Laparoscopic RYGB remains the most commonly performed bariatric operation and as such has provided endoscopists a large population of patients with challenging access to the papilla (Fig. 12.2). Patients who have had RYGB that require access to the biliary tree and pancreas by ERCP have several procedural options to consider (see Table 12.1 below). Since all options are invasive, in patients who are not critically ill or require emergent intervention, it is best to determine the nature of the biliary or pancreatic pathology with noninvasive imaging before attempting intervention. High-quality magnetic resonance imaging (MRI) with MRCP can be very helpful in determining the nature of biliary and pancreatic pathology in these patients. At expert centers, the accuracy of detecting pathology in the bile or pancreatic ducts rivals that of ERCP and EUS. One should be certain that further intervention is warranted either by finding treatable pathology on noninvasive imaging or by determining that the patient’s symptoms and findings are severe enough to warrant proceeding with intervention despite a lack of other objective findings. In patients without altered anatomy, one might proceed with EUS to further evaluate the pancreas and bile duct prior to ERCP. Unfortunately, the altered anatomy with RYGB makes complete EUS examination of the pancreas and biliary system very difficult if not impossible.

Once it has been determined from the patient’s presentation or noninvasive imaging that intervention is necessary, it is appropriate to involve a bariatric surgeon to discuss the therapeutic approach that would best benefit the patient. Unlike patients without altered anatomy, even a simple common bile duct stone removal can become a complicated endeavor. If operative intervention will ultimately be required (i.e., cholecystectomy for symptomatic gallstones), it may be best to plan all intervention at the time of operation instead of attempting an endoscopic approach prior to laparotomy or laparoscopy. Certain interventions that would usually be undertaken endoscopically, such as pseudocyst drainage, ampullectomy, or benign stricture management, may also be better undertaken surgically in this population.

Access to the papilla via the Roux limb may occasionally be possible with a push enteroscope or pediatric colonoscope in some patients. Usually, the anatomy of the RYGB includes two long limbs making access to the papilla with a standard duodenoscope or pediatric colonoscope unlikely. Several factors, including distance to the Roux anastomosis, length of the afferent limb, and mobility of the mesentery, contribute to the ability to reach the papilla. The addition of an overtube may increase the possibility of reaching the duodenum. Often this is the quickest and easiest procedure for investigating the ampulla and excluding tumors of the major papilla; however, none of these techniques have been studied in large series of patients, and the success rate of reaching the duodenum in this population with standard instruments is largely unknown.

In addition, biliary and pancreatic duct cannulation with the forward-viewing endoscopes can be challenging for any endoscopist. As these procedures can take longer than typical endoscopic procedures, it is advantageous to have a mechanism for delivering deep sedation or ­general anesthesia for these patients. Standard ERCP instruments may not pass through the pediatric colonoscope or dedicated enteroscope due to the endoscope length and operating channel diameter. This issue can be resolved by the creation of a list of compatible accessories with the specialty scopes used for deep enteroscopy and creating a separate “toolbox” of accessories that are compatible with the endoscopes being used. If available, CO₂ insufflation should be considered to reduce abdominal discomfort following the procedure [4].