Access to the Common Bile Duct in patients with surgically altered UGI anatomy such as RYGB is exceptionally challenging. Previously, these patients could only be treated by open surgery; however, multiple new advanced assisted ERCP techniques such as EDGE, LA-ERCP, and DEA-ERCP have now been developed and indeed successfully used to treat these patients. Despite growing experience, these techniques have yet to become part of our mainstream practice and many clinicians remain unfamiliar or even unaware of them; as a result, they are unfortunately often overlooked. We conducted this systematic
review to try and shed more light on them and understand which of these techniques resulted in the best patient outcomes. We conducted a systematic
review of PubMed database publications between December 2008 and December 2018. Keyword variants of \"EDGE, Enteroscopy-assisted & laparoscopy-assisted ERCP\" and \"altered surgical anatomy\" were combined to identify relevant papers for inclusion. We identified 34 studies, comprising a total of 1848 advanced assisted ERCPs in patients with altered UGI anatomy from 12 different countries. These papers were critically appraised, summarised, and presented in table format. EDGE and LA-ERCP were associated with both the highest overall combined CBD cannulation rates (99.3% for both vs 74.6% for DEA-ERCP) and ERCP interventional success (98.3% for EDGE vs 97.4% for LA-ERCP and 67.6% for DEA-ERCP). Advanced ERCP is associated with excellent success rates and a higher safety profile than surgery; however, patient selection and identification of the exact surgical anatomy are key.