Surgical complications are other conditions related to surgery that occur during the surgical treatment of a disease. These conditions have a certain probability of occurring and are not completely avoidable.
1. Bleeding
The incidence of postoperative bleeding in thyroid cancer is about 1% to 2%, mostly within 24 hours after surgery. The main manifestations are increased drainage and blood, swelling of the neck, and difficulty in breathing. If the drainage is more than 100 ml/h, active bleeding is considered to exist, and prompt debridement and hemostasis should be performed. Patients with respiratory distress should first control the airway, and in emergency cases the incision can be opened bedside to first relieve the compression of the trachea by the hematoma. Risk factors for postoperative bleeding in thyroid cancer include combined hypertension, patients taking anticoagulants or aspirin, etc.
2. Injury to the recurrent laryngeal nerve and superior laryngeal nerve
The incidence of laryngeal nerve injury in thyroid surgery is reported to be 0.3%-15.4% in the literature. The common causes of laryngeal nerve injury include tumor adhesion or invasion of the nerve and surgical operation. If the tumor invades the laryngeal nerve, the tumor can be removed or the nerve can be removed together, depending on the situation. If the nerve is resected, it is recommended to perform one-stage nerve grafting or repair if possible. Injury to the laryngeal nerve on one side, postoperative paralysis of the vocal cords on the same side, hoarseness and choking on water. The surgical operation itself may damage the recurrent laryngeal nerve, and this condition cannot be completely avoided. Bilateral laryngeal nerve injury, postoperative respiratory distress can occur, life-threatening, surgery should be performed at the same time tracheotomy to ensure the airway is open.
Injury to the superior laryngeal nerve, the patient’s voice becomes muffled after surgery. Intraoperative treatment of the supraglottic artery should pay attention to the fine dissection close to the thyroid gland, which can reduce the probability of supraglottic nerve injury.
Intraoperative neuromonitoring (IONM) technique can help to locate the recurrent laryngeal nerve intraoperatively, can detect the function of the recurrent laryngeal nerve after the specimen is lowered, and can help to locate the injured segment if there is nerve injury. IONM is recommended when available for cases such as secondary surgery, giant thyroid masses, and preoperative nerve palsy on one side.
Fine dissection along the perineum, intraoperative exposure of the recurrent laryngeal nerve, rational application of energy instruments, and standardized use of IONM can reduce the probability of nerve injury.
3. Hypoparathyroidism
The incidence of permanent postoperative hypoparathyroidism is about 2% to 15%, mostly after total thyroidectomy. The main manifestation is postoperative hypocalcemia, in which patients develop a feeling of tingling in the hands and feet, perioral tingling or hand and foot convulsions, which can be relieved by giving intravenous calcium drip. For temporary hypoparathyroidism, calcium may be given to relieve symptoms, with the addition of osteopontin if necessary. Prophylactic administration may be considered to alleviate the patient’s postoperative symptoms. In permanent hypoparathyroidism, lifelong calcium and vitamin D supplements are required. Intraoperative attention should be paid to the fine dissection along the perineurium, and care should be taken to protect the blood supply when preserving the parathyroid glands in situ; autologous transplantation is recommended for parathyroid glands that cannot be preserved in situ. Some staining techniques can assist in the intraoperative identification of the parathyroid glands, such as nano-carbon negative contrast.
4. Infection
Thyroid surgery is mostly a type I incision, with a few type II incisions involving the larynx, trachea, and esophagus. The incidence of postoperative thyroid incision infection is about 1% to 2%. Risk factors for incisional infections include cancer, diabetes, and immunocompromise. Manifestations of incisional infection include fever, cloudy drainage fluid, redness and oozing of the incision, elevated skin temperature, and local pain with pressure pain.
If incisional infection is suspected, antibiotic treatment should be given promptly, and if there is abscess accumulation, the incision should be opened for drug exchange. Superficial incision infection is easy to detect, but deep incision infection is often not easy to detect early, and can be combined with ultrasound to determine the accumulation of fluid deep in the incision. Very few patients may suffer from life-threatening rupture and bleeding of large blood vessels in the neck due to infection.
5. Lymphatic leak
It is commonly seen after lymph node dissection in the neck and is characterized by a continuous high drainage flow, up to 500-1000 ml per day or even more, mostly in the form of milky opaque fluid, also known as celiac leakage. Prolonged lymphatic drainage can lead to decreased volume, electrolyte disturbance, and hypoproteinemia. After lymphatic leak occurs, the drainage should be kept open. The first step is conservative treatment, which generally requires fasting and parenteral nutrition. After a few days, the drainage fluid can gradually change from milky white to yellowish clear fluid, and the drainage flow will gradually decrease. If conservative treatment has no obvious effect in 1 to 2 weeks, surgery should be considered. Surgery can be either cervical thoracic duct ligation, cervical transfer tissue flap to seal the leak, or thoracoscopic ligation of the thoracic duct.
6. Local effusion (seroma)
The incidence of localized effusion after thyroid surgery is approximately 1% to 6%. The greater the extent of surgery the higher the probability of its occurrence, mainly associated with residual postoperative dead space. Retention of a drain in the operative area helps to reduce local fluid formation. Treatment includes close observation, multiple needle aspirations, and negative pressure drainage.
7. Other rare complications
Thyroid surgery can also cause some other complications, but the incidence is low, such as pneumothorax (caused by pleural rupture from cervical root surgery), Horner syndrome (injury to the sympathetic chain in the neck), tongue extension deviation due to injury to the hypoglossal nerve, and orofacial distortion due to injury to the mandibular rim branch of the facial nerve.