Surgical method General anesthesia with tracheal intubation. Physiological saline 500ml was added to epinephrine 1ml to make “expansion fluid”. The patient was placed in a supine position with legs apart, and the operator stood between the patient’s legs and injected a mound of “expansion fluid” in the anterior sternum of the cleavage area, then made a transverse incision of 1.2 cm in length to reach the deep fascial layer, and used a 50 mL syringe to inject 250-300 ml of “expansion fluid” with a special injection needle from the small incision upward to the proposed subcutaneous separation of the subcutaneous injection, and used a special non-invasive subcutaneous separation rod (from the small incision into the subcutaneous layer) to puncture the subcutaneous pre-separation area several times. After puncture, the “expansion fluid” is squeezed out from the small incision with a gauze strip, a trocar is placed through the incision and a 30-degree lumpectomy, CO2 gas is injected (pressure 6 mmHg), then 10 mm and 5 mm curved incisions are made at the upper edge of the right and left areolas, a trocar is placed under the skin in front of the mammary gland, and the deep surface of the broad neck muscle is separated with an ultrasonic knife under direct vision. The remaining tissues after puncture separation were separated upward to the thyroid cartilage and on both sides to the lateral sternocleidomastoid muscle to complete the establishment of the subcutaneous surgical operating space. The subglottis muscle group and the cervical white line were cut with an ultrasonic knife to reveal the thyroid gland. For a single benign thyroid nodule, the nodule and part of the surrounding gland are removed directly with the ultrasonic knife after finding the thyroid nodule. In most thyroidectomies, the isthmus of the thyroid gland is first cut with an ultrasonic knife, the Berry ligament is severed, then the inferior artery of the thyroid gland on the affected side is revealed and freed, and the area as far away from the recurrent laryngeal nerve as possible is cut off with ultrasonic knife coagulation, and if the gland is large, it can be suspended with silk sutures outside the neck. The thyroid gland is turned medially and the thyroid gland is incised directly, most of the gland on the anterior side of the thyroid gland is removed and a small amount of glandular tissue on the dorsal side is retained. In the case of bilobar subtotal thyroidectomy, the left thyroid gland is removed first and then the right thyroid gland is removed. The thyroid wound does not require sutures. 000 absorbable sutures are used to close the cervical white line and the subglottic muscle group, and a drainage tube with a cut lateral hole is inserted through the subglottic muscle layer at the thyroid incision, and then the drainage tube is led out through the left areolar incision. Traditional thyroid surgery requires a 6cm to 10cm long surgical scar at the front of the neck, and the neck and face are the exposed parts of the body, making this method imperfect. With the help of image assisted magnification, lumpectomy thyroid surgery provides a clear surgical image and prevents bleeding by using an ultrasonic knife to cut the gland and thyroid blood vessels. The remote operation of slender surgical instruments changes the tradition of surgical procedures that require direct incision at the site of the lesion, so the surgical incision can be miniaturized and transferred to a hidden part of the body, achieving a bare neck without a surgical scar, which has obvious The advantages of The upper sternal fossa and subclavian approaches still leave small scars in the lower neck and upper chest, respectively; the surgical scar of the axillary approach can be concealed by the upper arm, but it is difficult to deal with the contralateral thyroid gland. In contrast, the sternomastoid approach allows for the simultaneous management of bilateral thyroid lesions and allows for more difficult surgeries such as hyperthyroidism. We believe that the sternomastoid approach to lumpectomy thyroid surgery has the best cosmetic results and is the most satisfactory of the four lumpectomy approaches to thyroid surgery, in line with the aesthetics of modern clothing. Surgical indications and contraindications Early on, it was pointed out that the safety and feasibility of lumpectomy thyroidectomy depends on strict and accurate case selection, and it was emphasized that only a small proportion of patients are suitable for lumpectomy thyroidectomy. We believe that the indications and contraindications for surgery are directly related to the experience of the surgeon, as the outcome of the procedure needs to be guaranteed first and foremost. Our current indications for surgery include: 1) substantial single thyroid nodules ≤6 cm in maximum diameter, cystic nodules can exceed 6 cm in diameter; 2) primary or secondary hyperthyroidism up to II0 enlargement. Contraindications include: 1, those with severe major organ insufficiency and poor systemic condition that cannot tolerate general anesthesia; 2, those with severe coagulation dysfunction that is difficult to correct. 