Surgery for thyrotoxicosis: mechanisms, outcomes and risks
THE CONTEXT
Surgery treats thyrotoxicosis by reducing or removing overactive thyroid tissue; the mechanism and subsequent thyroid function depend on the pattern of disease and extent of resection.
How surgery produces a cure
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In diffuse toxic goitre and toxic nodular goitre with overactive internodular tissue, surgery reduces the mass of overactive thyroid tissue below a critical level.
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For an autonomous toxic nodule or toxic nodular goitre with autonomous toxic nodules, removal of all overactive tissue allows the suppressed normal thyroid tissue to function again.
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An operation may also reduce TSH-RAb.
Extent of thyroidectomy and thyroid function
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After subtotal thyroidectomy, the patient should return to a euthyroid state after a variable period of hypothyroidism, but long-term risks include recurrence and eventual thyroid failure.
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Recurrence of thyrotoxicosis occurs in at least 5% of cases after subtotal thyroidectomy.
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Total or near-total thyroidectomy accepts immediate thyroid failure and lifelong thyroxine replacement to eliminate recurrence and simplify follow-up.
Benefits and operative risks
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Surgery removes the goitre, produces a rapid cure and has a high cure rate when the operation is adequate.
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Risks include permanent hypoparathyroidism and nerve injury. Young women tend to have a poorer cosmetic result from the scar.
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With suitable preparation and an experienced surgeon, operative mortality is negligible and morbidity is low.