SURGERY FOR HYPERPARATHYROIDISM

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What is the recommended treatment for hyperparathyroidism?

What is the surgical procedure for treating hyperparathyroidism?

What is MIRP (minimally invasive parathyroidectomy)?

What type of anesthesia is used for the MIRP?  What is the difference between “general” anesthesia and “LMA”?

Do all surgeons have training in MIRP?

What is the likelihood of a successful outcome with MIRP?

 

What is the recommended treatment for hyperparathyroidism?

Since the high calcium level is detrimental to the body’s system over time, it is usually recommended to fix the problem.  Currently there are no medications tor correct it. But the abnormal parathyroid gland can easily beremoved surgically, providing an immediate cure.  In most cases, the problem is limited to just one of the four glands.  Nothing needs to be done to the normal glands.

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What is the surgical procedure for treating hyperparathyroidism?

For the past hundred years, the surgical treatment for hyperparathyroidism involved making a long neck incision under general anesthesia, and searching all the nooks and crevices in the neck around (and even inside) the thyroid gland, for all four parathyroid glands.  The surgeon would then make a visual assessment of the four glands, to decide which one, or more, of the glands, looked “too big”, and presumably overactive.  Biopsies of one or more of the glands would be done, to try to decide which glands to completely remove.  In some cases, not all of the glands would be found, and in fact, it might be that the abnormal gland may never be identified. Up unitl about the 1980’s, the surgeon had no information prior to the surgery as to what he may find, and for this reason, a very long incision was used, and the “exploration” of the neck was extensive, tedious, and time-consuming.

The search for helpful pre-operative tests eventually identified the sestamibi scan, and the ultrasound, as being very helpful for providing a road map for the operation.

The sestamibi scan is named after the radioisotope used.  It is the same radioisotope used for patients undergoing evaluation of their heart function.  It works in both tests for the same reason—the isotope is taken up after injection into the bloodstream by the most metabolically active cells in the body.  These cells are using large amounts of energy constantly.  Less active cells do not take up much of the radioisotope.  As a result, the scan that is taken shows focal areas or “hot spots” that show where the most active cells are.  In the case of parathyroid glands, a single adenoma almost always shows as a  “hot spot” on the scan, since it is a “high energy” gland.  The other glands, which are in a resting state, will not show up.  As a result, the scan can identify a single gland that is overactive.  In most cases, if only a single “hot” gland is seen on the scan, then the other glands are usually (but not always) normal.

As more experience was gained with the sestamibi scan, it was thought that if this test was “positive”, showing a single enlarged gland, then a surgeon wouldn’t necessarily have to find all the other glands to achieve success in most cases. This was the original basis for the less invasive procedure, called a MIRP, or “minimally invasive radioguided parathyroidectomy”.  But with further experience, less reliance has been given to a sestamibi scan that shows a single “hot” gland.  It is not uncommon for there to be another parathyroid gland besides the “hot” one, that is also overactive.  So the sestamibi scan can give guidance regarding the most overactive gland, but it does not eliminate the possibility that another overactive gland is present.  It is this understanding that has led us to evolve to a minimally invasive procedure that incorporates the identification of all four glands if possible.  This is done regardless of what the sestamibi scan shows.

Another useful test for localizing a parathyroid adenoma is an ultrasound.  This test uses the same technology as is used in pregnancy to look at the fetus in the womb.  The ultrasound probe is placed on the neck, which shows the internal anatomy.  Normal parathyroid glands are so small that they will not be identified with ultrasound.  But the overactive glands will usually be large enough to be seen, as a distinctive dark, somewhat triangular shaped structure, just behind the thyroid gland.  This test can be helpful in knowing before the operation what the size of the abnormal gland is, but it does not provide the same information as the sestamibi scan, which correlates more closely with overactivity in an individual gland.  An ultrasound is also helpful to know if there is anything abnormal in the thyroid gland.  If there is any abnormality in the thyroid, it is helpful to know this in advance.

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What is MIRP (minimally invasive parathyroidectomy)?

These new tests have given birth to a less invasive surgical cure for hyperparathyroidism, the MIRP, or “minimally invasive radioguided parathyroidectomy”. But it’s important to know that this term is used differently by different surgeons, as newer variations have evolved since it was first described.

