WONDER-02: plastic stent vs. lumen-apposing metal stent for endoscopic ultrasound-guided drainage of pancreatic pseudocysts-study protocol for a multicentre randomised non-inferiority trial.

BACKGROUND: Endoscopic ultrasound (EUS)-guided transluminal drainage has become a first-line treatment modality for symptomatic pancreatic pseudocysts. Despite the increasing popularity of lumen-apposing metal stents (LAMSs), plastic stents may resolve non-necrotic fluid collections effectively with lower costs and no LAMS-specific adverse events. To date, there has been a paucity of data on the appropriate stent type in this setting. This trial aims to assess the non-inferiority of plastic stents to a LAMS for the initial EUS-guided drainage of pseudocysts. METHODS: The WONDER-02 trial is a multicentre, open-label, non-inferiority, randomised controlled trial, which will enrol pancreatic pseudocyst patients requiring EUS-guided treatment in 26 centres in Japan. This trial plans to enrol 80 patients who will be randomised at a 1:1 ratio to receive either plastic stents or a LAMS (40 patients per arm). In the plastic stent group, EUS-guided drainage will be performed using two 7-Fr double pigtail stents. In the LAMS group, the treatment will be performed in the same way except for LAMS use. The step-up treatment will be performed via endoscopic and/or percutaneous procedures at the trial investigator's discretion. The primary endpoint is clinical success, which is defined as a decrease in a pseudocyst size to ≤ 2 cm and an improvement in inflammatory indicators (i.e. body temperature, white blood cell count, and serum C-reactive protein). Secondary endpoints include technical success, adverse events including mortality, pseudocyst recurrence, and medical costs. DISCUSSION: The WONDER-02 trial will investigate the efficacy and safety of plastic stents compared to a LAMS in EUS-guided treatment of symptomatic pancreatic pseudocysts with a particular focus on the non-inferior efficacy of plastic stents. The findings will help establish a new treatment algorithm for this population. TRIAL REGISTRATION: ClinicalTrials.gov NCT06133023 registered on 9 November 2023. UMIN000052647 registered on 30 October 2023. jRCT1032230444 registered on 7 November 2023.

Trisectoral Metal Stenting Using Combined Stent-by-Stent and Stent-in-Stent Method for Malignant Hilar Biliary Obstruction: A Prospective Pilot Study.

BACKGROUND: Endoscopic trisectoral metal stent (MS) placement for malignant hilar biliary obstruction (MHBO) poses technical challenges, although it may prolong survival and stent patency. Combined stent-by-stent and stent-in-stent (SBSIS) methods can reduce technical difficulty. This study aimed to examine the use of the SBSIS in patients with Bismuth type III or IV MHBO. METHODS: This prospective pilot study enrolled 30 eligible patients between January 2020 and October 2022. The study outcomes included technical and clinical success, recurrent biliary obstruction (RBO), and adverse events (AE) besides RBO associated with SBSIS for MHBO. RESULTS: The technical success rate was 93.3% (28/30 patients). Clinical success was achieved in all patients with technical success. The early and late AEs rates were 6.7% (2/30) and 7.1% (2/28), respectively. The incidence of RBO was 35.7% (10/28). RBO was treated with an endoscopic transpapillary approach in eight patients and an endoscopic ultrasound-guided transmural approach in two patients. The median time to RBO was 162 days, and the median overall survival was 148 days. CONCLUSIONS: This first prospective study investigating the SBSIS method demonstrated good technical feasibility with a low AE rate. Therefore, it can be considered a better option when contemplating trisectoral MS placement for high-grade MHBO.

Prophylactic use of a self-assembling peptide hydrogel for preventing delayed bleeding after endoscopic sphincterotomy: A propensity score-matched analysis.

BACKGROUND AND AIM: Delayed endoscopic sphincterotomy-related bleeding (ES bleeding) is an unavoidable adverse event (AE) that can have serious ramifications. Intraoperative ES bleeding, which stops spontaneously in most cases, is a known risk factor for delayed bleeding. This study aimed to examine the preventive effect of a novel self-assembling peptide (SAP) for delayed ES bleeding in patients who attained spontaneous hemostasis after intraoperative ES bleeding. METHODS: A total of 1507 patients met the eligibility criteria for inclusion in this study. The rates of delayed ES bleeding and AE besides bleeding were compared between patients administered the SAP (SAP group) and those who were simply observed after spontaneous hemostasis of intraoperative ES bleeding (control group). Propensity score matching was performed to adjust for differences between the groups. RESULTS: The rate of delayed ES bleeding was significantly lower in the SAP group than that in the control group (0.9% vs 3.8%, P = 0.044). The rates of AEs other than bleeding were 2.4% and 3.8% in the SAP and control groups, respectively, and the difference lacked statistical significance (P = 0.481). Multivariate analysis revealed that the use of SAP was significantly associated with a lower frequency of delayed ES bleeding (odds ratio, 0.35; 95% confidence interval, 0.13-0.98; P = 0.047). CONCLUSIONS: Self-assembling peptide may be a simple, safe, and useful way to reduce the risk of delayed ES bleeding in patients who experienced intraoperative ES bleeding and obtained subsequent spontaneous hemostasis.

