Prospective evaluation of a new biflanged metal stent for the treatment of pancreatic fluid collections (with videos)

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.

Experimental study of a physician-controlled electrocautery-enhanced delivery system incorporating a newly developed lumen-apposing metal stent for interventional endoscopic ultrasound (with videos)

BACKGROUND/PURPOSE

Although the lumen-apposing metal stent (LAMS) is useful for interventional endoscopic ultrasound (EUS) procedures, there has been some concern about the potential for stent-induced adverse events because of the high lumen-apposing force. A newly designed LAMS with less lumen-apposing force has been developed for use with a physician-controlled electrocautery-enhanced delivery system. The aim of this animal study was to evaluate the feasibility of performing interventional EUS using this newly designed LAMS system.

METHODS

EUS-guided cystogastrostomy was performed using the novel LAMS 3 times in a wet simulation model. EUS-guided gastroenterostomy and EUS-guided gallbladder drainage were then performed using the system in 4 pigs.

RESULTS

The LAMS was successfully placed in all 3 EUS-guided cystogastrostomy procedures using the wet simulation model and in all 4 EUS-guided gastroenterostomy and gallbladder drainage procedures in the animal model. In the 3 weeks following the procedure, eating behavior was normal in all animals and there were no adverse events. The stents remained patent during this time and were removed without difficulty. The fistula was mature in all cases and a standard upper gastrointestinal endoscope was easily advanced via the fistula to observe the afferent and efferent loops or the lumen of the gallbladder. Necropsy confirmed complete adhesion between the stomach and the wall of the jejunum or gallbladder.

CONCLUSIONS

Our study findings demonstrate the feasibility of this new LAMS system and its potential clinical value for interventional EUS.

Comparative outcomes of endoscopic ultrasound-guided lumen-apposing mental stents drainage for pancreatic pseudocysts and walled-off necrosis: Case series and meta-analysis

Background

Endoscopic ultrasound (EUS)-guided transmural drainage for pancreatic fluid collections (PFCs) has become the first-line treatment with quicker recovery and more minor injury compared with surgery and percutaneous drainage. The efficacy of stents implantation and drainage for different PFCs remains controversial, especially lumen-apposing metal stents (LAMS). This study aimed to compare the efficacy and safety of LAMS drainage for pancreatic pseudocysts (PPC) and walled-off necrosis (WON).

Methods

A meta-analysis was performed for LAMS drainage for WON and PPC by systematically searching PubMed, Cochrane, and Embase databases from January 2010 to January 2020. From 2017 to 2019, 12 patients who were treated with LAMS drainage for PFCs in our medical center were also reviewed and included in this study.

Results

Combining 11 copies of documents with the data from our medical center, a total of 585 patients with PFCs were enrolled in this meta-analysis, including 343 patients with WON and 242 with PPC. The technical success rate in WON is not significantly different from that of PPC (P = 0.08 > 0.05). The clinical success of LAMS placement was achieved in 99% vs 89% in PPC and WON, respectively (RR = 0.92, 95% CI: 0.86-0.98, P = 0.01 < 0.05). The further intervention of direct endoscopic necrosectomy was required by 60% of patients in WON group. There was no significant difference in the incidence of adverse events, including infection, bleeding, stent migration and stent occlusion, after LAMS placement between WON and PPC.

Conclusions

Endoscopic ultrasound-guided LAMS for PFCs are feasible, effective with preferable technical and clinical success rates. The clinical effect of LAMS on PPC is slightly better than that of WON, but its adverse reactions still need to be verified in a large-sample prospective study.

Clinical practice of acute pancreatitis in Japan: An analysis of nationwide epidemiological survey in 2016

BACKGROUND

To provide updates on clinical practice of acute pancreatitis (AP) in Japan, we conducted a nationwide epidemiological survey.

METHODS

This study consisted of a two-staged survey; the number of AP patients was estimated by the first-stage survey and their clinical features were examined by the second-stage survey. We surveyed AP patients who had visited hospitals in 2016.