With this technique as originally described, a small incision, only about one inch in length, is used.  A sestamibi scan is done immediately before the surgery, so that the abnormal glands have the high concentration of sestamibi in them during the surgical procedure.  With this technique, the surgical dissection is very focused and limited.  The normal glands are left alone.  As a result, the operation is usually completed in 30-60 minutes, and can be done without general anesthesia if desired.  Patients can go home the same day.

As surgeons began using this minimally invasive technique, it was understood that there is no technique which will be successful 100% of the time.  Historically, if a surgeon was successful about 90% or more of the time, this was considered about as good as one could get with the traditional big incision “neck exploration”.  And so, as the minimally invasive procedures started to be done, this success rate of 90-95% was considered the target to match.

It became evident though, that there were ways to further increase the success rate, in the context of the minimally invasive procedure, or MIRP.  Although the initial MIRP procedures focused on making a small incision and limiting the dissection, surgeons would occasionally want to look at one or more of the other parathyroid glands.  But since a primary goal had been to keep the incision small, some surgeons (including us) began to get increasing experience with identifying the other glands, but still keep the incision small.  Now it is not something easily learned, to find all four parathyroid glands through a small incision, but this is possible for those surgeons with a concentrated experience, gained only through having performed a high volume of MIRPs.

With this increasing experience of identifying all four glands through a small incision, and realizing that occasionally the sestamibi scan will show a single “hot” gland, when there is also a second overactive gland, some surgeons began making it a policy to routinely look for all four glands, very similar to the old-fashinoned long incision “neck exploration”.  But now, the sestamibi scan and ultrasound provide a pre-op road map, and with the increased surgical experience, the success rate of the procedure has come closer to 100%.  And so, in a sense we’ve come almost full circle in parathyroid surgery, but with marked improvements in technique and in outcomes.  No longer does the operation take 4 hours, and require a Frankenstein incision.  No longer do we have only visual feedback based on gland size to determine which glands are abnormal.  No longer must patients be hospitalized after the operaton.

I still consider this most recent evolution of the MIRP to be a minimally invasive procedure, since it is still done through a small incision, and as an outpatient, with minimal complications.  But in most cases, all four glands can be identified, which decreases the possibility of missing a second overactive gland.  But there are many surgeons who are only now starting their experience with MIRPs, based on the first methods used, of trying to know in advance of the surgery which gland should be removed, and only finding and removing that one.  They may have a reasonable success rate, but will most certainly have patients with second adenomas which are only “discovered” when the serum calcium fails to normalize after the operation.

One particularly important thing we learn when the sestamibi scan is done is to be sure there are no parathyroid adenomas in unusual locations, such as up high in the neck, or down low in the chest.  Though uncommon, if you have an overactive parathyroid gland in one of these locations, the usual neck incision is not going to cure you.

Also important, if you have had a sestamibi scan done already, and it was read as “negative”, you can still have minimally invasive surgery.   One very good thing about a “negative” sestamibi scan is that it virtually rules out the possibility that you have a gland somewhere outside the usual locations.  This is actually very helpful for your surgeon,  even though you might have been told that you are “not eligible” for minimally invasive surgery.  That simply is not true.  In other words, seeing that there are no “hot spots” in either normal OR abnormal places means that even if not seen on the scan, they must be hiding in the usual positions behind your thyroid, where we can find them with the usual dissection.

Complications during the procedure are VERY UNCOMMON, but you should be aware of these possible problems.  Behind the thyroid, on either side is a nerve that activates each vocal cord in your larynx, or voice box.  These nerves are quite close to the parathyroid glands, so it is possible for them to be injured during the surgery.  If this happens, your voice is likely to be affected.  With the traditional parathyroid surgery, there is a lot of dissection done very close to both of these nerves.  Fortunately, even with the traditional operation, injuries to these nerves (recurrent laryngeal nerves) are uncommon.  But with the MIRP, even less dissection required.  This focused procedure, which is usually almost bloodless, does not require dissecting the nerves, thus minimizing the risk of any injury or bruising.  Excessive bleeding is a potential complication of any surgery, no matter how small or large the operation is.  This problem is only very rarely seen with the MIRP, since the dissection is limited to finding only the involved parathyroid gland.

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What type of anesthesia is used for the MIRP?  What is the difference between “general” anesthesia and “LMA”?

