EUS-guided biliary drainage is infrequently used even in high-volume centers of interventional EUS

Revolution of hands-on model for interventional EUS: How to make a training model

EUS interventions have an increasing role in the treatment for hepatobiliary-pancreatic diseases. However, the procedure itself is not frequently performed, needs expertise, and carries a high risk of complications. With these limitations, the hands-on practice model is very important for the endoscopist in training for EUS intervention. There have been various hands-on models for EUS interventions, ranging from in vivo living pig model to all-synthetic model. Although a living model provides realistic sensation, the preparation is complex and increases concerns for zoonotic issues. All-synthetic models are easier to prepare and store but not realistic and still need the room for improvement. Hybrid ex vivo model is more widely available and provides various training procedures but still needs special preparation for the porcine tissue.

Preoperative endoscopic ultrasound-guided biliary drainage for primary drainage in obstructive jaundice

INTRODUCTION

Endoscopic transpapillary approach by endoscopic retrograde cholangiopancreatography (ERCP) is the established technique for preoperative biliary drainage (PBD). Recently, endoscopic ultrasound-guided biliary drainage (EUS-BD) has been reported to be a useful alternative technique after ERCP fail. However, the optimal strategy remain controversial.

AREA COVERED

This review summarizes the literature on EUS-BD techniques for PBD with a literature search using PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials database between 2000 and 2023 using keywords for 'preoperative biliary drainage' and all types of EUS-BD techniques.

EXPERT OPINION

As there is no consensus on the optimal EUS-BD technique for PBD, selection of the EUS-BD approach depends on the patient's condition, the biliary obstruction site, the anastomosis after surgical intervention, and the preference of the endoscopist. However, we consider that EUS-HGS using a dedicated plastic stent may have some advantages in the adverse impact of surgical procedure because the location where the fistula is created by EUS-HGS is away from the site of the surgical procedure. Although there remain many issues that require further investigation, EUS-BD can be a feasible and safe alternative method of PBD for malignant biliary obstruction after ERCP fail.

Adverse events with EUS-guided biliary drainage: a systematic review and meta-analysis

BACKGROUND AND AIMS

Multiple meta-analyses have evaluated the technical and clinical success of EUS-guided biliary drainage (BD), but meta-analyses concerning adverse events (AEs) are limited. The present meta-analysis analyzed AEs associated with various types of EUS-BD.

METHODS

A literature search of MEDLINE, Embase, and Scopus was conducted from 2005 to September 2022 for studies analyzing the outcome of EUS-BD. The primary outcomes were incidence of overall AEs, major AEs, procedure-related mortality, and reintervention. The event rates were pooled using a random-effects model.

RESULTS

One hundred fifty-five studies (7887 patients) were included in the final analysis. The pooled clinical success rates and incidence of AEs with EUS-BD were 95% (95% confidence interval [CI], 94.1-95.9) and 13.7% (95% CI, 12.3-15.0), respectively. Among early AEs, bile leak was the most common followed by cholangitis with pooled incidences of 2.2% (95% CI, 1.8-2.7) and 1.0% (95% CI, .8-1.3), respectively. The pooled incidences of major AEs and procedure-related mortality with EUS-BD were .6% (95% CI, .3-.9) and .1% (95% CI, .0-.4), respectively. The pooled incidences of delayed migration and stent occlusion were 1.7% (95% CI, 1.1-2.3) and 11.0% (95% CI, 9.3-12.8), respectively. The pooled event rate for reintervention (for stent migration or occlusion) after EUS-BD was 16.2% (95% CI, 14.0-18.3; I2 = 77.5%).

CONCLUSIONS

Despite a high clinical success rate, EUS-BD may be associated with AEs in one-seventh of the cases. However, major AEs and mortality incidence remain less than 1%, which is reassuring.

