Endoscopic ultrasound-guided choledochoduodenostomy using a thin stent delivery system in patients with unresectable malignant distal biliary obstruction: A prospective multicenter study

Endoscopic biliary drainage for distal bile duct obstruction due to pancreatic cancer

Approximately 60% of pancreatic cancers occur in the pancreatic head and may present as obstructive jaundice due to bile duct invasion. Obstructive jaundice often leads to poor general conditions and acute cholangitis, interfering with surgery and chemotherapy and requiring biliary drainage. The first choice of treatment for biliary drainage is the endoscopic transpapillary approach. In unresectable tumors, self-expandable metal stents (SEMSs) are most commonly used and are classified into uncovered and covered SEMSs. Recently, antireflux metal stents and large- or small-diameter SEMSs have become commercially available, and their usefulness has been reported. Plastic stents are infrequently used in patients with resectable biliary obstruction; however, owing to the recent trend in preoperative chemotherapy, SEMSs are frequently used because of the long time to recurrent biliary obstruction. Endoscopic ultrasound-guided biliary drainage (EUS-BD) is often performed in patients who are not eligible for the transpapillary approach, and favorable outcomes have been reported. Different EUS-BD techniques and specialized stents have been developed and can be safely used in high-volume centers. The indications for EUS-BD are expected to further expand in the future.

Therapeutic Endoscopic Ultrasound and Endoscopic Ultrasound-Endoscopic Retrograde Cholangiopancreatography Interventions

Therapeutic endoscopic ultrasound (EUS) encompasses an array of procedures to manage pancreaticobiliary and luminal gastrointestinal disorders. Therapeutic EUS procedures include EUS-guided rendezvous of the pancreatic and biliary ducts, as well as direct drainage of the bile duct, pancreatic duct, and gallbladder, drainage of pancreatic fluid collections, and luminal anastomosis creation. These procedures have a range of required equipment, approaches, clinical outcomes, and adverse events dependent on both procedure-related and patient-related factors. In expert hands, these procedures provide patients with less invasive options and can achieve excellent clinical outcomes.

The New Potential for Using Franseen Needles in Interventional EUS

Objective Adverse events such as bile leakage and bleeding are among the issues that need to be resolved in EUS-guided choledochoduodenostomy (EUS-CDS). To overcome this problem, we developed a new EUS-CDS technique using a 19-G Franseen needle without tract dilation. This study aimed to evaluate the safety and efficacy of the new EUS-CDS technique. Methods This single-center retrospective study included 20 consecutive patients who underwent EUS-CDS for primary drainage using a 19-G Franseen needle between March 2020 and May 2023. The primary endpoint was the technical success rate of EUS-CDS without tract dilation. Results The technical success rate of EUS-CDS was 20/20 (100%). None of the patients required any additional tract dilation, such as by using a balloon or electric cautery. The median procedure time was 7.8 [range, 3.2-19.4] min. No early adverse events were observed. Conclusion The 19-G Franseen needle appeared to have a sufficient dilatory effect during puncturing. This EUS-CDS technique appears to be safe and effective and has the advantages of no adverse events and it is also a simplified procedure, which suggests its potential for widespread use in primary drainage.

Risk prediction of cholangitis after stent implantation based on machine learning

The risk of cholangitis after ERCP implantation in malignant obstructive jaundice patients remains unknown. To develop models based on artificial intelligence methods to predict cholangitis risk more accurately, according to patients after stent implantation in patients' MOJ clinical data. This retrospective study included 218 patients with MOJ undergoing ERCP surgery. A total of 27 clinical variables were collected as input variables. Seven models (including univariate analysis and six machine learning models) were trained and tested for classified prediction. The model' performance was measured by AUROC. The RFT model demonstrated excellent performances with accuracies up to 0.86 and AUROC up to 0.87. Feature selection in RF and SHAP was similar, and the choice of the best variable subset produced a high performance with an AUROC up to 0.89. We have developed a hybrid machine learning model with better predictive performance than traditional LR prediction models, as well as other machine learning models for cholangitis based on simple clinical data. The model can assist doctors in clinical diagnosis, adopt reasonable treatment plans, and improve the survival rate of patients.

