[Indications] Thyroglossal cyst, thyroglossal fistula or sinus tract. [Preoperative precautions] Careful examination of the neck for the presence of the thyroid gland in its normal position and efforts to exclude ectopic thyroid glands: the thyroid gland descends from the blind foramen of the tongue to its normal position in the neck during development. Impaired thyroid descent during embryonic development can be complete absence of descent: i.e., formation of an ectopic thyroid in the tongue; incomplete descent: ectopic thyroid around the hyoid bone; partial descent incomplete: thyroid partially in its normal position and partially at various locations along its course, the latter occurring significantly less frequently than the first two. In case of excessive descent, an intrathoracic thyroid is present. If cervical thyroid deficiency is suspected, an iodine 131 isotope scan is required, which can simply and accurately detect the ectopic thyroid and its location. It is not true that the ectopic thyroid gland cannot be surgically removed from the tongue. If it affects swallowing or even breathing, it needs to be surgically removed, but when it is removed, the glandular tissue can be transplanted under the skin in a hidden part of the body and the transplanted thyroid gland should be regularly monitored for function. Those with infection and sinus tracts should be flushed locally to control infection. [Surgical steps and techniques] Incision selection: Intraoral approach is used for ectopic thyroids at the blind foramen of the tongue. Other parts of the ectopic thyroid, thyroglossal cysts or sinus tracts are selected for cervical incision. Oral approach: general anesthesia via nasal cannula, supine or semi-recumbent position, unilateral or bilateral opener to keep the mouth in the maximum open position, frontal mirror light can be worn; 7# silk thread 1 cm from the tip of the tongue through the tongue muscle, clamped thread traction, so as to fully reveal the ectopic thyroid gland at the root of the tongue bulge, tissue clamp holding the bulge to further pull and rotate, so that the posterior lingual mucosa of the bulge is under high tension, 12# sickle The 12# sickle blade is used to dissect the mucosa along the edge of the bulge, and the index finger is separated under the incision, and to reduce bleeding, the suture is cut and separated. Cervical approach for thyroid duct fistula or sinus excision: Depending on the patient’s tolerance status, general anesthesia, local anesthesia or needle anesthesia is chosen; the shoulder pad is tilted back. A horizontal incision along the surface of the cervical mass along the dermatome should include a shuttle incision to remove the fistula. If the fistula is low, the incision needs to be extended appropriately or a horizontal incision needs to be added at the level of the hyoid bone to ensure adequate exposure of the operative field. The skin, subcutaneous tissue, and broad cervical muscle are incised, and the deep flap of the broad cervical muscle is turned above the plane of the hyoid bone, taking extra care not to damage the sinus tract when turning the upper flap. In patients with open sinus tracts or fistulas suggesting an internal opening, complete removal of the thyroglossal canal remains is the key to successful surgery. A longitudinal incision of the fascia between the sternocleidomastoid muscles exposes the hyoid bone above and includes the fistula below, with a pulling hook to distract the strap muscles. The main operative step to avoid postoperative recurrence is the removal of approximately 1 cm of tissue from the middle portion of the hyoid bone, i.e., the columnar resection of the fistula. The thyroglossal canal descends anteriorly to the lower edge of the hyoid bone to the medial side, returning upward and then folding back downward between the midline of the hyoid bone and the scaphoid hyoid muscles on both sides. The fistula is lifted and the fistula and its surrounding musculature are removed. The direction of the thyroglossal canal in the tongue is at an angle of 45° to the plane of the hyoid bone, and the midpoint of the hyoid bone is 2-4 cm from the blind foramen of the tongue. The fistula is often obvious in patients with recurrent inflammation, but not easy to find in those with infrequent inflammation, and can be inserted with a trocar needle at this angle to guide columnar resection. The procedure is not complicated and not dangerous, but the recurrence rate is extremely high when not handled properly. I met a patient who told me that she had undergone a total of 15 surgeries in several hospitals, almost once a year since she was young