Faculty Bibliography

This White Paper shares guidance on the important principles of training endoscopy teachers, the focus of an American Society for Gastrointestinal Endoscopy (ASGE)/World Endoscopy Organization Program for Endoscopic Teachers and Leaders of Endoscopic Training held at the ASGE Institute for Training and Technology. Key topics included the need for institutional support and continuous skills development, the importance of consensus and consistency in content and approach to teaching, the role of conscious competence and content breakdown into discreet steps in effective teaching, defining roles of supervisors versus instructors to ensure teaching consistency across instructors, identification of learning environment factors and barriers impacting effective teaching, and individualized training that incorporates effective feedback and adapts with learner proficiency. Incorporating simulators into endoscopy teaching, applying good endoscopy teaching principles outside the endoscopy room, key principles of hands-on training, and effective use of simulators and models in achieving specific learning objectives were demonstrated with rotations through hands-on simulator stations as part of the program. A discussion of competency-based assessment was followed by live sessions in which attendees applied endoscopy teaching principles covered in the program. Conclusions highlighted the need for the following: formal training of endoscopy teachers to a level of conscious competence, incorporation of formal training structures into existing training curricula, intentional teaching preparation, feedback to trainees and instructors alike aimed at improving performance, and competency-based trainee assessment. The article is intended to help motivate individuals who play a role in training other endoscopists to develop their teaching abilities, promote discussions about endoscopy training, and engage both endoscopy trainers and trainees in a highly rewarding learning process that is in the best interest of patients.

Interest in the use of simulation for acquiring, maintaining, and assessing skills in GI endoscopy has grown over the past decade, as evidenced by recent American Society for Gastrointestinal Endoscopy (ASGE) guidelines encouraging the use of endoscopy simulation training and its incorporation into training standards by a key accreditation organization. An EndoVators Summit, partially supported by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health, (NIH) was held at the ASGE Institute for Training and Technology from November 19 to 20, 2017. The summit brought together over 70 thought leaders in simulation research and simulator development and key decision makers from industry. Proceedings opened with a historical review of the role of simulation in medicine and an outline of priority areas related to the emerging role of simulation training within medicine broadly. Subsequent sessions addressed the summit's purposes: to review the current state of endoscopy simulation and the role it could play in endoscopic training, to define the role and value of simulators in the future of endoscopic training and to reach consensus regarding priority areas for simulation-related education and research and simulator development. This white paper provides an overview of the central points raised by presenters, synthesizes the discussions on the key issues under consideration, and outlines actionable items and/or areas of consensus reached by summit participants and society leadership pertinent to each session. The goal was to provide a working roadmap for the developers of simulators, the investigators who strive to define the optimal use of endoscopy-related simulation and assess its impact on educational outcomes and health care quality, and the educators who seek to enhance integration of simulation into training and practice.

OBJECTIVE During the last 25 years, more than 100,000 patients worldwide with trigeminal neuralgia (TN) have undergone stereotactic radiosurgery (SRS) with a standard dose of radiation. However, the radiobiological effect of radiation is determined by the amount of energy delivered to the tissue (integral dose [ID] = mean dose × target volume) and is directly associated with the nerve volume. Although the trigeminal nerve volume varies among patients with TN, the clinical impact of this variation in delivered energy is unknown. The objective of this study was to evaluate the effect of delivered ID on the outcome of TN radiosurgery. METHODS The authors evaluated 155 patients with unilateral TN who had undergone SRS as their initial surgical management over a 13-year period. The authors measured the postganglionic ID within the SRS target and retrospectively stratified patients into 3 groups: low (< 1.4 mJ), medium (1.4-2.7 mJ), and high (> 2.7 mJ) ID. Clinical outcomes, which included pain status (scored using the Barrow Neurological Institute Pain Scale) and sensory dysfunction (scored using the Barrow Neurological Institute Numbness Scale), were evaluated at a median follow-up of 71 months. RESULTS Patients who were treated with a medium ID had superior pain relief either with or without medications (p = 0.006). In the medium ID group, the rates of complete pain relief without medications at 1, 3, and 6 years after SRS were 67%, 54%, and 33%, respectively, while the rates in the rest of the cohort were 55%, 36%, and 19%, respectively. Patients given a high ID had a higher rate of post-SRS trigeminal sensory deterioration (p < 0.0001). At 1, 3, and 6 years after SRS, the high ID group had an estimated rate for developing sensory dysfunction of 35%, 45%, and 50%, respectively, while the rates in patients receiving low and medium IDs were 3%, 4%, and 9%, respectively. The optimal clinical outcome (maximum pain relief and minimal trigeminal sensory dysfunction) was obtained in patients who had received a medium ID. CONCLUSIONS With current dose selection methods, nerve volume affects long-term clinical outcomes in patients with TN who have undergone SRS. This study suggests that the prescribed SRS dose should be customized for each TN patient based on the nerve volume.

