New ex-vivo porcine model for endoscopic ultrasound-guided training in transmural puncture and drainage of pancreatic cysts and fluid collections (with videos)

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.

Impact and assessment of training models in interventional endoscopic ultrasound

Interventional endoscopic ultrasound (IEUS) has gained significant popularity in recent years because of its diagnostic and therapeutic capabilities. The proper training of endoscopists is critical to ensure safe and effective procedures. This review study aims to assess the impact of different training models on the competence of trainees performing IEUS. Eight studies that evaluated simulators for IEUS were identified in the medical literature. Various training models have been used, including the EASIE-R, Mumbai EUS, EUS Magic Box, EndoSim, Thai Association for Gastrointestinal Endoscopy model, and an ex vivo porcine model (HiFi SAM). The trainees underwent traditional didactic lectures, hands-on training using simulators, and direct supervision by experienced endoscopists. The effectiveness of these models has been evaluated based on objective and subjective parameters such as technical proficiency, operative time, diagnostic success, and participant feedback. As expected, the majority of skills were improved after the training sessions concluded, although the risk of bias is high in the absence of external validation. It is difficult to determine the ideal simulator among the existing ones because of the wide variation between them in terms of costs, reusability, design, fidelity of anatomical structures and feedback, and types of procedures performed. There is a need for a standardized approach for the evaluation of IEUS simulators and the ways skills are acquired by trainees, as well as a clearer definition of the key personal attributes necessary for developing a physician into a skilled endoscopist capable of performing basic and advanced therapeutic EUS interventions.

The use of simulation in medical ultrasound: Current perspectives on applications and practical implementation (WFUMB state-of-the-art paper)

Simulation has been shown to improve clinical learning outcomes, speed up the learning process, and improve trainee confidence, while taking the pressure off initial face-to-face patient clinical areas. The second part of The World Federation for Ultrasound in Medicine and Biology state-of-the-art paper on the use of simulators provides a general approach on the practical implementation. The importance of needs assessment before developing a simulation-based training program is outlined. We describe the current practical implementation and critically analyze how simulators can be integrated into complex task scenarios to train small or large groups. A wide range of simulation equipment is available especially for those seeking interventional ultrasound training, ranging from animal tissue models, simple synthetic phantoms, to sophisticated high-fidelity simulation platforms using virtual reality. Virtual reality simulators provide feedback and thereby allow trainees to not only to practice their motor skills and hand eye coordination but also to interact with the simulator. Future developments will integrate more elements of automated assessment and artificial intelligence, thereby enabling enhanced realistic training experience and improving skill transfer into clinical practice.

Evaluation of an all-in-one hybrid model (EUS Magic Box) for stepwise teaching and training in multiple interventional EUS procedures

Background and study aims  While multiple interventional endoscopic ultrasound (EUS)-guided procedures have evolved over the past two decades, there is no model that allows for training in all of these procedures. We aimed to develop and validate an all-in-one hybrid model for stepwise learning in multiple EUS interventions. Methods  A hybrid model was created utilizing a pig esophagus and stomach, a silicon-based duodenum and pancreato-biliary system, a pseudocyst, and biopsy targets. This model was designed to provide hands-on training in multiple interventional EUS procedures, such as EUS-guided fine-needle biopsy (EUS-FNB), biliary drainage (BD), pancreatic duct drainage (PD), pseudocyst drainage (PSD), and gastro-enterostomy (GE). Thirty-six trainees underwent training on this model over 6 days, in two batches. Lumen apposing metal stents were used for PSD and GE. Trainees were assessed for objective criteria of technical difficulties. Subjective assessment by trainees was done via a questionnaire. Results  All the trainees were able to complete the requisite steps for all the procedures under supervision. On subjective assessment, 30 trainees (83 %) graded the model as good or excellent. A total of 107 technical difficulties were noted (scope position 55, duct puncture 27, guidewire-related problems 25). Time taken to complete the requisite steps of biopsy, PSD, and GE (10.5 minutes; range 3.5 to 22) was significantly less than that for BD and PD (28 minutes; range 17 to 40) ( P  < 0.001). Conclusions  The hybrid model provided training for multiple EUS interventions with good acceptance by trainees. Stepwise mentoring with the possibility of performing multiple procedures in a single model with or without X-ray could prove useful in conference as well as institutional settings.

