Parathyroid Gland: The Function of the Parathyroid Gland
Guest: Dr. Denise Carneiro-Pla - Surgery
Host: Dr. Linda Austin – Psychiatry
Dr. Linda Austin: I’m Dr. Linda Austin. I’m interviewing Dr. Denise Carneiro-Pla, Assistant Professor of Surgery, Medical University of South Carolina. Dr. Carneiro-Pla, I know you have a special interest and very strong background in the field of endocrine surgery. What are the endocrine glands, to begin with?
Dr. Denise Carneiro-Pla: Endocrine surgery is an area of general surgery that includes surgeries for endocrinopathies of thyroids, parathyroids, adrenals, and the function tumors of the pancreas.
Dr. Linda Austin: Now, you said endocrinopathies, what is an endocrinopathy?
Dr. Denise Carneiro-Pla: Any endocrine tumor or hormone-related disease that, usually, is surgical.
Dr. Linda Austin: You started off by saying parathyroid. I know that the diseases and the surgical treatment of the parathyroid has been a very strong interest of yours, that you’ve published many papers in that area and book chapters, and so forth, so let’s focus on that first. First, where are the parathyroid glands?
Dr. Denise Carneiro-Pla: The parathyroids are located behind the thyroid, in the cervical area. You have four parathyroids, two in each side of the neck. The parathyroids are responsible for calcium metabolism. When the parathyroid starts producing too much hormone, the blood calcium is elevated and the hormone will take the calcium from the bones and lead to osteoporosis.
Dr. Linda Austin: Or a weakening of the bones?
Dr. Denise Carneiro-Pla: Or osteopenia, weakening of the bones, or you can spill the calcium, the excess calcium, in the urine, which could result in kidney stones. So, you can have all those symptoms, but these two are the problems that the parathyroid can develop. You could have fatigue, neuropsychological changes, difficulty concentrating, bone pain, muscle pain. All of these symptoms are subjective, but those are the two objective changes the parathyroid hormone can bring about in your body.
Dr. Linda Austin: The weakening of the bones and the kidney stones?
Dr. Denise Carneiro-Pla: Yes.
Dr. Linda Austin: Now, I would imagine, though, that oftentimes if a person has been getting a routine physical exam with blood work, it might be picked up at that time because of the change in calcium, is that right?
Dr. Denise Carneiro-Pla: Actually, nowadays, that’s how we diagnose primary hyperparathyroidism, which is dysfunction of the parathyroid itself. So, the patient goes to the family practice doctor. They get a workup, like for follow-up only, and learn that their calcium is elevated. At that time, you’re going to learn the reasons why the calcium is elevated, and one of them is hyperparathyroidism.
Dr. Linda Austin: So, let’s imagine a patient on a routine physical is found to have elevated calcium in their blood, what will the doctor do next?
Dr. Denise Carneiro-Pla: The primary care physician, then, will find in the routine lab work the aPTH, a parathyroid hormone, which, if elevated, the patient should be worked up for primary hyperparathyroidism.
Dr. Linda Austin: So, the patient, then, might be sent to you, an endocrine surgeon, what do you do next?
Dr. Denise Carneiro-Pla: First, I need to make sure that the parathyroid over function is causing something in the patient’s body, either symptoms, that I already mentioned, or if they have kidney stones, or high urinary calcium, which could cause kidney stones, or if they have osteoporosis on a bone mineral density check. So, we check the density of the bones, and we can see if you have osteoporosis or not. So, if the patient has any of these signs or symptoms caused by hyperparathyroidism, they’re usually offered surgery.
The way we prepare the patient for surgery is usually with an ultrasound. It’s part of my physical examination. So, I do an ultrasound of the neck. A lot of times we can find the parathyroid that way, or we can add a sestamibi scan, which is a nuclear study where they inject the technetium, which is picked up by the parathyroid, and we take an image of this. The parathyroid can be localized that way.
Dr. Linda Austin: So you basically take an image, or picture, of the parathyroids?
Dr. Denise Carneiro-Pla: Exactly.
Dr. Linda Austin: Right.
Dr. Denise Carneiro-Pla: Then, if we find a parathyroid that has an increased uptake on an EB scan, or is enlarged on the ultrasound, we try to do a minimally invasive parathyroidectomy. We do a small incision in the middle of the neck, about 3 centimeters, and we go through the site where we found the parathyroid on the imaging studies. When we take the gland out, we measure the hormone intraoperatively, the PTH itself, which has a very quick half life; it clears up pretty quickly, so in about five minutes, it will drop.