General anesthesia is defined as a state of unconsciousness and loss of protective reflexes, brought about by the use of one or more drugs or (inhalational) gases.  General anesthesia has been around for about 150 years.  It has its roots in Georgia, having first been used by Dr. Crawford Long in 1842, using ether as the inhaled gas.  For the next 120 years, ether was the only agent used for general anesthesia.  But in the 21st century, we have dozens of different agents to choose from, both gases that are inhaled, and drugs that are given by vein.

For the biggest operations (like in the chest or abdomen), general anesthesia includes drugs which temporarily paralyze the body, and your breathing is supported during that time with a machine.  But in lesser procedures, such as parathyroid surgery, paralysis is not necessary, even though you are unconscious.

When we say that “protective reflexes” are lost, one of the most important reflexes is the “gag reflex“, which you experience anytime something makes you choke or cough, or have something that “went down the wrong way”, or “down my windpipe”.  This reflex keeps us from getting anything other than air in our lungs.  If you are given drugs or gases that suppress your gag reflex, we say that you cannot “protect your airway”, and in that state, you are at risk for getting stomach contents, or oral secretions into your lungs.  This is called aspiration.  In order to avoid aspiration, some sort of tube is placed either all the way into your airway, or directly over the entrance to your airway in the back of your throat.

A tube which goes all the way into the airway is called anendotracheal tube.  A tube that fits the back of your throat is called an LMA (which stands for “laryngeal mask airway”).  Use of either of these tubes is only necessary if your gag reflex is (or could be) impaired.  If you are given a light sedation, you can protect your airway without a tube, but anything deeper requires one of these tubes for safety’s sake.  An LMA tube can be more easily inserted than an endotracheal tube, particularly since with the endotracheal tube, you have to be given drugs that paralyze you for just a few minutes.  But the LMA does not protect your airway as well as an endotracheal tube.  And if you have a history of reflux (GERD, GE reflux), an LMA probably is not the better choice.

If a surgeon says you’re having LMA anesthesia and NOT general anesthesia, it’s just not correct.  A person who is awake enough to protect their own airway will gag BECAUSE of the LMA, so you have to be receiving enough drugs to suppress that reflex.

Now there are surgical (or dental) procedures that can be done with just local anesthesia, like removing skin lesions, or filling cavities, or some breast biopsies.  Surgery for heart, lung, or intestinal problems simply cannot be done under local anesthesia, because the pain would not be controlled with just a local anesthetic.  Parathyroid operation involve more than removal of skin lesions, but less than doing a heart bypass.  And so, although it IS POSSIBLE to do a parathyroid operation with only local anesthesia, you would probably have more pain than you want to experience.  And of course, we don’t want you to have ANY pain.  For this reason, it is usually recommended that you have at least a light general anesthetic for the procedure.  This means that you are receiving drugs and/or gases that lower your consciousness and suppress your gag reflex enough to require either an endotracheal tube, or an LMA.

And so, there is not too much difference between what is called LMA anesthesia, and general (endotracheal) anesthesia.

In the past, no surgeon would have considered using anything but general anesthesia with an endotracheal tube for a parathyroid operation.  But as experience with MIRP has been gained, the necessary dissection has become more refined, allowing the less “deep” levels of anesthesia to be utilized.

Conventional

For many years, the surgical procedure for parathyroid disease involved a fairly long incision crossways on the lower part of your neck. Through this big incision, the neck muscles were widely mobilized, and the thyroid gland was thoroughly dissected away from the tissue behind it, where the parathyroid glands lid. All 4 parathyroid glands would be identified if possible, and one or more would be removed if they just looked abnormal. Any normal looking parathyroid glands would be identified but left in place. Patient would typically be kept in the hospital for several days afterward.

There are some surgeons who still use this traditional operation for parathyroid disease. But it really is much more surgery than is needed to fix this problem. Some surgeons may take 4 or more hours to do this operation, and they might not have near as much success as an experienced parathyroid surgeon using the minimally invasive techniques. Many surgeons have very little prior experience in parathyroid surgery, and if they choose to operate on someone with hyperparathyroidism, they will resort to what they know, which is the traditional LONG incision, with tedious exploration, looking for all 4 glands.