Efficacy of a dedicated plastic stent in endoscopic ultrasound-guided hepaticogastrostomy during the learning curve: cumulative multi-center experience

BACKGROUND AND OBJECTIVES

Currently, there are no reports on the learning curve of endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) using dedicated plastic stents. Therefore, we evaluated the outcomes of EUS-HGS using dedicated plastic stents at tertiary referral centers during the initial development phase of EUS-HGS.

MATERIALS AND METHODS

Endoscopic retrograde cholangiopancreatography (ERCP) was strictly prioritized over EUS-HGS. Twenty-three consecutive patients treated using EUS-HGS with a 7-Fr dedicated plastic stent over 4 years beginning in 2018 were analyzed retrospectively.

RESULTS

The most common primary disease was pancreatic cancer, and the most common reason for difficulty in ERCP was duodenal obstruction, followed by surgically altered anatomy. The overall technical success rate of EUS-HGS was 95.7% (22/23). One failed case was converted to EUS-guided choledochoduodenostomy. The clinical success rate was 90.9% (20/22). Adverse events (AEs) related to the procedure were observed in four (17.4%) patients, including mild biliary peritonitis in three (13.0%) and mild cholangitis in one (4.3%) patient; all patients received conservative therapy. No serious AEs, such as stent migration, bleeding, or gastrointestinal perforation, were observed. Recurrent biliary obstruction (RBO) was observed in eight (34.8%) patients. Of these, HGS stent replacement was performed in four patients, and other treatments were performed in the remaining four patients. Another four (17.4%) patients did not develop RBO but underwent periodic HGS stent replacement.

CONCLUSIONS

EUS-HGS using a dedicated plastic stent was performed safely even in its initial phase of introduction. The approach using this stent can be useful in case of ERCP failure for biliary decompression because of the high feasibility and low risk of serious adverse events.

Three-year evaluation of a novel, nonfluoroscopic, all-artificial model for EUS-guided biliary drainage training for the impact to practice: A prospective observational study (with videos)

Background and Objectives

EUS-guided biliary drainage (EUS-BD) required a dedicated training. We developed and evaluated a nonfluoroscopic, all-artificial training model known as Thai Association for Gastrointestinal Endoscopy Model 2 (TAGE-2) for the training of EUS-guided hepaticogastrostomy (EUS-HGS) and EUS-guided choledochoduodenostomy (EUS-CDS). We hypothesize that trainers and trainees would appreciate the ease of the nonfluoroscopy model and increase their confidence to start their real procedures in humans.

Materials and Methods

We prospectively evaluated the TAGE-2 launched in two international EUS hands-on workshops and have followed trainees for 3 years to see long-term outcomes. After completing the training procedure, the participants answered questionnaires to assess their immediate satisfaction of the models in and also the impact of these models on their clinical practice 3 years after the workshop.

Results

A total of 28 participants used the EUS-HGS model and 45 participants used the EUS-CDS model. The EUS-HGS model was rated as excellent by 60% of beginners and 40% by experienced and the EUS-CDS model was rated as excellent by 62.5% of beginners and 57.2% of experienced. The majority of trainees (85.7%) have started the EUS-BD procedure in humans without additional training in other models.

Conclusion

Our nonfluoroscopic, all-artificial model for EUS-BD training is convenient to be used with good-to-excellent satisfaction scored by the participants in most aspects. It can help the majority of trainees start their procedures in humans without additional training in other models.

Evaluation of an all-in-one hybrid model (EUS Magic Box) for stepwise teaching and training in multiple interventional EUS procedures

