficult to diagnose, as providers must first rule out other hepatobiliary disease. ROME IV Diagnostic Criteria for Functional Gastrointestinal Disorders was used in review of our case. Biliary pain, absence of bile duct stones or other structural abnormalities, and elevated LAEs fulfilled the criteria for this disorder. This case highlights the clinical evaluation and care of SOD. While all opioids have been shown to contract the Sphincter of Oddi (SO), morphine has been shown to strongly cause this contraction, and is one of the earliest reported causes of SOD in literature. Meperidine has been shown to have minimal effect on the SO contraction and is the ideal opioid to treat pain of biliary or pancreatic source.