Controversies in Endoscopic Ultrasound-Guided Biliary Drainage

In this 14th document in a series of papers entitled "Controversies in Endoscopic Ultrasound" we discuss various aspects of EUS-guided biliary drainage that are debated in the literature and in practice. Endoscopic retrograde cholangiography is still the reference technique for therapeutic biliary access, but EUS-guided techniques for biliary access and drainage have developed into safe and highly effective alternative options. However, EUS-guided biliary drainage techniques are technically demanding procedures for which few training models are currently available. Different access routes require modifications to the basic technique and specific instruments. In experienced hands, percutaneous transhepatic cholangiodrainage is also a good alternative. Therefore, in this paper, we compare arguments for different options of biliary drainage and different technical modifications.

Safety of skipping the tract dilation step for EUS-guided biliary drainage in patients with unresectable malignant biliary obstruction (with video)

BACKGROUND

Thin delivery system stents can be inserted directly without the need for a tract dilation step and are expected to reduce bile leakage during endoscopic ultrasound-guided biliary drainage (EUS-BD). The present study retrospectively compared the safety and efficacy of EUS-BD using a thin metal stent (< 7.5 Fr) with those of EUS-BD using a conventional stent (≥ 7.5 Fr).

METHODS

The present study enrolled 112 patients who underwent EUS-BD using metal stents for unresectable malignant biliary obstruction between April 2016 and July 2022. The primary endpoint was the rate of adverse events (AEs). The secondary endpoints were clinical success rate, procedure time, procedure success rate in the absence of the tract dilation step, recurrent biliary obstruction rate, time to biliary obstruction, and overall survival. Risk factors associated with early AEs were also evaluated.

RESULTS

The rate of early AEs was significantly lower (12% vs. 35%, P = 0.013) and the procedure success without the tract dilation step was significantly higher (82% vs. 33%, P < 0.001) in the thin than in the conventional delivery system stent group. None of the other secondary endpoints differed significantly between the two groups. Multivariate analysis showed that employing the tract dilation step during EUS-BD was a significant independent risk factor for early AEs (skipping vs. employing; HR, 9.66; 95% CI, 1.13-83.0, P = 0.028).

CONCLUSION

Employing the tract dilation step during EUS-BD was a significant risk factor for early AEs. Metal stents with a delivery diameter < 7.5 Fr can be inserted directly without the tract dilation step, resulting in lower early AE rates.

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.

Prospective clinical trial of EUS-guided choledochoduodenostomy without fistula dilation for malignant distal biliary obstruction

Background and Objectives

During EUS-guided choledochoduodenostomy (EUS-CDS), fistula dilation before stent insertion is associated with adverse events (AEs), such as bile leakage and peritonitis. We hypothesized that EUS-CDS without fistula dilation using a novel self-expandable metal stent (SEMS) with a thin delivery system could overcome this problem, and we conducted this study to evaluate its feasibility and safety.

Methods

This was an open-label, single-arm, phase II study at a single institution. We planned EUS-CDS without fistula dilation using a fully covered SEMS with a 5.9-Fr delivery system for unresectable malignant distal biliary obstruction. The primary outcome was overall technical success. Secondary outcomes were technical success without fistula dilation, procedure time, functional success, time to recurrent biliary obstruction, and AEs. The planned sample size was 25 patients.

Results

In total, 24 patients were included in this study. In 21 patients, EUS-CDS was performed as primary drainage. The overall technical success rate was 100% (24 of 24 patients). The technical success rate without fistula dilation was 96% (23 of 24). The median procedure time was 16 min (range, 10-66 min). The functional success rate was 96% (23 of 24). The median time to recurrent biliary obstruction was 148 days (95% confidence interval, 29-266 days). There were no procedure-related AEs. Furthermore, computed tomography immediately after the procedure showed no leakage of contrast medium into the abdominal cavity in any patient.

Conclusions

EUS-guided choledochoduodenostomy without fistula dilation using a fully covered SEMS with a 5.9-Fr delivery system is feasible with a high probability and can be achieved quickly while effectively preventing bile leakage and peritonitis.

