Thyroidectomy: A Step-Wise Explanation (BUT not meant to be a D.I.Y. Guide!)




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 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.

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