What is endoscopic thyroid surgery? The surgical approach has remained largely unchanged since Halstead and Kocher described the technique of thyroidectomy a century ago. Thyroid nodules are a common and frequent clinical condition, with a high prevalence in young and middle-aged women. The drawback of traditional open surgery is that it leaves significant scars on the patient’s neck and face, which affects the aesthetics of female patients and reduces their quality of life. Patients have a high demand for reducing the surgical incision and improving the appearance. The continuous development of endoscopic and extra-surgical science and technology in the past ten years or so has created conditions for endoscopic thyroid surgery. Zhang Bin, Department of Head and Neck Surgery, Cancer Hospital, Chinese Academy of Medical Sciences Historical review Gagner [1] was the first to apply endoscopic techniques to thyroid surgery in 1996 and successfully completed the first endoscopic subtotal parathyroidectomy. 1997 Hüscher et al [2] in Italy successfully reported the first endoscopic lobectomy of the thyroid gland via a three-port pathway in the neck. 1999 Bellantone et al. reported minimally invasive vedio-assisted thyroid lobectomy (MIVAT) with a small incision in the neck, a technique that formally introduced the concept of minimally invasive endoscopic thyroid surgery. Subsequently, Yeh et al [3] and Micooli et al [4] carried out endoscopic-assisted thyroidectomy (video-assisted thyroidectomy, VAT) with a similar surgical path to conventional open thyroid surgery, with the incision still located in the superior sternal fossa but reduced in length by more than 2/3. shimizu et al [5] used endoscopy to allow The subclavian route endoscopic thyroid surgery (scarless endoscopic thyroidectomy, SET) was reported by Shimizu et al [5] using the feature that the body surface incision can be operated away from the lesion. Endoscopic thyroid surgery was first published by Dr. Yeung in Hong Kong, China, in 1997 [6] and was successfully applied in China by Qiu Ming et al [7] in 2002. This technique then quickly gained popularity in the mainland and is now probably the most used in the world. Surgical access methods are divided into gas-injected and non-gas-injected endoscopic thyroid surgery according to whether CO2 gas is injected intraoperatively; endoscopic thyroid surgery with a small neck scar and endoscopic thyroid surgery without a scar in the neck according to the surgical access; total endoscopic thyroid surgery with complete endoscopic operation and endoscopic-assisted minimally invasive thyroid surgery according to the surgical approach; 1. Small neck incision approach. Miccoli et al. first proposed a small neck incision approach to thyroidectomy, which is known as the Miccoli procedure [4]. A single incision of about 2 cm in the superior sternal fossa is used to bluntly separate the subxiphoid space under the incision, cut the cervical white line, and create a surgical maneuvering space through a special pulling hook without CO2 gas injection to create a surgical cavity in the subxiphoid muscle, and endoscopically assisted by an ultrasonic knife to complete the thyroidectomy. However, because the chamber space built by this procedure is not large, less stable, and not easily adjustable, it is not conducive to operation, especially to hemostasis. In China, Gao Li [8] overcame the above disadvantages better by designing automatic traction pull hooks and appropriately extending the incision. The small cervical incision approach can easily reach the thyroid gland in the path, which is simple to operate and can well achieve the minimally invasive purpose, but the incision is still inevitably left in the neck. 2. Subclavian approach. A small 4-5 cm subclavian incision is made on the affected side, usually under the collar, as proposed by Shimizu et al [5]. Without CO2 gas injection, a wire suspension is used to create a tent-like operating space in the neck. The incision is placed simultaneously with the ultrasonic knife and the endoscope. The suspension method allows for adjustment and maintenance of the operating space without subcutaneous emphysema, while the instruments can be used repeatedly and at significantly lower cost. The disadvantage is that there is an obvious surgical scar under the clavicle and the operating space is not sufficiently exposed, especially the operation of the contralateral thyroid is not convenient enough. 3. anterior areolar chest wall approach. A 5-10 mm skin incision is made on the anterior chest wall at the upper edge of the bilateral areola and at the midpoint of the areola line, and a stent tube is placed under the skin in the anterior thoracic region with blunt separation. The endoscope, ultrasonic knife and operating instruments are placed in the incision. The advantage is that the operating space is more open, the visual field is clear, the endoscope is easy to operate, the neck surgical incision is avoided, and the appearance is good. However, the operation is complicated, time-consuming, with a large operation stripping area and high requirements for endoscopic operation. The axillary approach was reported by Ikeda in Japan in 2002 [9], in which an incision is generally made at the anterior border of the affected axilla, and the subxiphoid space is entered along the superficial fascia of the pectoralis major muscle, and a trocar is inserted, which is also perfused with CO2 and placed with the endoscope. This operation requires all operating instruments to have the same pathway to enter, the stripping area is small, and the incision is in the axilla, which can be completely covered in normal position, and the cosmetic effect is most prominent. The disadvantage is that it is difficult to reach the contralateral thyroid gland for surgery and is only suitable for unilateral lobar lesions. Surgical indications Different surgical approaches have different advantages and disadvantages, and the choice of patients may be somewhat different, and the scale of mastery varies greatly from operator to operator. The following are some of the more common patient choices. 