**1. Introduction**

Acute pancreatitis (AP) is the most serious emergent disease in the gastroenterology field. The most common cause of AP is naturally gallstones. The most cases have mild disease and the illness limits itself in a short time period. In 15–20% of cases, the severe form of AP develops. The triage of patients with AP in accordance with the severity of illness is the single most important factor affecting monitorisation and treatment protocol of these patients. Acute biliary pancreatitis (ABP) develops due to gall stones and or sludge mostly coming from gall bladder, impacted in ampulla Vateri (AV) leading to increased pancreatic ductal pressure, pancreatic edema, inflammation and possibly necrosis. A lot of human and animal studies displayed that biliary obstrucition lasting more than 48 hours creates pancreatic necrosis. Therefore, before the endoscopic retrograde cholangiography (ERCP)

area, surgery was used to induce biliary decompression and impede progression into pancreatic necrosis, however, new quests started after facing high rate of morbidities and mortalities associated with surgery.

Introduction of ERCP and endoscopic sphincterotomy into the daily practice, endoscopic relieving of biliary obstruction has come into reality. Nevertheless, occurence of complications even mortalitiy in association with ERCP initiated new debate about its indications and timing in patients with ABP. Although for the last 30 years, there has been many ongoing studies about to whom and when ERCP will be perforrmed in ABP, a certain conclusion has not been encountered yet. There has been 2 main strategies on debate [1].


Due to 2 different approaches, how an imminent ERCP will affect the existing clinical situation in patients with ABP holds its uncertainity. There has been also no agreement on the preference of an urgent ERCP (U-ERCP) within 24 hours of patients'admission or an emergent ERCP (E-ERCP) within 48–72 hours [2]. These terms; U-ERCP and E-ERCP have been used in recent reports and the first paper published by Neoptolemos and et al. defined U-ERCP and E-ERCP differently than the other papers; the first one within 72 hours and the later within 35 days after admission [3]. Later on, ERCP within first 72 hours was labeled as U-ERCP [4] and after the year of 2000, U-ERCP has been defined as ERCP within 24 hours and E-ERCP as ERCP within 24–72 hours [2]. In severe ABP, there are some risks such as patient's bad general situation, technical difficulties due to pancreatic edema and potential interruption of aggressive fluid resuscitation during and after the ERCP procedure. Therefore, valid only for patients having persisting indication for biliary decompression, seveal authors and our clinical experience favor E-ERCP together with immense supportive treament of these patients rather than U-ERCP in the absence of life threatining cholangitis.

### *Endoscopic Retrograde Cholangiopancreatography in Acute Biliary Pancreatitis DOI: http://dx.doi.org/10.5772/intechopen.96545*

In severe cases with AP, there can be pain, fever, cholestasis, mental confusion and hypotension due to ongoing pancreatic inflammation and necrosis and under this circumstances, an imminent ERCP can make the situation even worser [5]. Although, if we scrutinize the real life data, we will see that there is some kind of pressure on ERCP physicians to perform ERCP at night and or at weekends by the physicians seeing these patients with ABP in the emergency room [6]. However, in severe ABP, it would be impossible to guarentee the co-existence of cholangitis only by looking at some clinical and biochemical parameters, the use of harmless non-invasive methods such as magnetic resonance cholangiography (MRCP) and or endoscopic ultrasonography (EUS) seems to be more reasonable. Hence, endoscopist who will perform ERCP should estimate the clinical situation of patient with ABP correctly and know very well to whom and when ERCP should be done. Thirty four years after the first report by Neoptolemus [3] suggesting wider application of ERCP with ES during AP, Schepers NJ [4] reported a multicentric article (APEC study) which underlined the fact that U-ERCP with ES does not reduce AP associated complications and mortality compated with conservative approaches. These authors supported a conservative strategy in severe ABP with ERCP indicated only in patients with cholangitis or persistant cholestasis.

In this chapter, we will mention about the role of ERCP during ABP in accordance with the clinical studies and meta-analysis published on this subject and we will add our self clinical experience and practice in this area. The order of titles will be as such,