Background and study aims  While multiple interventional endoscopic ultrasound (EUS)-guided procedures have evolved over the past two decades, there is no model that allows for training in all of these procedures. We aimed to develop and validate an all-in-one hybrid model for stepwise learning in multiple EUS interventions. Methods  A hybrid model was created utilizing a pig esophagus and stomach, a silicon-based duodenum and pancreato-biliary system, a pseudocyst, and biopsy targets. This model was designed to provide hands-on training in multiple interventional EUS procedures, such as EUS-guided fine-needle biopsy (EUS-FNB), biliary drainage (BD), pancreatic duct drainage (PD), pseudocyst drainage (PSD), and gastro-enterostomy (GE). Thirty-six trainees underwent training on this model over 6 days, in two batches. Lumen apposing metal stents were used for PSD and GE. Trainees were assessed for objective criteria of technical difficulties. Subjective assessment by trainees was done via a questionnaire. Results  All the trainees were able to complete the requisite steps for all the procedures under supervision. On subjective assessment, 30 trainees (83 %) graded the model as good or excellent. A total of 107 technical difficulties were noted (scope position 55, duct puncture 27, guidewire-related problems 25). Time taken to complete the requisite steps of biopsy, PSD, and GE (10.5 minutes; range 3.5 to 22) was significantly less than that for BD and PD (28 minutes; range 17 to 40) ( P  < 0.001). Conclusions  The hybrid model provided training for multiple EUS interventions with good acceptance by trainees. Stepwise mentoring with the possibility of performing multiple procedures in a single model with or without X-ray could prove useful in conference as well as institutional settings.

The role of endoscopic ultrasound guidance for biliary and pancreatic duct access and drainage to overcome the limitations of ERCP: a retrospective evaluation

BACKGROUND

Endoscopic ultrasound (EUS)-guided ductal access and drainage (EUS-DAD) of biliary/pancreatic ducts after failed endoscopic retrograde cholangiopancreatography (ERCP) is less invasive than percutaneous transhepatic biliary drainage (PTBD). The actual need for EUS-DAD remains unknown. We aimed to determine how often EUS-DAD is needed to overcome ERCP failure.

METHODS

Consecutive duct access procedures (n = 2205; 95 % biliary) performed between June 2013 and November 2015 at a tertiary-care center were reviewed. ERCP was used first line, EUS-DAD as salvage after ERCP, and PTBD when both had failed. Procedures were defined as "index" in patients without prior endoscopic duct access and "combined" when EUS-DAD followed successful ERCP. The main outcomes were the EUS-DAD and PTBD rates.

RESULTS

EUS-DAD was performed in 7.7 % (170/2205) of overall procedures: 9.1 % (116/1274) index and 5.8 % (54/931) follow-up. Most index EUS-DADs were performed following (46 %) or anticipating (39 %) ERCP failure, whereas 15 % followed successful ERCP (combined procedures). Among index procedures, the EUS-DAD rate was higher in surgically altered anatomy (58.2 % [39 /67)] vs. 6.4 % [77/1207]); PTBD was required in 0.2 % (3/1274). Among follow-up procedures, ERCP represented 85.7 %, cholangiopancreatography through mature transmural fistulas 8.5 %, and EUS-DAD 5.8 %; no patient required PTBD. The secondary PTBD rate was 0.1 % (3/2205). Six primary PTBDs were performed (overall PTBD rate 0.4 % [9/2205]).

CONCLUSIONS

EUS-DAD was required in 7.7 % of ERCPs for benign and malignant biliary/pancreatic duct indications. Salvage PTBD was required in 0.1 %. This high EUS-DAD rate reflects disease complexity, a wide definition of ERCP failure, and restrictive PTBD use, not poor ERCP skills. EUS-DAD effectively overcomes the limitations of ERCP eliminating the need for primary and salvage PTBD in most cases.

Effect of echoendoscope angle on success of guidewire manipulation during endoscopic ultrasound-guided hepaticogastrostomy

BACKGROUND

With endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS), guidewire manipulation might be a critically limiting step for nonexperts. However, the causes of difficult guidewire manipulation remain unclear. The aim of this study was to evaluate factors associated with successful guidewire manipulation.

METHODS

This retrospective cohort study included consecutive patients who underwent EUS-HGS between October 2018 and October 2019. We measured scope angle between the long and needle axes of the echoendoscope using still fluoroscopic imaging immediately after puncturing the intrahepatic bile duct. Factors associated with successful guidewire insertion were assessed by multivariable analysis using logistic regression.

