ガスなし鎖骨下内視鏡下甲状腺摘出術（GTET）の外科的ステップにおけるヒントと落とし穴：約300例の経験

Gasless transaxillary endoscopic thyroidectomy (GTET) offers an extracervical approach with cosmetic benefits, yet spatial orientation around critical structures can be challenging for learners. We aimed to standardize and illustrate a stepwise GTET workflow with clearly annotated intraoperative landmarks. This single-center descriptive study presents a unified, stepwise technique for GTET. High-resolution intraoperative images were annotated in-figure (arrows and labels) to identify constant landmarks and "risk zones," including the recurrent laryngeal nerve (RLN; trunk/entry), inferior parathyroid and feeding vessels, Berry ligament, tracheal plane, external branch of the superior laryngeal nerve (EBSLN) corridor, upper-pole dissection plane, and central compartment boundaries. For each step, concise tips and pitfalls are provided to support reproducibility and teaching. An atlas-style, annotated workflow is presented that links exposure, landmark identification, and safe dissection planes. The figures and legends prioritize consistent orientation cues and highlight commonly hazardous areas (e.g., Berry ligament region, RLN entry, inferior parathyroid pedicle), aiming to reduce ambiguity for less-experienced surgeons. This annotated, stepwise description of GTET may facilitate surgical orientation, communication, and training. The framework is intended to be adaptable across learning environments; future prospective studies should evaluate learning curves and clinical outcomes using standardized endpoints.