Some folks really love gory details when it
comes to surgery or removing funky stuff from the body. Case in point: I’m often asked if I’ve seen
those You-Tube videos of someone lancing a huge skin abscess and watching
the pus drain out. My answer is
“no.” Frankly, that stuff sort of
grosses me out, and I’ve drained some really nasty deep neck abscesses in my
day, filling the operating room with such a stench that I swear I could still
smell it long after I’ve changed out of my scrubs and left for home.
Sorry to disappoint you, but this discussion
doesn’t contain gross photos or videos.
Instead I’ll use some simple drawings and picture here and there that
oughtn’t be too gruesome, and one of the best means of communication: the
written word.
What follows is how a thyroidectomy is done in step-wise
fashion. Keep in mind, this is not meant
to replace a surgical atlas or more elaborate textbook meant for surgeons and
resident surgeons-in-training. Likewise,
this isn’t a Do-It-Yourself (D.I.Y.) guide to surgery for the more adventurous
types, but merely simplified explanation of how the surgery is done. This is to improve one’s understanding, as
such discussions often help quell fears and misconceptions surrounding surgery,
provides insight into expectations afterwards aids in postop recovery.
Here comes The Disclaimer or “words of warning”
or whatever you care to call it to prevent some of you out there from doing
something really stupid:
With that out of the way, let’s move on.
Thyroid surgery typically involves removal of
one of both lobes of the thyroid gland, known as a thyroidectomy. We’ve
already discussed indications in the last post Thyroid Surgery: Indications and What
to Expect After. Also,
the nitty-gritty of thyroid anatomy and function can be found at The Thyroid Gland: Where is it and What is it?
By the way, surgery is actually far more complicated than what I’ll
describe. What seems simple in practice
only looks and seems that way. If
you’ve watched videos on surgery, the surgery itself looks straightforward and
easy, only because the surgeon makes it look easy, borne out of years and years
of training. What often is not recorded
are the unexpected occurrences—increased bleeding, altered surgical anatomy, an
unforeseen complication, a strange encounter, etc., which forces the surgeon to
change the routine and manage the unexpected.
You can’t teach this in a video, a formal surgical textbook, or even a
live-action course. It’s the experience
of the surgeon who operates on a regular basis that provides this level of
expertise. Ever wonder why it’s called
the “practice” of medicine? It’s due to
the complexities of the human body and ever-changing and ever-increasing
knowledge base that makes this an expanding and dynamic field. So for you DIYers who attempt this and make a
mistake, well…I told you so.
Anyway, here we go.
THE SURGERY:
THYROIDECTOMY
1. Anesthesia is first
administered since I’ll assume you want to be asleep during this
procedure. Often a special endotracheal
tube is placed through the larynx down in the trachea, which has a special
sensor to detect vocal cord movement. A nerve
stimulator is attached to the body via needle-like probes beneath the skin,
usually in the mid-chest or shoulder. So
if you see two tiny pricks in these areas and a little soreness, don’t be
surprised.
2. The incision.
Naturally, an incision is required. First the skin is cleaned with alcohol, a
surgical marking is made in a curvilinear fashion. We try to make this into, or parallel to,
natural skin creases to provide the most optimal cosmetic appearance. After the neck is the prepped with an antiseptic
solution and then draped with sterile towels, the skin is incised with a sharp
scalpel. One must cut not only through
skin and dermis (the thick layer just below the visible skin) but also the
subcutaneous fat beneath, and also through a thin sheet of muscle called the platysma.
3. Raising the flaps
This is done by incising under the platysma muscle with the edge
of a scalpel or a Bovie cautery (device that delivers electrical energy to
cauterize and cut tissue). We call this
a subplatysmal flap, and if you get into the right plane of dissection,
creating and raising these flaps is relatively bloodless. These flaps are raised superiorly (upwards)
and inferiorly (downwards).
4. Separating the strap
muscles
The strap muscles run up and down over the larynx and
thyroid gland, and are responsible for moving the larynx up and down during swallowing
or talking. There is a thin vertical
line of tissue running down the middle.
Called the median raphe of the strap muscles, this is incised,
allowing the strap muscles to then be retracted laterally (to the sides) to
expose the thyroid gland.
5. Identifying the thyroid
gland
Once the strap muscles are separated and retracted to the sides,
the thyroid comes into view. The gland
has a thin capsule and lots of blood vessels on its surface, so dissection is
done more gently. Any unnecessary
bleeding reduces visibility and makes the procedure more difficulty. The strap
muscles are retracted farther laterally and the beforementioned skin flaps are widely
retracted to provide optimal visualization.
