Frequently Used Endoscopic Procedure Fails To Reduce Abdominal Pain
In a clinical trial to examine a procedure used in clinical practice with the intent of relieving pain after gallbladder removal, researchers have found that this procedure, which carries considerable risk, may not be effective. The gallbladder is often removed to treat conditions such as chronic gallstones, local inflammation, or pain that is suspected to originate in the gallbladder or bile ducts. Patients occasionally experience recurrent abdominal pain after this surgery, but in many cases the source of the pain is not clearly established. One suspect has been a condition called sphincter of Oddi dysfunction (SOD). Although not proven, it has been suggested that this condition is caused when the sphincter (or circular muscle) that allows bile and pancreatic juices to flow into the intestine does not relax properly. To remedy SOD, patients typically undergo a procedure called sphincterotomy, where a tube with a small camera is inserted through the mouth and into the intestine, and the sphincter is cut open. Sometimes an additional procedure is carried out to measure pressure in the sphincter. However, the suggested benefits of these procedures are controversial, and they carry a substantial risk of significant complications, including pancreatitis or perforation of the bowel wall.
In an attempt to address the uncertainty surrounding the treatment of sphincter of Oddi dysfunction, a study was conducted across seven clinical centers to see if sphincterotomy actually reduced pain following gallbladder surgery. The trial included over 200 participants who experienced recurrent abdominal pain after their gallbladders were removed. The participants underwent either sphincterotomy or a mock procedure (where the camera was inserted but the sphincter was not cut) to treat their suspected SOD. In addition, pressure was measured in the sphincter using a standardized method. While both groups of participants experienced a reduction of pain severity, sphincterotomy did not reduce abdominal pain compared to the mock procedure. Additionally, between 11 and 15 percent of the participants developed pancreatitis after these procedures, underscoring the risk of complications that may occur as a result of the invasive operations. Furthermore, the sphincter pressure measurements had no correlation with the outcomes. The results of this trial suggest that sphincterotomy does not improve pain in cases of suspected SOD following gallbladder removal—information that could save patients from the burden of this unnecessary and risky procedure.
Cotton PB, Durkalski V, Romagnuolo J, Pauls Q, Fogel E, Tarnasky P, Aliperti G, Freeman M, Kozarek R, Jamidar P, Wilcox M, Serrano J, Brawman-Mintzer O, Elta G, Mauldin P, Thornhill A, Hawes R, Wood-Williams A, Orrell K, Drossman D, and Robuck P. Effect of endoscopic sphincterotomy for suspected sphincter of Oddi dysfunction on pain-related disability following cholecystectomy: the EPISOD randomized clinical trial. JAMA 311: 2101-2109, 2014.