What is the thyroid gland?
The thyroid gland is located in the neck, beneath the cartilage known as the Adam’s apple. It produces two hormones—triiodothyronine (T3) and thyroxine (T4)—that are involved in the body’s use and storage of energy. This process of the body using and storing energy is also referred to as “metabolism.”
Who undergoes surgery?
When we broadly categorize thyroid disorders into two groups, we encounter two types of conditions: one is functional thyroid disorders, and the other is nodular thyroid disorders. When we speak of functional thyroid disorders, there are again two distinct conditions: one is when the thyroid gland is overactive (hyperthyroidism), and the other is when it is underactive (hypothyroidism). The treatment for an underactive thyroid is not surgical. In such cases, the missing thyroid hormone must be administered externally in the form of medication. An overactive thyroid, on the other hand, is a condition that can be corrected surgically. However, surgery is not a mandatory treatment option. In cases of diffuse overactivity of the entire thyroid gland (diffuse toxic goiter, also known as Graves’ disease), the condition is initially treated with medication. If this proves unsuccessful, or if the disease recurs after thyroid hormone levels have been normalized, two advanced treatment options are recommended: the first is radioactive iodine ablation (RIA; commonly referred to as “atomic” treatment), and the second is surgical removal of the entire thyroid gland or a near-total portion of it. Another condition that can cause the thyroid gland to overfunction is the overactivity of one or more nodules (toxic nodular goiter). Unlike Graves’ disease, the remaining thyroid tissue is normal in this condition. Therefore, the primary treatment involves the surgical removal of the overactive thyroid nodule or nodules. However, RIA therapy may also be used in patients with serious comorbidities or those who refuse surgery. In toxic nodular goiter, the response to RIA therapy may be insufficient. For this reason, surgical treatment is the first-line preference.
The second type of thyroid disorders can be classified as nodular diseases. In this group, thyroid function is normal, but there is an anatomical structural abnormality of the thyroid. In this group, two important conditions take priority for surgery: The first and most important is the confirmed diagnosis of thyroid cancer in the nodule or nodules, and the second is the emergence of compression problems on adjacent organs due to the size of the thyroid and/or nodules. If a needle biopsy of a thyroid nodule clearly indicates a benign condition and radiological/clinical findings confirm this, surgery is not mandatory. These patients can be monitored with regular radiological and clinical follow-up. However, even if the nodules are benign, a significant increase in size over time (more than 50% growth within one year) or the presence of compression symptoms may warrant surgical treatment. Additionally, surgical treatment becomes unavoidable if a definitive diagnosis of cancer is made or if the needle biopsy results are suspicious for cancer. In some cases, despite a needle biopsy being performed, pathologists are unable to provide a definitive diagnosis because insufficient material was obtained. In such cases, surgery may be considered if imaging studies and clinical examination strongly suggest the possibility of malignancy. Alternatively, if all other findings suggest a higher likelihood that the nodule is benign, a repeat fine-needle aspiration biopsy may be considered within 1 to 3 months. If the biopsy report remains inconclusive after repeat biopsies, surgical removal of the thyroid lobe containing the nodule should be considered.
What are the potential complications that may arise during or after surgery?
Among the primary complications associated with thyroid surgery, postoperative bleeding is of primary concern. Because the space where the thyroid is removed is narrow and surrounds the airway, bleeding that fills this space can quickly restrict the patient’s breathing. Therefore, if such a complication occurs, the patient must undergo another surgery. During this procedure, the accumulated blood is drained, and the source of bleeding is controlled. This complication typically occurs within the first 12 hours following surgery. Its incidence rate is 2–4%. The risk of this complication increases with the size of the removed thyroid tissue.
The second major complication is hoarseness. This complication results from damage to the recurrent nerves, which are located on both sides near the thyroid gland, during surgery. If the damage is unilateral, symptoms may include hoarseness, aspiration of liquids into the windpipe, and a decrease in voice quality. In cases of bilateral damage, shortness of breath may also occur in addition to hoarseness. The incidence of this complication is 1–2% for each recurrent laryngeal nerve. Hoarseness is often temporary and may resolve within 1–4 months after surgery. However, if hoarseness does not improve within a year, a diagnosis of permanent hoarseness is made. The incidence of this complication is particularly higher in patients undergoing surgery for cancer and in those who have previously undergone thyroid surgery.
Apart from damage to the recurrent laryngeal nerve, patients’ voice quality may still be impaired following surgery. This is most commonly caused by damage to the superior laryngeal nerve during the procedure. This damage may lead not so much to hoarseness as to rapid vocal fatigue and difficulty producing high-pitched sounds.
Another complication that may occur following thyroid surgery is hypoparathyroidism/hypocalcemia (damage to the parathyroid glands and the resulting drop in blood calcium levels). The parathyroid glands are organs that regulate blood calcium levels. They are located immediately behind the thyroid gland and are usually attached to it. There are two of them on each side. These glands, which are quite small (approximately 40 mg), may be damaged during thyroid surgery, or one or more of them may be inadvertently removed along with the thyroid gland. Damage to these glands can result in a decrease in calcium levels, which is usually temporary but can rarely be permanent. This complication is generally seen after bilateral thyroid surgeries or in patients who have previously undergone thyroid surgery. The risk of this condition becoming permanent is 1–2%. When hypocalcemia develops, numbness around the mouth and muscle spasms in the hands may occur. Treatment involves administering calcium and vitamin D to the patient.
Wound infection occurs in 2–4% of patients. Although it is not a life-threatening complication, it leads to frequent hospital visits for wound checks and prolonged antibiotic use. The risk of this complication is higher in patients with multiple comorbidities, smokers, and those with active infections in other parts of the body.
Another concern for patients is the persistence of a visible scar. It is important to remember that an unwanted scar will form at the surgical incision site within the first year following surgery. Unless there is a family or personal predisposition, or a wound infection develops, the scar will quickly become faint in patients starting from the first 6 months.
Finally, it is necessary to briefly mention another condition that is no longer considered a complication by the scientific community. This is the inability to produce sufficient thyroid hormone following thyroidectomy (hypothyroidism). This is actually an intentional outcome. If a large portion or the entire thyroid gland is removed, the level of thyroid hormone in the blood will inevitably decrease. If the surgical procedure is deemed necessary for the treatment of the disease, this type of deficiency is considered an acceptable trade-off. To ensure this condition does not pose a life-threatening risk, it is necessary to take thyroid hormone externally (orally) on a regular basis for the rest of one’s life.