Why hemithyroidectomy is done instead of lobectomy
Reading File
Finding Sources
Finding Sources
Reading File
Finding Sources
Reading File
The Sabiston textbook directly answers this. Here is the full explanation:
Hemithyroidectomy vs. Lobectomy - Are They Different?
They are the same operation. "Hemithyroidectomy" is simply an alternate name for "thyroid lobectomy." The two terms are used interchangeably in surgical practice.
As stated explicitly in the Sabiston Textbook of Surgery:
"...thyroid lobectomy (also referred to as hemithyroidectomy), in which all of the visible thyroid on one side is excised along with the isthmus and, if present, the pyramidal lobe."
- Sabiston Textbook of Surgery, p. 1522
So there is no functional difference - the procedure involves:
- Removal of one complete lobe of the thyroid
- Removal of the isthmus
- Removal of the pyramidal lobe, if present
Why Is the Term "Hemithyroidectomy" Used?
The prefix "hemi-" (meaning "half") reflects the anatomical reality that the thyroid gland has two lobes. Removing one lobe is literally removing half the gland - hence "hemithyroidectomy." Surgeons and textbooks use both terms depending on convention, institution, or regional preference, but they describe the same resection.
Context: Where Does Lobectomy/Hemithyroidectomy Fit?
The modern spectrum of thyroid resections (from Sabiston) is:
| Procedure | What Is Removed |
|---|---|
| Isthmusectomy | Isthmus + pyramidal lobe only |
| Thyroid lobectomy = Hemithyroidectomy | One full lobe + isthmus + pyramidal lobe |
| Near-total thyroidectomy | All visible thyroid, leaving < 1 g at ligament of Berry |
| Total thyroidectomy | All or nearly all visible thyroid tissue |
When Is Lobectomy/Hemithyroidectomy Chosen?
It is preferred over total thyroidectomy in situations where:
- Benign thyroid nodules on one side (e.g., follicular adenoma)
- Low-risk differentiated thyroid cancer - recent guidelines (notably ATA 2015) allow lobectomy for tumors < 4 cm without extrathyroidal extension or node involvement
- Preserving thyroid function - avoids lifelong thyroid hormone replacement in many patients
- Reducing complication risk - bilateral RLN (recurrent laryngeal nerve) injury and permanent hypoparathyroidism are risks unique to total thyroidectomy; lobectomy eliminates the contralateral side risk
The rationale, as stated in Sabiston: "The rationale for these lesser-extent lobar resections has been to protect the RLN and blood supply to the parathyroids as well as to preserve thyroid function without the need for thyroid hormone replacement."
Bottom line: Hemithyroidectomy and lobectomy are the same surgery. "Hemithyroidectomy" emphasizes the anatomical concept (half the gland), while "lobectomy" emphasizes the anatomical unit (the lobe). No surgeon does one "instead of" the other - they are different names for the same procedure.
This is a shared conversation. Sign in to Orris to start your own chat.