ERCP-related adverse events: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

Patient safety incidents in endoscopy: a human factors analysis of nonprocedural significant harm incidents from the National Reporting and Learning System (NRLS)

BACKGROUND

Despite advances in understanding and reducing the risk of endoscopic procedures, there is little consideration of the safety of the wider endoscopy service. Patient safety incidents (PSIs) still occur. We sought to identify nonprocedural PSIs (nPSIs) and their causative factors from a human factors perspective and generate ideas for safety improvement.

METHODS

Endoscopy-specific PSI reports were extracted from the National Reporting and Learning System (NRLS). A retrospective, cross-sectional human factors analysis of data was performed. Two independent researchers coded data using a hybrid thematic analysis approach. The Human Factors Analysis and Classification System (HFACS) was used to code contributory factors. Analysis informed creation of driver diagrams and key recommendations for safety improvement in endoscopy.

RESULTS

From 2017 to 2019, 1181 endoscopy-specific PSIs of significant harm were reported across England and Wales, with 539 (45.6%) being nPSIs. Five categories accounted for over 80% of all incidents, with "follow-up and surveillance" being the largest (23.4% of all nPSIs). From the free-text incident reports, 487 human factors codes were identified. Decision-based errors were the most common act prior to PSI occurrence. Other frequent preconditions to incidents were focused on environmental factors, particularly overwhelmed resources, patient factors, and ineffective team communication. Lack of staffing, standard operating procedures, effective systems, and clinical pathways were also contributory. Seven key recommendations for improving safety have been made in response to our findings.

CONCLUSIONS

This was the first national-level human factors analysis of endoscopy-specific PSIs. This work will inform safety improvement strategies and should empower individual services to review their approach to safety.

Post-ERCP Pancreatitis Risk Factors: Is Post-Sphincterotomy Bleeding Another Risk Factor?

BACKGROUND

Despite advancements in technology and expertise, ERCP carries risks of significant complications, such as pancreatitis, bleeding, and perforation. Post-ERCP pancreatitis is the most common and important complication following ERCP. In our study, we aimed to examine the relationship between patient and procedure-related parameters and the development of pancreatitis.

METHODS

Four hundred patients who underwent ERCP between January 1, 2019 and December 31, 2020, at the General Surgery Clinic of the Bakirköy Dr. Sadi Konuk Health Application and Research Center of the University of Health Sciences Faculty of Medicine were retrospectively evaluated. Patient and procedure-related factors were analyzed statistically through univariate and multivariate analyses.

RESULTS

Age, urgent indication, ERCP history, cholangitis, precut sphincterotomy, common bile duct diameter, pancreatic cannulation, pancreatic stent, and bleeding were statistically significant risk factors for post-ERCP pancreatitis (+). In multivariate analysis, the effects of urgent indication, ERCP history, cholangitis, precut sphincterotomy, common bile duct diameter, and pancreatic cannulation on post-ERCP pancreatitis were statistically significant risk factors ( P <0.05).

DISCUSSION

This study demonstrates that emergency indication, ERCP history, cholangitis, precut sphincterotomy, and pancreatic cannulation are significant risk factors for the development of post- ERCP pancreatitis. One notable contribution of our study to the existing literature is the unique analysis of post-sphincterotomy bleeding as an independent factor.

Nafamostat Reduces the Incidence of post-ERCP Pancreatitis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Pancreatitis is the most common complication of endoscopic retrograde cholangiopancreatography (ERCP). As the management of pancreatitis is limited, clinical approaches focus on the prevention of post-ERCP pancreatitis (PEP). In theory, the serine protease inhibitor nafamostat can reduce circulating inflammatory mediators in pancreatitis. We aimed to investigate the effect of nafamostat in the prevention of PEP in this systematic review and meta-analysis. The protocol for this review was registered in PROSPERO (CRD42022367988). We systematically searched 5 databases without any filters on September 26, 2022. The eligible population was adult patients undergoing ERCP. We compared the PEP preventive effect of nafamostat to placebo. The main outcome was the occurrence of PEP. We calculated the pooled odds ratios (ORs), mean differences, and corresponding 95% confidence intervals (95% CIs) and multilevel model. The risk of bias was assessed using the Rob2 tool. Seven randomized controlled trials involving 2,962 patients were eligible for inclusion. Nafamostat reduced the overall incidence rate of PEP (20 mg, OR: 0.50, 95% CI: 0.30-0.82 and 50 mg, OR: 0.48, 95% CI: 0.24-0.96). However, the occurrence of mild PEP was significantly reduced only in the subgroup receiving 20 mg nafamostat (OR, 0.49, 95% CI: 0.31-0.77). Overall, nafamostat therapy reduced moderate PEP in high-risk patients (OR: 0.18, 95% CI: 0.0.4-0.84) and mild PEP in low-risk patients (OR: 0.32, 95% CI: 0.17-0.61). Nafamostat is an effective therapy in the prevention of mild post-ERCP pancreatitis. Further research is required to determine the cost-effectiveness of this therapy.

Endoscopic main duct stenting in refractory postoperative pancreatic fistula after distal pancreatectomy - a friend or a foe?

BACKGROUND

Clinically relevant (CR) postoperative pancreatic fistula (POPF) after distal pancreatectomy (DP) are common. Endoscopic treatment (ET) has only scarcely been explored. The aim of this study was to evaluate risk factors for CR POPF after DP and the efficacy of ET in adjunct to standard therapy.

METHODS

Consecutive patients without previous pancreatic surgery who underwent DP between 2011 and 2020 were evaluated, analyzing risk factors for CR POPF. The choice and performance of ET, main pancreatic duct (MPD) stenting, was not standardized. Healing time and complications after ET were registered.

RESULTS

406 patients underwent DP, CR POPF occurred in 29.6%. ET was performed in 17 patients 27 days (median) after index surgery. Risk for CR POPF was increased in ASA-PS 1-2 patients, MPD ≤ 3 mm, procedure time ≥ 3 h, and CRP ≥ 180 on postoperative day 3. POPF resolved with standard treatment after 32 days and 59 days in the ET group (p < 0.001). There was one mortality in the ET-group (not procedure related). Mild post-ERCP pancreatitis occurred in three patients.

CONCLUSIONS

CR POPF is common after DP. Long operating time, a narrow MPD, low ASA score, and high postoperative CRP were risk factors for CR POPF. ET was not beneficial but proper evaluation was not possible due to few patients and non-standardized treatment. Complications after ET appeared mild.

Optimal dilation duration of 10 mm diameter balloons after limited endoscopic sphincterotomy for common bile duct stones: a randomized controlled trial

Limited endoscopic sphincterotomy (EST) combined with endoscopic papillary balloon dilation (EPBD) is widely used. However, the optimal duration of small balloon dilation in choledocholithiasis remains controversial. We aimed to determine the optimal duration for 10 mm diameter balloon dilation after limited EST in choledocholithiasis. In this randomized controlled clinical trial, 320 patients were randomly assigned to receive small balloon dilation (10 mm in diameter) for 1 min (n = 160) or 3 min (n = 160) after deep bile duct cannulation. No significant difference in success rate of stone extraction between the two groups was observed. The incidence of post-ERCP pancreatitis (PEP) was higher in the 1 min group (10.6%) than in the 3 min group (4.4%) (P = 0.034). The logistic regression analysis showed that guidewire into the pancreatic duct, cannulation time > 5 min and 1 min balloon dilation were independent risk factors for PEP. There were no significant differences in other post-ERCP adverse events such as acute cholangitis, bleeding, perforation, etc. between the two groups. In conclusion, 3 min in duration was determined to be the optimal dilation condition for the removal of common bile duct stones.

Patient Radiation Exposure during Enteroscopy-Assisted Endoscopic Retrograde Cholangiopancreatography in Surgically Altered Anatomy (with Video)

BACKGROUND

Fluoroscopy must be used cautiously during endoscopic retrograde cholangiopancreatography (ERCP). Radiation exposure data in patients with surgically altered anatomy undergoing enteroscopy-assisted ERCP (EA-ERCP) are scarce.

METHODS

34 consecutive EA-ERCP procedures were compared with 68 conventional ERCP (C-ERCP) procedures. Patient and procedure characteristics and radiation data were collected.

RESULTS

Surgical reconstructions were gastrojejunostomy, Roux-en-Y hepaticojejunostomy, Roux-en-Y total gastrectomy, Roux-en-Y gastric bypass and Whipple's duodenopancreatectomy. Procedures were restricted to biliary indications. Mean fluoroscopy time was comparable in both groups (370 ± 30 s EA-ERCP vs. 393 ± 40 s C-ERCP, p = 0.7074), whereas total mean radiation dose was lower in EA-ERCP (83 ± 6 mGy) compared to C-ERCP (110 ± 11 mGy, p = 0.0491) and dose area product (DAP) was higher in EA-ERCP (2216 ± 173 µGy*m2) compared to C-ERCP (1600 ± 117 µGy*m2, p = 0.0038), as was total procedure time (77 ± 5 min vs. 39 ± 3 min, p < 0.0001). Enteroscope insertion to reach the bile duct during EA-ERCP took 28 ± 4 min, ranging from 4 to 90 min. These results indicate that C-ERCP procedures are generally more complex, needing magnified fluoroscopy, whereas EA-ERCP procedures take more time for enteroscope insertion under wide field fluoroscopic guidance (increased DAP) with less complex ERCP manipulation (lower total radiation dose).

