The extent of thyroid resection balances preservation of thyroid function, complications and the risk of recurrent nodularity.
Total and partial thyroid resection
•
Total thyroidectomy requires immediate and lifelong thyroxine replacement.
•
Partial resection aims to conserve enough functioning thyroid tissue for normal function while reducing the risk of hypoparathyroidism associated with total thyroidectomy.
•
Historical subtotal thyroidectomy removes the bulk of each lobe, leaving up to 8 g of relatively normal tissue in each remnant.
•
Regrowth is a significant problem after subtotal thyroidectomy. Unless thyroxine is locally scarce, most surgeons favour total thyroidectomy for bilateral disease.
Asymmetrical disease
•
When one lobe is substantially more affected, total lobectomy on that side is appropriate, particularly in older patients.
•
The Dunhill procedure combines total lobectomy with subtotal resection of the opposite lobe.
•
Most surgeons prefer to leave the less affected side untouched because of the potential for regrowth and the increased complications associated with reoperation.
•
Causative factors often persist, making recurrence likely.
Recurrence and further surgery
•
Reoperation for recurrent nodular goitre is more difficult and hazardous, contributing to a preference for total thyroidectomy in younger patients.
•
If the first operation was unilateral lobectomy alone for asymmetric goitre, completion total thyroidectomy is straightforward when nodularity progresses in the remaining lobe.
•
Total lobectomy and total thyroidectomy also provide treatment for incidental carcinomas.