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The role of endoscopic retrograde cholangiopancreatography (ERCP) in the management of acute biliary pancreatitis (ABP) of biliary origin has been the focus of much research in recent years. Two main issues have been extensively debated: which patients with ABP have an indication for ERCP and when should endoscopy be performed? A recent study shows that around 15% of stones demonstrated during an acute attack pass spontaneously with conservative treatment, before any invasive intervention is performed [4]. Taking into account this finding as well as the fact that ERCP is associated with a significant risk of procedure‐related complications (including a mortality rate of around 1%), accurate selection of the appropriate candidates for intervention as well as the optimal timing for endoscopy is very important. While these issues are still open for debate, there has been significant progress with regard to individualizing treatment modalities for patients with AP. Opie [5] reported the first case of impacted biliary stone at the level of the papilla in a patient with severe ABP more than a century ago and numerous subsequent case series have explored the pathophysiology of biliary pancreatitis [6,7]. Animal model studies have shown that ligating the pancreatic duct, thus simulating obstruction caused by an impacted stone at the level of the papilla, leads to pancreatic injury followed by systemic inflammation; furthermore, the degree of histological injury is related to the duration of the obstruction, while decompression of the duct is associated with improved outcomes [8]. It is currently believed that persistent obstruction of the pancreatic duct, which arises either through spasm of the sphincter of Oddi or by the impaction of a stone at the level of the papilla in patients with a common biliopancreatic channel (Figure 13.1), is correlated with a more severe course of disease and extensive pancreatic injury [9]. Furthermore, patients who do not have a patent Santorini duct and minor papilla are especially vulnerable to this mechanism of pancreatic injury [10]. This simple mechanistic model encouraged several studies exploring whether surgical [11] or endoscopic [12] relief of pancreatic duct obstruction could alter the course of ABP. Decompression through either surgical sphincteroplasty or endoscopic sphincterotomy were the main therapeutic modalities employed in these studies, which also explored the optimal timing of intervention. The promising results of these early endeavors were not confirmed by later studies, which showed mixed results for early endoscopic interventions in ABP [13–15]. The main reason for the conflicting data from earlier endoscopic studies is the heterogeneity in (i) inclusion criteria (especially time from onset of symptoms and inclusion of patients with ongoing cholangitis), (ii) timing of intervention (usually ranging between 24 and 72 hours after admission), and (iii) type of endoscopic intervention (especially with regard to the use of sphincterotomy in cases without radiological evidence of retained bile duct stones) between the compared trials. Despite differences in methodology, most trials involving urgent (<24 hours) or early (<72 hours) ERCP [16,17] demonstrate that only about one‐third of patients undergo biliary sphincterotomy for persistent common bile duct (CBD) stones. In fact, patients with acute cholangitis complicating the course of ABP constitute the only subgroup of patients consistently shown to benefit from early endoscopic intervention [16]. However, patients who do not develop cholangitis but show persistent CBD stones after an initial attack of ABP are also candidates for endoscopic therapy, with the timing of the intervention depending on several factors, such as the need for cholecystectomy and the local expertise of the medical team. As such, the timing of ERCP in ABP is one of the key points in managing these patients.

Figure 13.1 (a, b) Impacted stone at the level of the papilla.

Source: courtesy of Guido Costamagna.