CONCLUSIONS

Radiation exposure during EA-ERCP in surgically altered anatomy is different as compared to C-ERCP. EA-ERCP takes longer with a higher DAP because of the enteroscope insertion, but with lower total radiation dose because these ERCP procedures are usually less complex.

Consensus statements on endoscopic radiofrequency ablation for malignant biliary strictures

Endoscopy-guided endobiliary radiofrequency ablation has emerged as a novel treatment for malignant biliary strictures in recent years. When combined with biliary stenting and systemic chemotherapy, it can effectively postpone local tumor progression, improve patient's quality of life, and prolong their survival, which is mainly indicated for patients with inoperable extrahepatic cholangiocarcinoma and ampullary cancer. Based on the existing clinical evidence, the Digestive Endoscopology Branch of Chinese Medical Association, the Digestive Endoscopy Professional Committee, Endoscopic Physicians Branch of Chinese Medical Doctor Association, and the National Clinical Research Center for Digestive Diseases (Shanghai) organized relevant experts to discuss the indications, contraindications, technical operation specifications, and prevention and treatment of the complications during endoscopy-guided endobiliary radiofrequency ablation. Consensus statements were established, trying to provide references for standard treatment of malignant biliary tumors in clinical practice.

Urgent ERCP performed with single-use duodenoscope (SUD) in patients with moderate-to-severe cholangitis: Single-center prospective study

Background and study aims To assess the outcomes of urgent endoscopic retrograde cholangiopancreatography (ERCP) performed with a single-use duodenoscope (SUD) in patients with moderate-to-severe cholangitis. Patients and methods Between 2021 and 2022 consecutive patients with moderate-to-severe cholangitis were prospectively enrolled to undergo urgent ERCP with SUD. Technical success was defined as the completion of the planned procedure with SUD. Multivariate analysis was used to identify factors related to incidence of adverse events (AEs) and mortality. Results Thirty-five consecutive patients (15 female, age 81.4±6.7 years) were enrolled. Twelve (34.3%) had severe cholangitis; 26 (74.3%) had an American Society of Anesthesiologists (ASA) score ≥3. Twenty-eight patients (80.0%) had a naïve papilla. Biliary sphincterotomy and complete stone clearance were performed in 29 (82.9%) and 30 patients (85.7%), respectively; in three cases (8.6%), concomitant endoscopic ultrasound-gallbladder drainage was performed. Technical and clinical success rates were 100%. Thirty-day and 3-month mortality were 2.9% and 14.3%, respectively. One patient had mild post-ERCP pancreatitis and two had delayed bleeding. No patient or procedural variables were related to AEs. ASA score 4 and leucopenia were related to 3-month mortality; on multivariate analysis, leukopenia was the only variable independently related to 3-month mortality (odds ratio 12.8; 95% confidence interval 1.03-157.2; P =0.03). Conclusions The results of this "proof of concept" study suggest that SUD use could be considered safe and effective for urgent ERCP for acute cholangitis. This approach abolishes duodenoscope contamination from infected patients without impairing clinical outcomes.

Determining the Risk Factors of Complications Due to Endoscopic Retrograde Cholangiopancreatography

Background and objective The effective use of endoscopic retrograde cholangiopancreatography (ERCP) has been on the rise in diagnosing and treating benign and malignant pathologies of the common bile duct and pancreas. ERCP, a complex procedure requiring high knowledge, skills, and practice, differs from other endoscopic applications as it involves the use of different techniques and equipment and the occurrence of more complications. The most commonly observed complications of ERCP are pancreatitis, bleeding, perforation, and infections. In this study, we aimed to assess the incidence of post-ERCP complications to identify the associated risk factors and indications. Methodology In this study, 181 ERCP procedures performed on 122 consecutive patients in the endoscopy unit of Istanbul Training Hospital were prospectively evaluated by using an observational method to determine the frequency of and risk factors for post-ERCP complications. The patients were followed up in the course of the ERCP procedure and for 30 days after the procedure; the complications and clinical developments were recorded. Results The mean age of the cohort was 59.7 ± 17.7 (19-97) years; 40.9% were female and 59.1% were male. The cannulation success was achieved in 77.3% of the ERCP procedure performed. Among the ERCP procedures applied, 89% were performed for therapeutic purposes, and choledocholithiasis (60.2%) was the most common indication for ERCP. Major complications were detected in 25.4% of the patients after ERCP. The most common major complication was cholangitis (9.9%), followed by pancreatitis (7.2%), cholecystitis (5.5%), bleeding (3.9%), and perforation (1.1%). It was observed that sphincterotomy was associated with an increase in all complications. The incidence of cholangitis decreased in the presence of dilated bile ducts unrelated to obstruction. The increased incidence of pancreatitis was associated with the female gender, the use of sphincterotomy and basket, inexperienced endoscopists, and inpatient admissions. The incidence of cholecystitis, on the other hand, was found to be linked with sphincterotomy and inexperienced endoscopists. Conclusions ERCP is a complex endoscopic procedure that requires high technical knowledge and skill and can cause serious complications. For endoscopists to perform clinically effective and accurate ERCP, it is important that they correctly determine the indications for the procedure, know its potential complications, and refrain from practices that will create complications and are unnecessary as much as possible.

Jaundice in a Child with Sickle Cell Anemia: A Case Based Approach

Sickle cell anemia (SCA) is an autosomal recessive disorder caused by a mutation in beta globin gene. Hepatobiliary system is affected in 10-40% of patients with SCA and has a multifactorial etiology. The authors present a child with SCA and conjugated hyperbilirubinemia due to biliary obstruction. He underwent endoscopic retrograde cholangiopancreatography (ERCP) and biliary stenting, had complications of post sphincterotomy bleed, retroperitoneal hematoma and post laparoscopic cholecystectomy sepsis with acute sickle hepatic crisis. He was managed successfully and is doing well on follow-up. Here authors discuss a stepwise approach in management of jaundice in a patient with SCA. Patients with SCA are prone to develop vaso-occlusive crisis (VOC) during periods of stress. VOC affects the liver as acute sickle hepatic crisis, acute hepatic sequestration or sickle cell intrahepatic cholestasis and is collectively termed as sickle cell hepatopathy. Hemolysis due to sickling results in cholelithiasis with its associated complications. These patients are vulnerable to viral hepatitis and hemochromatosis due to multiple blood transfusions. There may be a concomitant acute viral hepatitis, drug induced liver injury, Budd-Chiari syndrome or other chronic liver diseases. These conditions have considerable clinical overlap and may coexist, making the evaluation more challenging. Detailed history, examination and investigations are required for differentiation of etiology. Periods of stress must be tackled with proper hydration, oxygen supplementation, maintaining hemoglobin >10 g/dL, and a low hemoglobin S fraction. Patients with SCA and conjugated hyperbilirubinemia are "high-risk" and best managed by a multidisciplinary team. Preventive strategies like timely vaccinations, chelation, etc. must be practised.

Endoscopic ultrasound-guided choledochoduodenostomy using single-step lumen-apposing metal stents for primary drainage of malignant distal biliary obstruction (SCORPION-p): a prospective pilot study

BACKGROUND

 This study aimed to assess the safety and feasibility of endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) using a lumen-apposing metal stent (LAMS) as a primary drainage strategy in patients with distal malignant biliary obstruction (MBO).

METHODS

 A prospective, single-center, pilot study was conducted in patients with pathology-confirmed MBO without gastric outlet obstruction. The primary outcome was technical success. Secondary outcomes included clinical success, adverse events (AEs), and reinterventions. The study was registered in the Netherlands Trial Registry (registry number NL9757).

RESULTS

 22 patients were enrolled (median age 69.5 years [interquartile range 64-75.3]). Technical success was achieved in 20/22 patients (91 %). AEs occurred in one patient, namely perforation following inadequate stent deployment (5 %), which was treated in the same procedure. Clinical success was achieved in 19/22 patients (86 %). Stent dysfunction was observed in 11/20 patients (55 %) after technically successful EUS-CDS: two patients were treated conservatively and nine patients underwent reintervention(s). One patient died within ≤ 30 days due to fulminant disease progression.

CONCLUSIONS

 The results confirmed the safety and feasibility of EUS-CDS using LAMS as a primary drainage strategy. The high incidence of stent dysfunction should be improved before EUS-CDS with LAMS can be seen as a valid alternative to endoscopic retrograde cholangiopancreatography.

[Interventional radiological and endoscopic technologies in diagnosis and treatment of chronic pancreatitis]

This review is devoted to internationally accepted diagnostic algorithms for complicated chronic pancreatitis (CP). In addition, the authors discuss interventional radiological and endoscopic diagnostic and therapeutic procedures, as well as their role in surgical approaches for this disease. Chronic pancreatitis is often diagnosed with severe symptoms following severe course of disease and complications. Imaging techniques, such as ultrasound, endoscopic ultrasound, CT, MRI/MR cholangiocreatography (MRCP), secretin-stimulated MRCP, are valuable to assess the pancreas in patients with initial manifestations of CP. Modern treatment of complicated CP includes transpapillary or transmural drainage of false cysts, shock wave lithotripsy and stenting for pancreatic duct strictures and/or stones, stenting for biliary hypertension, endovascular interventions for vascular complications and radical surgical treatment. Endoscopic methods are preferable regarding better short-term quality of life. Early surgical intervention (within 3 years after clinical manifestation) is effective to eliminate or significantly reduce pain and pancreatic insufficiency. Multidisciplinary team including surgeons, endoscopists and interventional radiologists should determine the most optimal diagnostic and treatment approach individually for each patient.

