Impact of endoprosthesis type on inflammatory response in patients undergoing endoscopic drainage of pancreatic fluid collections

Controversies in endoscopic ultrasonography-guided management of walled-off necrosis

Walled-off necrosis (WON) develops as local complications after acute necrotizing pancreatitis. Although less invasive interventions such as endoscopic ultrasonography (EUS)-guided drainage and endoscopic necrosectomy are selected over surgical interventions, delayed and step-up interventions are still preferred to avoid procedure-related adverse events. However, there is a controversy about the appropriate timing of drainage and subsequent necrosectomy. The advent of large-caliber lumen-apposing metal stents has also brought about potential advantages of proactive interventions, which still needs investigation in future trials. When step-up interventions of necrosectomy and additional drainage are necessary, a structured or protocoled approach for WON has been reported to improve safety and effectiveness of endoscopic and/or percutaneous treatment, but has not been standardized yet. Finally, long-term outcomes such as recurrence of WON, pancreatic endocrine, and exocrine function are increasingly investigated in association with disconnected pancreatic duct syndrome. In this review we discuss current evidence and controversy on EUS-guided management of WON.

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.

Efficacy and Safety of Anhydrous Ethanol-Assisted Endoscopic Ultrasound-Guided Transluminal Necrosectomy in Infected Necrotizing Pancreatitis

AIM

Endoscopic necrosectomy has become the first-line treatment option for infectious necrotizing pancreatitis (INP), especially walled-off necrosis. However, the problems, including operation-related adverse events (AEs) and the need for multiple endoscopic procedures, have not been effectively addressed. We sought to evaluate the clinical safety and efficacy of anhydrous ethanol-assisted endoscopic ultrasound (EUS)-guided transluminal necrosectomy in INP.

METHODS

A single-center observational cohort study of INP patients was conducted in a tertiary endoscopic center. Anhydrous ethanol-assisted EUS-guided transluminal necrosectomy (modified group) and conventional endoscopic necrosectomy (conventional group) were retrospectively compared in INP patients. The technical and clinical success rates, operation time, perioperative AEs, postoperative hospital stay, and recurrent INP rates were analyzed, respectively.

RESULTS

A total of 55 patients were enrolled. No statistically significant differences were observed between the two groups regarding baseline characteristics. Compared to patients in the conventional group, patients in the modified group demonstrated significantly reduced times of endoscopic transluminal necrosectomies (1.96 ± 0.89 vs. 2.73 ± 0.98; P = 0.004) and comparable perioperative AEs (P = 0.35). Meanwhile, no statistically significant differences were observed in the technical and clinical success rates (P = 0.92), operation time (P = 0.59), postoperative hospital stay (P = 0.36), and recurrent INP rates (P = 1.00) between the two groups.

CONCLUSION

Anhydrous ethanol-assisted EUS-guided transluminal necrosectomy seemed safe and effective in treating INP. Compared with conventional endoscopic transluminal necrosectomy, its advantage was mainly in reducing the number of endoscopic necrosectomies without increasing perioperative AEs.

Efficacy and Safety of Anhydrous Ethanol-Assisted Endoscopic Ultrasound-Guided Transluminal Necrosectomy in Infected Necrotizing Pancreatitis

AIM

Endoscopic necrosectomy has become the first-line treatment option for infectious necrotizing pancreatitis (INP), especially walled-off necrosis. However, the problems, including operation-related adverse events (AEs) and the need for multiple endoscopic procedures, have not been effectively addressed. We sought to evaluate the clinical safety and efficacy of anhydrous ethanol-assisted endoscopic ultrasound (EUS)-guided transluminal necrosectomy in INP.

METHODS

A single-center observational cohort study of INP patients was conducted in a tertiary endoscopic center. Anhydrous ethanol-assisted EUS-guided transluminal necrosectomy (modified group) and conventional endoscopic necrosectomy (conventional group) were retrospectively compared in INP patients. The technical and clinical success rates, operation time, perioperative AEs, postoperative hospital stay, and recurrent INP rates were analyzed, respectively.

RESULTS

A total of 55 patients were enrolled. No statistically significant differences were observed between the two groups regarding baseline characteristics. Compared to patients in the conventional group, patients in the modified group demonstrated significantly reduced times of endoscopic transluminal necrosectomies (1.96 ± 0.89 vs. 2.73 ± 0.98; P = 0.004) and comparable perioperative AEs (P = 0.35). Meanwhile, no statistically significant differences were observed in the technical and clinical success rates (P = 0.92), operation time (P = 0.59), postoperative hospital stay (P = 0.36), and recurrent INP rates (P = 1.00) between the two groups.

CONCLUSION

Anhydrous ethanol-assisted EUS-guided transluminal necrosectomy seemed safe and effective in treating INP. Compared with conventional endoscopic transluminal necrosectomy, its advantage was mainly in reducing the number of endoscopic necrosectomies without increasing perioperative AEs.

Risk of recurrence with or without plastic stent after EUS-guided treatment of peripancreatic fluid collections: A systematic review and meta-analysis

Background and study aims Recent advances in endoscopic transmural treatment have improved the clinical outcomes of patients with pancreatic fluid collections (PFCs). However, there is still a debate about the preventive effect of long-term placement of a transmural plastic stent (PS) on recurrence after successful endoscopic ultrasound (EUS)-guided treatment of PFCs. We conducted a systematic review and meta-analysis to evaluate PFC recurrence rates with and without a transmural PS after EUS-guided treatment. Patients and methods A systematic literature search of PubMed, Embase, and the Cochrane database was conducted to identify clinical studies comparing outcomes with and without transmural PS published until September 2022. Data on PFC recurrence and adverse events (AEs) were pooled using a random-effects model. Results Nine studies including 380 patients with long-term transmural PS and 289 patients without PS were identified. The rate of PFC recurrence was significantly lower in patients with transmural PS (pooled odds ratio [OR] = 0.23, 95% confidence interval [CI] [0.08-0.65], P = 0.005). In a subgroup analysis limited to studies focusing on patients with disconnected pancreatic duct syndrome, which has been reported to be a risk factor for PFC recurrence, the OR was numerically lower than that for the entire cohort (OR = 0.14, 95% CI [0.04-0.46]). The rate of AEs was significantly higher with long-term transmural PS (OR = 14.77, 95% CI [4.21-51.83]). Conclusions In this meta-analysis, long-term PS placement reduced the risk of PFC recurrence. Given the potential AEs of indwelling PS, further research is required to evaluate the overall benefits of long-term PS placement.

Endoscopic Ultrasound in Pancreatology: Focus on Inflammatory Diseases and Interventions

Background

Endoscopic ultrasound (EUS) is a main tool in pancreatology for both diagnosis and therapy. It allows minimally invasive differentiation of various diseases, with a minimal degree of inflammation or anatomic variations. EUS also enables interventional direct access to the pancreatic parenchyma and the retroperitoneal space, the pancreatic duct, the pancreatic masses, cysts, vascular structures for diagnostic and therapeutic purposes.

Summary

This review aimed to summarize the new developments of EUS in the field of pancreatology, with special interest on inflammation and interventions. EUS enables way to perform pseudocyst drainage, necrosectomy, transenteral drainage and transenteric access of the main pancreatic duct, or the direct visualization or therapy of vascular structures adjacent to the pancreas.

Key Messages

EUS has a deep impact on pancreatology, and the development of new diagnostic and interventional approaches to the retroperitoneal space and the pancreas has increased in the last years exponentially, allowing minimal invasive diagnostics and therapy and avoiding surgery and percutaneous therapy.