RESULT

The influence of the angle between the fine-needle aspiration (FNA) needle and echoendoscope on failed guidewire insertion was assessed using receiver operating characteristic (ROC) curves. Area under the ROC curve was 0.86 (95 % confidence interval [CI] 0.00 - 0.76), and an angle of 135° offered 88.0 % sensitivity and 82.9 % specificity for predicting successful guidewire insertion. According to multivariable analysis, only angle between the FNA needle and echoendoscope > 135° was independently associated with successful guidewire insertion (odd ratio 0.03, 95 %CI 0.01 - 0.14; P < 0.05), whereas sex, puncture site, and diameter of puncture site were not significant factors. After multivariable analysis, all variables were adjusted using age ≥ 70 or < 70 years, yielding the same results.

CONCLUSION

The angle between the FNA needle and echoendoscope might be associated with successful guidewire manipulation during EUS-HGS. Adjusting this angle to 135° before puncturing the intrahepatic bile duct might be helpful in achieving successful guidewire manipulation during EUS-HGS.

Efficacy and Safety of EUS-Guided Choledochoduodenostomy Using Electrocautery-Enhanced Lumen-Apposing Metal Stents (ECE-LAMS) in the Treatment of Biliary Obstruction: A Systematic Review and Meta-Analysis

Background. Electrocautery-enhanced lumen-apposing metal stents (ECE-LAMS) have been newly developed to perform EUS-guided choledochoduodenostomy (EUS-CDS), but its benefits and harms remain obscure. We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of EUS-CDS using ECE-LAMS. Method. In the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we searched PubMed, Embase, and Scopus databases through January 1, 2001, and April 27, 2020. The primary outcomes of the pooled analysis were to determine the technical success, clinical success, and overall adverse events rates. The secondary outcomes were pooled rates of short-term and long-term adverse events. Results. Six studies with 270 patients were finally included in this meta-analysis. The pooled rates of technical, clinical success, and adverse events were 95.1% (95% CI = 90.6–97.5%, I2 = 25%), 93.3% (95% CI = 87.4–96.5%, I2 = 28%), and 15.3% (95% CI = 10.6–21.6%, I2 = 13%), respectively. The pooled rates of short-term and long-term adverse events were 3.6% (95% CI = 1.3–9.6%, I2 = 0%) and 11.3% (95% CI = 7.6–16.5%, I2 = 0%), respectively. Conclusion. EUS-CDS using ECE-LAMS provides favorable outcomes in patients with biliary obstruction. It has been associated with a higher success rate and a lower rate of adverse events when compared with the biliary drainage approaches previously used. Large and randomized controlled observational studies are required to further refine the findings in the present analysis.

Endoscopic Ultrasound-Guided Hepaticogastrostomy: Technical Review and Tips to Prevent Adverse Events

Most patients who require biliary drainage can be treated by endoscopic retrograde cholangiopancreatography (ERCP)-guided procedures. However, ERCP can be challenging in patients with complications, such as malignant duodenal obstruction, or a surgically-altered anatomy, such as a Roux-en-Y anastomosis, which prevent advancement of the duodenoscope into the ampulla of Vater. Recently, endoscopic ultrasound (EUS)-guided biliary drainage via transhepatic or transduodenal approaches has emerged as an alternative means of biliary drainage. Typically, EUS-guided gallbladder drainage or choledochoduodenostomy can be performed via both approaches, as can EUS-guided hepaticogastrostomy (HGS). EUS-HGS, because of its transgastric approach, can be performed in patients with malignant duodenal obstruction. Technical tips for EUS-HGS have reached maturity due to device and technical developments. Although the technical success rates of EUS-HGS are high, the rate of adverse events is not low, with stent migration still being reported despite many preventive efforts. In this review, we described technical tips for EUS-HGS related to bile duct puncture, guidewire insertion, fistula dilation, and stent deployment, along with a literature review. Additionally, we provided technical tips to improve the technical success of EUS-HGS.