Combination of Precut Techniques in Difficult Biliary Cannulation

Background

Selective biliary cannulation (SBC) is a prerequisite for successful endoscopic retrograde cholangiopancreatography (ERCP). SBC has the potential to fail in as many as 20% of cases, even with skilled endoscopists. Precut incision techniques like needle-knife sphincterotomy (NKS) and transpancreatic septotomy (TPS) can be used in cases where standard cannulation techniques fail. However, these precut techniques may also fail in some cases. We aimed to evaluate the procedural success of the combined TPS + NKS technique in difficult biliary cannulation.

Patients and methods

The study included 289 patients who underwent ERCP with precut techniques from 2017 to 2022. Patients were classified into the following three groups and evaluated retrospectively in terms of cannulation success, and ERCP-related adverse effects: Transpancreatic septotomy, NKS, and TPS + NKS; statistical package for the social sciences (SPSS), version 29.0, software was used to analyze the data.

Results

The success rate of SBC was 69% in the TPS group, 75.3% in the NCS group, and 87% in the TPS + NCS group. There was no significant difference between the NKS and TPS + NKS groups. Cannulation success in both NKS group and NKS + TPS groups was significantly higher than in the TPS group (p < 0.001). Complication rates were similar.

Conclusion

In cases where standard sphincterotomy and precut techniques fail, a second precut technique can be used. A previous TPS does not prevent NKS.

How to cite this article

Abiyev A, Tuzcu B, Bilican G, et al. Combination of Precut Techniques in Difficult Biliary Cannulation. Euroasian J Hepato-Gastroenterol 2024;14(1):56-59.

Adverse events of self-expandable metal stent placement for malignant distal biliary obstruction: a large multicenter study

BACKGROUND AND AIMS

Endoscopic placement of self-expandable metal stents (SEMSs) for malignant distal biliary obstruction (MDBO) may be accompanied by several types of adverse events. The present study analyzed the adverse events occurring after SEMS placement for MDBO.

METHODS

The present study retrospectively investigated the incidence and types of adverse events in patients who underwent SEMS placement for MDBO between April 2018 and March 2021 at 26 hospitals. Risk factors for acute pancreatitis, cholecystitis, and recurrent biliary obstruction (RBO) were evaluated by univariate and multivariate analyses.

RESULTS

Of the 1425 patients implanted with SEMSs for MDBO, 228 (16.0%) and 393 (27.6%) experienced early adverse events and RBO, respectively. Pancreatic duct without tumor involvement (P = .023), intact papilla (P = .025), and SEMS placement across the papilla (P = .037) were independent risk factors for acute pancreatitis. Tumor involvement in the orifice of the cystic duct was an independent risk factor for cholecystitis (P < .001). Use of fully and partially covered SEMSs was an independent risk factor for food impaction and/or sludge. Use of fully covered SEMSs was an independent risk factor for stent migration. Use of uncovered SEMSs and laser-cut SEMSs was an independent risk factor for tumor ingrowth.

CONCLUSIONS

Pancreatic duct without tumor involvement, intact papilla, and SEMS placement across the papilla were independent risk factors for acute pancreatitis, and tumor involvement in the orifice of the cystic duct was an independent risk factor for cholecystitis. The risk factors for food impaction and/or sludge, stent migration, and tumor ingrowth differed among types of SEMSs.

Randomized Trial of Prophylactic Antibiotics for Endoscopic Retrograde Cholangiopancreatography in Patients With Biliary Obstruction

INTRODUCTION

The incidence of postendoscopic retrograde cholangiopancreatography (ERCP) infections is reported to be up to 18% in patients with biliary obstruction. Antibiotic prophylaxis may reduce the risk of infectious complications after ERCP; however, the clinical value of prophylactic antibiotics in ERCP remains controversial.

METHODS

We conducted a double-blind, placebo-controlled, randomized trial to investigate whether the use of prophylactic antibiotics would reduce infectious complications after ERCP in patients with biliary obstruction. We randomly assigned patients in a 1:1 ratio to receive either a single dose of 1 g intravenous cefoxitin or normal saline as a placebo 30 minutes before undergoing ERCP. The primary outcome was the incidence of infectious complications after ERCP.

RESULTS

We enrolled 378 patients, and 189 patients were assigned to each group. The risk of infectious complications after ERCP was 2.8% (5 of 176 patients) in the antibiotic prophylaxis group and 9.8% (17 of 173 patients) in the placebo group (risk ratio, 0.29; 95% confidence interval [CI], 0.11-0.74, P = 0.0073). The incidence rates of bacteremia were 2.3% (4 of 176 patients) and 6.4% (11 of 173 patients), respectively (risk ratio, 0.36; 95% CI, 0.12-1.04; P = 0.0599). The incidence rate of cholangitis was 1.7% (3 of 176 patients) in the antibiotic prophylaxis group and 6.4% (11 of 173 patients) in the placebo group (risk ratio, 0.27; 95% CI, 0.08-0.87; P = 0.0267).

DISCUSSION

Antibiotic prophylaxis before ERCP in patients with biliary obstruction resulted in a significantly lower risk of infectious complications, especially cholangitis, than placebo ( ClinicalTrials.gov trial number NCT02958059).

Efficacy of rectal indomethacin in prevention of post-operative hyperamylasemia following pancreatoduodenectomy: a randomized controlled trial

BACKGROUND

Post-operative hyperamylasemia (POH) following pancreatoduodenectomy (PD) may play a key role in pathogenesis of post-operative pancreatic fistula (POPF). Aim of the current study was to evaluate efficacy of perioperative administration of indomethacin in preventing POH.

METHODS

Single-center, double-blind, randomized controlled trial (RCT) conducted on consecutive patients undergoing PD. Patients received either 100 mg of indomethacin per-rectally at induction of anesthesia or standard care. Primary endpoint was incidence of POH in the two arms. POH was defined as postoperative day (POD) 1 serum amylase (S. amylase) levels greater than the upper limit of normal.

RESULTS

After exclusion 44 patients were randomized. The two arms were comparable for preoperative and intraoperative parameters. POH was noted in 20/44 (45.5%) with significantly lower incidence of POH (60.9% vs. 28.6%, p = 0.032) in intervention arm (IA). Median S. amylase, POD 1, 3, and 5 drain amylase, and incidence of clinically relevant POPF (CR-POPF) were lower in IA but failed to reach statistical significance (30.4% vs. 14.3%, p = 0.18). The severity of delayed gastric emptying (DGE) was significantly lower in the IA (grade B/C DGE 23.8% vs. 47.8%, p = 0.023). Evaluation of risk factors for POH showed IA to confer an independent protective effect and increased risk with soft pancreas.

CONCLUSION

Perioperative per-rectal indomethacin administration is effective in decreasing the incidence of POH following pancreatoduodenectomy.

Efficacy of nafamostat mesylate in the prevention of pancreatitis after endoscopic retrograde cholangiopancreatography: a systematic review and meta-analysis of randomized controlled trials

We conducted a systematic review and meta-analysis to evaluate the effect of nafamostat on the prevention of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). PubMed, Web of Science, and Ichushi Web were searched for randomized controlled trials (RCTs) using nafamostat to prevent PEP. In subgroup analyses, we studied the preventive effects of nafamostat according to the severity of PEP, risk category, and dose. A random-effects model was adopted; heterogeneity between studies was examined using the chi-squared test and I2 statistics. This analysis uses the PRISMA statement as general guidance. 9 RCTs involving 3321 patients were included. The risk of PEP was lower in the nafamostat group than in the control group [4.4% vs. 8.3%, risk ratio (RR): 0.50, 95% confidence interval (CI): 0.36-0.68]. In subgroup analyses, the protective effects were evident in low-risk patients for PEP before ERCP (RR: 0.34, 95% CI: 0.21-0.55). The association between PEP and nafamostat was significant only in patients who developed mild PEP (RR: 0.49; 95% CI: 0.36-0.69). The benefits were independent of the dose. The prophylactic use of nafamostat resulted in a lower risk of PEP. The subgroup analyses suggested uncertain benefits for severe PEP or high-risk patients for PEP. This warrants further investigation through additional RCTs.

