Overview
Definition:
Total thyroidectomy is the surgical removal of the entire thyroid gland
It is a definitive treatment for various thyroid pathologies, aimed at complete eradication of diseased tissue or to prevent future recurrence.
Epidemiology:
Thyroid nodules are common, with a higher prevalence in women and increasing incidence with age
Malignant nodules account for approximately 5-15% of all nodules
Total thyroidectomy is indicated in a significant proportion of these cases, as well as for benign conditions requiring gland removal.
Clinical Significance:
Total thyroidectomy is a critical procedure in managing thyroid cancer, symptomatic benign multinodular goiters, and hyperthyroidism refractory to medical or radioactive iodine therapy
Proper execution and management are essential to prevent significant morbidity, including hypoparathyroidism and recurrent laryngeal nerve injury.
Indications
Malignant Conditions:
Papillary thyroid carcinoma (all types >1cm or with extrathyroidal extension), follicular thyroid carcinoma, medullary thyroid carcinoma, anaplastic thyroid carcinoma
Suspicious or positive fine needle aspiration cytology (FNAC) findings suggesting malignancy.
Benign Conditions:
Large or symptomatic multinodular goiter causing compressive symptoms (dysphagia, dyspnea, hoarseness)
Toxic multinodular goiter or toxic adenoma unresponsive to other treatments
Rapidly growing benign nodules
Cosmetic disfigurement from large goiters.
Other Indications:
Graves' disease refractory to medical management or radioactive iodine therapy
Thyroid abscess or severe thyroiditis requiring gland removal
Prophylactic thyroidectomy in individuals with high-risk genetic syndromes (e.g., MEN 2)
Suspicious solitary nodules on ultrasound and FNAC.
Preoperative Preparation
History And Physical:
Detailed history including dysphagia, dyspnea, hoarseness, neck swelling, and symptoms of hyperthyroidism or hypothyroidism
Physical examination to assess nodule size, fixation, lymphadenopathy, and vocal cord function (indirect laryngoscopy).
Laboratory Investigations:
Thyroid function tests (TSH, free T4, free T3)
Calcitonin levels (if medullary thyroid carcinoma is suspected)
Serum calcium and parathyroid hormone (PTH) levels
Complete blood count (CBC) and coagulation profile
Tumor markers like thyroglobulin (Tg) and anti-Tg antibodies for follow-up of differentiated thyroid cancer.
Imaging Studies:
Thyroid ultrasonography to characterize nodules and assess lymph nodes
Fine needle aspiration cytology (FNAC) for suspicious nodules
CT or MRI may be used for large substernal goiters or to assess extent of disease
Radioactive iodine uptake (RAIU) scan to assess functional status and extent of multinodular goiter.
Patient Counseling:
Informed consent discussing risks (hypoparathyroidism, recurrent laryngeal nerve injury, bleeding, infection, anesthesia risks), benefits, alternatives, and expected recovery
Discussion on temporary or permanent voice changes and calcium supplementation
Smoking cessation advice.
Procedure Steps
Anesthesia:
General anesthesia is typically used
Careful airway management is crucial, especially in patients with large goiters or pre-existing airway issues.
Incison:
A transverse incision (e.g., collar incision or Langer's lines) is made 2-3 cm above the suprasternal notch, typically 2-3 cm in width, to ensure cosmetic healing
The platysma muscle is divided.
Dissection:
Subcutaneous tissue and platysma are dissected to expose the strap muscles (sternohyoid and sternothyroid)
These muscles are divided in the midline or retracted laterally to expose the thyroid isthmus
Identification and preservation of the recurrent laryngeal nerves (RLNs) and inferior parathyroid glands are paramount.
Thyroid Gland Removal:
The superior and inferior thyroid vessels are identified, ligated, and divided
The thyroid lobes are mobilized from the trachea and esophagus
The superior pole is dissected free, taking care to ligate the superior thyroid artery and vein away from the external laryngeal nerve
The entire gland is then removed, ensuring complete excision of both lobes and the isthmus
Hemostasis is meticulously achieved.
Ligation And Closure:
The specimen is sent for histopathological examination
The parathyroid glands, if identified and viable, may be reimplanted in the sternocleidomastoid muscle bed if removed inadvertently
The strap muscles are reapproximated
The platysma is closed with absorbable sutures, and the skin is closed with sutures or surgical staples for cosmetic outcome
A drain may be placed to monitor for bleeding or hematoma.
