EUS anatomy of the pancreatobiliary system in a swine model: The WISE experience

Computed tomographic diagnosis of a common bile duct abscess and secondary extrahepatic biliary duct obstruction in a potbelly pig

A potbelly pig was evaluated for anorexia and icterus. Clinicopathologic abnormalities suggested an active inflammatory hepatobiliary process. Ultrasound and CT of the abdomen revealed an extrahepatic biliary obstruction of the common bile duct (CBD). Surgical exploration and choledochotomy revealed a markedly dilated CBD containing a large volume of intraluminal inspissated biliary material. This case report describes the imaging findings of an extrahepatic biliary obstruction secondary to abscessation within the CBD in a pig.

Curriculum for diagnostic endoscopic ultrasound training in Europe: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

The European Society of Gastrointestinal Endoscopy (ESGE) has recognized the need to formalize and enhance training in diagnostic endoscopic ultrasound (EUS). This manuscript represents the outcome of a formal Delphi process resulting in an official Position Statement of the ESGE and provides a framework to develop and maintain skills in diagnostic EUS. This curriculum is set out in terms of the prerequisites prior to training; the recommended steps of training to a defined syllabus; the quality of training; and how competence should be defined and evidenced before independent practice. 1:  Trainees should have achieved competence in upper gastrointestinal endoscopy before training in diagnostic EUS. 2:  The development of diagnostic EUS skills by methods that do not involve patients is advisable, but not mandatory, prior to commencing formal training in diagnostic EUS. 3:  A trainee's principal trainer should be performing adequate volumes of diagnostic EUSs to demonstrate maintenance of their own competence. 4:  Training centers for diagnostic EUS should offer expertise, as well as a high volume of procedures per year, to ensure an optimal level of quality for training. Under these conditions, training centers should be able to provide trainees with a sufficient wealth of experience in diagnostic EUS for at least 12 months. 5:  Trainees should engage in formal training and supplement this with a range of learning resources for diagnostic EUS, including EUS-guided fine-needle aspiration and biopsy (FNA/FNB). 6:  EUS training should follow a structured syllabus to guide the learning program. 7:  A minimum procedure volume should be offered to trainees during diagnostic EUS training to ensure that they have the opportunity to achieve competence in the technique. To evaluate competence in diagnostic EUS, trainees should have completed a minimum of 250 supervised EUS procedures: 80 for luminal tumors, 20 for subepithelial lesions, and 150 for pancreaticobiliary lesions. At least 75 EUS-FNA/FNBs should be performed, including mostly pancreaticobiliary lesions. 8:  Competence assessment in diagnostic EUS should take into consideration not only technical skills, but also cognitive and integrative skills. A reliable valid assessment tool should be used regularly during diagnostic EUS training to track the acquisition of competence and to support trainee feedback. 9:  A period of supervised practice should follow the start of independent activity. Supervision can be delivered either on site if other colleagues are already practicing EUS or by maintaining contacts with the training center and/or other EUS experts. 10:  Key performance measures including the annual number of procedures, frequency of obtaining a diagnostic sample during EUS-FNA/FNB, and adverse events should be recorded within an electronic documentation system and evaluated.

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.

Intraoperative HIFU Ablation of the Pancreas Using a Toroidal Transducer in a Porcine Model. The First Step towards a Clinical Treatment of Locally Advanced Pancreatic Cancer

Apart from palliative chemotherapy, no other therapy has been proven effective for the treatment of locally advanced pancreatic tumors. In this study, an intraoperative high-intensity focused ultrasound (HIFU) device was tested in vivo to demonstrate the feasibility of treating the pancreatic parenchyma and tissues surrounding the superior mesenteric vessels prior to clinical translation of this technique. Twenty pigs were included and treated using a HIFU device equipped with a toroidal transducer and an integrated ultrasound imaging probe. Treatments were performed with energy escalation (from 30 kJ to 52 kJ). All treatments resulted in visible (macroscopically and in ultrasound images) homogeneous thermal damage, which was confirmed by histology. The dimensions of thermal lesions measured in ultrasound images and those measured macroscopically were correlated (r = 0.82, p < 0.05). No arterial spasms or occlusion were observed at the lowest energy setting. Temporary spasm of the peripancreatic artery was observed when using an energy setting greater than 30 kJ. The possibility of treating the pancreas and tissues around mesenteric vessels without vascular thrombosis holds great promise for the treatment of locally advanced pancreatic cancers. If clinically successful, chemotherapy followed by HIFU treatment could rapidly become a novel treatment option for locally advanced pancreatic cancer.

Endoscopic simulators: training the next generation

PURPOSE OF REVIEW

To provide a review of current evidence evaluating endoscopic simulators as teaching platforms in gastroenterology training, with emphasis on upper gastrointestinal anatomy.

RECENT FINDINGS

Endoscopic simulators have leveraged mechanical, virtual reality and ex-vivo or live animal platforms to deliver training in both general and therapeutic endoscopy. Simulators have demonstrated their greatest utility in training novice endoscopists. Intermediate and expert endoscopists may additionally benefit from simulator exposure when learning advanced therapeutic techniques including large tissue resection or natural orifice transluminal endoscopic surgery.

