Training and simulators

Introduction

Since its introduction, endoscopic ultrasound (EUS) has evolved as a vital endoscopic procedure for the diagnosis and staging of pancreaticobiliary and luminal gastrointestinal (GI) malignancies. EUS-guided fine-needle aspiration (EUS-FNA) and EUS-guided fine-needle biopsy (FNB) is a standard practice for tissue acquisition (EUS-TA) for diagnostic purposes from pancreatic masses, lymph nodes, mediastinal and subepithelial lesions, and other lesions within the region of the upper and lower GI tract. ^, The diagnosis, staging, and treatment of GI cancers have evolved into a multidisciplinary approach often utilizing EUS as a central tool for both diagnosis and staging. ^, EUS is the most sensitive imaging modality for the detection of pancreatic masses and is particularly useful when results of other cross-sectional imaging modalities are inconclusive. ^, In addition, the accuracy of EUS-FNA has been evaluated in several studies in patients with pancreatic cancer and other GI malignancies. ^, Recently, the role of EUS has expanded from a diagnostic modality to one that is capable of guiding therapeutic interventions (interventional EUS). Numerous advances have been made in the field of interventional EUS, and some of these applications include drainage of pancreatic fluid collections, biliary and pancreatic access and drainage, angiotherapy for varices, treatment of premalignant and malignant conditions such as pancreatic cystic lesions, fiducial marker placement and celiac plexus neurolysis and block, and anastomosis creation.

The clinical effectiveness of EUS and EUS-TA depends on the judicious use of these techniques and competency of the performing endosonographer. The increasing sophistication of this technique, higher-risk profiles for some of the EUS-guided interventions, and the need for additional interventions or repeat procedures following a failed or nondiagnostic EUS underscore the importance of adequate training. ^, As the applications for EUS have become increasingly recognized, the demand for well-trained endosonographers has increased, and the limited availability of EUS is largely due to a lack of skilled endosonographers. It is clear that EUS is operator dependent and that additional training is required for the development of technical, cognitive, and integrative skills beyond those required for standard endoscopic procedures. Several guidelines have been published for EUS training based primarily on expert opinion and limited published data. This chapter highlights the current status of training in EUS and the methods of EUS training and recommendations for training programs. It will also review the current state of competency assessment during EUS training and discuss the shifting paradigm from procedure volume as a surrogate of competency to validated competency thresholds. The current guidelines in training, credentialing, and privileging will be reviewed and, finally, the importance of quality metrics in EUS during training will be highlighted.

Training in EUS

Training in endoscopy entails cognitive, technical, and integrative elements that are required to safely and proficiently perform these procedures. Over the last decade, training in EUS has evolved from a self-directed training model to a formal and supervised training model. The consensus opinion on the ideal format for EUS training is through a structured, hands-on experience with patients in a supervised setting. The duration of training can vary; however, self-education, reliance on animal models or computer-based courses or short training courses as the sole method of training is discouraged. A core curriculum for training in EUS has been established by the American Society for Gastrointestinal Endoscopy (ASGE) and the European Society of Gastrointestinal Endoscopy (ESGE). ^, Prior to embarking on learning EUS, trainees are required to master standard upper endoscopy and colonoscopy. Trainees are expected to have completed at least 18 months of standard GI training and should have expertise in basic endoscopy, including thorough visualization of the GI tract, minimizing patient discomfort, proper identification of normal and abnormal findings, and proficiency in basic therapeutic techniques. Although some trainees may be exposed to EUS during their standard GI training, procedural exposure should not be equated with procedural competence.

EUS training should focus on the cognitive and technical aspects of the procedure. Understanding procedural indications, contraindications, risks, and limitations in addition to learning how to interpret EUS findings (normal and abnormal) and incorporating them into management algorithms are an integral part of this process. Cognitive education is also achieved through reading, reviewing videos and atlases, and attending lectures and conferences combined with supervised hands-on experience under the mentorship of expert endoscopists. The training process usually begins by observing a primary endoscopist performing EUS and becoming acquainted with the unique endoscopic and endoscopic ultrasound view of the echoendoscope. The trainee should have the understanding of how relevant equipment such as the processors work and ultimately gain proficiency in the use of radial array and curvilinear array echoendoscopes. As with general endoscopy, one of the initial challenges is intubating the esophagus. Trainees are expected to safety intubate and traverse the esophagus, the gastroesophageal junction, and the duodenal sweep. Trainees should be proficient in evaluating structures visualized at various stations during EUS ( Table 3.1 ). Trainees should be adept at TNM (tumor, node, and metastasis) staging. Proficiency in EUS-TA using EUS-FNA and EUS-FNB needles is expected at the end of training. Trainees are also expected to understand the advantages and limitations of different EUS-TA techniques. Understanding the basics of specimen handling and the role of on-site cytopathology evaluation is critical. ^, Trainees should maintain a procedure log of only those procedures during which they had hands-on training. This log should include the indication and the endpoints achieved by the trainee. This not only will be helpful for credentialing purposes but will also allow for competency assessment. The key technical, cognitive, and integrative competencies of training in EUS are highlighted in Table 3.1 .

