Pancreaticobiliary Pain and Suspected Sphincter of Oddi Dysfunction

Definitions

Confusing terminology and varied clinical presentations partly explain the complexity regarding SOD. Biliary dyskinesia is the encompassing term for a group of disorders with acalculous biliary-type pain. Subgroup diagnoses include chronic acalculous cholecystitis, gallbladder dyskinesia, cystic duct syndrome, and SOD. SOD may occur in patients with or without a gallbladder but is most commonly diagnosed in patients with postcholecystectomy symptoms.

Attempts have been made to develop consensus on defining the signs and symptoms of SOD, culminating in the latest iteration of the Rome criteria (Rome IV). Diagnostic criteria for biliary pain and functional gallbladder disorders are listed in Box 47.1 . The Rome criteria are meant to provide a general framework for clinicians but obviously do not describe all patients. A unifying symptom, present in all patients with SOD, is pain. When evaluating a patient with possible SOD, the most important aspect of the evaluation is the history. It is imperative that the clinician gain a clear understanding of the nature, location, and timing of pain. The Rome criteria specify that the pain should be intermittent, with pain-free intervals. Although typical biliary pain is classically intermittent, in some cases patients will have constant low-grade discomfort with exacerbations. The concept of chronic biliary pain is thought to be related to heightened visceral hypersensitivity, altered central nervous system processing, and/or generalized motility disorders. Patients with more persistent pain should undergo careful review and extensive evaluation for other causes of pain ( Box 47.2 ) but should not be arbitrarily excluded from evaluation for SOD based solely on there being a constant component to their pain. However, if associated symptoms such as nausea, vomiting, abdominal distension, or bowel dysfunction are dominant, the patient likely does not have SOD. Based on observations and after developing correlations between patients' presentations and outcomes after endoscopic sphincterotomy, Joseph Geenen, Walter Hogan, and Wylie Dodds published what have come to be known as the Geenen-Hogan (G-H) criteria ( Table 47.1 ). These have been modified over the years but provide a guide for clinicians to direct their evaluation and decision making. The original criteria were applied to patients who had previously undergone cholecystectomy and were based on three factors that could be assessed without endoscopic retrograde cholangiopancreatography (ERCP): (1) presence of “typical” pancreatic-type or biliary-type pain, (2) presence or absence of elevated liver or pancreas tests during or shortly after an episode of pain (that returned to normal when the pain subsided), and (3) presence or absence of bile and/or pancreatic duct dilation. The original criteria also included measurement of pancreatic and biliary drainage times, but these are no longer considered valid.

The G-H criteria defined three subtypes and are important because they represent a framework around which a clinician can plan patient evaluation. If one obtains an appropriate history of pain, bile duct imaging should be obtained and the patient should be given a prescription directing health care providers (in an emergency room, hospital laboratory, or clinic) to obtain a liver panel and pancreatic tests (amylase and/or lipase) during or shortly after a pain episode. These data then can be used to stratify patients as to their likelihood of having SOD.

Clinical Evaluation in Patients With Suspected SOD

The first step is a detailed review of prior health care encounters pertinent to the clinical presentation, with a focus on questions of when, where, and what ( Box 47.3 ). A complete history and thorough review of records will define the clinical symptoms, reveal what tests have been done, what treatments (surgical, endoscopic, medical) have been tried, and what the impact has been on the patient. Patients with unexplained symptoms that may be attributed to SOD often end up undergoing a massive assault, which may diagnostic and therapeutic. It can be helpful to organize objective data regarding prior laboratory testing, imaging, and treatments ( Box 47.4 ).