Endoscopic gallbladder inside-stenting combined with aspirated lavage for calculous cholecystitis in poor surgical candidates: a prospective pilot study.

Although long-term stent placement via endoscopic gallbladder stenting (EGBS) reportedly reduces cholecystitis recurrence in patients unfit to undergo cholecystectomy, it can increase the frequency of other late adverse events (AEs) such as cholangitis. This study aimed to examine the feasibility of endoscopic gallbladder inside-stenting (EGB-IS) with lavage and aspiration. This prospective, single-center, pilot study enrolled 83 patients with acute calculous cholecystitis who were poor candidates for surgery. A dedicated catheter with eight side holes was used for lavage and aspiration, and a dedicated single-pigtail stent equipped with a thread was used for EGB-IS. Outcomes such as technical success, clinical success, early AEs, recurrence of cholecystitis, and other symptomatic late AEs associated with EGB-IS with lavage and aspiration were evaluated. The technical and clinical success rates were 80.7% (67/83) and 98.5% (66/67), respectively. The rate of early AEs was 3.6% (3/83). The rate of recurrent cholecystitis was 4.5% (3/66) and that of symptomatic late AEs (besides cholecystitis) was 6.1% (4/66). Consequently, the rate of overall late AEs (cholecystitis plus other events) was 10.6% (7/66). The 1-, 2-, and 3-year cumulative incidence rates of all late AEs were 3.2%, 11.2%, and 18.9%, respectively. EGB-IS with lavage and aspiration for calculous cholecystitis showed promising results in poor surgical candidates. EGB-IS may be useful when EGBS with long-term stent placement is planned, since prevention of cholecystitis recurrence, without a rise in the incidence of other AEs, is anticipated.

Endoscopic Ultrasound-Guided Naso-gallbladder Drainage Using a Dedicated Catheter for Acute Cholecystitis After Transpapillary Metal Stent Placement for Malignant Biliary Obstruction.

BACKGROUND: Acute cholecystitis is a significant adverse event after self-expandable metal stent (SEMS) placement for malignant biliary obstruction (MBO); however, no appropriate treatment strategy has been established for its management. AIMS: This study aimed to examine the feasibility and utility of endoscopic ultrasound-guided naso-gallbladder drainage (EUS-NGBD) for the management of acute cholecystitis occurring after SEMS placement. METHODS: This retrospective study investigated consecutive patients with acute cholecystitis after SEMS placement for unresectable MBO, in whom EUS-NGBD was attempted. The study outcomes included technical success, clinical success, procedure time, adverse event, and cholecystitis recurrence, associated with the procedure. RESULTS: During the study period, EUS-NGBD was performed for SEMS-related acute cholecystitis in 30 patients with MBO. The technical and clinical success rates were 96.7% (29/30) and 96.6% (28/29), respectively. The median procedure time was 15 min, and rate of procedure-related adverse event was 3.3% (1/30). The median duration from the procedure to tube removal was 9 days. No adverse events were observed after removal. The median hospitalization duration after the procedure was 14 days, and the median duration to the (re-)start of chemotherapy from cholecystitis onset was 13 days. The median overall survival after EUS-NGBD was 123 days, and the rate of cholecystitis recurrence until death was 4.2% (1/28). CONCLUSIONS: This study demonstrated that EUS-NGBD possesses good technical and clinical feasibility with an acceptable adverse event rates and short hospitalization and chemotherapy withdrawal period. Therefore, EUS-NGBD may be a good option for the treatment of SEMS-related cholecystitis in patients with MBO.

Long-term disease control by endobiliary radiofrequency ablation in localized extrahepatic cholangiocarcinoma: a first case report.

