ERCP for common bile duct stone extraction: Sphincterotomy, balloon dilation, or both?

Since the introduction of endoscopic retrograde cholangiopancreatography (ERCP) over 40 years ago, our ability to tackle large common bile duct stones has continued to improve largely due to the use of various lithotripsy methods. Nevertheless, the search for the ideal common bile duct stone extraction technique continues despite the recent advances in technology. To be able to extract a whole stone or a large fragment of it has always remained limited by the size of the one end outlet of the biliary tree – that is the biliary orifice. ERCP-practicing gastroenterologists have waxed and waned on how to best navigate a large stone through a small orifice. In 2015, most would consider endoscopic sphincterotomy (ES) as the key intervention and the backbone for all biliary therapeutic procedures. Despite the efficacy of ES, balancing this with the risks of post-sphincterotomy adverse events like bleeding and perforation remains a very fine act. This fueled the search for an alternative safe technique for stone extraction – either to supplement a “limited ES” or to replace it altogether.

Endoscopic papillary large bile duct dilation (EPLBD) emerged as an acceptable technique that theoretically could achieve large stone extraction without necessarily having to resort to mechanical or electrohydraulic lithotripsy and limits the number of ERCP procedures needed to achieve this task. However, the lack of enthusiasm towards such a technique and its rather limited adoption stemmed from some of the literature reports on the risk of potentially serious adverse events, such as pancreatitis and bile duct perforation.[123]

But is it time that we revisit our stand on EPLBD? In the current issue of the Saudi Journal of Gastroenterology, Akiyama et al.[4] report on the utility of endoscopic papillary balloon dilation (EPBD) in biliary stone extraction and the short- and long-term outcomes of 10- and 8-mm EPBD for extraction of CBD stones. The study addressed technical success and adverse events rates over the short and intermediate term. The authors reported that their ability to remove stones in a single session was higher in the 10-mm EPBD group than in the 8-mm EPBD group (69% vs. 44%, P < 0.001). In addition, the use of lithotripsy was less frequent in the 10-mm EPBD group (23% vs. 56%, P < 0.001). Among the adverse events assessed, post-ERCP pancreatitis rates were no different between the 10- and 8-mm EPBD groups (11% vs. 8%). Cumulative biliary complication-free rates were not statistically different between the two groups: 88% and 94% at 1 year and 69% and 80% at 2 years in the 10- and 8-mm EPBD groups, respectively. In the 10-mm EPBD group, ascending cholangitis was not reported, and pneumobilia was found in 5% during the follow-up period.

The current study demonstrates a likely incremental benefit in using the 10-mm size balloon over the 8-mm balloon. Interestingly, the current study does not include large balloon dilations (EPLBD), which typically exceed 12 mm in size and were the subject of several recent studies. Despite that, the conclusions of Akiyama et al. appear to endorse the findings of previous studies reporting less costly and more efficient management of CBD stones using EPLBD after ES compared to ES alone, with no increased risk of adverse events.[56] In fact, a recent met-analysis including six randomized controlled studies totaling 835 patients clearly demonstrated that ES plus EPLBD caused fewer overall complications than ES alone, including perforation [odds ratio (OR) =0.53, P = 0.008]. The use of mechanical lithotripsy in the ES plus EPLBD group decreased significantly (OR = 0.26, P = 0.02), especially in patients with a stone size larger than 15 mm.

Although further data is needed to answer the question of whether a partial ES before EPLBD is necessary, the current evidence points toward a benefit in decreasing the risk of post-ERCP pancreatitis. This could be theoretically due to the separation between pancreatic and biliary orifices that result from ES, resulting in more axial balloon force exerted toward the bile duct than the pancreatic orifice during ES. What remains unclear is where exactly a limited or partial ES ends, a matter currently left entirely to the discretion of the endoscopist.

Despite this evidence in favor of combining ES with EPLBD for large CBD stone extractions, there remains some hesitation among advanced endoscopists to routinely adopt this technique for large stones. This could be the result of earlier literature that tainted its safety profile or the increased comfort of most recently trained endoscopists with ES. Further head-to-head studies comparing large stone extraction with and without EPLBD following ES, as well as refinements of the existing techniques might entice more endoscopists to adopt this technique and make this a mainstream practice.