OBJECTIVE Contrast enhancement of the retrogasserian trigeminal nerve on MRI scans frequently develops after radiosurgical ablation for the management of medically refractory trigeminal neuralgia (TN). The authors sought to evaluate the clinical significance of this imaging finding in patients who underwent a second radiosurgical procedure for recurrent TN. METHODS During a 22-year period, 360 patients underwent Gamma Knife stereotactic radiosurgery (SRS) as their first surgical procedure for TN at the authors' center. The authors retrospectively analyzed the data from 59 patients (mean age 72 years, range 33-89 years) who underwent repeat SRS for recurrent pain at a median of 30 months (range 6-146 months) after the first SRS. The isocenter was 4 mm, and the median maximum doses for the first and second procedures were 80 Gy and 70 Gy, respectively. A neuroradiologist and a neurosurgeon blinded to the treated side evaluated the presence of nerve contrast enhancement on MRI series at the time of the repeat procedure. The authors correlated the presence of this imaging change with clinical outcomes. Pain outcomes and development of trigeminal sensory dysfunction were evaluated with the Barrow Neurological Institute (BNI) Pain Scale and BNI Numbness Scale, respectively. The mean length of follow-up after the second SRS was 58 months (95% CI 49-68 months). RESULTS At the time of the repeat SRS, contrast enhancement of the trigeminal nerve on MRI scans was observed in 31 patients (53%). Five years after the SRS, patients with this enhancement had lower actuarial rates of complete pain relief after the repeat SRS (27% [95% CI 7%-47%]) than patients without the enhancement (76% [95% CI 58%-94%]) (p < 0.001). At the 5-year follow-up, patients with the contrast enhancement also had a higher risk for trigeminal sensory loss after repeat SRS (75% [95% CI 59%-91%]) than patients without contrast enhancement (26% [95% CI 10%-42%]) (p = 0.001). Dysesthetic pain after repeat SRS was observed for 8 patients with and for 2 patients without contrast enhancement. CONCLUSIONS Trigeminal nerve contrast enhancement on MRI scans observed at the time of a repeat SRS for TN was associated with less satisfactory pain control and more frequently detected facial sensory loss. Residual contrast enhancement at the time of a repeat SRS may warrant consideration of dose reduction or further separation of the radiosurgical targets.

BACKGROUND:Management of older patients with medically refractory trigeminal neuralgia (TN) is yet a matter of debate. OBJECTIVE:We sought to determine the benefit of stereotactic radiosurgery (SRS) as the sole surgical management in older patients (≥70 years). METHODS:One hundred and twenty-seven patients (≥70 years) with typical TN underwent SRS as initial surgical management. The median maximum dose for the first procedure was 80 Gy. Repeat SRS was performed in 46 patients who developed recurrent pain. RESULTS:After the first SRS, the initial pain control was achieved in 91% of patients. Complete pain relief (Barrow Neurological Institute [BNI] score I) developed in 75 patients (59%) and was maintained in 59, 39, and 22% of patients at 1, 3, and 5 years. Following repeat SRS, the rate of complete pain relief was 79, 55, and 41% at 1, 3, and 5 years. The chance of BNI I preservation was greater after repeat SRS compared to initial SRS (hazards ratio: 2.02, p < 0.0001). The incidence of trigeminal sensory loss was 17% after initial SRS but increased to 39% after repeat SRS. CONCLUSIONS:SRS alone was used effectively in older TN patients to achieve pain control. Recurrent pain responded to retreatment but was associated with an increased risk of sensory dysfunction.

PURPOSE: To pool data across multiple institutions internationally and report on the cumulative experience of brainstem stereotactic radiosurgery (SRS). METHODS AND MATERIALS: Data on patients with brainstem metastases treated with SRS were collected through the International Gamma Knife Research Foundation. Clinical, radiographic, and dosimetric characteristics were compared for factors prognostic for local control (LC) and overall survival (OS) using univariate and multivariate analyses. RESULTS: Of 547 patients with 596 brainstem metastases treated with SRS, treatment of 7.4% of tumors resulted in severe SRS-induced toxicity (grade >/=3, increased odds with increasing tumor volume, margin dose, and whole-brain irradiation). Local control at 12 months after SRS was 81.8% and was improved with increasing margin dose and maximum dose. Overall survival at 12 months after SRS was 32.7% and impacted by age, gender, number of metastases, tumor histology, and performance score. CONCLUSIONS: Our study provides additional evidence that SRS has become an option for patients with brainstem metastases, with an excellent benefit-to-risk ratio in the hands of experienced clinicians. Prior whole-brain irradiation increases the risk of severe toxicity in brainstem metastasis patients undergoing SRS.

Over the past decade, the capabilities and use of endoscopic simulators have steadily expanded. Nevertheless, simulator use has yet to become fully integrated into standard endoscopic training programs. There are two obstacles. First, we lack adequate knowledge about how competency should be defined and how people become proficient in various specific techniques. Second, there has not been an affordable and convenient model to effectively assist in training and assessment. This paper explores the barriers to incorporation of simulators in training programs, and discusses currently available mechanical, computer, and ex vivo tissue models for assessment.