Covered versus uncovered double bare self-expandable metal stent for palliation of unresectable extrahepatic malignant biliary obstruction: a randomized controlled multicenter trial

Identification of risk factors associated with post-ERCP pancreatitis in patients with easy cannulation: a prospective multicenter observational study (with videos)

BACKGROUND AND AIMS

Difficult biliary cannulation is an independent risk factor for post-ERCP pancreatitis (PEP); however, there is a noticeable lack of studies focusing on the incidence and risk factors of PEP among patients undergoing easy cannulation. Therefore, we systematically investigated the risk factors for PEP in patients who underwent easy cannulation.

METHODS

We prospectively enrolled patients with naive major papillae who underwent diagnostic or therapeutic ERCP between June 2018 and June 2023. The primary endpoint was to determine the incidence of PEP in patients with easy cannulation; secondary endpoints were identifying PEP risk factors and evaluating procedure-related adverse events (AEs).

RESULTS

Overall, 1930 patients were included, with 1061 (54.9%) undergoing easy cannulation. Within this cohort, PEP incidence was 3.0%, whereas 2.9% experienced procedure-related AEs, excluding PEP. A history of acute pancreatitis (odds ratio [OR], 6.75; 95% confidence interval [CI], 1.83-20.14; P = .001) and acute cholangitis on admission (OR, 2.25; 95% CI, 1.07-5.08; P = .039) were identified as independent risk factors for PEP in patients with easy cannulation. Endoscopic sphincterotomy and biliary stent placement were independent factors for procedure-related AEs.

CONCLUSIONS

Our findings underscore the importance of assessing patient- and procedure-related factors to mitigate the risk of PEP in patients undergoing easy cannulation. Despite the low incidence of PEP, the potential for the occurrence of severe cases emphasizes the need for cautious intervention, particularly in patients with a history of acute pancreatitis and acute cholangitis on admission. (Clinical trial registration number: KCT0005950.).

The usefulness of percutaneous bile duct metal stent insertion for malignant biliary obstruction: a retrospective study

BACKGROUND

Percutaneous transhepatic bile duct stent insertion is a useful alternative to the endoscopic approach for malignant biliary strictures. This study retrospectively reviewed the cases of percutaneous metallic stent insertion at our institution to evaluate its safety and usefulness.

METHODS

The study included cases of percutaneous bile duct stent insertion performed between April 2016 and August 2024. All patients included those with malignant biliary obstruction and those in whom an endoscopic approach was first attempted but could not reach or cannulate the papilla of Vater. Two procedures were used: a two-stage procedure, in which a drain was inserted to create an external or internal fistula, followed by stent insertion, and a one-stage procedure, in which the stent was inserted at the same time as the approach to the bile duct. The causes of biliary strictures and complications were examined.

RESULTS

The study included 14 cases: seven patients had pancreatic head cancer, including biliary tract cancer (n = 4) and postoperative gastric cancer (n = 3); three patients who underwent a one-stage insertion. The number of inserted stents tended to increase in patients with postoperative cholangiocarcinoma recurrence. No complication occurred in any patient. One patient had severe cholangitis, eight had moderate cholangitis, and four had mild cholangitis; two patients who underwent one-stage procedures had moderate cholangitis and one had mild cholangitis. In cases of two-stage expandable metal stent (EMS) insertion, the average time from initial drainage to EMS insertion was 10.5 days (4-25).

CONCLUSIONS

The stent can be safely inserted in a one-stage procedure without compromising the patient's quality of life. Therefore, one-stage insertion of EMS for malignant biliary stricture may be performed aggressively unless the patient has severe cholangitis.

Secondary uncovered versus fully-covered metal stents for the management of occluded stent in unresectable distal malignant biliary obstruction

INTRODUCTION

Self-expandable metallic stents (SEMS) have been widely placed for unresectable distal malignant biliary obstruction (UDMBO). However, the dysfunction rate is 19-40% and its treatment is controversial. We aimed asses the efficacy and safety of a secondary biliary stents (uncovered (UC) versus fully-covered (FC) stent) for the management of occluded SEMS.