until she was 19 years old. The cause of recurrence was a lack of awareness of the causes of the disease. The thyroglossal duct cyst and thyroglossal fistula are caused by the unclosed thyroglossal duct during the development of the thyroid gland. The thyroglossal duct is formed during the development of the thyroid gland by descending from the blind lingual foramen to the isthmus of the thyroid gland, where it first reaches the lower edge of the hyoid bone in front of the hyoid bone and then descends to the isthmus of the thyroid gland after sparing a distance up the medial side of the hyoid bone. After the thyroid gland is fully developed and reaches its normal position, the thyroglossal duct eventually disappears in embryonic form as a solid cord. Because the thyroglossal duct is lined with epithelial cells, any residual epithelium in any part of the duct can form thyroglossal cysts, thyroglossal sinus tracts and thyroglossal fistulas. Due to the special adjacent anatomical relationship with the hyoid bone, a section of the hyoid bone should be amputated intraoperatively. Lesions located above the level of the hyoid bone are less common, and such lesions can be removed without removing the hyoid bone. The thyroglossal cyst excision is almost identical to fistulotomy. The absence of fistula formation may be due to the closure of the lingual blind foramen and the absence of recurrent infections, but it is still necessary to trace to the lingual blind foramen for insurance purposes. [Postoperative complications, analysis of causes and management] 1. hypothyroidism When the ectopic thyroid gland of the tongue needs to be removed due to local hematoma or other causes of dysphagia and dyspnea, it should be realized that the ectopic thyroid gland of the tongue may have all the functions of the thyroid gland, and if all of it is removed, hypothyroidism as well as hypoparathyroidism may occur. Postoperatively, blood thyroxine levels should be routinely tested, and thyroxine replacement therapy should be administered if necessary, even for life. Preoperatively, when a swelling is found at the blind foramen of the tongue, especially if the surface is red and there are blood vessels on its surface, the ectopic thyroid gland should be alerted and the glandular tissue can be transplanted elsewhere intraoperatively. The thyroid tissue transplanted elsewhere should be followed up to observe the function on the one hand and the changes in the transplanted ectopic gland on the other. 2. Upper respiratory tract obstruction or asphyxia [Cause]: Intraoperative hemostasis is not perfect, postoperative pressure bandage is too tight, tongue root tissue edema is serious, secretions are sticky and cannot be coughed out. [Prevention]: Intraoperative hemostasis is complete, especially in the tongue, the muscle section around the broken section of the hyoid bone should be tightly sutured and firmly tied. Postoperative nebulized inhalation, containing hormones to prevent edema and chymotrypsin to dilute sputum. Pressure bandage moderate, avoid bandage ring rap neck pressure bandage. [Treatment]: Apply hemostatic drugs, apply corticosteroids intravenously in high doses, reopen the incision if necessary to remove blood clots and stop bleeding completely, and perform tracheotomy urgently in case of emergency. 3, postoperative recurrence [Cause]: Residual thyroglossal duct epithelium in any part can lead to recurrence of the lesion. The thyroglossal canal almost surrounds the anterior, inferior and medial sides of the midline of the hyoid bone, and failure to make a mid hyoid resection and full columnar resection of the lesion is the cause of recurrence. [Prevention]: In case of sinus tract or fistula, it is recommended to use epidural anesthesia to carefully insert a plastic tube into the fistula tract and close the fistula opening, and inject dye, such as methylene blue, azulene blue, etc. In case of cyst, the dye should be injected directly to clearly understand the extent of the lesion, the course of the fistula, and the presence or absence of an internal opening, so as to facilitate complete excision of the lesion to prevent residual. Repeated inflammation or recent septic lesions can cause dye spillage after dye injection, making the surgical field unclear and affecting the surgical operation. The middle portion of the hyoid bone, which is closely related to the fistula, should be removed during surgery, and the fistula should be peeled off along with 1-2 cm of muscle tissue around the leaky tube for columnar excision to avoid leaving epithelial tissue. [Treatment]: The standardized surgery should be performed at an elective stage.