SUMMARY

Simulator-based learning offers promise to complement conventional endoscopic training modalities for novice trainees. Nevertheless, additional evidence demonstrating a clear benefit is required for simulators to become an integral part of gastroenterology training. As novel advanced endoscopic therapies are developed, endoscopic simulators may assume a larger role in training prior to clinical practice.

Feasibility study of MR-guided pancreas ablation using high-intensity focused ultrasound in a healthy swine model

Purpose: Pancreatic cancer is typically diagnosed in a late stage with limited therapeutic options. For those patients, ultrasound-guided high-intensity focused ultrasound (US-HIFU) can improve local control and alleviate pain. However, MRI-guided HIFU (MR-HIFU) has not yet been studied extensively in this context. To facilitate related research and accelerate clinical translation, we report a workflow for the in vivo HIFU ablation of the porcine pancreas under MRI guidance.Materials and methods: The pancreases of five healthy German landrace pigs (35-58 kg) were sonicated using a clinical MR-HIFU system. Acoustic access to the pancreas was supported by a specialized diet and a hydrogel compression device for bowel displacement. Organ motion was suspended using periods of apnea. The size of the resulting thermal lesions was assessed using the thermal threshold- and dose profiles, non-perfused volume, and gross examination. The effect of the compression device on beam path length was assessed using MRI imaging.Results: Eight of ten treatments resulted in clearly visible damage in the target tissue upon gross examination. Five treatments resulted in coagulative necrosis. Good agreement between the four metrics for lesion size and a clear correlation between the delivered energy dose and the resulting lesion size were found. The compression device notably shortened the intra-abdominal beam path.Conclusions: We demonstrated a workflow for HIFU treatment of the porcine pancreas in-vivo under MRI-guidance. This development bears significance for the development of MR-guided HIFU interventions on the pancreas as the pig is the preferred animal model for the translation of pre-clinical research into clinical application.

Novel swine biliary dilatation model with temperature-controlled endobiliary radiofrequency ablation: An effective tool for training in EUS-guided biliary drainage

Background and Objectives:

EUS-guided biliary drainage (EUS-BD) is used as a rescue method after failed endoscopic retrograde cholangiography. However, it is considered a technically challenging procedure. Phantoms and ex vivo biliary dilatation models have been used to enhance the learning of EUS-BD, but they provide a limited level of realism. The aim of this study was to develop a swine biliary dilatation model that uses temperature-controlled endobiliary radiofrequency ablation (EB-RFA) for training in EUS-BD.

Materials and Methods:

Target temperature-controlled (80°C at 7 or 10 W for 60–120 s) EB-RFA was performed on seven pigs. Two weeks after the EB-RFA, EUS examination was performed to confirm biliary dilatation, and EUS-BD was then attempted by performing a hepaticogastrostomy (HGS) or cholecystogastrostomy (CGS).

Results:

Twelve sessions of EB-RFA (11 at the distal common bile duct [CBD] and one at the proximal CBD) were successfully performed on the seven pigs. There were no immediate postprocedural adverse events. Two weeks after the procedures, clinical signs of jaundice were observed in all the pigs. EUS examination revealed massive intrahepatic and extrahepatic biliary dilatations in all the pigs, and EUS-BD was attempted in the same session. HGS was performed on six pigs. Technical success was achieved in five of the six pigs (83.3%). Technical failure in HGS occurred during the stent deployment, and CGS was successfully performed on one pig.

Conclusions:

Our study shows that EB-RFA is an effective minimally invasive method for creating biliary dilatation models. It may be considered suitable for training in EUS-BD.

Exploration of an effective training system for the diagnosis of pancreatobiliary diseases with EUS: A prospective study

Background and Objective:

There are limited data on multistage-based training programs focused on EUS. We aimed to explore an effective training system for diagnosing pancreaticobiliary diseases with EUS.

Materials and Methods:

Nine advanced endoscopy trainees (AETs) with less EUS experience from nine institutions were recruited. The training system consisted of multiple stages and multi-teaching methods, including biliopancreatic standard scanning, anatomy and imaging knowledge, simulator, hands-on operations, error correction, and case analysis over a 12-month training period. Grading for technical and cognitive skills was assessed using The EUS Skills Assessment Tool.

Results:

After training, the overall scores for radial (4.16 ± 0.21 vs. 1.46 ± 0.16, P < 0.01) and linear (4.43 ± 0.20 vs. 1.63 ± 0.23, P < 0.01) scanning were significantly improved. The aortopulmonary window/mediastinum station can be learned more easily by AETs compared with other stations (P = 0023). The scanning of the descending part of the duodenum seemed to improve the slowest after training (P = 0.0072), indicating that the descending part of the duodenum can be more difficult and should be the focus of training. Every teaching method heightened EUS competence, especially case analysis and hands-on operations. AETs achieved equivalent EUS competence after training despite their initial experience. Through a poststudy questionnaire, it was found that all AETs strongly agreed they were satisfied with the training system, and their confidence was greatly enhanced when EUS was performed independently.

Conclusions:

The current multistage and multi-methods training system showed efficient performance in the cognitive and technical competence of EUS. Descending part of duodenum scanning was difficult for beginners and should be the focus of training.