Such retraction really stretches the tissue which can lead to some of
the discomfort with talking and swallowing afterwards. However, the body’s tissues are pretty
resilient and can tolerate quite a bit of manipulation and will heal quite
well.
6. Ligating and dividing
blood vessels.
Most of the surgery requires blunt dissection, meaning gently
separating tissue without cutting. There
are several veins leading from the lower (inferior) and side (lateral) of the
gland that once isolated can be ligated and then cut. There are several ways to ligate blood
vessels. In the old days, we often used
thin sutures to tie off the cut ends of blood vessels. Another method is a hemoclip, a metal
device that looks very much like a staple that clamps onto a blood vessel. The method that I and many other surgeons use
is a Harmonic Scalpel. This
device uses low temperature, ultrasonic energy that first seals the blood
vessel and then divides it, all in one step.
This really saves time.
7. Identifying the recurrent
laryngeal nerve (RLN)
As the dissection moves deeper, we focus our attention inferior to
the gland. Before dividing any more
tissue, more blunt dissection is carried out in search of the RLN, which runs
upwards close to the side of the trachea and inserts itself into the larynx. The RLN moves the larynx on that side, namely
allowing movement of the vocal cord. If
the nerve is injured or severed, the vocal cord will be weak or paralyzed,
causing hoarseness and altered voice quality.
If the RLN on both sides is affected, this will lead to both vocal cords
being weak or paralyzed which can lead to breathing problems (since both vocal
cords will tend to remain in the closed position, narrowing or obstructing the
airway). Such a rare occurrence may
require a tracheotomy tube into the neck below the vocal cords (see Tracheotomy
and Trach Tubes).
Fortunately, this is a rare occurrence but the patient ought to be
informed of this complication especially when a total thyroidectomy is
considered.
This is where the nerve stimulator is useful. If we see a structure that looks like the
RLN, it can be stimulated, causing the vocal cord to move, which is detected by
the special endotracheal tube, creating an audible signal and waveform on the
monitor. Once the RLN is identified, the
gland is carefully dissected off this and retracted upwards and medially
(towards the center or middle of the neck).
8. Identifying the
parathyroid glands
These are small, tannish, pea-sized glands found on the back side
of the gland. Given fat and lymph nodes
have similar appearances, these little guys can be a challenge to
identify. Every effort is made to
preserve and leave these in the neck, as they regulate the calcium in the body
by creating parathyroid hormone (PTH).
If calcium is low in the blood stream, the parathyroid glands secrete
PTH triggering the body to preserve calcium.
If PTH is low or absent, the body will not preserve calcium and allow it
to excrete through the kidneys and into the urine. The parathyroids have a tiny blood supply and
so even if they are seen and left behind, dissection on these glands can cause
a sort of shock effect, where they aren’t producing PTH even in a setting of low
circulating calcium.
9. Removing the gland
Once the parathyroids and RLN are found, that particular thyroid
lobe is dissected further upwards. The superior
pole blood vessels are carefully dissected out, ligated and divided. There is another nerve, called the superior
laryngeal nerve (SLN), that travels in this area. Though not as crucial as the RLN, the SLN
still contributes to laryngeal function and some vocal qualities may be
affected if this nerve is weak or nonfunctional.
The gland is then dissected off the lower part of the larynx, the
cricoid and the trachea. There is a
thick attachment called Berry’s Ligament between the thyroid and trachea that
is divided. It try to first bluntly
dissect into this tough ligament to insure we are well away from the RLN prior
to dividing it (which often leaves my fingers quiet sore at the end of the
day).
10. Opposite side or not
Once the particular thyroid lobe is freed, it is attached only by
the isthmus (bridge of intervening thyroid) to the opposite side. If we are planning on doing only one side,
then this isthmus is divided, usually with the Harmonic Scalpel. If we’ve planned for a total thyroidectomy at
the get-go (i.e., for known cancer or a gland that is large on both sides), we
often leave the isthmus attached and proceed to remove the opposite lobe in the
same fashion as above.
