Transoral thyroid and parathyroid surgery

Translumenal endoscopic interventions via so-called natural orifices are gaining increasing interest because they allow surgical treatment without any incision of the skin. Moreover, minimally invasive procedures have found their way into thyroid and parathyroid surgery. Our goal was to develop a new access for thyroid and parathyroid resection via an entirely transoral approach. We managed to find an entirely transoral sublingual access to the thyroid region in pigs and human cadavers. Using a modified rigid rectoscope (oraloscope) hemithyroidectomies as well as resection of parathyroid glands were performed via this new approach. Preparation and resection was performed using conventional laparoscopic instruments. In living pigs, integrity of the recurrent laryngeal nerve after resection could be documented by neuromonitoring. An absorbable suture was used to seal the mucosal incision. First, hemithyroidectomy was performed via the transoral access in 10 porcine cadavers, then in 10 living and orally intubated pigs, and finally in five human corpses. In humans, resection of parathyroid glands also was performed. We gained access to the thyroid region by blunt dissection of the layer behind the hyoid bone and the strap muscles of the neck. We did not observe any complication during the insertion, resection, and removal part of the new procedure. Entirely transoral thyroid and parathyroid surgery via sublingual access seems to be feasible. However, further investigations are needed to evaluate the safety of the new technique, especially potential and clinically relevant contamination of the access route has to be excluded.