EUS-guided biliary drainage for difficult cannulation

EUS-guided biliary drainage (EUS-BD) has been recognized as a new alternative to failed ERCP. The alternatives for failed/impossible ERCP in cases of difficult and selective bile duct cannulation include percutaneous transhepatic BD (PTBD) with precut papillotomy. EUS-BD is reportedly more convenient than PTBD and more successful than precut papillotomy, suggesting that EUS-BD is the next step following failed/impossible ERCP.

Novel swine biliary dilatation model with temperature-controlled endobiliary radiofrequency ablation: An effective tool for training in EUS-guided biliary drainage

Background and Objectives:

EUS-guided biliary drainage (EUS-BD) is used as a rescue method after failed endoscopic retrograde cholangiography. However, it is considered a technically challenging procedure. Phantoms and ex vivo biliary dilatation models have been used to enhance the learning of EUS-BD, but they provide a limited level of realism. The aim of this study was to develop a swine biliary dilatation model that uses temperature-controlled endobiliary radiofrequency ablation (EB-RFA) for training in EUS-BD.

Materials and Methods:

Target temperature-controlled (80°C at 7 or 10 W for 60–120 s) EB-RFA was performed on seven pigs. Two weeks after the EB-RFA, EUS examination was performed to confirm biliary dilatation, and EUS-BD was then attempted by performing a hepaticogastrostomy (HGS) or cholecystogastrostomy (CGS).

Results:

Twelve sessions of EB-RFA (11 at the distal common bile duct [CBD] and one at the proximal CBD) were successfully performed on the seven pigs. There were no immediate postprocedural adverse events. Two weeks after the procedures, clinical signs of jaundice were observed in all the pigs. EUS examination revealed massive intrahepatic and extrahepatic biliary dilatations in all the pigs, and EUS-BD was attempted in the same session. HGS was performed on six pigs. Technical success was achieved in five of the six pigs (83.3%). Technical failure in HGS occurred during the stent deployment, and CGS was successfully performed on one pig.

Conclusions:

Our study shows that EB-RFA is an effective minimally invasive method for creating biliary dilatation models. It may be considered suitable for training in EUS-BD.

Palliative therapy in pancreatic cancer-interventional treatment with stents

Interventional treatment with stents in pancreatic cancer is a topic that developed during recent years and new fields of palliative stent therapy have evolved. The increasing life expectancy of patients with unresectable pancreatic cancer increases the need for clinical and cost effective therapeutic interventions. Current literature, guidelines, practice and evidence were reviewed. Besides the most obvious biliary stenting via endoscopic retrograde cholangiopancreatography (ERCP), pancreatic and gastroduodenal stenting as well as percutaneous transhepatic cholangiography (PTC) and the rapidly growing field of endosonographic stent implantation in the palliative care of patients with pancreatic cancer are being discussed from several points of view in this review.

The underutilization of EUS-guided biliary drainage: Perception of endoscopists in the East and West

Background and Objectives

EUS-guided biliary drainage (EUS-BD) is increasingly utilized to manage unresectable malignant biliary obstruction after a failed ERCP. However, there is no data on how endoscopists perceive EUS-BD. The aim of this study was to investigate the perception of endoscopists on EUS-BD.

Patients and Methods

A survey questionnaire of six topics with 22 survey statements was developed. A total of 17 pancreatobiliary endoscopists (10 from East and 7 from West) were invited to survey. The participants were asked to answer the multiple choice questionnaire and give comments. The opinions of the participants for individual survey statements were assessed using 5-point Likert scale.

Results

All participants completed the survey. The endoscopists had a trend to perceive EUS-BD as a procedure indicated after a failed ERCP. Various EUS-BD methods were regarded as having different efficacy and safety. The superiority of EUS-BD over percutaneous transhepatic BD (PTBD) with regard to efficacy, procedure-related adverse events, and unscheduled re-intervention was not in agreement.