11. Closing the wound.
Once the lobe or entire gland is removed, we irrigate the surgical
site with sterile saline solution, look for any bleeding sites and carefully cauterize
these. Sometimes a hemostatic agent is
placed as a preventative measure into the site, especially over the RLN (we try
to minimize cautery near the RLN since this could damage the nerve). Often a drain is placed, which exists from a
separate small incision to the side of the main surgical incision. The strap muscles are reattached in the
midline with an absorbable suture. The
skin flaps are reapproximated by suturing in layers with absorbable
sutures. The skin is closed with either
a removable or absorbable suture just underneath the epidermis (the exterior
surface of skin). If removable sutures
are used (i.e., with Prolene suture which is blue) you will find loops of blue
suture on each side of the incision.
These are cut and pulled out.
POSTOPERATIVE COURSE:
This surgery often is done in a hospital setting. Some surgeons send patients home after
several hours, especially if only once side is done (ie, one thyroid lobe is
removed). Many surgeons keep patients overnight at least. The following occurs during your hospital
stay.
1. Calcium levels are
monitored with blood draws every 8-12 hours.
Since the parathyroids might not “wake up” right away, PTH can be low or
absent. Also your doctor and nurse may
tap on your face to check for twitching.
This is called a Chvostek’s sign and if positive, is an indictor
of low calcium. If calcium is too low,
you can have tingling in the lips or other parts of the body (called paresthesias),
twitching, cramping or tetany. If really
low, laryngospasm can occur, causing breathing problems. Calcium can be administered intravenously
(i.v.) if needed in a jiffy. Otherwise,
calcium will be given by mouth in the form of calcium carbonate (such as Tums). Often, vitamin D in the form of
calcitriol (Rocaltrol) is given, which is a prescription and more potent and
quicker onset of action than other forms of vitamin D. This vitamin aids in preventing calcium
wasting, raising calcium levels more quickly.
Often this is temporary and the vitamin D supplement is slowly decreased
over a matter of days or weeks.
Hypocalcemia (low calcium) more often occurs in patients having a
total thyroidectomy. Although the
parathyroids are manipulated where only one lobe is removed, the PTH and
calcium tend to remain normal especially if the opposite side was not
dissected. Thus, most patients having
one side operated often can go home the day after surgery. In those who’ve had a total thyroidectomy,
two or more days in the hospital are not uncommon in order to monitor calcium
levels and provide immediate treatment with iv calcium if needed.
2. Pain control: many
patients need nothing more than Tylenol or ibuprofen. I find this more so in the older generation
(ages 60 years and up, for some curious reason). I always prescribe hydrocodone in the event
OTC meds don’t help. Infrequently, some
patients need i.v. pain medication.
3. Drain output is
monitored and if there is too much blood coming out, this could be an
indication of a blood vessel that has opened up. The drain prevents formation of a hematoma
which can cause choking and airway obstruction, thus letting the blood out. If
bloody drainage persists, we may need to return to the O.R. to open the wound
and control the bleeding. More often
though the drainage is low, and usually blood tinged and later a serous
amberish or pink color. If the drain output is low, the drain is often removed
24-36 hours after surgery.
4. Wound care is simple,
keeping the suture line dry, applying an antibiotic ointment such as Neosporin
to the site before and after showering or bathing.
5. Light activity is
recommended for 1-2 weeks, avoiding strenuous exercise or heavy weight
lifting. Some swelling can occur on the
neck especially above the suture line since this flap is usually longer and is
retracted very high up towards the chin.
Sleeping with your head above the level of your heart (ie, on 2-3
pillows) aids in reducing swelling but also improves comfort. An ice pack can be applied for no more than
15 minutes at a time.
6. Diet is started slowly,
first with clear liquids and then advancing as tolerated. Since the larynx moves up and down in a fresh
surgical site with the act of swallowing, there can be a bit of tenderness when
eating and drinking. Many patients are
eating normal food 1-2 days following surgery.
The key is to take it slow.
7. Upon discharge, you may
have a prescription for pain medication and vitamin D. Also make sure you buy a large bottle of Tums
or other form of calcium carbonate, as your doctor will advise you on how to
take this, if needed.
8. Sutures are removed 6-7
days after surgery in the office. Sometimes
calcium levels are checked. Thyroid
hormone level can be tested by checking a TSH (see The
Thyroid Gland: Where is it and What is it?
for the reasons for this) usually after
2-3 weeks, since the half life of one of the hormones (T4) is quite high.
Looking back, I think I got carried away as this is a rather long
post. But I tried to impart as much informative as
possible, short of giving an entire textbook-like surgical instructions. Again for the sake of repeating myself ad
infinitum, no matter how tempting, avoid DIY surgery!
©Randall S. Fong, M.D.
Comments
Post a Comment