Experience-Related Factors in the Success of Beginner Endoscopic Ultrasound-Guided Biliary Drainage: A Multicenter Study

Endoscopic ultrasound-guided biliary drainage (EUS-BD) has become comparable to endoscopic retrograde cholangiopancreatography and is now considered a first-line intervention for certain biliary obstructions. Although analysis of experience-related factors may help achieve better outcomes and contribute to its wider adoption, no concrete evidence exists regarding the required operator or institutional experience levels. This study aimed to analyze experience-related factors at beginner multicenters. Patients who underwent EUS-BD using self-expandable metal stents and/or dedicated plastic stents during the study period (up to the first 25 cases since introducing the technique) were retrospectively enrolled from seven beginner institutions and operators. Overall, 90 successful (technical success without early adverse events) and 22 failed (technical failure and/or early adverse events) cases were compared. EUS-BD-related procedures conducted at the time of applicable EUS-BD by each institution/operator were evaluated. The number of institution-conducted EUS-BD procedures (≥7) and operator-conducted EUS screenings (≥436), EUS-guided fine-needle aspirations (FNA) (≥93), and EUS-guided drainages (≥13) significantly influenced improved EUS-BD outcomes (p = 0.022, odds ratio [OR], 3.0; p = 0.022, OR, 3.0; p = 0.022, OR, 3.0; and p = 0.028, OR, 2.9, respectively). Our threshold values, which significantly divided successful and failed cases, were assessed using receiver operating characteristic curve analysis and may provide useful approximate indications for successful EUS-BD.

Development of devices for interventional endoscopic ultrasound for the management of pancreatobiliary diseases

A variety of devices have been developed for interventional endoscopic ultrasound (EUS). EUS-guided drainage of the bile duct and pancreatic duct, as well as fluid collection adjacent to the gastrointestinal tract, is performed by a procedure involving puncture, guidewire manipulation, tract dilation, and stent placement. Devices specialized for interventional EUS are being developed for each step of the procedure. Mechanical dilators such as bougie, balloon, and electrocautery dilators are used for tract dilation. Various types of plastic stents, self-expandable metal stents, and lumen-apposing metal stents specifically designed for interventional EUS are now available, including one-step devices developed to improve the efficacy and safety of interventional EUS. In addition, radiofrequency ablation and the placement of fiducial markers and radioactive seeds under EUS guidance are now becoming established for pancreatic neoplasms. Such development of specialized devices has expanded the indications for interventional EUS, increased the success rate, and lowered the adverse event rate.

Society of Gastrointestinal Endoscopy of India Consensus Guidelines on Endoscopic Ultrasound-Guided Biliary Drainage: Part I (Indications, Outcomes, Comparative Evaluations, Training)

Endoscopic management of bile duct obstruction is a key aspect in gastroenterology practice and has evolved since the first description of biliary cannulation by McCune et al in 1968. Over many decades, the techniques and accessories have been refined and currently, the first-line management for extrahepatic biliary obstruction is endoscopic retrograde cholangiopancreaticography (ERCP). However, even in expert hands the success rate of ERCP reaches up to 95%. In almost 4 to 16% cases, failure to cannulate the bile duct may necessitate other alternatives such as surgical bypass or more commonly percutaneous transhepatic biliary drainage (PTBD). While surgery is associated with high morbidity and mortality, PTBD has a very high reintervention and complication rate (∼80%) and poor quality of life. Almost parallelly, endoscopic ultrasound (EUS) has come a long way from a mere diagnostic tool to a substantial therapeutic option in various pancreatico-biliary diseases. Biliary drainage using EUS-guidance (EUS-BD) has gained momentum since the first report published by Giovannini et al in 2001. The concept of accessing the bile duct through a different route than the papilla, circumventing the shortcomings of PTBD and sometimes bypassing the actual obstruction have enthused a lot of interest in this novel strategy. The three key methods of EUS-BD entail transluminal, antegrade, and rendezvous approach. Over the past decade, with growing experience, EUS-BD has been found to be equivalent to ERCP or PTBD for malignant obstruction with better success rates.

EUS-BD, albeit, is not devoid of adverse events and can carry fatal adverse events. However, neither the technique of EUS-BD, nor the accessories and stents for EUS-BD have been standardized.

Additionally, different countries and regions have different availability of the accessories making generalizability a difficult task. Thus, technical aspects of this evolving therapy need to be outlined. For these reasons, the Society of Gastrointestinal Endoscopy India deemed it appropriate to develop technical consensus statements for performing safe and successful EUS-BD.

