How Minimally Invasive Radioguided Parathyroid Surgery (MIRP) Is Performed
How Minimally Invasive Parathyroid (MIRP) Surgery Works
Step 1: Make the overproducing parathyroid gland radioactive, so it can be differentiated from all the other structures in the neck. The key to the success of this technique was the development of the Sestamibi scan in the early 1990s, which makes only parathyroid tumors radioactive; normal parathyroid glands will not become radioactive. An example is shown on the right. Note that there is only one radioactive (bright yellow) spot in this patient's neck. This test has now become an extremely dependable tool for all patients with parathyroid problems.
Step 2: Operate only where necessary. Now that the surgeon knows what general area of the neck to operate upon, he or she can make a much smaller incision and only operate in a small area of the neck. The old standard operation requires a neck incision that is 6 to 8 in in length. The picture on the left shows the 1-in incision in the lower neck that is typically made for the minimally invasive parathyroid operation (MIRP). The patient's head is at the top of the picture and a blue pen was used to mark the outline of her collar bones and the top of her breast bone (the sternum). Now it's easy to see how this small operation can be performed using only local anesthesia rather than putting the patient asleep under general anesthesia. Note that even when undergoing the operation under local anesthesia, the anesthesiologist will give the patient a bit of sedative medications through their veins, so the patient really won't be aware what is going on and almost always won't remember the procedure.
Step 3: Use a miniature hand-held radiation detecting probe to find the radioactive parathyroid. Next, the surgeon places a miniature probe into the incision. This probe will make noise when it is placed near the parathyroid because it detects radioactivity. The probe shown here is made by US Surgical Corporation (Norwalk, CT) and was designed and patented by Dr. Norman.
Since the radioactivity lasts only 2 to 4 hours, the operation needs to be completed during this period of time. By placing the probe into the incision and following the radioactivity, the dissection leads directly to the radioactive gland. The picture on the left shows the probe (wrapped in a sterile plastic cover) being placed into the small incision so the surgeon knows where the radioactive parathyroid tumor is located. What Dr. Norman discovered is that this parathyroid tumor can be found very easily using the probe, so that the entire operation can be performed through a 1-in (or less) incision in an average of under 25 minutes. The old way of operating throughout the entire neck is giving way to this much improved minimally invasive operation for the majority of patients.
Step 4: Remove the radioactive parathyroid tumor. In the next step, the surgeon dissects the overactive parathyroid tumor away from the rest of the neck structures and removes it. In this picture, yellow dots are around the parathyroid tumor to make it easier to see. This overactive parathyroid was about the size of a large black olive, which is fairly typical. Remember, parathyroids are supposed to be the size of a pea or smaller. Parathyroids only have a single small artery and vein. This picture shows Dr. Norman putting a metal clip on the artery and vein prior to removing the enlarged parathyroid.
Step 5: Measure the radioactivity in the parathyroid tumor to help make sure that the patient is cured of their disease. Once the enlarged parathyroid is out, the probe is placed on the parathyroid to make sure that the radioactive tumor has been removed. The amount of radioactivity contained within the gland helps the surgeon be confident that the operation is complete and whether another "normal" gland will need to be dissected out. Usually, it is not necessary to find any other parathyroid glands, but the experience of the surgeon will determine whether more operating is needed.
The picture on the right shows several things: First, it shows a patient's sestamibi scan on the left side and predicts a tumor in this patient that would be cylindrical and about 1.5 in in length. Second, it shows the tumor sitting on a blue towel after it has been removed from the patient. The scalpel next to it helps show that the parathyroid tumor is the exact size that the scan predicted. This tumor was removed during an operation that took 18 minutes, and the patient left the hospital in time to go out for lunch with her children.
Step 6: Put on the bandage and get ready to go home. Because the MIRP operation can usually be performed quickly and with very limited dissection, patients are quite anxious to go home. Patients can return to normal duties as soon as they wish (usually the next day). The bandage should be kept dry for about 48 hours, then the patient can shower. The bandage should be left in place about a week. No laboratory tests are required for the vast majority of patients for about a week or two. Of course, this and all of the other decisions and treatments discussed in this article will be up to your doctors. The key is to treat every patient like an individual; each has a special case and special needs. Your case may be different depending on many variables, so discuss all of this in detail with your surgeon and work with him or her so you get what is best for you.
On June 14, 2005 Dr James Norman performed a MIRP mini-parathyroid operation live over the Internet. This 1-hour program (including a short lecture by Dr. Norman) is still available for you to watch. Click here to watch a mini-parathyroid operation exactly as it happened without any editing.
Please understand the difference between the standard parathyroid surgery performed by general surgeons and the minimally invasive parathyroid surgery that is performed by specialists. The new procedures have a much higher cure rate and a much lower complication rate (near zero). The operation is smaller, quicker, and safer than the standard operation performed by general surgeons. Please educate yourself and discuss this with your doctor.