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.

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.

The ultrasound use of simulators, current view, and perspectives: Requirements and technical aspects (WFUMB state of the art paper).

Simulation has been shown to improve clinical learning outcomes, speed up the learning process and improve learner confidence, whilst initially taking pressure off busy clinical lists. The World Federation for Ultrasound in Medicine and Biology (WFUMB) state of the art paper on the use of simulators in ultrasound education introduces ultrasound simulation, its advantages and challenges. It describes different simulator types, including low and high-fidelity simulators, the requirements and technical aspects of simulators, followed by the clinical applications of ultrasound simulation. The paper discusses the role of ultrasound simulation in ultrasound clinical training, referencing established literature. Requirements for successful ultrasound simulation acceptance into educational structures are explored. Despite being in its infancy, ultrasound simulation already offers a wide range of training opportunities and likely holds the key to a broader point of care ultrasound education for medical students, practicing doctors, and other health care professionals. Despite the drawbacks of simulation, there are also many advantages, which are expanding rapidly as the technology evolves.

How to perform EUS-guided biliary drainage.

EUS-guided biliary drainage (EUS-BD) has recently gained widespread acceptance as a minimally invasive alternative method for biliary drainage. Even in experienced endoscopy centers, ERCP may fail due to inaccessibility of the papillary region, altered anatomy (particularly postsurgical alterations), papillary obstruction, or neoplastic gastric outlet obstruction. Biliary cannulation fails at first attempt in 5%-10% of cases even in the absence of these factors. In such cases, alternative options for biliary drainage must be provided since biliary obstruction is responsible for poor quality of life and even reduced survival, particularly due to septic cholangitis. The standard of care in many centers remains percutaneous transhepatic biliary drainage (PTBD). However, despite the high technical success rate with experienced operators, the percutaneous approach is more invasive and associated with poor quality of life. PTBD may result in long-term external catheters for biliary drainage and carry the risk of serious adverse events (SAEs) in up to 10% of patients, including bile leaks, hemorrhage, and sepsis. PTBD following a failed ERCP also requires scheduling a second procedure, resulting in prolonged hospital stay and additional costs. EUS-BD may overcome many of these limitations and offer some distinct advantages in accessing the biliary tree. Current data suggest that EUS-BD is safe and effective when performed by experts, although SAEs have been also reported. Despite the high number of clinical reports and case series, high-quality comparative studies are still lacking. The purpose of this article is to report on the current status of this procedure and to discuss the tools and techniques for EUS-BD in different clinical scenarios.

A structured Endoscopic Ultrasound training program in Germany improves knowledge and competence.

AIMS: Limited evidence on how to organize pre-patient training in Endoscopic Ultrasound (EUS) and how to evaluate its effect on knowledge and skills are available. The aim of our study was to assess the impact of a structured multi-site training program on EUS competence in Germany. MATERIAL AND METHODS: In a prospective study design, evaluation of 64 trainees was conducted during four three-day training courses with equal curricula at three sites. Participants completed a structured pre- and post-test questionnaire consisting of 4 items to evaluate the relevance and acceptance of the training components (theoretical teaching, video sessions, live demonstration, hands-on experience) on a 5-point Likert scale, as well as a Likert scale to judge the self-rated improvement in EUS competence. To assess knowledge, 12 multiple choice (MC) questions had to be answered by all participants in a pre- and a post-test design. Also differences between beginners and advanced learners were analysed. RESULTS: Overall evaluation on acceptance received above-average results with a median of 4 or 5 (IQR 1-2) on Likert scale (1=completely disagree, 5=completely agree). In the post-test self-rated EUS skills improved from 4 to 2 on the Likert scale (IQR=1, p=0.001, 1=excellent EUS skills, 5=no EUS skills). Results of the MC-test of all trainees showed significant improvement in theoretical knowledge from 7.9±1.9 to 8.8±1.9 points (mean±SD, p=0.001). CONCLUSIONS: Our study provides arguments for the usefulness of a structured EUS training program resulting in a positive acceptance and high self-rated EUS competence by the participants and significant improvements in knowledge.

