[Tips and technical issues for performing transoral endoscopic thyroidectomy with vestibular approach (TOETVA): a novel scarless technique for neck surgery].

BACKGROUND: Nowadays, minimally invasive thyroid and parathyroid gland resections for both benign and malignant tumors are rarely performed. Recently, promising new endoscopic transoral approaches to the anterior neck have been described with good results and few complications. This study describes the first clinical series in Germany using transoral endoscopic thyroidectomy-vestibular approach (TOETVA) and identifies technical issues and solutions.

METHODS: The technique is indicated for hemithyroidectomy in patients without pre-existing neck operations. The technical steps consist of a 10 mm incision at the center of the oral vestibule, followed by subplatysmal hydrodissection. A blunt dissector stick is inserted creating a space below the platysma to the anterior neck and the infrahyoid muscles then three trocars are inserted in the vestibular area. After separation of the infrahyoid muscles, the thyroid isthmus is transected. Anatomical structures, such as the superior thyroid artery, parathyroid glands and the recurrent laryngeal nerve can be easily identified with magnification. Intraoperative neuromonitoring is used routinely, adding safety in avoiding nerve damage.

RESULTS: An optimal operative field due to subplatysmal dissection enables exposure of the thyroid and parathyroid glands. Several critical steps and suitable solutions were identified in the study. 1 Positioning of the team and technical improvements using the a 4K laparoscopic tower allowing enhanced view of the anatomy especially for dissection of the recurrent laryngeal nerve. 2. Lateral and upper positioning of lateral trocars avoiding mental nerve injury. 3. Initial hydrodissection of the subplatysmal space. 4. Use of one dissector progressively creating the operative space in the anterior cervical region. 5. Using internal-external sutures to retract the infrahyoid muscles. 6. Intraoperative neuromonitoring used routinely through the trocars or percutaneously through a 1 mm incision. 7. Extraction of the specimen through a recovery bag. 8. Drainages are possible, but can be avoided in small operative fields.

CONCLUSION: The new TOETVA technique for thyroid surgery is a promising option for selected patients to enable transoral thyroid and parathyroid surgery through the vestibular approach. Further studies in clinical series, especially regarding safety are needed to evaluate the indications of the technique.