Lumen-apposing metal stents (with videos)

BACKGROUND AND AIMS

Lumen-apposing metal stents (LAMSs) are a novel class of devices that have expanded the spectrum of endoscopic GI interventions. LAMSs with their dumbbell configuration, short saddle length, and large inner luminal diameter provide favorable stent characteristics to facilitate anastomosis formation between the gut lumen and adjacent structures.

METHODS

The MEDLINE database was searched through April 2021 for articles related to LAMSs by using additional relevant keywords such as "walled-off pancreatic necrosis," "pseudocysts," "pancreatic fluid collection," "cholecystitis," "gastroenterostomy," in addition to "endoscopic treatment" and "endoscopic management," among others.

RESULTS

This technology review describes the full spectrum of LAMS designs and delivery systems, techniques for deployment, procedural outcomes, safety, training issues, and financial considerations.

CONCLUSIONS

Although LAMSs were initially introduced for drainage of pancreatic pseudocysts and walled-off necrosis, the versatility of these devices has led to a variety of off-label uses including gallbladder drainage, enteric bypass with the creation of gastroenterostomies, and treatment of luminal GI strictures.

Clinical Practice Guidelines for the Endoscopic Management of Peripancreatic Fluid Collections

Endoscopic ultrasonography-guided intervention has gradually become a standard treatment for peripancreatic fluid collections (PFCs). However, it is difficult to popularize the procedure in Korea because of restrictions on insurance claims regarding the use of endoscopic accessories, as well as the lack of standardized Korean clinical practice guidelines. The Korean Society of Gastrointestinal Endoscopy (KSGE) appointed a Task Force to develope medical guidelines by referring to the manual for clinical practice guidelines development prepared by the National Evidence-Based Healthcare Collaborating Agency. Previous studies on PFCs were searched, and certain studies were selected with the help of experts. Then, a set of key questions was selected, and treatment guidelines were systematically reviewed. Answers to these questions and recommendations were selected via peer review. This guideline discusses endoscopic management of PFCs and makes recommendations on Indications for the procedure, pre-procedural preparations, optimal approach for drainage, procedural considerations (e.g., types of stent, advantages and disadvantages of plastic and metal stents, and accessories), adverse events of endoscopic intervention, and procedural quality issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This will be revised as necessary to address advances and changes in technology and evidence obtained in clinical practice and future studies.

Clinical Practice Guidelines for the Endoscopic Management of Peripancreatic Fluid Collections

Endoscopic ultrasonography-guided intervention has gradually become a standard treatment for peripancreatic fluid collections (PFCs). However, it is difficult to popularize the procedure in Korea because of restrictions on insurance claims regarding the use of endoscopic accessories, as well as the lack of standardized Korean clinical practice guidelines. The Korean Society of Gastrointestinal Endoscopy appointed a Task Force to develop medical guidelines by referring to the manual for clinical practice guidelines development prepared by the National Evidence-Based Healthcare Collaborating Agency. Previous studies on PFCs were searched, and certain studies were selected with the help of experts. Then, a set of key questions was selected, and treatment guidelines were systematically reviewed. Answers to these questions and recommendations were selected via peer review. This guideline discusses endoscopic management of PFCs and makes recommendations on Indications for the procedure, pre-procedural preparations, optimal approach for drainage, procedural considerations (e.g., types of stent, advantages and disadvantages of plastic and metal stents, and accessories), adverse events of endoscopic intervention, and procedural quality issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This will be revised as necessary to address advances and changes in technology and evidence obtained in clinical practice and future studies. (Gut Liver 2021;15:-693)

Endoscopic simulators

BACKGROUND AND AIMS

Simulation refers to educational tools that allow for repetitive instruction in a nonpatient care environment that is risk-free. In GI endoscopy, simulators include ex vivo animal tissue models, live animal models, mechanical models, and virtual reality (VR) computer simulators.