Performance of European and American Societies of Gastrointestinal Endoscopy Guidelines for Prediction of Choledocholithiasis in Patients with Acute Biliary Pancreatitis

Background and Objectives: Up to one-third of patients with acute biliary pancreatitis also present with choledocholithiasis. Guidelines from the European Society of Gastrointestinal Endoscopy (ESGE) and the American Society for Gastrointestinal Endoscopy (ASGE) for investigating suspected choledocholithiasis suggest endoscopic retrograde cholangiopancreatography in patients with high-likelihood (ESGE)/high-probability (ASGE) predictors and endoscopic ultrasound in those with intermediate-likelihood (ESGE)/intermediate-probability (ASGE) predictors. Although both guidelines are similar, they are not identical. Furthermore, these algorithms were mainly developed from cohorts of patients without pancreatitis and are therefore poorly validated in a subset of patients with acute pancreatitis. We aimed to assess the performance of the ESGE and ASGE algorithms for the prediction of choledocholithiasis in patients with acute biliary pancreatitis. Materials and Methods: This was a retrospective analysis of 86 consecutive patients admitted to a tertiary referral centre in the year 2020 due to acute biliary pancreatitis. Results: Choledocholithiasis was confirmed in 29/86 (33.7%) of patients (13 with endoscopic retrograde cholangiopancreatography and 16 with endoscopic ultrasound). All 10/10 (100%) ESGE high-likelihood and 14/19 (73.7%) ASGE high-probability patients had choledocholithiasis. Only 19/71 (26.8%) patients with ESGE intermediate likelihood and 15/67 (22.4%) with ASGE intermediate probability had choledocholithiasis. Only 8/13 (61.5%) patients with the ASGE high-probability predictor of dilated common bile duct plus bilirubin > 68.4 µmol/mL had choledocholithiasis. Since this predictor is not considered high likelihood by ESGE, this resulted in a superior specificity of the European compared to the American guideline (100% vs. 91.2%). Following the American instead of the European guidelines would have resulted in five unnecessary endoscopic retrograde cholangiopancreatographies and five unnecessary endoscopic ultrasound examinations. Conclusions: This retrospective analysis suggests that the European guidelines may perform better than the American guidelines at predicting choledocholithiasis in the setting of acute pancreatitis. This was because dilated common bile duct plus bilirubin > 68.4 µmol/mL was not a reliable predictor for persistent bile duct stones.

Predictive models in EUS/ERCP

Predictive models (PMs) in endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) have the potential to improve patient outcomes, enhance diagnostic accuracy, and guide therapeutic interventions. This review aims to summarize the current state of predictive models in ERCP and EUS and their clinical implications. To be considered useful in clinical practice a PM should be accurate, easy to perform, and may consider objective variables. PMs in ERCP estimate correct indication, probability of success, and the risk of developing adverse events. These models incorporate patient-related factors and technical aspects of the procedure. In the field of EUS, these models utilize clinical and imaging data to predict the likelihood of malignancy, presence of specific lesions, or risk of complications related to therapeutic interventions. Further research, validation, and refinement are necessary to maximize the utility and impact of these models in routine clinical practice.

Finding the ideal sedative: a non-inferiority study of remimazolam vs propofol in endoscopic retrograde cholangiopancreatography

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) requires an ideal sedative that provides a predictable action duration and meets safety requirements. We compared the efficacies and safeties of remimazolam and propofol in patients who had undergone ERCP.

METHODS

In this prospective, randomized, single-blind, single-center study, we compared the performances of remimazolam and propofol for inpatient ERCP. Study medications were administered under the supervision of an endoscopist. One hundred and ten patients scheduled to undergo ERCP were randomly assigned to receive remimazolam or propofol. The primary endpoint was a composite of successful completion of the procedure and no requirement for rescue medication. Secondary endpoints included sedation efficacy, recovery time, and adverse events.

RESULTS

Of the 110 patients randomized, 108 underwent sedation, and ERCP (53 received remimazolam and 55 propofol). The primary endpoint was met for remimazolam and propofol in 100% of patients in both arms. Incidences and frequencies of emergent adverse events, including desaturation, requiring treatment were comparable in both arms. However, ERCP was started sooner in the propofol arm (mean, 63.18 ± 16.56 s) than in the remimazolam arm (75.23 ± 32.27 s; P-value = 0.02). Time to full alertness after ERCP was also significantly shorter in the propofol arm (304.18 ± 146.25 vs 448.34 ± 224.09 s; P-value <0.001).

CONCLUSION

Remimazolam is not inferior to propofol in achieving successful ERCP completion without rescue medication. Incidences of adverse events were comparable. Remimazolam is a safe and effective alternative to propofol for ERCP sedation, expanding options for clinicians and improving patient outcomes.

Effectiveness and complication rates of percutaneous transhepatic fluoroscopy-guided management of common bile duct stones: a single-arm meta-analysis

OBJECTIVES

To perform a systematic review and meta-analysis to determine the success and complication rate of percutaneous transhepatic fluoroscopy-guided management (PTFM) for the removal of common bile duct stones (CBDS).

METHODS

A comprehensive literature search of multiple databases was conducted to identify original articles published between January 2010 and June 2022, reporting the success rate of PTFM for the removal of CBDS. A random-effect model was used to summarize the pooled rates of success and complications with 95% confidence intervals (CIs).

RESULTS

Eighteen studies involving 2554 patients met the inclusion criteria and were included in the meta-analysis. Failed or infeasible endoscopic management was the most common indication of PTFM. The meta-analytic summary estimates of PTFM for the removal of CBDS were as follows: rate of overall stone clearance 97.1% (95% CI, 95.7-98.5%); stone clearance at first attempt 80.5% (95% CI, 72.3-88.6%); overall complications 13.8% (95% CI, 9.7-18.0%); major complications 2.8% (95% CI, 1.4-4.2%); and minor complications 9.3% (95% CI, 5.7-12.8%). Egger's tests showed the presence of publication bias with respect to the overall complications (p = 0.049). Transcholecystic management of CBDS had an 88.5% pooled rate for overall stone clearance (95% CI, 81.2-95.7%), with a 23.0% rate for complications (95% CI, 5.7-40.4%).

CONCLUSION

The systematic review and meta-analysis answer the questions of the overall stone clearance, clearance at first attempt, and complication rate of PTFM by summarizing the available literature. Percutaneous management could be considered in cases with failed or infeasible endoscopic management of CBDS.

CLINICAL RELEVANCE STATEMENT

This meta-analysis highlights the excellent stone clearance rate achieved through percutaneous transhepatic fluoroscopy-guided removal of common bile duct stones, potentially influencing clinical decision-making when endoscopic treatment is not feasible.

KEY POINTS

• Percutaneous transhepatic fluoroscopy-guided management of common bile duct stones had a pooled rate of 97.1% for overall stone clearance and 80.5% for clearance at the first attempt. • Percutaneous transhepatic management of common bile duct stones had an overall complication rate of 13.8%, including a major complication rate of 2.8%. • Percutaneous transcholecystic management of common bile duct stones had an overall stone clearance rate of 88.5% and a complication rate of 23.0%.

Development and external validation of a nomogram for prediction of post-endoscopic retrograde cholangiopancreatography pancreatitis

BACKGROUND AND AIMS

Endoscopic retrograde cholangiopancreatography (ERCP) is widely performed for management of pancreatobiliary diseases; however, post-ERCP pancreatitis (PEP) remains as an unsolved problem. Although various risk factors for PEP have been reported, the prediction of PEP remains controversial. This study aimed to develop a predictive model for PEP.

METHODS

Consecutive patients undergoing ERCP for biliary indications at two centers were retrospectively studied. Using data from a training cohort, we utilized a multivariable model to select five variables to construct a nomogram. The predictive model was internally and externally validated. Based on the nomogram, the patients were categorized into low-, moderate-, and high-risk groups.

RESULTS

Using the data of 2224 patients in the training cohort, five variables were selected to generate a nomogram: 1) sex, 2) indication for ERCP, 3) difficult cannulation, 4) guidewire insertion into the pancreatic duct, and 5) endoscopic sphincterotomy or sphincteroplasty. The most significant risk factor was endoscopic papillary balloon dilation such as endoscopic sphincterotomy or sphincteroplasty. The bias-corrected concordance index was 0.72 in the training cohort and 0.72 in the validation cohort. Calibration curves for both cohorts demonstrated good agreement between the predicted and observed frequencies of the actual outcome. In the validation cohort, PEP developed in 5.0% and 14% of patients in the moderate- and high-risk groups, respectively.

CONCLUSIONS

We successfully developed a good predictive model for PEP. The prevention of PEP in high risk patients should be investigated further.

Face and content validity of a biological papilla designed for the Boškoski-Costamagna ERCP simulator

BACKGROUND AND AIMS

A biological papilla made of chicken heart tissue, incorporated into the Boškoski-Costamagna ERCP Trainer simulator, was recently designed to allow training in sphincterotomy. This study aimed to evaluate the face and content validity of this tool.

METHOD

Participants from 2 groups (nonexperienced and experienced [<600 or >600 lifetime ERCPs, respectively]) were invited to perform standardized assignments on the model: sphincterotomy and precut for both groups and papillectomy for the experienced group. Following these assignments, all participants filled out a questionnaire to rate their appreciation of the realism of the model, and experienced endoscopists were also asked to evaluate its didactic value using a 5-point Likert scale.

RESULTS

A total of 19 participants were included (nonexperienced, n = 10; experienced, n = 9). Parameters regarding the realism of the tool in terms of general appearance, sphincterotomy, precut, and papillectomy were overall considered realistic (4 of 5), with good agreement rates in terms of overall realism between groups. Experienced operators reported the highest realism for "positioning the scope and needle-knife in the field of view" and "during precut," "cutting in small increments during precut," and "controlling the scope during papillectomy," and they highly agreed that this papilla should be included for training novice and intermediate trainees in sphincterotomy, precut, and papillectomy.

CONCLUSIONS

Our results show good face validity and excellent content validity of this biological papilla combined with the Boškoski-Costamagna ERCP Trainer. This new tool provides a useful, inexpensive, versatile, and easy tool for training regarding sphincterotomy, precut, and papillectomy. Future studies should explore whether including this model in real-life training improves the learning curve of endoscopy trainees.

Risk of Complications After Endoscopic Retrograde Cholangiopancreatography in Pregnancy: A Propensity-Matched Analysis

BACKGROUND

Studies have suggested higher complication rates after endoscopic retrograde cholangiopancreatography (ERCP) in pregnancy.