Usefulness of a laser-cut covered metal stent with a 7F delivery sheath in endoscopic ultrasound-guided biliary drainage without fistula dilation

Background and study aims  Recently, the utility of endoscopic ultrasound-guided intervention without fistula dilation (EUS-IV WoD) has been reported to prevent adverse events. We clinically evaluated cases in which EUS-IV WoD was attempted using a novel self-expandable metallic stent (SEMS); this is a fully covered, laser-cut SEMS that has a tapered and stiff tip specifically designed for a 0.025-inch guidewire and a relatively thin, 7F delivery system. Patients and methods  We retrospectively evaluated cases wherein EUS-IV WoD was attempted using the novel SEMS between March and December 2021. Results  Treatment of 11 patients by EUS-IV WoD with the novel SEMS was attempted. The technical success rate for EUS-IV was 100 % and the clinical success rate was 100 %; the success rate for EUS-IV WoD was 72.8 %. Of these, the procedural success rate for EUS-IV WoD was 100 % in EUS-biliary drainage (BD) and 57.1 % in non-EUS-BD. Early adverse events were observed in 27.3 % of patients (3/11): mild abdominal pain in two patients and moderate bleeding in one patient. The abdominal pain cases were both cases of EUS-IV WoD failure and required fistula dilation. Conclusions  The novel stent may be useful for EUS-IV WoD, especially in EUS-BD.

Investigator initiated clinical trial to validate usefulness of specific system for endoscopic ultrasound guided hepaticogastrostomy (HG01) in malignant biliary obstruction (HG01)

INTRODUCTION

Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is a novel drainage option for patients with an inaccessible papilla. Although EUS-HGS has clinical benefits in patients for whom endoscopic retrograde cholangiopancreatography (ERCP) has failed, the rates of adverse events (AEs) associated with EUS-HGS, such as bile peritonitis and stent migration, are higher than for other procedures. The development of a dedicated system for EUS-HGS is therefore desirable to reduce the rate of AEs. We developed a dedicated system for EUS-HGS (HG01 system) which is composed of a 19-gauge needle, 0.025-inch guidewire, a thin delivery system for tract dilation, and an antimigration metal stent. This study is designed to evaluate the efficacy and safety of EUS-HGS using the HG01 system in malignant biliary obstruction.

METHODS/DESIGN

This is a single-arm multicenter prospective study involving 40 patients across six tertiary centers in Japan. Patients with an unresectable malignant biliary obstruction in whom biliary drainage with ERCP failed, is not possible, or is very difficult will be registered in the study. The primary endpoint is the clinical success rate. The secondary endpoints are the technical success rate, procedure-related AE rate, procedure time, procedure success rate using only the HG01 system, stent patency rate, re-intervention success rate, re-intervention method, survival rate, and distance of movement of the stent position.

DISCUSSION

We expect use of the HG01 system to reduce the rate of AEs during EUS-HGS, especially bile leakage and stent migration. If the efficacy and safety of EUS-HGS using the HG01 system is confirmed in the present study, it is likely to be considered the first-choice device for use during EUS-HGS.

Endoscopic ultrasound‐guided choledochoduodenostomy without fistula dilation using a stent with a 5.9‐Fr delivery system: Comparison to a conventional procedure with fistula dilation

Objectives

To evaluate the feasibility and safety of endoscopic ultrasound‐guided choledochoduodenostomy (EUS‐CDS) without fistula dilation using a novel self‐expandable metal stent (SEMS).

Methods

This retrospective study examined patients who underwent EUS‐CDS for malignant distal biliary obstruction between October 2017 and May 2021 at the National Cancer Center, Japan. The primary outcome was a technical success without fistula dilation. Secondary outcomes were the overall technical success, clinical success, adverse events (AEs), procedure time, recurrent biliary obstruction (RBO), and time to RBO (TRBO).

Results

Forty‐one patients were enrolled; 31 patients underwent EUS‐CDS with fistula dilation using a conventional SEMS with 7.5–8.5‐Fr delivery system (conventional SEMS group), and 10 patients underwent EUS‐CDS without fistula dilation using the novel SEMS with a 5.9‐Fr delivery system (novel SEMS group). In the novel SEMS group, the rate of technical success without fistula dilation was 90%. There were no differences in overall technical success (100% vs. 97%, p = 1.00), clinical success (80% vs. 90%, p = 0.58), and overall AEs (10% vs. 23%, p = 0.65) rates between the novel and conventional SEMS groups. In the novel SEMS group, no early AEs were observed and no bile leakage into the abdominal cavity was observed on the computed tomography scan after the procedure. The median procedure time was significantly shorter in the novel SEMS group (17 min vs. 24 min, p = 0.03). RBO and median TRBO did not differ between the 2 groups.