Do we need contrast agents for EUS?

We recently introduced a series of articles that dealt with controversies in EUS. In Part I, the authors discussed which clinical information is necessary prior to EUS and whether other imaging modalities are required before embarking on EUS examinations. Part II focuses on technical details and controversies about the use of EUS in special situations. In this article, important practical issues regarding the application of contrast-enhanced EUS in various clinical settings are raised and controversially discussed from different points of view.

EFSUMB Recommendations for Gastrointestinal Ultrasound Part 3: Endorectal, Endoanal and Perineal Ultrasound.

This article represents part 3 of the EFSUMB Recommendations and Guidelines for Gastrointestinal Ultrasound (GIUS). It provides an overview of the examination techniques recommended by experts in the field of endorectal/endoanal ultrasound (ERUS/EAUS), as well as perineal ultrasound (PNUS). The most important indications are rectal tumors and inflammatory diseases like fistula and abscesses in patients with or without inflammatory bowel disease (IBD). PNUS sometimes is more flexible and convenient compared to ERUS. However, the technique of ERUS is quite well established, especially for the staging of rectal cancer. EAUS also gained ground in the evaluation of perianal diseases like fistulas, abscesses and incontinence. For the staging of perirectal tumors, the use of PNUS in addition to conventional ERUS could be recommended. For the staging of anal carcinomas, PNUS can be a good option because of the higher resolution. Both ERUS and PNUS are considered excellent guidance methods for invasive interventions, such as the drainage of fluids or targeted biopsy of tissue lesions. For abscess detection and evaluation, contrast-enhanced ultrasound (CEUS) also helps in therapy planning.

Endoscopic ultrasound elastography of small solid pancreatic lesions: a multicenter study.

BACKGROUND: The prevalence of malignancy in patients with small solid pancreatic lesions is low; however, early diagnosis is crucial for successful treatment of these cases. Therefore, a method to reliably distinguish between benign and malignant small solid pancreatic lesions would be highly desirable. We investigated the role of endoscopic ultrasound (EUS) elastography in this setting. METHODS: Patients with solid pancreatic lesions ≤ 15 mm in size and a definite diagnosis were included. Lesion stiffness relative to the surrounding pancreatic parenchyma, as qualitatively assessed and documented at the time of EUS elastography, was retrospectively compared with the final diagnosis obtained by fine-needle aspiration/biopsy or surgical resection. RESULTS: 218 patients were analyzed. The average size of the lesions was 11 ± 3 mm; 23 % were ductal adenocarcinoma, 52 % neuroendocrine tumors, 8 % metastases, and 17 % other entities; 66 % of the lesions were benign. On elastography, 50 % of lesions were stiffer than the surrounding pancreatic parenchyma (stiff lesions) and 50 % were less stiff or of similar stiffness (soft lesions). High stiffness of the lesion had a sensitivity of 84 % (95 % confidence interval 73 % - 91 %), specificity of 67 % (58 % - 74 %), positive predictive value (PPV) of 56 % (50 % - 62 %), and negative predictive value (NPV) of 89 % (83 % - 93 %) for the diagnosis of malignancy. For the diagnosis of pancreatic ductal adenocarcinoma, the sensitivity, specificity, PPV, and NPV were 96 % (87 % - 100 %), 64 % (56 % - 71 %), 45 % (40 % - 50 %), and 98 % (93 % - 100 %), respectively. CONCLUSIONS: In patients with small solid pancreatic lesions, EUS elastography can rule out malignancy with a high level of certainty if the lesion appears soft. A stiff lesion can be either benign or malignant.

Serous pancreatic neoplasia, data and review.

AIM: To describe the imaging features of serous neoplasms of the pancreas using ultrasound, endoscopic ultrasound, computed tomography and magnetic resonance imaging. METHODS: This multicenter international collaboration enhances a literature review to date, reporting features of 287 histologically confirmed cases of serous pancreatic cystic neoplasms (SPNs). RESULTS: Female predominance is seen with most SPNs presenting asymptomatically in the 5th through 7th decade. Mean lesion size was 38.7 mm, 98% were single, 44.2% cystic, 46% mixed cystic and solid, and 94% hypoechoic on B-mode ultrasound. Vascular patterns and contrast-enhancement profiles are described as hypervascular and hyperenhancing. CONCLUSION: The described ultrasound features can aid differentiation of SPN from other neoplastic lesions under most circumstances.