Conclusions

EUS-BD was not yet perceived as the initial procedure to relieve the unresectable malignant biliary obstruction. Various EUS-BD methods were regarded as having different efficacy and safety. The superiority of EUS-BD over PTBD was not in agreement. Refining the procedure, developing dedicated devices, and gaining expertise in the procedure are necessary to popularize EUS-BD.

Endoscopic Ultrasound-Guided Biliary Drainage

Endoscopic ultrasound (EUS)-guided biliary drainage is an emerging technique that combines the advantages of the endoscopic and percutaneous approaches, without the inconveniences and discomfort of an indwelling external catheter. There has been growing interest and experience in EUS-biliary drainage. Several different EUS-guided techniques have been developed to access the obstructed biliary tree from either the stomach or duodenum, according to the location of the stricture, the anatomy of the patient, and the experience of the endoscopist.

Pursuing excellence in ERCP

The term "ERCP cannulation" returns 1,563 items in Pubmed. In 1980 there were 7 papers, and 92 were included in 2015. Any gastroenterologist knows ERCP is often a complex procedure, at times with uncertain results, that unfortunately leads every so often to lawsuits. Most issues derive from attempts at biliary cannulation, despite the improved instruments available since the days of the first sphincterotomy back in 1974. The initial priority goal of ERCP learning is a satisfactory rate of choledochal cannulation. Such rate has been somewhat arbitrarily set as at least 80% of successful biliary access.

Recent advances in endoscopic ultrasound-guided biliary drainage

Endoscopic ultrasound-guided biliary drainage (EUS-BD) is increasingly used as an alternative in patients with biliary obstruction who fail standard endoscopic retrograde cholangiopancreatography (ERCP). The two major endoscopic approach routes for EUS-BD are the transgastric intrahepatic and the transduodenal extrahepatic approaches. Biliary drainage can be achieved by three different methods, transluminal biliary stenting, transpapillary rendezvous technique, and antegrade biliary stenting. Choice of approach route and drainage method depends on individual anatomy, underlying disease, and location of the biliary stricture. Recent meta-analyses have revealed that cumulative technical success and adverse event rates were 90-94% and 16-23%, respectively. Development of new dedicated devices for EUS-BD would help refine the technical aspects and minimize the possibility of complications, making it a more promising procedure.

EUS-guided antegrade metal stenting with hepaticoenterostomy using a dedicated plastic stent with a review of the literature (with video)

Background and Objectives:

Recently, a novel EUS-guided biliary drainage (EUS-BD) technique consisting of EUS-guided antegrade stenting and EUS-guided hepaticoenterostomy (EUS-AS+HES) using two conventional metal stents (MS) has been reported to decrease adverse events and maintain longer stent patency for malignant biliary obstruction (MBO). However, only a few limited reports have evaluated this technique. Finally, dedicated plastic stents (PSs) have been developed to perform EUS-HES safely. The aim of the present study was to evaluate the outcome in EUS-AS+HES for MBO using the dedicated HES PSs.

Methods:

The results of a total of 23 patients who underwent EUS-AS+HES (18 simultaneous cases and 5 sequential cases) for MBO from October 2014 to July 2017 were retrospectively reviewed.

Results:

Technical and clinical success rates were 100% (23/23). Adverse events were seen in 8.7% (2/23); 2 cases of mild biliary peritonitis, which were successfully managed conservatively. Overall survival was 96 days and the median duration of stent patency, including stent dysfunction, patient death, and last follow-up, was 66.0 days (53 days in simultaneous cases and 78 days in sequential cases). Stent dysfunction was seen in 13.0% (3/23) of patients in 267, 263, and 135 days after the procedure.