Conclusions

EUS‐CDS without fistula dilation using the novel SEMS with a 5.9‐Fr delivery system is technically feasible, straightforward, quick, and safe.

Therapeutic endoscopic ultrasound: European Society of Gastrointestinal Endoscopy (ESGE) Technical Review

1:  ESGE recommends a prolonged course of a prophylactic broad-spectrum antibiotic in patients with ascites who are undergoing therapeutic endoscopic ultrasound (EUS) procedures.Strong recommendation, low quality evidence. 2:  ESGE recommends placement of partially or fully covered self-expandable metal stents during EUS-guided hepaticogastrostomy for biliary drainage in malignant disease.Strong recommendation, moderate quality evidence. 3:  ESGE recommends EUS-guided pancreatic duct (PD) drainage should only be performed in high volume expert centers, owing to the complexity of this technique and the high risk of adverse events.Strong recommendation, low quality evidence. 4:  ESGE recommends a stepwise approach to EUS-guided PD drainage in patients with favorable anatomy, starting with rendezvous-assisted endoscopic retrograde pancreatography (RV-ERP), followed by antegrade or transmural drainage only when RV-ERP fails or is not feasible.Strong recommendation, low quality evidence. 5:  ESGE suggests performing transduodenal EUS-guided gallbladder drainage with a lumen-apposing metal stent (LAMS), rather than using the transgastric route, as this may reduce the risk of stent dysfunction.Weak recommendation, low quality evidence. 6:  ESGE recommends using saline instillation for small-bowel distension during EUS-guided gastroenterostomy.Strong recommendation, low quality evidence. 7:  ESGE recommends the use of saline instillation with a 19G needle and an electrocautery-enhanced LAMS for EUS-directed transgastric endoscopic retrograde cholangiopancreatography (EDGE) procedures.Strong recommendation, low quality evidence. 8:  ESGE recommends the use of either 15- or 20-mm LAMSs for EDGE, with a preference for 20-mm LAMSs when considering a same-session ERCP.Strong recommendation, low quality evidence.

Usefulness of a newly designed laser-cut metal stent with an anchoring hook and thin delivery system for EUS-guided hepaticogastrostomy in experimental settings (with video)

BACKGROUND AND AIMS

EUS-guided hepaticogastrostomy (EUS-HGS) is associated with high rates of adverse events. The present study evaluated the feasibility of a newly designed stent equipped with a dilatation and antimigration system for EUS-HGS in phantom and animal models.

METHODS

The newly designed stent was a partially covered laser-cut stent with antimigration anchoring hooks and a thin tapered tip (7.2F). The feasibility of these stents for biliary obstruction was compared with that of conventional stents. Evaluated outcomes were resistance force to migration in phantom and ex vivo models, rates of technical success and adverse events, and histology in an in vivo model.

RESULTS

The resistance forces on the distal (3.59 vs 1.73 N and 6.21 vs 1.74 N) and proximal (3.58 vs 1.5 N and 5.97 vs 1.67 N) sides in phantom and ex vivo models were significantly higher for hook stents than for conventional stents. Although EUS-HGS was successfully performed in all cases with both stents (100% [10/10] vs 100% [8/8]), the success rate of EUS-HGS without using a fistulous tract dilation device was significantly higher with hook stents (100% [10/10]) than with conventional stents (13% [1/8]). No adverse events occurred with either stent. Pathologic examination showed adhesion between the stomach and liver.

CONCLUSIONS

The strong resistance to migration and the absence of the dilation step are important advantages of newly designed hook stents. These stents may therefore be feasible and safe for EUS-HGS.

Efficacy of lumen-apposing metal stents or self-expandable metal stents for endoscopic ultrasound-guided choledochoduodenostomy: a systematic review and meta-analysis

BACKGROUND

Endoscopic ultrasound (EUS)-guided biliary drainage is becoming an option for palliation of malignant biliary obstruction. Lumen-apposing metal stents (LAMS) are replacing self-expandable metal stents (SEMS). The aim of this meta-analysis was to evaluate the efficacy and safety of LAMS and SEMS for EUS-guided choledochoduodenostomy (EUS-CDS).

