Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) is the inevitable and most common adverse event after ERCP, which have been reported in a wide range of incidence from 1% to 40% because it depends on patient- and procedure-related factors, or even endoscopic techniques/maneuvers. Although its determinants are not clear, development of PEP is thought to be basically based on an inflammatory cascade caused by pancreatic acinar cell injury that promote to systematic cytokine release. In addition, various chemical, enzymatic, microbiologic, mechanical, hydrostatic or thermal irritations are considered as the key pathophysiology of the PEP. 
Numerous studies reported that many specific risk factors, acting independently or synergistically, have been proposed as predictors for the risk of PEP. However, the reported patient- or procedure-related risk factors revealed wide discrepancies between the studies which may be attributable to inhomogeneous populations of patients, different levels of endoscopic skill, personal preference for cannulation techniques and disparate definition of PEP. Furthermore, numerous trials have suggested various strategies for the prevention of PEP which can be categorized into (1) assessment of patient related risk factors; (2) procedural techniques for prevention; and (3) pharmaco-prevention. Among these, identification of high-risk patients is one of the first and most important step for the prevention of PEP. In patients with high risk factors, non-invasive diagnostic or therapeutic modalities which are irrelevant to PEP can be considered as a reasonable alternative for ERCP after careful assessment. Regarding to the procedural techniques, endoscopic nasobiliary drainage, pancreatic stent placement, wire-guided biliary cannulation, and needle knife sphincterotomy has been recommended for the reduction of PEP development and the facilitation of bile duct cannulation for to all patients with high-risks. However, complete prevention of PEP is difficult through targeting any specific one causative factor because of the multifactorial pathophysiology of the PEP. Thus, risk stratification will allow endoscopists to better identify patients who are at significant risk and permit detailed informed consent as well as possibly defer examinations in the highest-risk groups. Appropriate technical “prophylaxis” during ERCP, such as pancreatic ductal stenting, should also be carefully considered in high-risk patients to prevent the development of pancreatitis.
Thus, the aims of present study were to identify predictive factors among simplified clinical and endoscopic criteria to perform a new score assessing the probability of PEP, and to consolidate prophylactic impacts of each of these interventional approaches on the prevention of PEP through prospective multicenter cohort.

Cohort/Group Label

All consecutive patients undergoing retrograde cholangiopancreatography (ERCP) for benign or malignant pancreatic biliary tract disease

Cohort/Group Description

The risk factors for PEP were evaluated in the derivation cohort using logistic regression analysis. Variables with P-values <0.2 in the univariable logistic regression model were selected as covariates in the multivariable analysis. Point scores were assigned to each significant variable in the model by dividing the regression coefficient of the significant predictors by the smallest coefficient (assigning a score of 1 for the predictor with the smallest coefficient). Then, we calculated the risk scores of each patient in both the derivation and validation cohorts. Patients were classified into three groups according to their risk score as follows: low-risk (0 points), intermediate-risk (1–2 points), and high-risk (≥3 points).

Not collect nor Archive

All consecutive patients undergoing retrograde cholangiopancreatography (ERCP) for benign or malignant pancreatic biliary tract disease

Previous studies have recommended that the traditional method be used for analysis, which states that the target number of subjects should include at least 100 events or at least 100 non-events (Van Calster et al. Clin Epidemiol 2016, 74:167-176 and Collins GS et al. St at Med 2016, 35(2):214-226). Accordingly, sample size calculations for several prognostic models have been reported, and it is traditionally recommended that this methodology should be followed. For example, assuming that the probability of an event is 9%, a total of 1,112 subjects are required for generating 100 events; therefore, of these 1,112 subjects, 100 events and 1,012 non-events could satisfy the number of subjects recommended in the traditional virtual model.

Gender

Age

Description

1. All consecutive patients undergoing retrograde cholangiopancreatography (ERCP) for benign or malignant pancreatic biliary tract disease
2.  Age of 18 or more years old

(1) acute pancreatitis within 2 weeks before ERCP
(2) a history of chronic pancreatitis
(3) non-naïve major papilla, such as previous sphincterotomy, pancreatic sphincterotomy, or balloon dilatation
(4) the major papilla could not be reached because of anatomical or surgical alteration (total gastrectomy with Roux en Y anastomosis, choledocho-jejunostomy, or hepatico-jejunostomy)
(5) refusal to participate in the study or declining to provide informed consent
(6) pregnancy or breastfeeding

Prediction accuracy in internal and external prospective cohorts of pancreatitis prediction model after endoscopic retrograde cholangiopancreatography constructed from retrospective analysis data

1 day after ERCP

PEP risk factor analysis

30 days after ERCP

the length of hospitalization  to PEP

from admission to discharge

Procedure related adverse events

30 days after ERCP

All other adverse events

30 days after ERCP