Conclusions:

The novel EUS-BD technique, EUS-AS using MS plus HES employing a dedicated PS, was shown to be a feasible procedure for MBO and should yield longer duration of stent patency. Furthermore, sequential antegrade stenting in cases of occluded HES seems to be one other option instead of HES stent exchange. Further large-scale comparison studies with EUS-HES or EUS-AS are required to confirm its clinical efficacy.

Evaluation of a novel, hybrid model (Mumbai EUS II) for stepwise teaching and training in EUS-guided biliary drainage and rendezvous procedures

BACKGROUND AND AIMS

 EUS-guided biliary drainage (EUS-BD) and rendezvous (EUS-RV) are acceptable rescue options for patients with failed endoscopic retrograde cholangiopancreatography (ERCP). However, there are limited training opportunities at most centers owing to low case volumes. The existing models do not replicate the difficulties encountered during EUS-BD. We aimed to develop and validate a model for stepwise learning of EUS-BD and EUS-RV, which replicates the actual EUS-BD procedures.

METHODS

 A hybrid model was created utilizing pig esophagus and stomach, with a synthetic duodenum and biliary system. The model was objectively assessed on a grade of 1 - 4 by two experts. Twenty-eight trainees were given initial training with didactic lectures and live procedures. This was followed by hands-on training in EUS-BD and EUS-RV on the hybrid model. Trainees were assessed for objective criteria of technical difficulties.

RESULTS

 Both the experts graded the model as very good or above for all parameters. All trainees could complete the requisite steps of EUS-BD and EUS-RV in a mean time of 11 minutes (8 - 18 minutes). Thirty-six technical difficulties were noted during the training (wrong scope position, 13; incorrect duct puncture, 12; guidewire related problems, 11). Technical difficulties peaked for EUS-RV, followed by hepaticogastrostomy (HGS) and choledochoduodenostomy (CDS) (20, 9, and 7, P  = 0.001). At 10 days follow-up, nine of 28 trainees had successfully performed three EUS-RV and seven EUS-BD procedures independently.

CONCLUSIONS

 The Mumbai EUS II hybrid model replicates situations encountered during EUS-RV and EUS-BD. Stepwise mentoring improves the chances of success in EUS-RV and EUS-BD procedures.

Endoscopic Ultrasonography-Guided Techniques for Accessing and Draining the Biliary System and the Pancreatic Duct

When endoscopic retrograde cholangiopancreatography (ERCP) fails to decompress the biliary system or the pancreatic duct, endoscopic ultrasonography (EUS)-guided biliary or pancreatic access and drainage can be used. Data show a high success rate and acceptable adverse event rate for EUS-guided biliary drainage. The outcomes of EUS-guided biliary drainage seem equivalent to percutaneous drainage and ERCP, whereas only retrospective studies are available for pancreatic duct drainage. In this article, revision of the technical and clinical status and the current evidence of interventional EUS-guided biliary and pancreatic duct access and drainage are presented.

Endoscopic management of acute cholangitis according to the TG13

The Tokyo Guidelines 2013 (TG13) recommend that endoscopic drainage should be the first-choice treatment for biliary decompression in patients with acute cholangitis. Timing of biliary drainage for acute cholangitis should be based on the severity of the disease. For patients with severe acute cholangitis, appropriate organ support and urgent biliary drainage are needed. For patients with moderate acute cholangitis, early biliary drainage is needed. For patients with mild acute cholangitis, biliary drainage is needed when initial treatment such as antimicrobial therapy is ineffective. There are three methods of biliary drainage: endoscopic drainage, percutaneous transhepatic drainage, and surgical drainage. Endoscopic drainage is less invasive than the other two drainage methods. The drainage method (endoscopic nasobiliary drainage and stenting) depends on the endoscopist's preference but endoscopic sphincterotomy should be selected rather than endoscopic papillary balloon dilation from the aspect of procedure-related complications. In the TG13, balloon enteroscopy-assisted and endoscopic ultrasound-guided biliary drainages have been newly added as specific drainage methods. Recent studies have demonstrated their usefulness and safety. These drainage methods will become more widespread in the future.