An 84-year-old woman with cerebrovascular disease, dementia, and chronic kidney disease developed jaundice because of localized extrahepatic cholangiocarcinoma (eCCA) at the lower bile duct. Aggressive treatment, including surgery and chemotherapy, was difficult because of the underlying disease; therefore, only metal stent placement with endobiliary radiofrequency ablation (RFA) was performed. Subsequently, six additional RFA sessions were performed 12, 16, 24, 27, 33, and 36 months after the initial RFA using the same settings as the first RFA session. All these procedures were performed for tumor ingrowth. Computed tomography performed 42 months after the initial procedure revealed no stent with stricture resolution and no other metastatic lesion. Thereafter, no recurrence or adverse events have been observed with persisting stent-free status until the reporting of this study (72 months after the initial procedure). This is the first report of a stent-free status and long-term survival in a patient with localized eCCA that was achieved using only endobiliary RFA without any other anti-tumor treatment. Although several problems and issues associated with endobiliary RFA remain unelucidated, it may be a useful therapeutic option for early and localized eCCA in poor surgical candidates.

Endoscopic intraductal radiofrequency ablation for extrahepatic cholangiocarcinoma: An update (2023).

Recently, endoscopic intraductal radiofrequency ablation (ID-RFA) has attracted attention as a local treatment method for malignant biliary obstruction (MBO). ID-RFA causes coagulative necrosis of the tumor tissue in the stricture and induces exfoliation. Its effects are expected to extend the patency period of biliary stents and prolong the survival period. Evidence for extrahepatic cholangiocarcinoma (eCCA) is gradually accumulating, and some reports show significant therapeutic effects in eCCA patients without distant metastasis. However, it is still far from an established treatment technique, and many unsolved problems remain. Therefore, when performing ID-RFA in clinical practice, it is necessary to understand and grasp the current evidence well and to operate appropriately for the true benefit of the patients. This paper reviews the current status, issues, and prospects of endoscopic ID-RFA for MBO, especially for eCCA.

Comparison of the mechanical properties of retrieval basket catheters for bile duct stones: An experimental study.

BACKGROUND: Although numerous retrieval baskets are currently available for the extraction of bile duct stones, their mechanical properties have not been evaluated. This study aimed to ascertain the characteristics of retrieval baskets for bile duct stones by examining their mechanical properties. METHODS: This experimental study tested the mechanical properties of seven retrieval baskets for bile duct stones. The radial force (RF) was measured using a dedicated measurement device and the axial force (AF) was measured using the conventional manual method. RESULTS: The mean RF differed significantly among the baskets (p < 0.001) and was the strongest for VorticCatch (1.62 N ± 0.02) and COAXIS (1.62 N ± 0.04), followed by RASEN (1.27 N ± 0.02), Memory Basket (0.95 N ± 0.01), 8-wire Nitinol Basket (0.93 N ± 0.01), StoneHunter (0.78 N ± 0.01) and Flower Basket (0.37 N ± 0.01), respectively. The mean AF differed significantly among the baskets (p < 0.001) and was the highest for VorticCatch (0.668 N ± 0.032), followed by COAXIS (0.629 N ± 0.041), StoneHunter (0.574 N ± 0.037), 8-wire Nitinol Basket (0.546 N ± 0.010), Memory Basket (0.542 N ± 0.024), RASEN (0.435 N ± 0.008) and Flower Basket (0.297 N ± 0.011), respectively. The baskets were categorized into four groups with comparable mechanical properties based on the RF and AF: group 1, low RF and low AF; group 2, moderate RF and moderate AF; group 3, high RF and moderate AF; and group 4, high RF and high AF. CONCLUSIONS: This study revealed distinct mechanical properties of various retrieval baskets used for extracting bile duct stones, which may enhance the understanding of their action. Our results could also aid the development of retrieval baskets in future.

WONDER-01: immediate necrosectomy vs. drainage-oriented step-up approach after endoscopic ultrasound-guided drainage of walled-off necrosis-study protocol for a multicentre randomised controlled trial.

