In recent years, the incidence of thyroid diseases requiring surgical treatment in children is increasing year by year [1]. The surface scars caused by traditional surgery have a significant psychological burden and social impact on children and their families. However, laparoscopic or robotic thyroid surgery with different approaches is most commonly used in adults, among which the transoral vestibular approach can achieve the requirement of an utterly scarless body surface in children, and the therapeutic efficacy of this approach in pediatric endoscopic thyroid surgery has been clinically verified [2, 3]. However, there are no reports on applying this approach to pediatric robotic thyroid surgery. In this paper, we present the experience of the application of transoral vestibular robotic thyroidectomy (TOVRT) in five pediatric cases.

Retrospective analysis of clinical data of 5 cases of robotic thyroid surgery via the transoral vestibular approach admitted to the Thyroid and Breast Surgery Department of the 960th Hospital of the PLA Joint Logistics Support Force (Former Jinan Military General Hospital of PLA) from February 2021 to April 2023. All surgeries were performed by the same robotic surgeon, and the chief surgeon communicated sufficient with the monitoring of the five children before surgery. After obtaining informed consent, the child’s guardian signed a consent form for surgical risks and complications, and this study has been reviewed and approved by the Ethics Committee of the 960th Hospital of the Chinese People’s Liberation Army Joint Logistics Support Force (2022 Scientific Research Ethics Review No. 125).

Inclusion criteria: (1) age ≤18 years; (2) tumor diameter ≤6 cm; (3) hyperthyroidism, thyroid volume ≤50 ml.

Exclusion criteria: (1) previous neck surgery and ablation history; (2) thyroid tumor with severe thyroid inflammatory disease; (3) thyroid malignancy; (4) oral infection; (5) cervical deformity.

The cosmetic effect was evaluated using the Visual analogue scale (VAS), with higher scores indicating higher satisfaction. Postoperative pain was evaluated using the numerical rating scale (NRS), with lower scores indicating less pain.

Laryngoscopy showed normal vocal cords. Preoperative psychological counseling and oral care were performed. Antibiotics were used prophylactically before and after surgery for 30 min to prevent incision infection. Before surgery, ultrasound-guided thyroid nano-carbon suspension injection (Chongqing Lummy Pharmaceuticals, China) was performed to facilitate negative visualization of the parathyroid gland. The incision position was marked on the body surface before surgery. The fine needle aspiration cytology results of the thyroid nodules were considered follicular tumors. The procedure was performed by da Vinci Si surgical system (Intuitive Surgical, Inc., Sunnyvale, CA).

All patients underwent general anesthesia via oral intubation with a nerve monitoring tube (Shanghai NCC Medical Co., LTD, China), and the tube was fixed above the left corner of the mouth, as shown in Fig. 1A. The patient is placed in a supine position with the neck extended. Use sterile film to seal both ears, nostrils, and eyes. The mouth and vestibule were washed with 0.1% retouch povidone iodine and then washed with 0.9% sodium chloride solution. An inverted “U” incision about 20 mm long was made at the end of the frenulum of the lower lip with monopolar electrocautery, and the incision was made to the periosteal surface as a lens hole. Use monopolar electrocautery to make longitudinal incisions near the mouth corners on both sides, with a length of about 5 mm as operating holes, without additional incisions. Inject 10 mL of saline containing adrenaline (1 mL:500 mL) into the submental region and the incision channels on both sides. Blunt dissociation to the thyroid cartilage plane was performed using a dissection stick along the tunnel and trocars were placed (Fig. 1B). Children’s skin is delicate, do not use brute force to operate, to avoid the dissection stick through the skin.

A Body surface marking tunnel running. B Two trocars with a diameter of 8 mm were placed in the corner incision and one trocar with a diameter of 10 mm was placed in the lower lip frenulum

The mechanical arm was docked. During the operation, the CO2 insufation pressure was maintained at a low pressure of 5 mmHg (1 mmHg = 0.133 kPa) and high flow state. Prograsp forceps was placed into trocar for the left corner incision, and harmonic curved shears or Maryland bipolar forceps were placed into trocar for the right corner. Harmonic curved shears was used for coagulating tissue. Maryland bipolar forceps was used with Prograsp forceps to separating tissues or to seek recurrent laryngeal nerves (RLN). The harmonic curved shears was used to expand the operating space, down to the suprasternal notch, and on both sides to the lateral margin of the sternocleidomastoid (SCM) muscle. The harmonic curved shears was used to cut the midline fascia of the strap muscles, expose the enlarged thyroid gland, locate the cricothyroid muscle and thyroid cartilage, cut off the pyramidal lobe, expose the trachea, and dissected the isthmus. Pull the thyroid gland inward, and the anterior cervical muscle group was suspended and draw outward with laparoscopic hook or suture. The peripheral thyroid fascia was severed along the true thyroid envelope, the middle thyroid vein was closed, and the common carotid artery was exposed. Then fully exposed along the cricothyroid space, free the upper pole of the thyroid, if necessary, part of the sternothyroid muscle can be severed. The harmonic curved shears was used to cut off the upper pole of the thyroid gland and double migrate to coagulate the blood vessels in the upper pole of the thyroid gland. Pay attention to protect the external branches of the superior laryngeal nerve and the upper parathyroid gland and its blood supply. The RLN was located with the help of an intraoperative nerve monitor attached to electrodes at the tail of the Maryland bipolar forceps (Fig. 2A). After identifying the route of RLN and fully protecting it, Berry’s ligament was cut with harmonic curved shears. Coagulation of free glands along the true capsule of the thyroid gland from top to bottom, closure of the lower polar blood vessels, and complete removal of the thyroid gland lobe. Pay attention to protecting the parathyroid gland during surgery (Fig. 2B). An endoplastic bag was used to collect the excised thyroid gland lobe from the operation area, and remove it from the lens hole. Repeatedly rinse the surgical area and subcutaneous tunnel with sterile distilled water (42 °C), and suture the midline fascia of the strap muscles. The detailed operation has been described in a previous study from our team [4,5,6].

A Right recurrent laryngeal nerve. B Right inferior parathyroid gland