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Endoscopic

There are some surgeons who have taken the “minimally invasive” aspect to a further level. I am not a proponent of the endoscopic methods which have been described. These methods involve the use of scopes and video camera visualization projected onto a television screen, using very small instruments. Although the concept is attractive, it does not decrease the operating time, and can introduce the possibility of new complications not typically seen with either the traditional surgery, or with the minimally invasive parathyroidectomy described above.

Direct

The “direct” endoscopic procedure makes an incision in the neck similar to what is done in the minimally invasive radio guided parathyroid procedure. But instead of operating directly through this opening, a scope with an attached video camera is inserted, and while watching the image on a television screen, tiny instruments are passed through the same small incision, or through other adjacent small incisions, the abnormal gland is identified and removed. Although the visualization can be excellent, there’s not much difference between the size of the incision for this procedure compared with the minimally invasive parathyroid operation described above. And the success rate is not going to be any better than with the minimally invasive technique, and possibly could be lower.

Transaxillary

Some surgeons have even developed a method of operating through small incisions under the arm, instead of an incision on your neck. A pathway is dissected underneath the skin up to your neck, behind the thyroid, and the abnormal parathyroid gland is identified and removed. The only reason to even consider such an indirect approach to your parathyroid glands is to try to avoid any scar on the neck whatsoever. However, there will be no guarantee that a neck incision will not be necessary after all, and it would be difficult for this technique to have as high a success rate as can be achieved with the minimally invasive technique. Our first priority is to complete a successful operation, and any variation in the technique which threatens to lower the rate of success should only be considered with great caution. At DeKalb Surgical Associates, we have not felt it appropriate to utilize these very indirect surgical techniques for this disease, since our success rates are so high, and the incisions are quite small anyway. 

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Do all surgeons have training in parathyroid surgery?

Parathyroid surgery is not a common procedure for most surgeons, simply because hyperparathyroidism is not nearly as common as other things that surgeons take care of, like hernias, gallbladder problems, and breast problems.  As a result, many surgeons either don’t do any parathyroid surgery, or perhaps one every year or so.  In their five years of training, they may have only actually seen just a few cases, and may have only done just a handful.  They are likely not skilled in doing the MIRP, and in most cases will recommend doing the traditional bigger operation, under general anesthesia, with a hospital stay of one or two days.  And if a surgeon only does maybe one of these operations a year, they do not have enough experience to know what their rate of success is.  You should probably not allow such a surgeon to do your parathyroid surgery, when the outcome is so unpredictable.

A surgeon with limited experience will mistakenly think that only patients with a “positive” sestamibi scan are candidates for MIRP.  But nearly all patients with hyperparathyroidism are candidates for MIRP by an experienced surgeon.

There are also surgeons who do more parathyroid surgery than most surgeons, but who still recommend the bigger traditional operation.  They may have a very good success rate, using the older techniques, typically a much larger incision, and a hospital admission, with specific plans to find every single gland. But the newer MIRP technique has clearly demonstrated to be highly successful in experienced hands, without the need for a long incision, or a hospital admission in most cases.

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What is the likelihood of a successful outcome with MIRP?

The sestamibi scan, coupled with an appropriate pre-operative evaluation and an experienced surgeon, will almost always lead to immediate cure for hyperparathyroidism.  At DeKalb Surgical Associates, we track our results for all parathyroid patients. Over the past 10 years, our success rate is 97%.  Dr. Kennedy performs about 50-80 operations per year.  If you are seeing a surgeon for possible parathyroid surgery, you should ask how many procedures they do each year, and what their success rate is.

If you would like more information you can contact us at 404-508-4320, or by email to Dr. Kennedy.  There is NO EXTRA FEE for a consultation over and above the usual charge.  If you travel from out of town, we can provide information of hotel accommodations.  Atlanta is a convenient hub for most airlines from anywhere in the US.  If we have information in advance from you, which confirms the diagnosis of hyperparathyroidism, and the indications for surgery, we can tentatively schedule your surgery in advance of your arrival.  Dr. Kennedy would see you in the office on the day before the planned surgery to review your medical history and perform a physical exam in person, and explain the procedure in more detail.  After surgery the next day, you will be able to return to your hotel for just one more night in town before returning home.  There are lots of fun things to do in and around Atlanta, so you could even combine your trip for your surgery with some sightseeing.

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