PATIENTS AND METHODS

Between 2015 and June 2023, 41 patients with UDMBO underwent secondary biliary stent placement as "stent-in-stent" (20 FCSEMS and 21 UCSEMS). The primary outcomes were technical and clinical success of SEMS placement. Secondary outcomes included adverse events (AEs), patency and survival. Patients were prospectively followed until death or loss of follow-up.

RESULTS

Technical (100% vs 85.5%) and clinical (100% vs 95.2%) success rates were similar in FCSEMS and UCSEMS groups. The median follow-up period was 510 days (range 290-630). The median duration of stent patency of FCSEMS (220 days, IQR 137.5-442.5) was longer than UCSEMS (150 days, IQR 110-362.5) (P=0.395), although stent dysfunction within 6 months was not different between groups. Multivariate analysis indicated that sex (HR=0.909, 0.852-0.970), antitumor treatment (HR=0.248, 0.032-0.441), stent patency (HR=0.992, 0.986-0.998) and clinical success (HR=0.133, 0.026-0.690) were significant factors for overall survival. There were no remarkable differences in AEs.

CONCLUSIONS

The placement of additional biliary stent using the stent-in-stent method is an effective and safe rescue treatment for patients with UDMBO and occluded stent. In addition, the use of FCSEMS compared UCSEMS has unclear benefits regarding stent patency and overall survival.

TOKYO criteria 2024 for the assessment of clinical outcomes of endoscopic biliary drainage

The consensus-based TOKYO criteria were proposed as a standardized reporting system for endoscopic transpapillary biliary drainage. The primary objective was to address issues arising from the inconsistent reporting of stent outcomes across studies, which has complicated the comparability and interpretation of study results. However, the original TOKYO criteria were not readily applicable to recent modalities of endoscopic biliary drainage such as biliary drainage based on endoscopic ultrasound or device-assisted endoscopy. There are increasing opportunities for managing hilar biliary obstruction and benign biliary strictures through endoscopic drainage. Biliary ablation has been introduced to manage benign and malignant biliary strictures. In addition, the prolonged survival times of cancer patients have increased the importance of evaluating overall outcomes during the period requiring endoscopic biliary drainage rather than solely focusing on the patency of the initial stent. Recognizing these unmet needs, a committee has been established within the Japan Gastroenterological Endoscopy Society to revise the TOKYO criteria for current clinical practice. The revised criteria propose not only common reporting items for endoscopic biliary drainage overall, but also items specific to various conditions and interventions. The term "stent-demanding time" has been defined to encompass the entire duration of endoscopic biliary drainage, during which the overall stent-related outcomes are evaluated. The revised TOKYO criteria 2024 are expected to facilitate the design and reporting of clinical studies, providing a goal-oriented approach to the evaluation of endoscopic biliary drainage.

Fully covered versus partially covered self-expandable metal stents for palliation of distal malignant biliary obstruction: a systematic review and meta-analysis

BACKGROUND AND AIMS

Self-expandable metal stents (SEMSs) are standardly used for distal malignant biliary obstruction (dMBO). Although data suggest that covered versus uncovered SEMSs increase the time to recurrent biliary obstruction (TRBO), no data are available for fully covered (FC) versus partially covered (PC) designs.

METHODS

PubMed, Scopus, and Cochrane databases were screened up to January 2023 for studies concerning dMBO treated by an FC- or PC-SEMS and describing adverse events (AEs), recurrences, or TRBO for specific design subpopulations. Pooled proportions or means were calculated using a random-effects model. Several subanalyses were preplanned, including a subanalysis restricted to prospective studies and unresectable diseases. Heterogeneity and publication bias were explored. Standardized differences (d-values) were calculated between groups.

RESULTS

From 1290 records, 62 studies (3327 using FC-SEMSs and 2322 using PC-SEMSs) were included. FC- versus PC-SEMSs showed negligible differences in the rate of total AEs (12% vs 9.9%) and all specific AEs, including cholecystitis (2.5% vs 2.6%). In a subanalysis restricted to prospective studies and unresectable diseases, the rate of RBO was comparable between FC-SEMSs (27.3% [95% confidence interval {CI}, 23.7-31.2], I2 = 35.34%) and PC-SEMSs (25.3% [95% CI, 20.2-30.7], I2 = 85.09%), despite small differences (d-values between .186 and .216) in the rate of ingrowth (.5% vs 2.9%) favoring FC-SEMSs and migration (9.8% vs 4.3%) favoring PC-SEMSs. TRBO was shorter for FC-SEMSs (238 days [95% CI, 191-286], I2 = 63.1%) versus PC-SEMSs (369 days [95% CI, 290-449], I2 = 71.9%; d-value = .116).