RESULTS

The estimated number of AP patients in 2016 was 78,450, with an overall incidence of 61.8 per 100,000 persons. We obtained detailed clinical information of 2994 AP patients, including 706 (23.6%) severe cases classified according to the Japanese severity criteria. The male-to-female sex ratio was 2.0, and the mean age at onset was 59.9 years in males and 66.5 years in females. Alcohol was the most common etiology (42.8%) in males and gallstones in females (37.7%). The AP-associated mortality was 6.1% in severe AP cases, which was decreased by 40% compared to the 2011 survey. Antibiotics were administered to most cases, with carbapenem being frequently used. Enteral nutrition was given in 31.8% of severe cases, but majority cases received after 48 h. Among the 107 patients who received intervention for walled-off necrosis, five patients received surgery-first approach, 66 received endoscopic ultrasound-guided transluminal drainage, and 19 underwent step-up approach.

CONCLUSIONS

We clarified the current status of AP in Japan including the significant reduction of mortality in severe cases, shift to endoscopic approaches for walled-off necrosis, and poor compliance of the recommendations in the guidelines including management of enteral nutrition and antibiotic administration.

Advancements in the endoscopic treatment of pancreatic fluid collections

Endoscopic drainage of pancreatic fluid collections (PFCs) with fewer complications and less trauma has gradually replaced surgery or percutaneous drainage to become the first-line treatment for PFCs. In recent years, the differential efficacy of various stent techniques to drain different types of PFCs has been controversial. This review summarizes the clinical applications of endoscopic ultrasound-guided stent placement for PFCs drainage.

Ex vivo assessment of anchoring force of covered biflanged metal stent and covered self-expandable metal stent for interventional endoscopic ultrasound

BACKGROUND AND AIMS

Endoscopic ultrasound (EUS)-guided transmural drainage using a covered biflanged metal stent (CBFMS) and a conventional tubular biliary covered self-expandable metal stent (CSEMS) has recently been performed by EUS experts. However, appropriate traction force of the sheath to prevent the migration during stent deployment is well unknown. Herein, we assessed the anchoring force (AF) of the distal flange in CBFMSs and CSEMSs.

METHODS

The AFs of four CBFMSs (Stents AX, NG, PL, and SX) and six CSEMSs (Stents BF, BP, EG, HN, SP, and WF) were compared in an ex vivo setting. We assessed the AF produced by each stent using an EUS-guided transmural drainage model and an EUS-guided hepaticogastrostomy model consisting of sheet-shaped specimens of the stomach, gelatin gel, and gelatin tubes.

RESULTS

For CBFMSs, the maximum AF of Stent AX was significantly higher than those of Stents PL and SX (P < 0.05) in the porcine model. In the gelatin series, all stents except Stent NG showed a nearly similar AF. For CSEMSs, Stents HN, EG, BF, and WF showed gradual AF elevation in the porcine stomach. Stents SP and BP showed a lower AF than the other four stents. For the gelatin setting, the maximum AF of Stents HN, EG, and WF was higher than those of the other stents regardless of the type of specimens.

CONCLUSIONS

The significance of the AF and traction distance according to the property of various CBFMSs and CSEMSs could be elucidated using ex vivo models.

The Role of Endoscopic Ultrasound-guided Drainage for Autoimmune Pancreatitis-associated Pancreatic Cysts: A Report of Five Cases and a Literature Review

Objective Autoimmune pancreatitis (AIP) has been recognized as a benign disease, which that shows a prompt response to corticosteroid treatment (CST). It was previously believed to not be associated with cyst formation; however, a few cases of AIP-associated pancreatic cyst (PC) have been reported. Some cases were reported to have been effectively treated by CST, while others were refractory to CST. Many of the patients received interventional treatment. Until now, there has been no consensus on the therapeutic strategies for AIP-associated PC. The aim of the present study is to describe a therapeutic strategy for this condition. Methods We conducted a retrospective study of 5 cases of AIP-associated PC that were treated by endoscopic ultrasonography-guided pancreatic fluid collection drainage (ESPD) or CST at Tokyo Medical University Hospital between March 2012 and October 2016, analyzed the therapeutic outcomes, and performed a literature review. Results The initial treatments included CST (n=2) and ESPD (n=3). All of the PCs disappeared after treatment In 1 of the patients who received CST case and 3 of the patients who received ESPD; however, the PC did not disappear in one of the patients who received CST (corticosteroid maintenance therapy), even after the dose of corticosteroids was increased; ESPD was eventually performed and the PC disappeared. There were no procedure-related complaints. Conclusion We propose that CST be administered as the first-line treatment for AIP-associated PC, particularly in cases of PC without a history of CST. However, ESPD can be applied to treat cases of corticosteroid refractory PC.