Evaluation Criteria and Surgical Technique for Transoral Access to the Thyroid Gland: Experimental Study

Background: The development of endoscopic techniques motivated surgeons to search for alternative and more cosmetic approaches for thyroid and parathyroid surgery. Several variations of transoral access to the anterior neck areas were applied in recent years. One of them is a premandibular access proposed by Nakajo et al, it is performed through the oral vestibule by creating the working space by means of the lifting method. Materials and methods: Nineteen unfixed human cadavers were used to develop the endoscopic access to the thyroid gland and surgical techniques of its resection. The Nakajo access was modified by altering the spatial location of the working instruments, resulting in practically no impact on the cosmetic outcome but providing a more comfortable operation for the thyroid gland. We determined evaluation criteria of the cadaver model before initiation of the experimental trial. Parameters that influence on alteration of these criteria were registered. Results: Of the 19 operated objects, the first 7 were used to practice the access technique from the incision in the oral vestibule to the thyroid gland in order to evaluate the possibility of endoscopic dissection of the important anatomical. The next 12 surgeries were carried out by manipulating the thyroid gland in the settings maximally close to real. Access implied good cosmetic results, less surgical traumatic due to a smaller area of detachment of the musculocutaneous flap. Conclusions: The achieved results show feasibility of introducing the described modification of transoral thyroidectomy into clinical practice.