AIMS

We performed a propensity-matched cohort analysis to assess the risk of ERCP-related complications among pregnant women in the United States.

METHODS

The TriNetX database was analyzed to identify pregnant and non-pregnant females between 18 and 50 years of age who underwent ERCP. One-to-one propensity score matching was performed for age and race. Outcomes included risk of post-ERCP pancreatitis (PEP), gastrointestinal (GI) bleeding, perforation within 7 days, and infections within 30 days of ERCP. Subgroup analysis was performed to assess the risk of PEP based on indication for ERCP.

RESULTS

The risk of PEP was higher in the pregnant cohort compared to controls, 10.3% vs 6.08%, adjusted odds ratio (aOR) 1.77, 95% confidence interval (CI) 1.20-2.61; p = 0.003. We found no difference in the risk of GI bleeding, perforation, and infections between the two cohorts. There was no difference in the risk of PEP in the pregnant cohort compared to controls who underwent ERCP for acute choledocholithiasis (4.2% vs 2.1%, aOR 1.98, 95% CI 0.97-4.03, p = 0.5) or ascending cholangitis (18.6% vs 14.7%, aOR 1.32, 95% CI 0.52-3.39, p = 0.55). There was no difference in the risk of PEP in the pregnant cohort after sensitivity analysis based on age, race, obesity, and indomethacin use.

CONCLUSION

Pregnant females are at an increased risk of PEP but not GI bleeding, perforation, and infections when compared to non-pregnant controls. Clinicians should be cautious when proceeding with ERCP during pregnancy.

Initial experience of visualized biliary cannulation during ERCP

BACKGROUND : Selective biliary cannulation is the most challenging step in endoscopic retrograde cholangiopancreatography (ERCP) because only indirect radiographic images can be obtained. Therefore, we developed a novel endoscopic retrograde direct cholangioscopy (ERDC) technology to facilitate visible biliary cannulation. METHODS : In this case series, we used ERDC to treat 21 patients with common bile duct stones who were enrolled consecutively between July 2022 and December 2022. The procedure details and complications were recorded, and all patients were followed up for 3 months after the procedure. The learning curve effect was analyzed by comparing the early and later cases. RESULTS : Biliary cannulation was successful in all patients, and the stones were removed completely. The median (interquartile range [IQR]) time for cholangioscopy-guided biliary cannulation was 240.0 (10.0-430.0) seconds, and the median (IQR) number of cannulation procedures was 2 (1-5). Despite there being one episode of post-ERCP pancreatitis, one of cholangitis, and three patients developing asymptomatic hyperamylasemia, all of the patients recovered after symptomatic treatment, being discharged and with no serious adverse events occurring during the 3-month follow-up period. Compared with the early cases, the number of intubations and the use of guidewire guidance decreased in later cases. CONCLUSION : Our research confirms that ERDC is a feasible technology for biliary cannulation under direct vision.

Endoscopic retrograde cholangiopancreatography for diagnosing and treating pediatric biliary and pancreatic diseases

BACKGROUND

This study evaluated the safety and effectiveness of endoscopic retrograde cholangiopancreatography (ERCP) in pediatric patients with biliary and pancreatic diseases. A retrospective analysis was conducted on 57 ERCP procedures performed in 41 children, primarily for treating pancreatic diseases. The overall success rate was 91.2%, with no major complications observed. Post-ERCP pancreatitis (PEP) occurred in 8.8% of cases. Follow-up examinations over one year showed no recurrence of biliary or pancreatic diseases. Notably, endoscopic treatment led to a significant increase in body mass index (BMI). These findings demonstrate the valuable role of ERCP in managing such conditions.

AIM

To evaluate the safety and efficacy of ERCP for the management of biliary and pancreatic diseases in pediatric patients.

METHODS

We conducted a retrospective analysis of data from children aged 1-18 years who underwent ERCP for biliary and pancreatic diseases at Beijing Children's Hospital between January 2021 and December 2022. The collected data included procedure time, endoscopic treatment, success rate, and postoperative complications.

RESULTS

Forty-one children underwent 57 ERCP procedures, including 14 with biliary duct disease and 27 with pancreatic disease. The mean age of the patients was 7.48 ± 3.48 years. Biliary duct-related treatments were performed 18 times, and pancreatic disease treatments were performed 39 times. ERCP was primarily used to treat pediatric pancreatic diseases [68.4% (39/57) of the procedures]. The overall success rate was 91.2% (52/57 patients). PEP was noted in five patients (8.8%, 5/57), and no instances of bleeding, perforation, or cholangitis were observed. The patients were followed up for over one year, and no recurrence of biliary or pancreatic diseases was detected. Importantly, BMI significantly increased after endoscopic treatment compared to that before treatment (P = 0.001).

CONCLUSION

The high success rate and lack of major complications support the valuable role of ERCP in the management of pediatric biliary and pancreatic diseases in the pediatric population.

Nafamostat mesilate for prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis: A systematic review and meta-analysis based on prospective, randomized, and controlled trials

OBJECTIVES

To evaluate the efficacy of nafamostat mesilate in the prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) by conduct a systematic review and meta-analysis.

METHOD

We retrieved for all randomized controlled trials (RCTs) about compare nafamostat mesilate with placebo in preventing PEP published before August 23, 2022, in 5 major electronic databases. The primary outcome was PEP rate, and the secondary outcome was post-ERCP hyperamylasemia (PEHA) rate. Subgroup analyses were performed to reveal the factors that may affect the preventive effect of nafamostat. Assessment of the quality of evidence was conducted based on Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system.

RESULTS

According to the search strategy and criteria of inclusion and exclusion, 8 articles with a number of 3210 patients were included. The PEP incidence of the nafamostat group was inferior compared with the placebo group (4.6% vs 8.5%, RR = 0.50, 95% CI: 0.38-0.66). Subgroup analyses revealed that nafamostat had a preventive effect on patients with different risk stratification (High-risk: RR = 0.61, 95% CI: 0.43-0.86, Low-risk: RR = 0.28; 95% CI: 0.17-0.47). Different doses (20 mg: RR = 0.50, 95% CI: 0.36-0.69, 50 mg: RR = 0.45, 95% CI: 0.27-0.74) and duration (<12 hour: RR = 0.55, 95% CI: 0.37-0.81, ≥12 h: RR = 0.44, 95% CI: 0.29-0.66) of administration of nafamostat are adequate for the prevention of PEP, but postoperative administration may not help (preoperative: RR = 0.52, 95% CI: 0.39-0.69, postoperative: RR = 0.54, 95% CI: 0.23-1.23). Nafamostat may not efficacious in preventing severe PEP (Mild: RR = 0.49, 95% CI, 0.35-0.68, Moderate: RR = 0.47, 95% CI: 0.25-0.86, Severe: RR = 0.91, 95% CI, 0.25-3.29) or in low-quality studies (Low-quality: RR = 0.69, 95% CI: 0.13-3.60, High-quality: RR = 0.49, 95% CI: 0.37-0.65).

CONCLUSION

Preoperative use of nafamostat can effectively prevent PEP in patients with various risk stratification. Nafamostat can prevent mild and moderate PEP, but may not prevent severe PEP and PEHA. There should be more high-quality RCTs in future to strengthen the evidence of nafamostat in preventing PEP.

Predictors of technical success of percutaneous transhepatic common bile duct stone removal: is it only a matter of stone size?

OBJECTIVES

The common practice is to remove symptomatic common bile duct (CBD) stones in patients. This study aimed to investigate the factors affecting the percutaneous transhepatic removal of CBD stones.

METHODS

We retrospectively analyzed the data of 100 patients (66 men and 34 women; age: 25-105 years, mean 79.1 years) with symptomatic CBD stones who underwent percutaneous transhepatic stone removal (PTSR) from January 2010 through October 2019. After balloon dilation of the ampulla of Vater or bilioenteric anastomosis, the stones were pushed out of the CBD into the small bowel with a balloon catheter. If failed, basket lithotripsy was performed. Technical success was defined as complete clearance of the bile ducts on a cholangiogram.

RESULTS

The technical success rate was 83%, and achieved 90.2% in patients with altered gastroduodenal/pancreatobiliary anatomy. Multivariable analysis revealed that CBD diameter (odds ratio [OR]: 506.460, p = 0.015), failed ERCP (OR: 16.509, p = 0.004), Tokyo guidelines TG18/TG13 severity (grade III; OR: 60.467, p = 0.006), and left-sided transhepatic approach (OR: 21.621, p = 0.012) were risk factors for technical failure. The appropriate cutoff CBD size was 15.5 mm (area under the curve: 0.91). CBD stone size, radiopacity of stones, and CBD angle between retroduodenal and pancreatic portion did not influence technical success.

CONCLUSIONS

PTSR is effective for CBD stone removal in older adults and individuals with altered gastrointestinal tract anatomy. The aforementioned risk factors for technical failure should be considered in preoperative evaluation before PTSR to improve the success rate.

KEY POINTS

• PTSR is effective in symptomatic CBD stone management among older adults and individuals with altered anatomy. Investigating clinical /anatomic factors can guide radiologists toward a more comprehensive preoperative evaluation to maximize the success rate. • Our data indicate that dilated CBD (diameter ≥ 15.5 mm) and left-sided PTBDs reduce the technical success rate by 506-fold and 22-fold, respectively. • Clinical factors such as previous failed ERCP for stone removal and higher severity of acute cholangitis lessen the technical success rate.