BACKGROUND: With the increasing popularity of endoscopic ultrasound (EUS)-guided transmural interventions, walled-off necrosis (WON) of the pancreas is increasingly managed via non-surgical endoscopic interventions. However, there has been an ongoing debate over the appropriate treatment strategy following the initial EUS-guided drainage. Direct endoscopic necrosectomy (DEN) removes intracavity necrotic tissue, potentially facilitating early resolution of the WON, but may associate with a high rate of adverse events. Given the increasing safety of DEN, we hypothesised that immediate DEN following EUS-guided drainage of WON might shorten the time to WON resolution compared to the drainage-oriented step-up approach. METHODS: The WONDER-01 trial is a multicentre, open-label, superiority, randomised controlled trial, which will enrol WON patients aged ≥ 18 years requiring EUS-guided treatment in 23 centres in Japan. This trial plans to enrol 70 patients who will be randomised at a 1:1 ratio to receive either the immediate DEN or drainage-oriented step-up approach (35 patients per arm). In the immediate DEN group, DEN will be initiated during (or within 72 h of) the EUS-guided drainage session. In the step-up approach group, drainage-based step-up treatment with on-demand DEN will be considered after 72-96 h observation. The primary endpoint is time to clinical success, which is defined as a decrease in a WON size to ≤ 3 cm and an improvement of inflammatory markers (i.e. body temperature, white blood cell count, and C-reactive protein). Secondary endpoints include technical success, adverse events including mortality, and recurrence of the WON. DISCUSSION: The WONDER-01 trial will investigate the efficacy and safety of immediate DEN compared to the step-up approach for WON patients receiving EUS-guided treatment. The findings will help us to establish new treatment standards for patients with symptomatic WON. TRIAL REGISTRATION: ClinicalTrials.gov NCT05451901, registered on 11 July 2022. UMIN000048310, registered on 7 July 2022. jRCT1032220055, registered on 1 May 2022.

Comparison of the long-term outcomes of EUS-guided gallbladder drainage and endoscopic transpapillary gallbladder drainage for calculous cholecystitis in poor surgical candidates: a multicenter propensity score-matched analysis.

BACKGROUND AND AIMS: Although long-term stent placement using endoscopic transpapillary gallbladder drainage (ETGBD) and EUS-guided gallbladder drainage (EUS-GBD) reportedly reduces cholecystitis recurrence, comparative evidence of their safety and efficacy is scarce. This study aimed to examine and compare the long-term utility of EUS-GBD versus that of ETGBD in poor surgical candidates. METHODS: A total of 379 high-risk surgical patients with acute calculous cholecystitis met the eligibility criteria for enrollment in this study. The technical success and adverse events (AEs) were compared between the EUS-GBD and ETGBD groups, and propensity score matching was performed to adjust for differences between the groups. Both groups underwent plastic stent placement, and scheduled stent exchange and removal were not performed in either group. RESULTS: The technical success rate of EUS-GBD was significantly higher than that of ETGBD (96.7% vs 78.9%, P < .001), whereas the early AE rate did not differ significantly between the 2 methods (7.8% vs 8.9%, P = 1.000). The rate of recurrent cholecystitis did not differ significantly (3.8% vs 3.0%, P = 1.000), but the rate of symptomatic late AEs, in addition to cholecystitis, was significantly lower with EUS-GBD than with ETGBD (1.3% vs 13.4%, P = .006). Consequently, the overall late AE rate was significantly lower with EUS-GBD (5.0% vs 16.4%, P = .029). Multivariate analysis revealed that EUS-GBD was associated with a significantly longer time to late AE (hazard ratio, .26; 95% confidence interval, .10-.67; P = .005). CONCLUSIONS: Long-term stent placement via EUS-GBD is a promising potential option for limiting late AEs, including recurrence, in poor surgical candidates with calculous cholecystitis.

A novel controllable cannula with a short flexible tip for reintervention after stent-by-stent placement in malignant hilar biliary obstruction.

N/A.

A novel non-slip banded balloon catheter for endoscopic sphincteroplasty: an ex vivo and in vivo pilot study.

Endoscopic balloon sphincteroplasty is an established procedure for the extraction of bile duct stones. However, the balloon often slips during the inflation process, and its length is an impediment if the distance between the papilla and scope is limited and/or the stone is located close to the papilla. This animal experimental study aimed to evaluate the feasibility of a novel short non-slip banded balloon measuring 15-20 mm in length for sphincteroplasty. The ex vivo component of this study was conducted using porcine duodenal papilla. Miniature pigs were subjected to endoscopic retrograde cholangiography in the in vivo component. The technical success of sphincteroplasty without any slippage was the primary outcome of the study and was compared between cases managed with the non-slip banded balloon (non-slip balloon group) and conventional balloon (conventional balloon group). The technical success rate of the ex vivo component, i.e., absence of any slippage, was significantly higher in the non-slip balloon group than in the conventional balloon group with the 8-mm (96.0% vs. 16.0%, P < 0.001) and 12-mm diameter balloons (96.0% vs. 0%, P < 0.001). The technical success rate of endoscopic sphincteroplasty without slippage in the in vivo component was significantly higher in the non-slip balloon group than in the conventional balloon group (100% vs. 40%, P = 0.011). No immediate adverse events were observed in either group. The slippage rate was significantly lower with sphincteroplasty using a non-slip balloon, despite the balloon length being considerably shorter than that of conventional balloons, demonstrating its potential utility in difficult cases.