METHODS

A meta-analysis was performed using PRISMA protocols. Electronic databases were searched for studies on EUS-CDS. The primary outcome was clinical success. Secondary outcomes were technical success, reintervention, and adverse events. We used the random effects model with the DerSimonian-Laird estimation, and the results were depicted using forest plots. Subgroup analyses were also performed with data stratified by selected variable.

RESULTS

Overall, 31 studies (820 patients) were included. The pooled rates of clinical and technical success were 93.6 % (95 % confidence interval [CI] 88.6 %-96.5 %) and 94.8 % (95 %CI 90.2 %-97.3 %) for LAMS, and 91.7 % (95 %CI 88.1 %-94.2 %) and 92.7 % (95 %CI 89.9 %-94.9 %) for SEMS, respectively. The pooled rates of adverse events were 17.1 % (95 %CI 12.5 %-22.8 %) for LAMS and 18.3 % (95 %CI 14.3 %-23.0 %) for SEMS. The pooled rates of reintervention were 10.9 % (95 %CI 7.7 %-15.3 %) for LAMS and 13.9 % (95 %CI 9.6 %-19.7 %) for SEMS. Subgroup analyses confirmed these results.

CONCLUSIONS

This meta-analysis showed that LAMS and SEMS are comparable in terms of efficacy for EUS-CDS. Clinical and technical success, post-procedure adverse events, and reintervention rates were similar between LAMS and SEMS use; however, adverse events require further investigation.

A novel electrocautery-enhanced delivery system for one-step endoscopic ultrasound-guided drainage of the gallbladder and bile duct using a lumen-apposing metal stent: a feasibility study

BACKGROUND

The use of a lumen-apposing metal stent (LAMS) capable of one-step endoscopic ultrasound-guided transmural drainage (EUS-TD) can increase the effectiveness of the procedure. We evaluated the newly developed electrocautery-enhanced (EC) delivery system with a LAMS for one-step EUS-guided gallbladder drainage (EUS-GBD) or choledochoduodenostomy (EUS-CDS).

METHODS

In the animal experiment, an EC-LAMS was advanced into the gallbladder without prior tract dilation in four pigs. A conventional LAMS was inserted in another four pigs as a control group. After the animal experiment, 17 patients underwent EUS-TD using the EC-LAMS (EUS-GBD in 10 patients, EUS-CDS in 7). The primary outcome was the technical success rate.

RESULTS

In the animal study, the mean procedure time was significantly shorter in the EC-LAMS group than in the conventional LAMS group. In the human study, the overall technical success rate was 94.1 %, with one EUS-GBD failure. The clinical success rate was 100 %. The overall adverse event rate was 17.6 %.

CONCLUSIONS

One-step EUS-GBD or EUS-CDS using the novel EC-LAMS is a feasible approach that achieves a high success rate and maintains safety.

Technical tips and recent development of endoscopic ultrasound-guided choledochoduodenostomy

Various efforts to improve technical success rates and decrease adverse event rates have also been described in endoscopic ultrasound (EUS)-guided choledochoduodenostomy (CDS). In particular, lumen-apposing metal stents (LAMS) may open novel opportunities in EUS-biliary drainage (BD). To date, various studies have been reported with EUS-CDS using LAMS, so we should clarify the benefits and limitations of recent EUS-CDS based on developments in both techniques and devices. In this review, we provide technical tips and describe recent developments in EUS-CDS, along with a review of the recent literature (between 2015 and 2020). The overall technical success rate is 95.0% (939/988), and the overall clinical success rate is 97.0% (820/845). The most frequent adverse event is cholangitis or cholecystitis (24.5%, 27/110). According to previous review, pneumoperitoneum (28%, 9/34) or peritonitis associated with bile leak (23.5%, 8/34) was most commonly observed. This difference might be based on improvements in dilation devices or the use of covered metal stents. Several randomized controlled trials comparing EUS-CDS and endoscopic retrograde cholangiopancreatography (ERCP) for malignant biliary obstruction have recently been reported. To summarize, overall technical success rates for ERCP and EUS-CDS were 92.7% (101/109) and 91.1% (72/79), respectively (p = 0.788). Overall clinical success rates for ERCP and EUS-CDS were 94.1% (96/102) and 93.6% (72/78), respectively (p = 0.765). Further high-quality evidence is needed to establish EUS-CDS as a primary drainage technique.