Endotherapy for Pancreas Divisum

Pancreas divisum (PD) is a common anatomic variant of the pancreatic duct. Causal association between PD and pancreatitis has been debated for many years. Minor papilla sphincterotomy (miES) is offered in clinical practice to patients with idiopathic acute recurrent pancreatitis (iRAP) and PD. However, available data originate mainly from observational studies with many limitations. An ongoing international, multicenter, sham-controlled trial is evaluating the efficacy of miES in iRAP and PD. Endoscopic therapy for pain relief has limited to no benefit in patients with chronic abdominal pain or chronic pancreatitis who have PD and is not recommended.

Pure Cut or Endocut for Biliary Sphincterotomy? A Multicenter Randomized Clinical Trial

INTRODUCTION

Adverse events (AE) after endoscopic retrograde cholangiopancreatography (ERCP) are not uncommon and post-ERCP acute pancreatitis (PEP) is the most important one. Thermal injury from biliary sphincterotomy may play an important role and trigger PEP or bleeding. Therefore, this study evaluated the outcomes of 2 electric current modes used during biliary sphincterotomy.

METHODS

From October 2019 to August 2021, consecutive patients with native papilla undergoing ERCP with biliary sphincterotomy were randomized to either the pure cut or endocut after cannulation. The primary outcome was PEP incidence. Secondary outcomes included intraprocedural and delayed bleeding, infection, and perforation.

RESULTS

A total of 550 patients were randomized (272 pure cut and 278 endocut). The overall PEP rate was 4.0% and significantly higher in the endocut group (5.8% vs 2.2%, P = 0.034). Univariate analysis revealed >5 attempts ( P = 0.004) and endocut mode ( P = 0.034) as risk factors for PEP. Multivariate analysis revealed >5 attempts ( P = 0.005) and a trend for endocut mode as risk factors for PEP ( P = 0.052). Intraprocedural bleeding occurred more often with pure cut ( P = 0.018), but all cases were controlled endoscopically during the ERCP. Delayed bleeding was more frequent with endocut ( P = 0.047). There was no difference in perforation ( P = 1.0) or infection ( P = 0.4999) between the groups.

DISCUSSION

Endocut mode may increase thermal injury leading to higher rates of PEP and delayed bleeding, whereas pure cut is associated with increased intraprocedural bleeding without clinical repercussion. The electric current mode is not related to perforation or infection. Further RCT assessing the impact of electric current on AE with overlapping preventive measures such as rectal nonsteroidal anti-inflammatory drugs and hyperhydration are needed. The study was submitted to the Brazilian Clinical Trials Platform ( http://www.ensaiosclinicos.gov.br ) under the registry number RBR-5d27tn.

Postendoscopic Retrograde Cholangiopancreatography Pancreatitis Pathophysiology and Prevention

Endoscopic retrograde cholangiopancreatography (ERCP) is an essential procedure for the management of pancreato-biliary disorders. Pancreatitis remains the most frequent complication of the ERCP procedure, and it is, therefore, necessary to recognize the pathophysiology and risk factors contributing to the development of pancreatitis and understand the methods to prevent this complication.

Role of Biliary Stent in Recurrence of Biliary Stones and Complications After Stone Clearance in Patients Awaiting Cholecystectomy: A Randomized Trial

INTRODUCTION

The role of prophylactic biliary stenting after clearance of choledocholithiasis in patients awaiting cholecystectomy for concomitant cholelithiasis is controversial. We planned a randomized controlled trial to study the effect of prophylactic biliary stenting after achieving biliary clearance in reducing recurrence of choledocholithiasis and biliary complications in patients awaiting cholecystectomy.

METHODS

Patients with concomitant cholelithiasis and choledocholithiasis were included, and those who had evidence of clearance of choledocholithaisis (documented on occlusion cholangiogram during endoscopic retrograde cholangiography [ERC]) were randomized to prophylactic biliary stenting or no stenting. Choledocholithaisis recurrence rate (primary outcome), biliary complications and need for repeat/emergency ERC (secondary outcomes) were compared till 3 months after clearance.

RESULTS

Between September 2021 and July 2022, 70 patients were randomized into group A, stenting (n = 35), and group B, no stenting (n = 35). Sixty-six patients were included in the final analysis. Baseline characteristics were comparable between the 2 groups. Ten (15.2%) patients had recurrence of choledocholithiasis, and it was comparable between the 2 groups (7/34 [20.6%] and 3/34 [9.4%], P = 0.306). Five patients (2 cholecystitis and 3 post-ERC pancreatitis) from the stent group while none from the no stent group developed complications, and this difference was statistically significant ( P = 0.024). None of the patients in both the groups needed emergency ERC during the follow-up.

DISCUSSION

This randomized trial shows a higher complication rate with prophylactic stenting, while there is no benefit in preventing choledocholithiasis recurrence in patients waiting for cholecystectomy after biliary clearance (CTRI registration number: CTRI/2021/09/036538).

Endoclip papillaplasty (ECPP) versus limited EST plus EPLBD for a decrease in recurrent choledocholithiasis: a prospective cohort study

BACKGROUND AND AIMS

Limited EST plus EPLBD has been widely used for the therapy of large CBDS; however, long-term complication-relevant studies suggested that it damaged the function of the sphincter of Oddi (SO) and resulted in recurrent choledocholithiasis. Thus, we designed Endoclip papillaplasty (ECPP) and previous studies have shown that it successfully restored the function of SO. In this study, we designed a prospective cohort and aimed to verify the safety and effectiveness of ECPP.

METHODS

Eligible patients were divided into the ECPP group and the limited EST plus EPLBD group based on papillary morphology and the ratio of maximum size of stones to length of intramural segments of CBD. All participants in the ECPP group received endoscopy at 3 weeks to retrieve the biliary stent, perform SOM, and were divided into grade A and grade B based on the healing grade of SO. All patients were followed up every 6 months until recurrent choledocholithiasis, patient death, or at the 36-month follow-up end. The primary outcome was the incidence of recurrent choledocholithiasis. The secondary outcomes included mechanical lithotrip usage and adverse events.

RESULTS

The incidences of recurrent choledocholithiasis in the ECPP group and limited EST plus EPLBD group were 13.6 and 22.1%, respectively (P = 0.204). The ECPP-A group had a lower incidence of recurrent choledocholithiasis than the limited EST plus EPLBD groups (5.1 vs. 22.1%, P = 0.020*), and certified the function of SO successfully restored in the ECPP-A group.

CONCLUSION

The ECPP-A group had a decrease in recurrent choledocholithiasis, and ECPP was safe and effective for CBDS.

A novel concept of passive loop-forming wire-guided biliary cannulation using an ultra-deep angled tip guidewire (with video)

Background and study aims Wire-guided biliary cannulation (WGBC) is a standard technique during endoscopic retrograde cholangiopancreatography-related interventions. However, no dedicated guidewire is available. We investigated a novel "passive loop-forming WGBC" concept using a 0.035-inch ultra-deep angled tip guidewire. Patients and methods This single-arm, single-center, retrospective study included consecutive 111 patients who underwent passive loop-forming WGBC as the first biliary intervention between October 2021 and December 2022. Results WGBCs were completed within 5 minutes and overall were performed at a median papillary negotiation time of 81 seconds (interquartile range [IQR], 39-170) and 114 seconds (IQR, 49-303) in 83 (74.8%) and 106 (95.5%) cases, respectively. Logistic regression analysis identified age ≥ 80 years (odds ratio [OR]: 3.56, 95% confidence interval [CI]: 1.12-11.31) and unintentional pancreatic guidewire insertion (OR: 17.67, 95% CI: 5.75-54.31) as significant risk factors for failed WGBC within 5 minutes. Among the 106 obtained cannulations, the guidewire leading part formed a small-looped tip and wide-looped body in 83 (78.3%) and 23 (21.7%) cases, respectively. Adverse events included post-procedure pancreatitis (2/111 [1.8%]) and guidewire penetration (3/111 [2.7%]). Conclusions Passive loop-forming WGBC using an ultra-deep angled tip guidewire is a feasible procedure.

Informed consent for endoscopic procedures: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

All endoscopic procedures are invasive and carry risk. Accordingly, all endoscopists should involve the patient in the decision-making process about the most appropriate endoscopic procedure for that individual, in keeping with a patient's right to self-determination and autonomy. Recognition of this has led to detailed guidelines on informed consent for endoscopy in some countries, but in many no such guidance exists; this may lead to variations in care and exposure to risk of litigation. In this document, the European Society of Gastrointestinal Endoscopy (ESGE) sets out a series of statements that cover best practice in informed consent for endoscopy. These statements should be seen as a minimum standard of practice, but practitioners must be aware of and adhere to the law in their own country. 1:  Patients should give informed consent for all gastrointestinal endoscopic procedures for which they have capacity to do so. 2:  The healthcare professional seeking consent for an endoscopic procedure should ensure that the patient has the capacity to consent to that procedure. 3:  For patients who lack capacity, healthcare personnel should at all times try to engage with people close to the patient, such as family, friends, or caregivers, to achieve consensus on the appropriateness of performing the procedure. 4:  Where a patient lacks capacity to provide informed consent, the best interest decision should be clearly documented in the medical record. This should include information about the capacity assessment, reason(s) that the decision cannot be delayed for capacity recovery (or if recovery is not expected), who has been consulted, and where relevant the form of authority for the decision. 5:  There should be a systematic and transparent disclosure of the expected benefits and harms that may reasonably affect patient choice on whether or not to undergo any diagnostic or interventional endoscopic procedure. Information about possible alternatives, as well as the consequences of doing nothing, should also be provided when relevant. 6:  The information provided on the benefit and harms of an endoscopic procedure should be adapted to the procedure and patient-specific risk factors, and the preferences of the patient should be central to the consent process. 7:  The consent discussion should be undertaken by an individual who is familiar with the procedure and its risks, and is able to discuss these in the context of the individual patient. 8:  Patients should confirm consent to an endoscopic procedure in a private, unrushed, and non-coercive environment. 9:  If a patient requests that an endoscopic procedure be discontinued, the procedure should be paused and the patient's capacity for decision making assessed. If a competent patient continues to object to the procedure, or if a conclusive determination of capacity is not feasible, the examination should be terminated as soon as it is safe to do so. 10: Informed consent should be sufficiently detailed to cover all findings that can be reasonably anticipated during an endoscopic examination. The scope of this consent should not be expanded, nor a patient's implicit consent for additional interventions assumed, unless failure to proceed with such interventions would result in immediate and predictable harm to the patient.