3. History of neck radiotherapy, thyroiditis, relatively large and fixed substantial masses recurring after thyroid surgery, substantial single nodules of the thyroid with a maximum diameter >6 cm or large goiter (II0 enlargement or more), and malignant tumors of the thyroid requiring extended resection and lymph node dissection. The excellent hemostatic effect of ultrasonic knife solves the problem of bleeding. The application of ultrasonic knife to cut the thyroid blood vessels and glands does not require additional sutures, ligatures and titanium clips, and unlike the electric knife, ultrasonic knife does not generate electric current and produces very little thermal damage to the nerves and parathyroid glands, so it greatly shortens the operation time and improves the safety of the operation. However, there are still reports of thermal injury to the trachea due to the functional knife head facing the tracheal surface when cutting the isthmus [2]; as well as reports of temporary paralysis of the recurrent laryngeal nerve due to the ultrasonic knife head being too close to the recurrent laryngeal nerve (about 3 mm), it is recommended that the safe distance between the ultrasonic knife head and the recurrent laryngeal nerve and parathyroid gland should be at least 5 mm. We have performed 200 lumpectomy thyroidectomies with the ultrasonic knife and have not experienced complications such as paralysis of the recurrent laryngeal nerve due to improper handling. Our experience has been to use the ultrasonic knife near the recurrent laryngeal nerve, parathyroid glands, and trachea keeping the functional tip as close to them as possible (turning the gland to be removed upward) and to pay attention to the duration of action, avoiding prolonged coagulation in favor of fractionated coagulation cuts. Fractional thyroid excision is practical in large volume lumpectomy thyroid surgery, because the ultrasonic knife does not bleed when cutting the thyroid wound, which provides conditions for fractional excision, such as in hyperthyroidism excision, if the isthmus is enlarged, the isthmus can be excised first to provide surgical space for the left and right lobe excision, and in addition, after excision, carefully observe whether the excised gland is sufficient, if not, it can be cut again until satisfied, to avoid Insufficient excision of the gland. How to avoid complications and avoid intermediate open surgery In lumpectomy thyroidectomy, complications such as injury to the recurrent laryngeal nerve, injury to the parathyroid p-trachea by mistake, and vascular bleeding are less frequent because of the magnification of the lumpectomy, clear tissue structure of the operative field, and more delicate operation than traditional surgery. We believe that familiarity with the anatomical structure p pathology of the thyroid gland, proficiency in lumpectomy techniques (including microscopic suture tying), experience in open thyroid surgery, and having an ultrasonic knife and being able to operate it correctly are the main conditions to avoid serious complications. The main reasons for conversion to open surgery in lumpectomy thyroidectomy are reported in the literature: vascular bleeding and intraoperative frozen section examination for cancer. We converted 7 cases to open surgery, mainly because of bleeding, too large mass (6-cm diameter nail tumor, nodular goiter of III° or hyperthyroidism) or severe adhesions (history of open surgery, cancer infiltration). We have learned that strict selection of cases according to the operator’s skill level p instrumentation and equipment conditions is the key to reduce the rate of conversion. In addition, we found that preoperative iodine administration time for hyperthyroid patients needs to be about one week longer than that of open surgery, so that intraoperative cutting of the gland with ultrasonic knife can achieve a completely bloodless effect and significantly reduce surgical bleeding and staging rate. Problems At present, lumpectomy is still in its initial stage of development, and there are still many problems, such as the loss of direct palpation of the target organ by the surgeon, which may lead to the omission of small thyroid nodules and mistakenly cutting parathyroid glands with atypical anatomical sites, as well as the difficulty in correctly estimating the amount of residual thyroid gland; the long operation time and high operation cost; the outstanding cosmetic effect, but whether the minimally invasive effect is obvious needs to be further explored. We believe that thoracic breast approach lumpectomy thyroid surgery is a safe surgical method with good cosmetic effect, which is very popular among patients and is an ideal surgical method for thyroid surgery. The recent results are satisfactory, but the long-term postoperative results need to be observed for a long time.