Endoscopic ultrasound guided rendezvous technique versus precut sphincterotomy as a salvage technique for difficult bile duct cannulation without inadvertent pancreatic duct cannulation: a randomized controlled trial

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. Though there are advances in techniques and advanced endoscopic imaging, still 5 to 20% of cases of ERCP succumb to failure in biliary cannulation. The difficult cannulation (DBC) itself carries the increased risk of post ERCP complications, mainly post ERCP pancreatitis (PEP), bleeding and perforation. Various salvage techniques used to manage DBC are needle knife pre-cut papillotomy, double wire technique, trans-pancreatic septotomy and EUS guided rendezvous technique (EUS-RV). The conventional rescue strategy for DBC is to perform a pre-cut sphincterotomy or needle knife sphincterotomy, as endorsed even by various society guidelines. Only a single randomized controlled trial (RCT) exists comparing EUS-RV versus pre-cut sphincterotomy (PcP) in benign biliary diseases with DBC by Choudhury et al showed that there is no difference in the technical success rate (92% vs. 90%; P = 1.00) between the two techniques. Five patients (10%) in the EUS-RV group and 5 patients (10%) in the precut sphincterotomy group had developed post-endoscopic retrograde cholangiopancreatography pancreatitis. Interestingly, on exploratory analysis of the sub-cohort that did not have 1 or more inadvertent PD cannulation (n=72), it was noted that 2 (5.6% [CI, 0.6% to 17.3%) patients in the precut group had PEP, whereas none of the patients in the EUS-RV had PEP (relative risk, 0.21 [CI, 0.01 to 4.25]). But this study was not powered enough to answer this question. Through the findings of this study, one can speculate, that if guidewire has not entered the pancreatic duct (PD), EUS-RV has a “zero incidence” of PEP, which makes this procedure more attractive compared to other salvage ERCP techniques. Even though sub-group analysis is not available across published literature, Dhir et al and Dalal et al also reported zero PEP rates with the EUS-RV procedure, compared to pre-cut technique (2.8% and 8.7%), respectively. Both EUS-RV and PcP are techniques wherein direct papilla orifice contact is avoided, which can theoretically reduce or nullify the risk of PEP. So, in situations wherein, after encountering a difficult bile duct cannulation, where the pancreatic duct has not been cannulated inadvertently while performing ERCP, which salvage technique would prove to be better needs to be investigated. Hence, this randomized controlled trial has been designed to answer this question.