In addition, EUS training should take place at a center fitted with all the basic equipment necessary to perform EUS and where an adequate number of experienced trainers are present who have a track record of adequate case volume and effective endoscopic teaching. An ideal environment also provides interaction with a multidisciplinary team that includes surgeons, oncologists, radiation oncologists, cytopathologists, and radiologists. Training programs should educate trainees on preparing a comprehensive written report of important normal and abnormal findings, and communication of findings and results to referring physicians, patients, and family members. The trained endosonographer should be able to deliver results in a clear and comprehensive manner. A recent survey study showed that the comfort level for disclosing a pancreatic cancer diagnosis after EUS was higher among experienced (>5 years in practice) and high-volume endosonographers. Although the vast majority of endosonographers felt obligated to share the diagnosis of cancer, the lack of proper training and time were limiting factors. This highlights the need for formal communication skills training during GI fellowship training. Unfortunately, the majority of EUS programs across the United States have limited, if any, extramural funding and may require additional clinical responsibilities to help support the trainee’s salary. While understanding the financial limitations of most institutions, training programs should strive to limit the clinical responsibilities unrelated to EUS when developing their core curriculum. Ideally, programs should provide protected research time and encourage academic pursuits such as designing research protocols, preparing manuscripts, writing grant proposals, and attending EUS courses. Creating an environment emphasizing endoscopic research and clinical investigation should be a fundamental goal for each training program. Exposure to endoscopy unit management, including scheduling, staffing, equipment maintenance, and management skills, is also a valuable asset to any training program. Many trainees in EUS may pursue future academic positions, and these are invaluable skills to be acquired early in an academic career. Although a common goal for most training programs is the development of future academic endosonographers, some trainees may express different career interests that conflict with the goals of the training program. Understanding and recognizing the program’s expectations and trainee’s career interests is crucial to an enjoyable and successful training experience.

The minimum EUS volumes that should be offered per trainee in a “high-quality” advanced endoscopy training program was not defined until recently. In a recent prospective multicenter study, we aimed to define the number of EUS procedures required by an “average” trainee to achieve competence in technical and cognitive EUS. Results of this study showed that the average trainee achieved competence in EUS at approximately 225 cases. This threshold may be used by GI societies and training programs in establishing minimum standards for case volume exposure for trainees during training. Because of a lack of consensus criteria on what constitutes a high-quality advanced endoscopy training program, programs are unable to perform the necessary self-assessment to improve training. We recently proposed structure, process, and outcome measures that may be used by GI societies to establish minimum standards for high-quality advanced endoscopy training programs ( Table 3.2 ).

Current status of EUS training in the United States

In the United States, training in EUS has shifted to dedicated advanced endoscopy fellowships, occurring in a fourth year of training after a standard GI fellowship. Many programs recognized that comprehensive training in endoscopic retrograde cholangiopancreatography (ERCP) and EUS could not be achieved within the 3-year curriculum of an Accreditation Council for Graduate Medical Education (ACGME)-accredited fellowship in gastroenterology, hepatology, and nutrition. The number of advanced endoscopy fellowship programs (typically a 1-year training program of combined training in EUS and ERCP) has increased dramatically. A total of 70 programs (78 positions) offering EUS training were listed in the 2020–2021 Advanced Endoscopy Fellowship match program through the ASGE ( http://www.asgematch.com ), some of which train more than one trainee per year. These programs are typically offered to physicians who have completed formal GI fellowship training. The number of programs listed may be an underestimate, as there are programs and applicants that do not participate in the match. It should be noted that these programs are not recognized by the ACGME. Roughly one in three fellows graduating from an accredited ACGME fellowship program applies for an advanced endoscopy training position, despite the fact that these procedures comprise <10% of GI endoscopy practices.

Due to the lack of a fixed mandatory curriculum, there are limited data on the composition and outcomes of EUS training among advanced endoscopy trainees completing these programs. Results from a recent prospective multicenter study evaluating competence among advanced endoscopy trainees showed that the median number of EUS exams performed per trainee was 300 (range: 155–650). In terms of indications, suspected pancreatic mass accounted for 24.5% of the graded procedures, whereas pancreatic cyst (17.8%), subepithelial lesion (7%), and luminal malignancy (6.9%) represented the other major indications. The majority of the graded EUS exams were performed using the linear echoendoscope (67.5%) and in the ambulatory setting (82.6%). At the end of the training, nearly all trainees felt comfortable in independently performing EUS, EUS-FNA, EUS-guided celiac plexus block and neurolysis, and EUS-guided pseudocyst drainage. However, 50% of trainees were not comfortable placing fiducials and performing interventional EUS procedures such as biliary and pancreatic drainage. Nearly half of the trainees planned to practice at an academic center and expected a majority of their practice to be in advanced endoscopy. Results of another recent multicenter prospective trial that included trainees participating in a competency-based fellowship program for EUS and ERCP demonstrated that nearly all trainees (94%) were comfortable in independently performing EUS and EUS-TA. Most trainees began their independent practice in an academic setting (58%) or in a practice with a high-volume senior partner performing EUS (68%). Nearly all trainees expressed some difficulty in finding an advanced endoscopy position at the completion of training. Credentialing was most often determined by the number of procedures performed and/or completion of an advanced endoscopy fellowship. Similarly, a recent survey study of advanced endoscopy trainees participating in the ASGE advanced endoscopy matching program showed that 91% of trainees rated their training as very good/excellent, 72% expressed difficulty in finding a job after fellowship, and 70% reported that advanced endoscopic procedures comprised ≤50% of their procedure volume in their first job.