A thyroidectomy is a surgical procedure involving the removal of all or part of the thyroid gland located at the base of the neck. This operation is commonly performed to treat conditions such as thyroid cancer, an enlarged gland known as a goiter, or hyperthyroidism, which is an overproduction of thyroid hormones. While thyroid surgery is generally considered safe and highly effective, it is a major operation that carries potential risks and complications, much like any other surgical intervention. These complications range from issues specific to the delicate anatomy of the neck to more general surgical concerns.
Vocal Cord and Nerve Injury
Injury to the nerves responsible for voice and breathing control is a specialized and concerning complication. The proximity of the thyroid gland to the Recurrent Laryngeal Nerve (RLN) and the Superior Laryngeal Nerve (SLN) makes them vulnerable during the dissection process. The RLN travels along the windpipe and voice box to innervate nearly all the muscles that move the vocal cords.
Damage to the RLN can result from stretching, bruising, or accidental cutting, which leads to varying degrees of vocal cord paralysis. Temporary injury, often caused by inflammation or bruising, can occur in approximately 1.5% to 14% of cases and typically causes hoarseness (dysphonia). This transient paralysis usually resolves spontaneously as the nerve recovers over a few weeks or months.
Permanent injury to the RLN, defined as paralysis lasting more than six months, is a less frequent occurrence, typically seen in 1% to 2% of surgeries. When only one side is affected (unilateral paralysis), the primary symptom is a weak, breathy voice and sometimes difficulty swallowing thin liquids. If both RLNs are permanently damaged (bilateral paralysis), the vocal cords can remain stuck in a closed position, causing a severe, life-threatening obstruction of the airway that requires immediate intervention.
The SLN is responsible for controlling the pitch of the voice. Injury to the external branch of the SLN may not cause obvious hoarseness but results in a loss of projection and the inability to hit high notes. Surgeons take meticulous steps to identify and preserve these nerves, sometimes using specialized nerve monitoring equipment during the procedure.
Post-Surgical Calcium Imbalance
A specific complication of thyroidectomy is a temporary or permanent drop in the body’s calcium levels, known as hypocalcemia. This occurs due to trauma or damage to the parathyroid glands, four small glands located immediately behind the thyroid. These glands produce Parathyroid Hormone (PTH), which is the primary regulator of calcium levels in the blood.
During the removal of the thyroid gland, the parathyroid glands can be inadvertently injured, have their blood supply disrupted, or be accidentally removed. Even if the glands are preserved, surgical manipulation can cause them to become temporarily stunned, leading to transient hypoparathyroidism. This immediate post-operative complication is relatively common, sometimes affecting up to 30% of patients.
When PTH production is insufficient, the blood calcium level drops, leading to the symptoms of hypocalcemia. Patients may first notice a tingling or pins-and-needles sensation (paresthesia) around the lips, fingers, and toes. More severe hypocalcemia can lead to muscle cramps, spasms, and twitching (tetany).
The majority of these calcium imbalances are transient, resolving within a few weeks to months as the stunned parathyroid glands regain normal function. While temporary hypocalcemia is common, permanent hypoparathyroidism, requiring lifelong supplementation, occurs in a much smaller percentage of patients, generally less than 5%. Management typically involves carefully monitored oral supplementation with calcium and an active form of Vitamin D.
Acute and General Surgical Risks
Beyond the complications specific to the neck’s delicate anatomy, thyroidectomy carries several acute and general risks common to any major surgery. Postoperative bleeding that leads to a hematoma (a collection of blood) is an infrequent but potentially life-threatening complication that requires immediate attention. The thyroid region is highly vascular, and while the incidence of significant bleeding is low, typically less than 1%, it poses a unique danger in the neck.
A rapidly expanding hematoma can quickly swell and compress the trachea, leading to acute respiratory distress and the need for an emergency return to the operating room for drainage. Most serious hematomas develop within the first six to 24 hours following surgery, which is why patients are closely monitored during this period. Surgeons take meticulous steps to ensure all blood vessels are sealed before closing the incision.
Infection at the surgical site is a standard risk, though it is relatively uncommon following a thyroidectomy due to the excellent blood supply in the neck. Signs of a wound infection usually appear a few days after the operation and include increased redness, swelling, unusual discharge, or fever. Infections are typically treated with a course of antibiotics, though sometimes drainage is necessary.
The cosmetic outcome of the procedure is also a consideration, as an incision is made across the front of the neck. While surgeons strive to place the incision within a natural skin crease, there is a risk of developing noticeable scarring, such as a raised, thickened scar known as a hypertrophic scar or keloid.