Risk Factors Associated With Cannulation Success Rate By Trainees During Hands-on Training Of ERCP

Background Endoscopic Retrograde Cholangiaopancreatography(ERCP)was first introduced in 1968 by Mc Cune.It has been developed as an advanced endoscopic technology in the diagnosis and treatment of biliary and pancreatic diseases in the past decades.Selective cannulation of the targeted duct(common biliary duct or pancreatic duct)is the prerequisite step for a successful ERCP.Meanwhile,selective cannulation is also the most important high-risk factor for post-ERCP complications.Successfully and rapidly selective cannulation of the desired duct is sometimes difficult for inexperienced endoscopy doctors.ERCP cannulation can be even more difficult because of additional anatomy variation,pathological condition and other patient-related factors.Currently,there is no uniform standard or guideline for ERCP training in our country.Thus,the training idea and mode is largely apart from the requirement of the ERCP performance.ERCP training in China still has a long way to go.To obtain adequate techniques of selective cannulation and Endoscopic sphincterotomy(EST),hands-on practice in patients remains the gold standard of ERCP training for trainees.It is also the key step for trainees to independently engage in ERCP in future.Therefore,the training of selective cannulation of the desired duct is one of the most important contents for the success of hands-on ERCP training.The standardized training is also important for trainees to improve cannulation success rate,increase the confidence of operation and reduce the incidence of adverse events.Based on previous studies,the success of cannulation was influenced by many factors,including case volume,the grade of difficulty,cannulation time and cannulation methods.Although the relationship between procedure-related factors and cannulation success has been widely investigated,the influences of patient-related factors(for example,age,gender and the types of diseases etc.)on cannulation remain largely unknown.The aim of this study was to identify the risk factors(especially patient-related factors)associated with cannulation success for trainees receiving hands-on ERCP training.The post-ERCP complications were also investigated.Through this work,we hope to improve the performance level and surgery safety of trainees,which may be helpful for the ERCP patients and the establishment of standardized training of ERCP.Objective To improve the performance level and safety during early ERCP training,the risk factors associated with cannulation success rate and postoperative complications by trainees receiving hands-on ERCP training were investigated.Methods Clinical data of 1193 ERCP cases involved by trainees in Xijing Hospital of Digestive Disease from December 2012 to December 2014 were retrospectively collected.The following data were recorded:(1)the demographic data of patients: gender,age,comorbidities(pancreatitis,coexisting hypertension,diabetes,coronary heart disease,chronic obstructive pulmonary disease,cerebral infarction,liver cirrhosis),prior history of surgery(cholecystectomy,billroth ? anastomosis or Rouxen-Y-anastomosis after subtotal gastrectomy or bile intestinal anastomosis),preoperative laboratory tests(white blood cell,platelet,hematocrit,red cell volume distribution width,total bilirubin,alanine amino transferase,alkaline phosphatase,blood urea nitrogen,serum creatinine).(2)procedure-related parameters:ERCP indications(common biliary duct stone,malignant biliary stricture,benign or undetermined biliary stricture,suspected sphincter of Oddi dysfunction,benign pancreatic disease,others),targeted duct(common biliary duct or pancreatic duct),duodenum stenosis,cannulation time and cannulation success by trainees.(3)post-procedure complications: Complications and severity classification were determined based on previous criteria.Statistical analysis was performed using SPSS software version 19.0.Results were reported as mean and standard deviation for continuous data,and as percentage for categorical data.Univariate analyse was used to identify risk factors for cannulation success rate.The risk factors entered multivariate regression model when P<0.1,and results were presented as Odds ratio(OR)with 95% Confidence Interval(CI).All tests were two-sided,and a p value of less than 0.05 was considered statistically significant.Result From December 2012 to December 2014,more than 20 trainees underwent hands-on ERCP training in our endoscopic center.A total of 1193 consecutive procedures were performed.The targeted duct were 1165(97.7%)for common biliary duct(CBD)and 28(2.3%)for pancreatic duct(PD)respectively.581(48.7%)of male patients and 612(51.3%)of female patients were included.Mean age was 58.3 years(standard deviation [SD] 15.7,range 11-92).The success rate of CBD cannulation by trainees was 58.5%(681/1165)and the overall success rate was 97.9%(1140/1165).PD cannulation success rate by trainees was 39.3%(11/28)and the overall success rate was 89.3%(25/28).The overall complication incidence was 8.0%(96/1193)and the incidence of post-ERCP pancreatitis was 4.4%(53/1193).Bleeding and cholangitis occurred in 22(1.8%)and 21(1.8%)respectively.There were no perforation,cardiopulmonary cerebral accident,death and other adverse events.The mean cannulation time for CBD and PD by trainees were 6.5±4.7 min and 7.7±6.0 min respectively.Univariate analyse showed that ERCP indications,prior cholecystectomy,coexisting hypertension,targeted duct,total bilirubin,hematocrit,red cell volume distribution width and platelet were statistically associated with the cannulation success rate of trainees(all P<0.05).Multivariate analysis showed that the selective cannulation by trainees were more likely to fail in patients with malignant biliary stricture(OR=0.44,95%CI: 0.28-0.67,P<0.01),benign or undetermined biliary stricture(OR=0.32,95%CI: 0.17-0.60,P<0.01),suspected SOD(OR=0.28,95%CI: 0.16-0.47,P<0.01),coexisting hypertension(OR=0.65,95%CI: 0.44-0.96,P < 0.05),RDW?48fl(OR=0.69,95%CI: 0.51-0.92,P < 0.05),PLT?100×109/L(OR=0.59,95%CI:0.37-0.95,P<0.05).Conclusion Biliary stricture,suspected sphincter of Oddi dysfunction,coexisting hypertension,abnormal RDW and PLT were independent risk factors associated with cannulation success rate by trainees during hands-on ERCP training.According to the findings of this study and our experience of ERCP training,we can improve the performance level of trainees and patient safety by preoperatively adequate assessment,identifying risk factors and screening appropriate patients for ERCP.Based on these findings,we may establish a better training protocol for trainees in future to increase their cannulation success,improve the confidence of operation and reduce the incidence of adverse events.