OBJECTIVETo find an approach for trans-oral endoscopic thyroidectomy (TOET) and cervical lymphadenectomy using conventional endoscopic surgical instruments on frozen fresh cadavers.

METHODSSix frozen fresh cadavers were used in three groups of trans-oral trocar installation experiments: oral vestibule installation, sublingual region installation, and combined bi-vestibular and sublingual installation. TOET (with pretrachealis method to thyroid fixation removal) and cervical lymphadenectomy were performed experiments on another 6 frozen fresh cadavers using the best access approach found in the aforementioned experiments.

RESULTSIn oral vestibule trocar installations, the trocars caused large lacerated wound and damaged air tightness. In sublingual installations, only one trocar could be installed in the sublingual area because the space in sublingual area was limited. In combined bi-vestibular and sublingual installations, no gland, vessel or nerve was damaged. Combined bi-vestibular and sublingual access were selected as the surgical approach on the basic of analysis the merits of each approach. TOET and cervical lymphadenectomy in area III, IV, VI, VII were performed without making any accessory damage through combined bi-vestibular and sublingual access approach.

CONCLUSIONSTOET is feasible. Combined bi-vestibular and sublingual approach is available for TOET. Part of the cervical lymph nodes could be resected. Pretrachealis approach to thyroid fixation removal can still be used.