Combinatorial Effect of Prophylactic Interventions for Post-ERCP Pancreatitis among Patients with Risk Factors: A Network Meta-Analysis

Background/Aims

The combinatorial effects of prophylactic methods for postendoscopic retrograde cholangiopancreatography pancreatitis (PEP) in patients with risk factors remain unclear. In this network meta-analysis, we compared the efficacy of various prophylactic strategies to decrease the risk of PEP among patients with risk factors.

Methods

A systematic review was performed to identify randomized controlled trials from PubMed, Embase, and the Cochrane Library through July 2021. We used frequentist network meta-analysis to compare the rates of PEP among patients who received prophylactic treatments as follows: class A, rectal nonsteroidal anti-inflammatory drugs; class B, prophylactic pancreatic stent; class C, aggressive hydration; or control, no prophylaxis or active control. We selected those studies that included patients with risk factors for PEP.

Results

We identified 19 trials, comprising 4,328 participants. Class ABC (odds ratio [OR], 0.08; 95% confidence interval [CI], 0.03 to 0.24), class AC (OR, 0.10; 95% CI, 0.02 to 0.47), class AB (OR, 0.12; 95% CI, 0.05 to 0.26), class BC (OR, 0.13; 95% CI, 0.04 to 0.41), class A (OR, 0.16; 95% CI, 0.05 to 0.50), and class B (OR, 0.26; 95% CI, 0.14 to 0.46), were associated with a reduced risk of PEP as compared to that of the control. The most effective prophylaxis was ABC (0.87), followed by AC (0.68), AB (0.65), BC (0.56), A (0.49), and B (0.24) according to P-score.

Conclusions

The results of this network meta-analysis suggest that the more prophylactic methods are employed, the better the outcomes. It appears that for patients with risk factors, we need to prevent PEP through the use of these well proven combination strategies.

SASE, Success and Adverse event Score in Endoscopic Retrograde Cholangiopancreatography: a Novel Grading System

BACKGROUND

Validated, accepted grading tools for preprocedural complexity assessment in ERCP are lacking. We therefore created a grading system for ERCP based on the classification used by the American Society for Gastrointestinal Endoscopy (ASGE).

METHODS

Data on ERCP adverse events (AE) and success were collected in a multicenter, prospective uncontrolled study. Multiple logistic regressions were applied to success and AEs in accordance with the ASGE classification. Each procedure suggested by ASGE was tested against different outcomes. Results were used to create a score and were evaluated in a control cohort.

RESULTS

16,327 ERCPs were documented in 27 centers. Analysis of ASGE categorization (10,904 cases) showed that this model fails to adequately predict parameters of complexity; only for cardiopulmonary AEs and perforation was no significant variance evident. Depending on the specific clinical circumstances, probability of success of the intervention sometimes varied significantly in risk, implying a twofold score, one part for probability of success and one for risk. A split score with three levels each was designed and tested in a validation cohort (5,423 procedures). Achieving therapeutic targets / post-ERCP pancreatitis could be correctly predicted in 87.0%/95.3%.

CONCLUSIONS

Grading ERCP success and AEs have to be considered independently. Onefold grading systems appear incomplete and unable to provide an adequate classification of severity. SASE (Success and Adverse Event Score in Endoscopic Retrograde Cholangiopancreatography) was created to incorporate these findings. Showing high predictive value, this score could be a potent tool for planning ERCP and training in endoscopy.

The Role of Cholangioscopy in Biliary Diseases

Endoscopy plays a central role in diagnostic and therapeutic approaches to biliary disease in both benign and malignant conditions. A cholangioscope is an endoscopic instrument that allows for the direct exploration of the biliary tree. Over the years, technology has improved endoscopic image quality and allowed for the development of an operative procedure that can be performed during cholangioscopy. Different types of instruments are available in this context, and they can be used in different anatomical access points according to the most appropriate clinical indication. The direct visualization of biliary mucosa is essential in the presence of biliary strictures of unknown significance, allowing for the appropriate allocation of patients to surgery or conservative treatments. Cholangioscopy has demonstrated excellent performance in discriminating malignant conditions (such as colangiocarcinoma) from benign inflammatory strictures, and more recent advances (e.g., artificial intelligence and confocal laser endomicroscopy) could further increase its diagnostic accuracy. Cholangioscopy also plays a primary role in the treatment of benign conditions such as difficult bile stones (DBSs). In this case, it may not be possible to achieve complete biliary drainage using standard ERCP. Therapeutic cholangioscopy-guided lithotripsy allows for stone fragmentation and complete biliary drainage. Indeed, other complex clinical situations, such as patients with intra-hepatic lithiasis and patients with an altered anatomy, could benefit from the therapeutic role of cholangioscopy. The aim of the present review is to explore the most recent diagnostic and therapeutic advances in the roles of cholangioscopy in the management of biliary diseases.

Hepatico-Duodenal Fistula Following Iatrogenic Strasberg Type E4 Bile Duct Injury: A Case Report

INTRODUCTION

Gallstone disease (GSD) is among the most common disorders worldwide. Gallstones are established in up to 15% of the general population. Laparoscopic cholecystectomy (LC) has become the "gold standard" for treatment of GSD but is associated with a higher rate of certain complications, namely, bile duct injury (BDI). Biliary fistulas (BF) are a common presentation of BDI (44.1% of all patients); however, they are mainly external. Post-cholecystectomy internal BF are exceedingly rare.

CASE REPORT

a 33-year Caucasian female was admitted with suspected BDI after LC. Strasberg type E4 BDI was established on endoscopic retrograde cholangiopancreatography (ERCP). Urgent laparotomy established biliary peritonitis. Delayed surgical reconstruction was planned and temporary external biliary drains were positioned in the right and left hepatic ducts. During follow-up, displacement of the drains occurred with subsequent evacuation of bile through the external fistula, which resolved spontaneously, without clinical and biochemical evidence of biliary obstruction or cholangitis. ERCP established bilio-duodenal fistula between the left hepatic duct (LHD) and duodenum, with a stricture at the level of the LHD. Endoscopic management was chosen with staged dilation and stenting of the fistulous tract over 18 months until fistula maturation and stricture resolution. One year after stent extraction, the patient remains symptom free.

DISCUSSION

Management of post-cholecystectomy BDI is challenging. The optimal approach is determined by the level and extent of ductal lesion defined according to different classifications (Strasberg, Bismuth, Hannover). Type E BDI are managed mainly surgically with a delayed surgical approach generally deemed preferable. Only three cases of choledocho-duodenal fistulas following LC BDI currently exist in the literature. Management is controversial, with expectant approach, surgical treatment (biliary reconstruction), or liver transplantation being described. Endoscopic treatment has not been described; however, in the current paper, it proved to be successful. More reports or larger case series are needed to confirm its applicability and effectiveness, especially in the long term.

Short Peptide Nanofiber Biomaterials Ameliorate Local Hemostatic Capacity of Surgical Materials and Intraoperative Hemostatic Applications in Clinics

Short designer self-assembling peptide (dSAP) biomaterials are a new addition to the hemostat group. It may provide a diverse and robust toolbox for surgeons to integrate wound microenvironment with much safer and stronger hemostatic capacity than conventional materials and hemostatic agents. Especially in noncompressible torso hemorrhage (NCTH), diffuse mucosal surface bleeding, and internal medical bleeding (IMB), with respect to the optimal hemostatic formulation, dSAP biomaterials are the ingenious nanofiber alternatives to make bioactive neural scaffold, nasal packing, large mucosal surface coverage in gastrointestinal surgery (esophagus, gastric lesion, duodenum, and lower digestive tract), epicardiac cell-delivery carrier, transparent matrix barrier, and so on. Herein, in multiple surgical specialties, dSAP-biomaterial-based nano-hemostats achieve safe, effective, and immediate hemostasis, facile wound healing, and potentially reduce the risks in delayed bleeding, rebleeding, post-operative bleeding, or related complications. The biosafety in vivo, bleeding indications, tissue-sealing quality, surgical feasibility, and local usability are addressed comprehensively and sequentially and pursued to develop useful surgical techniques with better hemostatic performance. Here, the state of the art and all-round advancements of nano-hemostatic approaches in surgery are provided. Relevant critical insights will inspire exciting investigations on peptide nanotechnology, next-generation biomaterials, and better promising prospects in clinics.