Conversion of percutaneous transhepatic biliary drainage to endoscopic ultrasound-guided biliary drainage

INTRODUCTION

Percutaneous transhepatic biliary drainage (PTBD) is a useful alternative treatment for malignant biliary obstruction (MBO) when patients have difficulty with endoscopic transpapillary drainage. We examined the feasibility of conversion of PTBD to endoscopic ultrasound-guided biliary drainage (EUS-BD) in patients with MBO unsuited for endoscopic transpapillary biliary drainage.

METHODS

This retrospective study included patients who underwent conversion of PTBD to EUS-BD between March 2017 and December 2019. Eligible patients had unresectable MBO, required palliative biliary drainage, and were not suited for endoscopic transpapillary drainage. Initial PTBD had been performed for acute cholangitis or obstructive jaundice in all patients. EUS-BD was performed following improvements in cholangitis. Sixteen patients underwent conversion of PTBD to EUS-BD. We evaluated technical success, procedure time, clinical success (defined as subsequent external catheter removal), adverse events (AEs), time to recurrent biliary obstruction (TRBO), and re-intervention rates.

RESULTS

Technical success was achieved in all patients (100%). The median procedure time was 45.0 minutes (interquartile range [IQR] 30.0-50.0 minutes). Clinical success was achieved in all patients (100%). There were mild early AEs in two patients (12.5%) (acute cholangitis: 1, bile peritonitis: 1), which improved with antibiotic administration alone. Recurrent biliary obstruction (RBO) occurred in six patients (37.5%). Kaplan-Meier analysis revealed a 50% TRBO of 95 days (IQR 41-246 days). Endoscopic treatment was possible in all RBO cases, and repeat PTBD was not required.

CONCLUSIONS

Conversion of PTBD to EUS-BD for the management of MBO is both feasible and safe. This approach is expected to be widely practiced at centers with little experience in EUS-BD.

Comparison of endoscopic ultrasound-guided choledochoduodenostomy and endoscopic retrograde cholangiopancreatography in first-line biliary drainage for malignant distal bile duct obstruction: A multicenter randomized controlled trial

INTRODUCTION

In patients with malignant distal bile duct obstruction and normal gastrointestinal anatomy, endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) is indicated when endoscopic retrograde cholangiopancreatography (ERCP) fails. The ERCP drainage route passes through the tumor, whereas the EUS-CDS route does not. Therefore, EUS-CDS is expected to have a longer stent patency than ERCP. However, for first-line biliary drainage, it remains unclear whether EUS-CDS or ERCP is superior in terms of stent patency. To reduce the frequency of highly adverse events (AEs) such as bile peritonitis or stent migration following EUS-CDS, we developed an antimigration metal stent with a thin delivery system for tract dilatation. This study is designed to assess whether EUS-CDS with this novel stent is superior to ERCP with a traditional metal stent in terms of stent patency when the two techniques are used for first-line drainage of malignant distal biliary obstruction.

METHODS/DESIGN

This study is a multicenter single-blinded randomized controlled trial (RCT) involving 95 patients in four tertiary centers. Patients with malignant distal biliary obstruction that is unresectable or presents a very high surgical risk and who pass the inclusion and exclusion criteria will be randomized to EUS-CDS or ERCP in a 1:1 proportion. The primary endpoint is the stent patency rate 180 days after stent insertion. Secondary outcomes include the rates of technical success, clinical success, technical success in cases not requiring fistulous-tract dilation (only EUS-CDS group), procedure-related AEs, re-intervention success, patients receiving post-drainage chemotherapy, procedure time, and overall survival time.

DISCUSSION

If EUS-CDS is superior to ERCP in terms of stent patency and safety for the first-line drainage of malignant distal biliary obstruction, it is expected that the first-line drainage method will be changed from ERCP to EUS-CDS, and that interruption of chemotherapy due to stent dysfunction can be avoided.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR), ID: UMIN000041343. Registered on August 6, 2020. https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000047201Version number: 1.2, December 7, 2020.