Differential diagnosis of small solid pancreatic lesions.

BACKGROUND AND AIMS: Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed at a late stage. Little is known about the incidental finding of early-stage PDAC. The aim of the current study was to determine the etiology of small solid pancreatic lesions (≤15 mm) to optimize clinical management. METHODS: Inclusion criterion for the retrospective study analysis was the incidental finding of primarily undetermined small solid pancreatic lesions ≤15 mm in 394 asymptomatic patients. Final diagnoses were based on histology or cytology obtained by imaging-guided biopsy (and at least 12-month follow-up) and/or surgery. Contrast-enhanced US or contrast-enhanced EUS was performed in 219 patients. RESULTS: The final diagnoses of 394 patients were as follows: 146 PDACs, 156 neuroendocrine tumors, 28 metastases into the pancreas from other primary sites, and 64 various other etiologies. Contrast-enhanced US allowed differential diagnosis of PDAC and non-PDAC in 189 of 219 patients (86%). CONCLUSIONS: Approximately 40% of patients with small solid pancreatic lesions had very early stage PDAC. Approximately 60% of small solid pancreatic lesions ≤15 mm are not PDAC and, therefore, do not require radical surgery. Without preoperative diagnosis, an unacceptably large proportion of patients would be exposed to radical surgery with significant morbidity and mortality.

Computer-based anatomy a prerequisite for computer-assisted radiology and surgery.

RATIONALE AND OBJECTIVES: The aim of the study is to show the possibilities opened up by three-dimensional (3D) computer-based models of the human body for education in anatomy, training of radiological and endoscopic examinations, and simulation of surgical procedures. MATERIALS AND METHODS: Based on 3D data sets obtained from the Visible Human and/or clinical cases, virtual body models are created that provide an integrated spatial and symbolic description of the anatomy by using interactive color/intensity-based segmentation, ray casting visualization with subvoxel resolution, a semantic network for knowledge modeling, and augmented QuickTime VR (Apple Computer, Inc, Cupertino, CA) movies for presentation. RESULTS: From these models, various radiological, endoscopic, or haptic manifestations of the body can be derived. This is shown with examples from anatomy teaching, correlation of x-ray images with 3D anatomy for education in radiology, gastrointestinal endoscopy, correlation of ultrasound images with 3D anatomy in endoscopic ultrasonography, and simulation of drilling in temporal bone surgery. CONCLUSION: The presented models provide a means for realistic training in interpretation of radiological and endoscopic images of the human body. Furthermore, certain surgical procedures may be simulated realistically. Used as a complement to the current curriculum, these models have the potential to greatly decrease education times and costs.

EUS-cholangio-drainage of the bile duct: report of 4 cases.

BACKGROUND: Endoscopic retrograde cholangiography with stent insertion is an established procedure for palliation of patients with malignant pancreaticobiliary strictures. In some patients, however, placement of a stent by means of a duodenoscope is not possible. Percutaneous transhepatic biliary drainage is an alternative method that has a complication rate of up to 15%. Four cases of successful EUS-guided-cholangio-drainage are presented in which the major papilla could not be cannulated at endoscopic retrograde cholangiography. METHODS: For puncture of the intrahepatic or extrahepatic bile duct, a modification of the one-step technique for the drainage of pancreatic pseudocysts was used. RESULTS: Stent insertion was successful in 3 of the 4 patients. In these 3 patients cholestasis resolved promptly. CONCLUSIONS: EUS-guided cholangio-drainage is a potential alternative to percutaneous transhepatic biliary drainage and endoscopic retrograde cholangiography in the therapy of malignant pancreaticobiliary strictures, especially in patients who have undergone gastrectomy or partial gastrectomy with Billroth II reconstruction.