A rare case of pedunculated ampulloma: EUS view and resection

Video 1Video showing a rare case of pedunculated ampulloma: imaging evaluation and resection technique.

A simple clinical score to stratify the risk of procedure-related adverse events in ERCP procedures with trainee involvement

BACKGROUND : Optimal training strategies in endoscopic retrograde cholangiopancreatography (ERCP) remain controversial despite the shift toward competence-based training models, with limited data available on patient safety during training. We aimed to assess whether pre-procedural clinical predictors could identify patients at low risk of developing procedure-related adverse-events (AEs) in a training environment. METHODS : We performed a prospective, multicenter, cohort study in five training centers. A data collection system documenting indication, clinical data, trainee performance (assessed using a validated competence assessment tool), technical outcomes, and AEs over a 30-day follow-up was utilized. We developed a clinical risk score (Trainee Involvement in ERCP Risk Score [TIERS]) for patients undergoing ERCP and compared the rate of AEs in a training environment between low-risk and high-risk groups. The association between trainee performance and AE rate was also evaluated. RESULTS : 1283 ERCPs (409 [31.9 %, 95 %CI 29.3 %-34.4 %] with trainee involvement) performed by 11 trainers and 10 trainees were analyzed. AEs were more frequent in the high-risk compared with the low-risk group: 26.7 % (95 %CI 20.5 %-34.7 %) vs. 17.1 % (95 %CI 12.8 %-22.2 %). TIERS demonstrated a high negative predictive value for AEs (82.9 %, 95 %CI 79.4 %-85.8 %) and was the only predictor of AEs on multivariable analysis (odds ratio 1.38, 95 %CI 1.09-1.75). Suboptimal trainee performance was associated with an increase in AE rates. CONCLUSION : Simple, clinical-based predictive tools could improve ERCP training by selecting the most appropriate cases for hands-on training, with the aim of increasing patient safety.

Impact of center and endoscopist ERCP volume on ERCP outcomes: a systematic review and meta-analysis

BACKGROUND AND AIMS

Endoscopist experience and center volume might be associated with ERCP outcomes, as in other fields of endoscopy and in surgery. An effort to assess this relationship is important to improve practice. This systematic review and meta-analysis aimed to evaluate these comparative data and to assess the impact of endoscopist and center volume on ERCP procedure outcomes.

METHODS

We performed a literature search in PubMed, Web of Science, and Scopus through March 2022. Volume classification included high- and low-volume (HV and LV) endoscopists and centers. The primary outcome was the impact of endoscopist and center volume on ERCP success. Secondary outcomes were the overall adverse event (AE) rate and the specific AE rate. The quality of the studies was assessed using the Newcastle-Ottawa scale. Data synthesis was obtained by direct meta-analyses using a random-effects model; results are presented as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Of 6833 relevant publications, 31 studies met the inclusion criteria. Procedure success was higher among HV endoscopists (OR, 1.81; 95% CI, 1.59-2.06; I2 = 57%) and in HV centers (OR, 1.77; 95% CI, 1.22-2.57; I2 = 67%). The overall AE rate was lower for procedures performed by HV endoscopists (OR, .71; 95% CI, .61-.82; I2 = 38%) and in HV centers (OR, .70; 95% CI, .51-.97; I2 = 92%). Bleeding was less frequent in procedures performed by HV endoscopists (OR, .67; 95% CI, .48-.95; I2 = 37%) but did not differ based on center volume (OR, .68; 95% CI, .24-1.90; I2 = 89%). No statistical differences were detected concerning pancreatitis, cholangitis, and perforation rates.

CONCLUSIONS

HV endoscopists and centers provide higher ERCP success rates with fewer overall AEs, especially bleeding, compared with respective LV comparators.

Validity evidence for observational ERCP competency assessment tools: a systematic review

BACKGROUND : Assessment of competence in endoscopic retrograde cholangiopancreatography (ERCP) is critical for supporting learning and documenting attainment of skill. Validity evidence supporting ERCP observational assessment tools has not been systematically evaluated. METHODS : We conducted a systematic search using electronic databases and hand-searching from inception until August 2021 for studies evaluating observational assessment tools of ERCP performance. We used a unified validity framework to characterize validity evidence from five sources: content, response process, internal structure, relations to other variables, and consequences. Each domain was assigned a score of 0-3 (maximum score 15). We assessed educational utility and methodological quality using the Accreditation Council for Graduate Medical Education framework and the Medical Education Research Quality Instrument, respectively. RESULTS : From 2769 records, we included 17 studies evaluating 7 assessment tools. Five tools were studied for clinical ERCP, one for simulated ERCP, and one for simulated and clinical ERCP. Validity evidence scores ranged from 2 to 12. The Bethesda ERCP Skills Assessment Tool (BESAT), ERCP Direct Observation of Procedural Skills Tool (ERCP DOPS), and The Endoscopic Ultrasound (EUS) and ERCP Skills Assessment Tool (TEESAT) had the strongest validity evidence, with scores of 10, 12, and 11, respectively. Regarding educational utility, most tools were easy to use and interpret, and required minimal additional resources. Overall methodological quality (maximum score 13.5) was strong, with scores ranging from 10 to 12.5. CONCLUSIONS : The BESAT, ERCP DOPS, and TEESAT had strong validity evidence compared with other assessments. Integrating tools into training may help drive learners' development and support competency decision making.

Multicenter randomized trial comparing diagnostic sensitivity and cellular abundance with aggressive versus standard biliary brushing for bile duct stenosis without mass syndrome

BACKGROUND : The diagnosis of cholangiocarcinoma in patients with a biliary stricture without mass syndrome can be obtained by biliary brushing with a sensitivity of ~50 %. We performed a multicenter randomized crossover trial comparing the aggressive Infinity brush with the standard RX Cytology Brush. The aims were to compare sensitivity for cholangiocarcinoma diagnosis and cellularity obtained. METHODS : Biliary brushing was performed consecutively with each brush, in a randomized order. Cytological material was studied with blinding to the brush type used and order. The primary end point was sensitivity for cholangiocarcinoma diagnosis; the secondary end point was the abundance of cellularity obtained with each brush, with cellularity quantified in order to determine if one brush strongly outperformed the other. RESULTS : 51 patients were included. Final diagnoses were cholangiocarcinoma (n = 43; 84 %), benign (n = 7; 14 %), and indeterminate (n = 1; 2 %). Sensitivity for cholangiocarcinoma was 79 % (34 /43) for the Infinity brush versus 67 % (29/43) for the RX Cytology Brush (P = 0.10). Cellularity was rich in 31/51 cases (61 %) with the Infinity brush and in 10/51 cases (20 %) with the RX Cytology Brush (P < 0.001). In terms of quantification of cellularity, the Infinity brush strongly outperformed the RX Cytology Brush in 28/51 cases (55 %), while the RX Cytology Brush strongly outperformed the Infinity brush in 4/51 cases (8 %; P < 0.001). CONCLUSIONS : This randomized crossover trial showed that the Infinity brush is not significantly more effective than the RX Cytology Brush for biliary stenosis without mass syndrome in terms of sensitivity for cholangiocarcinoma diagnosis, but does offer a significantly higher abundance of cellularity.

A comparative study on the application of different endoscopic diagnostic methods in the differential diagnosis of benign and malignant bile duct strictures

Objective

To compare the diagnostic value of cytobrush, ERCP-guided biopsy, SpyGlass direct visual impression and SpyGlass-guided biospy (SpyBite) in the differential diagnosis of benign and malignant bile duct strictures.

Methods

The data of 1,008 patients who were clinically diagnosed with indeterminate biliary strictures and underwent ERCP-guided biopsy, cytobrush, SpyGlass direct visual impression or SpyBite at the First Affiliated Hospital of Nanchang University between January 2010 and December 2019 were collected and analyzed retrospectively. The final diagnose was determined by surgical pathological specimen or follow-up (Malignant stricture can be identified if the stricture showed malignant progression during one year of follow-up). The differential diagnostic value of the above endoscopic diagnostic methods was evaluated by means of sensitivity, specificity, accuracy, positive predictive value, negative predictive value, etc. and safety was evaluated by the incidence rate of adverse events.

Results

In terms of sensitivity, standard biopsy group (48.6%) and SpyBite group (61.5%) were significantly higher than cytobrush group (32.0%), and visual impression group (100%) was significantly higher than any other group. As far as specificity was concerned, cytobrush group (99.0%), standard biopsy group (99.3%) and the SpyBite group (100%) were significantly higher than visual impression (55.6%), but there was no statistical difference among the three groups above. As far as accuracy was concerned, standard biopsy group (65.3%), and SpyBite group (80.0%) were significantly higher than cytobrush group (44.4%), and SpyBite group (80.0%) was significantly higher than visual impression group (54.8%). In terms of safety, visual impression group and SpyBite group were significantly higher than cytobrush group and standard biopsy group in post-ERCP cholangitis.

Conclusion

SpyBite combined with SpyGlass-guided visual impression was better for differential diagnosis of benign and malignant bile duct strictures in terms of sensitivity and accuracy compared with conventional endoscopic diagnostic methods such as cytobrush and standard biopsy. Furthmore, the incidence rates of adverse events after SpyGlass examination was similar to those after conventional endoscopic diagnostic methods except for higher cholangitis, which could be controlled by antibiotics and might be avoided by adequate biliary drainage.