A Thyroid Cancer Awareness Blog sponsored by Stevie JoEllie's Cancer Care Fund.
Friday, April 27, 2012
Thyroid Surgery Complications: Low Serum Calcium
One of the risks factors associated
with a total thyroidectomy is the possibility of low serum calcium after the
operation, either on a temporary or permanent basis.
There are four small glands, a
little less than pea-size, that live next to the thyroid gland that are called
“parathyroid glands’. They get their name from their location and have
absolutely nothing to do with thyroid gland function.
These glands make a hormone
called PTH, or parathyroid hormone, a hormone whose job it is to keep the level
of calcium in the blood normal. It does this by many mechanisms, helping you
absorb calcium from your diet, managing the calcium in bones, and so on.
If one were to lose all four of
his or her parathyroid glands, the serum calcium would take a serious drop and
replacement calcium and Vitamin D would probably have to be taken for life.
When performing thyroid surgery,
it is prudent to look for and preserve these glands immediately after locating
and preserving the recurrent laryngeal nerve, discussed elsewhere. On the
surface this seems like a simple thing to do, but it isn’t always for several
First, not everyone has 4 parathyroid glands, some
have 5 or more and others may have only three or less.
Next, their location in the neck can be extremely
variable, in fact, one or more may not actually be in the neck at all, but
rather in the upper chest or other atypical location.
Finally, they are sometimes rather nicely camouflaged
sitting in the soft fatty tissues of the neck. It can often require an
experienced thyroid surgeon to discern the very subtle color differences
between parathyroid tissue and normal adjacent fat and soft tissue.
If one were to lose all four
glands, or if all four glands died from lack of blood supply secondary to the
trauma of surgery, that patient would in all likelihood have permanent low
calcium after surgery. This, of course, assumes the patient has the normal
number of parathyroid glands. It is possible to lose the function of one or two
parathyroids and have no calcium difficulties whatsoever, because the remaining
two glands can almost always take up the slack and maintain normal calcium
levels. This is why we virtually never see even temporary low calcium after
only a partial thyroidectomy since the glands on the unoperated side are left
Again, this always assumes the
patient started out with 4 parathyroid glands, and there is never any guarantee
or that. Temporary low calcium levels can be seen after thyroidectomy
simply because the parathyroid glands became bruised or swollen after surgery,
thus making it difficult for them to produce normal amounts of parathyroid
hormone. These patients may have a temporary low calcium that requires minimal
or no calcium replacement and in time the parathyroid glands function well once
When a patient with thyroid
cancer undergoes a radical or total thyroidectomy all of the thyroid
gland is always removed and there is the risk of low calcium after
surgery. The treatment for low calcium after total thyroidectomy is to
supplement the diet with calcium and perhaps Vitamin D until the situation
There are a number of calcium supplements in various forms
such as pills, syrups, and liquids that perform the job quite nicely. Most
instances of temporary low calcium resolve in as little as a few days to as
long as a month or two. As long as sufficient living parathyroid tissue is left
behind after surgery, the calcium levels should ultimately be just fine.