Risk factor analysis for adverse events and stent dysfunction of endoscopic ultrasound-guided choledochoduodenostomy

BACKGROUND AND AIMS

Although the technique of endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) is becoming standardized, its safety issues have not been sufficiently investigated. Therefore, we aimed to identify factors associated with adverse events and stent patency in EUS-CDS.

METHODS

Consecutive patients who underwent EUS-CDS between September 2003 and July 2017 were included. Technical/clinical success, adverse events and stent dysfunctions were analyzed retrospectively.

RESULTS

A total of 151 patients underwent EUS-CDS. In nine patients, procedures were discontinued before puncture. Technical and clinical success rates were 96.5% (137/142) and 98.5% (135/137), respectively. The adverse event rate was 20.4% (29/142). As a risk factor for peritonitis, plastic stents (PS) showed a significantly high odds ratio (OR) compared with covered self-expandable metal stents (CSEMS; OR, 4.31; P = 0.030). CSEMS cases showed a significantly longer patency period than PS cases (329 vs 89 days; HR, 0.35; P < 0.001). As a risk factor for early stent dysfunction (within 14 days), stent direction to the oral side showed a significantly high OR (OR, 43.47; P < 0.001). In cases with oblique-viewing EUS, double penetration of the duodenum occurred at significantly higher frequency than in cases with forward-viewing EUS (7.0 vs 0.0%; P = 0.024).

CONCLUSIONS

Plastic stents and stent direction to the oral side were risk factors for peritonitis and early stent dysfunction, respectively. Using covered self-expandable metal stents and changing stent direction to the anal side seemed appropriate to prevent peritonitis and early stent dysfunction.

Advances in the endoscopic management of malignant biliary obstruction

Biliary obstruction is common in pancreatobiliary malignancies and has a negative impact on the patient's quality of life, postoperative complications, and survival rates. Particularly in the last decade, there has been enormous progress regarding the diagnostic and therapeutic options in patients with malignant biliary obstruction. Endoscopy has given a new insight in this direction and novel techniques have been developed for the better characterization and treatment of malignant strictures. We herein summarize the available data on the different endoscopic techniques, and clarify their role in the diagnosis and treatment of malignant biliary obstructive disease. Finally, we propose an algorithm that can facilitate management decisions in these patients.

Effectiveness and safety of EUS-guided choledochoduodenostomy using lumen-apposing metal stents (LAMS): a systematic review and meta-analysis

BACKGROUND

Endoscopic ultrasound-guided choledochoduodenostomy (CDD) is emerging as an alternative technique for biliary drainage in patients who fail conventional endoscopic retrograde cholangiopancreatography (ERCP). The lumen-apposing metal stents (LAMS) are being increasingly used for CDD. We performed a systematic review and meta-analysis to evaluate the effectiveness and safety of CDD using LAMS.

METHODS

We performed a systematic search of multiple databases through May 2019 to identify studies on CDD using covered self-expanding metal stents. Pooled rates of technical success, clinical success, adverse events, and recurrent jaundice associated with CDD using LAMS were estimated. A subgroup analysis was performed based on use of LAMS with electrocautery-enhanced delivery system (EC-LAMS).

RESULTS

Seven studies on CDD using LAMS (with 284 patients) were included in the meta-analysis. Pooled rates of technical and clinical success (per-protocol analysis) were 95.7% (95% CI 93.2-98.1) and 95.9% (95% CI 92.8-98.9), respectively. Pooled rate of post-procedure adverse events was 5.2% (95% CI 2.6-7.9). Pooled rate of recurrent jaundice was 8.7% (95% CI 4.5-12.8). On subgroup analysis of CDD using EC-LAMS (5 studies with 201 patients), the pooled rates of technical and clinical success (per-protocol analysis) were 93.8% (95% CI 90.4-97.1) and 95.9% (95% CI 91.9-99.9), respectively. Pooled rate of post-procedure adverse events was 5.6% (95% CI 1.7-9.5). Pooled rate of recurrent jaundice was 11.3% (95% CI 6.9-15.7). Heterogeneity (I2) was low to moderate in the analyses.

CONCLUSION

CDD using LAMS/EC-LAMS is an effective and safe technique for biliary decompression in patients who failed ERCP. Further studies are needed to assess CDD using LAMS as primary treatment modality for biliary obstruction.