CONCLUSIONS

Despite considerable heterogeneity and small standardized differences, PC-SEMSs consistently exhibited longer TRBO than FC-SEMSs across analyses, without any other differences in AE rates, potentially proposing PC-SEMSs as the standard comparator and TRBO as the primary outcome for future randomized studies on dMBO. (Clinical trial registration number: CRD42023393965.).

Characteristics of four commonly used self-expanding biliary stents: an in vitro study

BACKGROUND

Knowledge of the characteristics of self-expanding metal stents (SEMSs) is essential during selection process to ensure the best therapeutic outcomes for patients with malignant biliary obstruction. The aim of this study was to evaluate the characteristics of four commonly used SEMSs.

METHODS

This in vitro study analyzed the radial force (RF), crush resistance (CR), axial force (AF), conformability, surface quality, foreshortening, and radiopacity of the following SEMSs: uncovered Wallflex™, EGIS single bare, Zilver 635®, and E-Luminexx™. Two samples of each SEMS type were included in this study, all having identical specifications with a diameter of 10 mm and a length of 6 cm. One sample from each type was analyzed for surface quality, followed by CR, conformability, and foreshortening. The other sample was analyzed for radiopacity, followed by RF and AF.

RESULTS

The uncovered Wallflex™ exhibited low RF, high CR, high AF, good conformability, poor surface quality, high foreshortening, and good radiopacity. The EGIS single bare demonstrated high RF, high CR, low AF, moderate conformability, good surface quality, high foreshortening, and poor radiopacity. The Zilver 635® displayed moderate RF, low CR, low AF, moderate conformability, moderate surface quality, no foreshortening, and good radiopacity. The E-Luminexx™ showed high RF, moderate CR, high AF, poor conformability, poor surface quality, no foreshortening, and good radiopacity.

CONCLUSIONS

There was considerable variation in the characteristics among the four evaluated SEMSs. These characteristics should be carefully considered during selection to ensure optimal therapeutic outcomes for patients.

RELEVANCE STATEMENT

The selection of self-expanding metal stents for treating malignant biliary obstruction requires careful consideration of various characteristics, including their radial force, crush resistance, axial force, conformability, surface quality, foreshortening, and radiopacity.

KEY POINTS

• The characteristics of self-expanding metal stents (SEMSs) can vary considerably. • Specific situations may warrant the use of SEMSs with particular characteristics over others. • Characteristics of SEMSs must be considered during selection for optimal outcomes.

Clinical impact of pancreatic steatosis measured by CT on the risk of post-ERCP pancreatitis: a multicenter prospective trial

BACKGROUND AND AIMS

Pancreatic steatosis (PS) may be a risk factor for acute pancreatitis. Whether it is also a risk factor for post-ERCP pancreatitis (PEP) has not been evaluated. This study aimed to determine the impact of PS on PEP development.

METHODS

This multicenter prospective trial enrolled 786 consecutive patients who underwent contrast-enhanced abdominal CT and subsequent first-time ERCP. PS was evaluated based on pancreatic attenuation on unenhanced CT images. The risk of PS for the development of PEP was evaluated using a logistic regression model.

RESULTS

Of 527 patients included in the study, 157 (29.8%) had PS and 370 (70.2%) did not. At 24 hours after ERCP, there was a significant difference in the PEP identified in 22 patients (14.0%) in the PS group and 23 patients (6.2%) in the "no PS" (NPS) group (P = .017). Diabetes and hypertension were more common in the PS group than in the NPS group; no differences in dyslipidemia were found. Patients with PS had a higher risk for the development of PEP than those with NPS (odds ratio, 2.09; 95% confidence interval, 1.08-4.03). No other variables were identified as risk factors for PEP.

CONCLUSIONS

PS is a significant risk factor for PEP for which preventive measures should be considered. Standardized measurement protocols to assess PS by CT are needed. (Clinical trial registration number: KCT0006068.).