So, we measure the blood during surgery and if in ten minutes after we take the gland the hormone drops properly, the surgery is finished. On the other hand, if the hormone does not drop, it means that there is more than one gland that is over functioning. That’s why the hormone is so important intraoperatively. It prevents you from having an operative failure.
Dr. Linda Austin: I see. Now, is that a standard practice to check the PTH level during the surgery itself?
Dr. Denise Carneiro-Pla: More and more, I think, the endocrine surgery centers have been accepting and using the intraoperative PTH guided parathyroidectomy as the gold standard. I have to be careful about calling this a gold standard because for years and years, exploring both sides of the neck and looking at all four parathyroids was considered the gold standard for treatment. This procedure, guided with the hormone, has been done for the past ten years, and we’ve had great results with it, which is the area of my research. And we have found that patients that have resection guided by the function of the parathyroid have fewer parathyroids resected, less dissection of the neck, because you take only the ones that are over functioning and do well for many years, like a patient who has all the glands examined would. About three percent of the patients with recurring disease can go between five and ten years without further treatment.
Dr. Linda Austin: Well, it makes a great deal of sense because the reason you’re operating to begin with is because the PTH is elevated. So, if you can actually check that and document that during the operation and know you’re successful, how wonderful, then, when the patient wakes up to be able to say to them, we got it!
Dr. Denise Carneiro-Pla: It’s a 98 percent chance that, when the hormone drops, you are cured. And cured means your calcium should be normal for six months. And, if after that period, your calcium becomes elevated, the disease has recurred. But we prove, with the drop of the hormone intraoperatively, you will have normal calcium levels for at least six months.
Dr. Linda Austin: What are some side effects, or adverse effects, problems, that patients might have after this surgery?
Dr. Denise Carneiro-Pla: I think the main things you have after parathyroidectomy are the risks of the surgery, complications of the surgery, which are mainly two. One of them is recurrent laryngeal nerve injury. This is a nerve we have on each side of the trachea, right in the neck, that goes to your vocal cords. This nerve can be scratched or hurt which can cause a voice change. This is usually temporary, but it can be permanent.
The other problem is when you’re considered for a parathyroidectomy, either with the hormone or bilateral neck exploration, because you look at all four parathyroids, there’s a chance of hurting the other parathyroids that are normal functioning. And if that happens, your calcium will be low. That’s a very difficult complication to handle. That’s why we try to be as minimally invasive as possible, trying to go to one single spot in the neck and take the gland out. Most of the patients wouldn’t need anything else, so we would not hurt the other parathyroids.
Dr. Linda Austin: Right. So, with the approach that you take then, that would be very unusual? Now, the first risk that you mentioned, the damage to the recurrent laryngeal nerve, how common is that?
Dr. Denise Carneiro-Pla: It’s about less than one percent.
Dr. Linda Austin: So, very rare?
Dr. Denise Carneiro-Pla: Yeah.
Dr. Linda Austin: So, you obviously go to great lengths to make sure you know where that nerve is.
Dr. Denise Carneiro-Pla: Yeah. That’s what makes the surgery challenging.
Dr. Linda Austin: I bet. How long does the surgery actually take?
Dr. Denise Carneiro-Pla: If it’s a parathyroid that’s visualized in the localization study and they have only one gland, which 95 percent of patients will, it takes about an hour and a half, and they go home the same day.
Dr. Linda Austin: Wow. Is the patient asleep during the surgery?
Dr. Denise Carneiro-Pla: It could be done under local anesthesia with a cervical block, injection of a local anesthetic in the neck, but we usually use general anesthesia. It’s easier to operate. The patient can leave the operating room more quickly. But if the patient is very ill and has cardiac disease, and the surgery is a risk for the patient, we could do it under local anesthesia.
Dr. Linda Austin: And, how many days, then, does a patient need or maybe get to stay out of work after that?
Dr. Denise Carneiro-Pla: Very little, about two or three days maximum. You asked me about the consequences of the surgery, a lot of times you just take one parathyroid out. But the bones are so hungry and depleted of calcium that as soon as you take the hormone, the calcium goes very low. It’s called hungry bone syndrome. So, you might have very low calcium after surgery, not due to the fact that you hurt all the other parathyroids, but because your bones are so osteoporotic, so weak. That’s something that happens postoperatively, but is resolved the majority of the time.
Dr. Linda Austin: We are so lucky to have you here on our faculty and offering this surgery to patients. Thanks so much for talking with us today.
Dr. Denise Carneiro-Pla. Thank you.
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