Postoperative Care
Monitoring:
Close monitoring for vital signs, airway patency, and signs of bleeding or hematoma formation in the immediate postoperative period
Pain management with analgesics
Monitor for symptoms of hypocalcemia (tetany, paresthesias, Chvostek's sign, Trousseau's sign).
Calcium And Vitamin D:
Prophylactic or therapeutic calcium and vitamin D supplementation is usually initiated, especially if parathyroid glands were removed or devascularized
Serial monitoring of serum calcium and PTH levels guides management.
Voice Assessment:
Regular assessment of voice quality
Patients are advised to avoid straining their voice
Persistent hoarseness warrants laryngoscopy to assess vocal cord function.
Thyroid Hormone Replacement:
Lifelong thyroid hormone replacement therapy (levothyroxine) is mandatory after total thyroidectomy to maintain euthyroidism and suppress TSH levels in the case of differentiated thyroid cancer to prevent recurrence
Dosing is adjusted based on TSH levels.
Diet And Activity:
Soft diet initially, advancing as tolerated
Patients are encouraged to ambulate early
Avoid heavy lifting and strenuous activities for several weeks
Follow-up appointments are scheduled for wound assessment, drain removal, and further management.
Complications
Early Complications:
Hemorrhage and hematoma formation (can compromise airway)
Vocal cord paralysis due to recurrent laryngeal nerve injury (unilateral or bilateral)
Hypoparathyroidism (temporary or permanent) leading to hypocalcemia and tetany
Wound infection
Seroma.
Late Complications:
Permanent hypoparathyroidism requiring lifelong calcium and vitamin D supplementation
Permanent vocal cord paralysis causing chronic hoarseness or stridor
Recurrence of thyroid cancer
Adhesions and scarring in the neck.
Prevention Strategies:
Meticulous surgical technique with careful identification and preservation of RLNs and parathyroid glands
Careful hemostasis
Liberal use of cautery and energy devices away from critical structures
Intraoperative nerve monitoring can aid in RLN identification
Appropriate patient selection and preoperative optimization
Postoperative calcium monitoring and prompt management of hypocalcemia.
Prognosis
Factors Affecting Prognosis:
The prognosis largely depends on the underlying pathology
For differentiated thyroid cancers (papillary, follicular), prognosis is generally excellent with complete surgical resection and appropriate follow-up
Medullary and anaplastic thyroid cancers have a poorer prognosis
Presence of lymph node metastases, extrathyroidal extension, and distant metastases negatively impact prognosis.
Outcomes:
In differentiated thyroid cancers, cure rates can be as high as 90-95% with complete surgical removal and adjuvant therapy if indicated
For benign conditions, total thyroidectomy resolves compressive symptoms and hyperthyroidism, leading to a good quality of life with hormone replacement.
Follow Up:
Lifelong follow-up is essential for patients undergoing total thyroidectomy, especially for thyroid cancer
This includes regular physical examinations, neck ultrasonography to detect recurrence or lymph node metastases, serum thyroglobulin levels (for differentiated thyroid cancer), and periodic assessment of thyroid hormone replacement needs
TSH suppression therapy is continued for cancer patients.
Key Points
Exam Focus:
Key concepts for DNB/NEET SS include the precise indications for total thyroidectomy versus less extensive surgery, meticulous identification and preservation of recurrent laryngeal nerves and parathyroid glands, management of postoperative hypocalcemia and vocal cord dysfunction, and the principles of postoperative surveillance and TSH suppression for thyroid cancer.
Clinical Pearls:
Always perform a baseline vocal cord assessment preoperatively
Consider intraoperative nerve monitoring, especially in reoperative cases or difficult dissections
Handle parathyroid glands gently and consider autotransplantation if devascularized or accidentally removed
Early recognition and aggressive management of hematoma are critical due to airway compromise risk
Patient education regarding lifelong hormone replacement is paramount.
Common Mistakes:
Failure to identify or preserve the recurrent laryngeal nerves leading to vocal cord paralysis
Inadvertent removal or devascularization of parathyroid glands causing hypoparathyroidism
Inadequate hemostasis leading to postoperative hematoma
Insufficient dissection of tumor margins in malignant cases
Inadequate postoperative follow-up and management of hormone replacement.