METHODS

After a structured search of the peer-reviewed medical literature, this document reviews commercially available GI endoscopy simulation systems and clinical outcomes of simulation in endoscopy.

RESULTS

Mechanical simulators and VR simulators are frequently used early in training, whereas ex vivo and in vivo animal models are more commonly used for advanced endoscopy training. Multiple studies and systematic reviews show that simulation-based training appears to provide novice endoscopists with some advantage over untrained peers with regard to endpoints such as independent procedure completion and performance time, among others. Data also suggest that simulation training may accelerate the acquisition of specific technical skills in colonoscopy and upper endoscopy early in training. However, the available literature suggests that the benefits of simulator training appear to attenuate and cease after a finite period. Further studies are needed to determine if meeting competency metrics using simulation will predict actual clinical competency.

CONCLUSIONS

Simulation training is a promising modality that may aid in endoscopic education. However, for widespread incorporation of simulators into gastroenterology training programs to occur, simulators must show a sustained advantage over traditional mentored teaching in a cost-effective manner. Because most studies evaluating simulation have focused on novice learners, the role of simulation training in helping practicing endoscopists gain proficiency using new techniques and devices should be further explored.

Consensus guidelines on the optimal management in interventional EUS procedures: results from the Asian EUS group RAND/UCLA expert panel

OBJECTIVES

Interventional endoscopic ultrasonography (EUS) procedures are gaining popularity and the most commonly performed procedures include EUS-guided drainage of pancreatic pseudocyst, EUS-guided biliary drainage, EUS-guided pancreatic duct drainage and EUS-guided celiac plexus ablation. The aim of this paper is to formulate a set of practice guidelines addressing various aspects of the above procedures.

METHODS

Formulation of the guidelines was based on the best scientific evidence available. The RAND/UCLA appropriateness methodology (RAM) was used. Panellists recruited comprised experts in surgery, interventional EUS, interventional radiology and oncology from 11 countries. Between June 2014 and October 2016, the panellists met in meetings to discuss and vote on the clinical scenarios for each of the interventional EUS procedures in question.

RESULTS

A total of 15 statements on EUS-guided drainage of pancreatic pseudocyst, 15 statements on EUS-guided biliary drainage, 12 statements on EUS-guided pancreatic duct drainage and 14 statements on EUS-guided celiac plexus ablation were formulated. The statements addressed the indications for the procedures, technical aspects, pre- and post-procedural management, management of complications, and competency and training in the procedures. All statements except one were found to be appropriate. Randomised studies to address clinical questions in a number of aspects of the procedures are urgently required.

CONCLUSIONS

The current guidelines on interventional EUS procedures are the first published by an endoscopic society. These guidelines provide an in-depth review of the current evidence and standardise the management of the procedures.

Comparative evaluation of two porcine ex vivo models for training in endoscopic ultrasound-guided drainage of pancreatic fluid collections

INTRODUCTION

 EUS-guided cystoenterostomy (EUCE), a technique used for the drainage of pancreatic pseudocysts and peri-enteric collections, requires specific skills for which dedicated models are needed. Based on a compact EASIE model (Erlangen Active Simulator for Interventional Endoscopy), we developed two ex vivo porcine models of retrogastric cysts and evaluated learning performance within the frame of a structured training program.

MATERIAL AND METHODS

 The first model was made of porcine colon (i. e. "natural cyst"), the second one with an ostomy bag (i. e. "artificial cyst"). All procedures were achieved with an EUS scope under fluoroscopy. Both models were evaluated prospectively over a 2-day session involving 14 students and five experts. The primary end point was overall satisfaction with each model.

