Technical overview of difficult biliary cannulation in endoscopic retrograde cholangiopancreatography: A guide for the endoscopist

Abstract

Endoscopic retrograde cholangiopancreatography (ERCP) is one of the most technically challenging procedures in the field of therapeutic endoscopy and remains the standard of care for the management of extrahepatic biliary obstruction (both benign and malignant causes). The prerequisite for defining the success of this procedure is to achieve deep biliary cannulation and the guidewire assisted technique is the most commonly performed procedure. A latest meta-analysis of 15 randomized controlled trials in 4426 patients reported the unweighted pooled primary cannulation success rate (using this technique) of 85.4% (at the hands of experienced endoscopists), with a failure of approximately 5%-20% overall, and in less than 5% at high volume centers. As a result, achieving deep cannulation is a substantial barrier to success of ERCP, both for experts and novices alike. Despite improvements in endoscopic technologies and accessories, development of advanced endoscopy fellowship programs, and advances in ancillary imaging techniques, biliary cannulation in ERCP can still be unsuccessful in up to 20% of patients, even in referral centers. Once cannulation has been deemed to be difficult, the risk of post-ERCP pancreatitis and technical failure inherently increases. A number of factors, including endoscopist experience and patient anatomy, have been associated with difficult biliary cannulation (DBC), but predicting a case of difficult cannulation a priori is often not possible. Numerous techniques such as pancreatic guidewire and stenting, early pre-cut, and endoscopic ultrasound-guided rendezvous may be employed when standard approaches fail. Data regarding the rate of success and adverse events of these techniques have been variable, though most studies suggest that pancreatic duct stenting generally reduces the rate of post-ERCP pancreatitis in instances of DBC. Here we provide a technical review on DBC (with images) and discuss how the choice of which techniques to employ and how to best employ them should be individualized and take into account the skill of the endoscopist, the disorder being treated, the anatomy of the patient, and the available biomedical literature.

Keywords: Endoscopic retrograde cholangiopancreatography; Bile duct; Needle knife; Double guidewire; Rendezvous; Transpancreatic sphincterotomy; Pancreatitis

Core Tip: Difficult biliary cannulation remains a significant challenge during endoscopic retrograde cholangiopancreatography, even in expert hands and high-volume centers, which has been shown to directly impact technical success and patient outcomes. This comprehensive review highlights current strategies available in hand for managing such clinical scenarios when encountered, including early identification of risk factors, optimized guidewire techniques, and the judicious use of advanced approaches such as pre-cut sphincterotomy, double guidewire technique, transpancreatic septotomy and endoscopic ultrasound-guided rendezvous technique. Understanding the timing and escalation to alternative methods or referral is critical. A structured, stepwise approach by practicing endoscopists enhances technical success and reduces complications in such challenging clinical scenarios.