1. Indications for surgery: ① benign thyroid nodules considered by preoperative ultrasound and CT examination; ② tumor diameter less than 4 cm; ③ no signs of lymph node metastasis in the neck; ④ hyperthyroidism with insignificant enlargement of the thyroid gland. 2. Contraindications to surgery: ① history of neck surgery; ② preoperative suspicion of lymph node metastasis; ③ larger nodular goiter or hyperthyroidism. Miccoli et al [10] concluded that in patients with early-stage papillary and follicular thyroid carcinoma, preoperative examination and intraoperative exploration did not reveal clear extraperitoneal infiltration and there was no local lymph node metastasis, minimally invasive lobectomy or lobectomy of one gland plus isthmus plus contralateral macroscopic resection or total thyroidectomy was feasible, and prophylactic central lymph node dissection was performed according to their own The decision to perform prophylactic central lymph node dissection is based on one’s own endoscopic surgical technique of thyroid surgery. However, Yeh et al [3] concluded that unless the endoscopic thyroid surgery technique is sufficiently mature to perform lymph node dissection of the carotid sheath, resection of malignant tumors is generally not favored. The final conclusion awaits the report of a study with a large sample with long-term follow-up. Complications of endoscopic thyroid surgery 1. Complications of endoscopic thyroid surgery ① The incidence of laryngeal recurrent nerve palsy is low, about 0-1%;; [8-11], similar to open surgery; ② Goliath reported temporary hypocalcemia 83.3%;; (35/42) and permanent 0%;;; [12] after total thyroidectomy using Grave’s disease; ③ Intraoperative bleeding while in turned into developmental surgery is a surgical complication specific to endoscopic thyroid, with reports accounting for 0-4%;; [8-11]; accidental surgical bleeding is caused by mishandling of the upper and lower thyroid arteries or middle veins, rupture of the substantial tumor tumor, and accidental injury to the internal jugular vein or common carotid artery [13]; ④ the actual incidence of wound epidermal burns is high, probably because of the mild effect, which is not reported in most of the literature, mainly because the ultrasonic cutter head caused by inadvertent contact with the skin of the incision in the working state; 2. Prevention and management of complications The main points for the prevention of complications in general are: ① endoscopic operation should be proficient, with ≥ 72 hours of operation box training in the beginning phase and computer simulated surgical operation and animal experiments if available. Traction should be gentle, using inflatable or pulling hooks to establish a suitable operating space as much as possible; ② have a lot of experience in open thyroid and parotid surgery, especially the anatomy of the recurrent laryngeal nerve and the “cis” anatomy of the common facial nerve trunk; each step of the microscopic anatomy should be clear; ③ master the use of ultrasound knife, well-known vessels should be cut in Avoid thermal damage to the recurrent laryngeal nerve or facial nerve by the ultrasonic knife; ④ Select the indications for surgery well, and it is advisable to select simple cases in the early stage of the “learning curve”, such as small diameter and superficial location of the mass, and then select more difficult cases for surgery after accumulating a certain number. The main complication of endoscopic thyroid surgery is accidental bleeding, once it occurs, firstly, use gauze to stop the bleeding by compression, find the bleeding point after aspirating the accumulated blood, and then use ultrasonic knife or titanium clip to stop the bleeding accurately; if the bleeding is caused by rupture of the tumor, it is recommended to use suture to control the bleeding of the tumor; if the above methods are ineffective, it can only be transferred to open surgery to stop the bleeding and surgery [13] Other considerations for endoscopic thyroid surgery include ① careful operation (2) preoperative CT/B ultrasound positioning of thyroid nodules to facilitate accurate intraoperative excision; (3) CO2 inflation pressure ≤5 mmHg to prevent complications of hypercapnia and venous gas embolism; (4) selection of special instruments to facilitate the establishment of the operating space and use of ultrasound knives from reliable professional companies to achieve effective cutting and safe hemostasis; (5) relative fixation of the operating room, assistants and nurses to facilitate hemostasis. assistants and nurses are relatively fixed to facilitate business familiarity. With the rapid development of China’s economy and the improvement of people’s living standards, patients’ requirements for appearance have also increased. Endoscopic-assisted thyroidectomy and parotidectomy with small and hidden incisions and low complication rates is one of the methods of choice for surgery of benign tumors of the head and neck glands.