Endoscopic retrograde cholangiopancreatography in periampullary diverticulum: The challenge of cannulation.

Periampullary diverticulum (PAD) is duodenal outpunching defined as herniation of the mucosa or submucosa that occurs via a defect in the muscle layer within an area of 2 to 3 cm around the papilla. Although PAD is usually asymptomatic and discovered incidentally during endoscopic retrograde cholangiopancreatography (ERCP), it is associated with different pathological conditions such as common bile duct obstruction, pancreatitis, perforation, bleeding, and rarely carcinoma. ERCP has a low rate of success in patients with PAD, suggesting that this condition may complicate the technical application of the ERCP procedure. Moreover, cannulation of PAD can be challenging, time consuming, and require the higher level of skill of more experienced endoscopists. A large portion of the failures of cannulation in patients with PAD can be attributed to inability of the endoscopist to detect the papilla. In cases where the papilla is identified but does not point in a suitable direction for cannulation, different techniques have been described. Endoscopists must be aware of papilla identification in the presence of PAD and of different cannulation techniques, including their technical feasibility and safety, to allow for an informed decision and ensure the best outcome. Herein, we review the literature on this practical topic and propose an algorithm to increase the success rate of biliary cannulation.