Navigating the learning landscape: Comprehensive training in third space endoscopy - training, techniques, and practical recommendations.

Third space endoscopy (TSE), including ESD, POEM, or STER are advanced procedures requiring precise endoscopic control and tissue recognition. Despite its increasing adoption, evidence-based curricula, and standardized training protocols for TSE are lacking. This review explores training methods, cognitive skills, and technical proficiency requirements for endoscopists performing TSE, with a primary emphasis on POEM. Generally, it seems wise to recommend a step-up approach to TSE training, starting with ex-vivo models or POEM simulators; mechanical and virtual reality (VR) simulators are commonly used during early training. Preclinical training involving ex-vivo and live animal models is suggested to prepare trainees for safe and effective procedures. Studies suggest varying numbers of procedures for training, with approximately 20-40 cases needed before a first plateau is achieved in terms of complications and speed. The duration of on-patient clinical training varies depending on prior experience. Mentorship programs, workshops, and case discussions may facilitate dynamic knowledge transfer. In addition, adverse event management is a crucial aspect of any TSE training program. Existing evidence supports the use of preclinical models and emphasizes the importance of specialized training programs for TSE in alignment with our proposed step-up training approach. This review outlines practical recommendations for the theoretical knowledge and technical skills required before commencing TSE training, covering clinical understanding, diagnostic and outcome assessment, procedural requirements, and the role of mentorship programs.