RESULTS

 The "natural cyst" and "artificial cyst" were prepared within 10 and 16.5 minutes ( P  = 0.78), respectively. Model grading showed a non-significant trend for overall satisfaction in favor of the artificial model ( P  = 0.06). As secondary end points, difference was not significant for impression of realism ( P  = 0.75) whereas the "artificial cyst" was graded significantly better by experts and students in terms of ability to teach procedural steps ( P  = 0.01) and ease of puncture ( P  = 0.03). Moreover, experts considered the ability to improve students' proficiency to be superior with the "artificial cyst" ( P  = 0.008).

CONCLUSION

 Both "artificial" and "natural cysts" are efficient for EUCE training in terms of overall satisfaction. However, the "artificial cyst" model appears to make the procedure easier with a higher ability to teach procedural steps and improve the students' proficiency. Larger applications of this model are needed to validate as a standard of training.

Interventional Therapy for Pancreatic Cancer

BACKGROUND

Palliative therapy and primarily chemoradiotherapy are the mainstream treatments in patients with locally advanced or metastatic pancreatic cancer (PC). Conventional endoscopy and endoscopic ultrasound (EUS)-guided interventional therapy has emerged as an important procedure for PC management. In this review, the progress in conventional endoscopy and EUS for PC management is discussed.

SUMMARY

For local palliative therapy against PC, EUS-guided fine needle injection (FNI) could deliver different kinds of agents, such as radioactive seeds and fiducials. Although their feasibility and safety have been proven, the long-term efficiency of EUS-FNI is still not established. For pain, EUS-celiac plexus neurolysis (CPN) is effective. However, CPN can only relieve the pain to a limited degree, with short duration. Endoscopy-guided stent placement is the preferred strategy for biliary and duodenal obstruction. Plastic and metal stents are equally effective for the relief of obstructive jaundice. The functional times of metal stents are longer than those of a plastic stent.

KEY MESSAGE

For biliary obstruction, a metal stent is the first choice. The long-term efficiency of EUS-FNI still needs further study.

PRACTICAL IMPLICATIONS

Endoscopy and EUS-guided interventions have gradually become the mainstream method for local treatment of PC due to mini-invasiveness and real-time observation. PC is the second most common gastrointestinal malignancy and the sixth leading cause of cancer mortality in the United States, leading to about 4.0% of all cancer deaths [Siegel et al: CA Cancer J Clin 2014;64:9-29]. The only curative approach for patients with PC is surgical resection, but unfortunately 80-90% of patients have a surgically inoperable disease, with 53% having local metastases at the time of diagnosis [Weinberg et al: Oncology (Williston Park) 2015;29:809-820, 886]. Therefore, palliative therapy and primarily chemoradiotherapy are the mainstream of treatment in patients with locally advanced or metastatic PC. Although overall survival has improved from 6 to 8.5-11 months (some of them even survived for a year or more), the overall survival rate has not improved, and the 5-year survival is less than 4% [Weinberg et al: Oncology (Williston Park) 2015;29:809-820, 886; Greenlee et al: CA Cancer J Clin 2001;51:15-36; Zhang et al: Gastroenterol Res Pract 2016;2016:8962321]. Hence, it is crucial to develop more effective local treatment strategies for tumor tissue and symptom palliation. At present, endoscopy has gradually become the mainstream method for local treatment of gastrointestinal cancer due to mini-invasiveness and real-time observation. Conventional endoscopy can be used to manage the complication caused by PC, including endoscopic biliary stent placement for obstructive jaundice, and duodenal stent placement for duodenal obstruction. In addition, in those cases in whom obstructive jaundice failed to be relieved by endoscopic biliary stent placement, EUS-guided biliary drainage has emerged as an alternative procedure. Furthermore, antitumor agents can be delivered into tumor tissue or celiac plexus directly under interventional EUS guided to manage the tumor or the pain caused by the tumor. In this review, the progress in conventional endoscopy and EUS for PC management is discussed.