The History of Minimally Invasive Parathyroid Surgery
Although most surgeons focus on specialized “tools of the trade” when discussing minimally invasive surgery, the real key to the advent of these new endocrine procedures has been the development of better diagnostic imaging procedures, like Sestamibi scanning and high resolution ultrasound for parathyroids, and high resolution CT scanning for adrenals. Once these new imaging procedures provided a roadmap for finding small parathyroid, thyroid and adrenal nodules, it was only a matter of time before enterprising surgeons would develop less invasive surgical techniques for removing them.
With the realization in the mid 1990’s that intravenously administered Sestamibi lit up abnormal parathyroid glands, Dr. James Norman, at the University of South Florida, fashioned a thin, Sestamibi-detecting radioactive probe that he used as a guide for minimally invasive parathyroid detection and resection. Large incisions for full visualization of all four parathyroid glands were no longer necessary, since most hyperparathyroidism is caused by single parathyroid tumors that are easily located when the Sestamibi probe is introduced through a carefully placed 1” surgical opening in the neck.
Unfortunately, 10% of patients with hyperparathyroidism have more than one enlarged parathyroid gland and these patients will not be cured by the radioguided probe technology that Dr. Norman continues to champion. The solution for the multiple parathyroid tumor dilemma waited until the late 1990’s and the brilliant work of Dr. George Irvin at the University of Miami. Dr. Irvin developed a rapid parathyroid hormone assay that could easily be deployed in the operating room with a turnaround time of less than 10 minutes. Using this assay before and 5-10 minutes after the removal of parathyroid tumors, Dr. Irvin demonstrated that a 50% drop in blood parathyroid hormone levels after tumor resection reflected surgical cure in almost all circumstances. Thus, the multiple gland problem was largely solved by using the rapid intra-operative parathyroid hormone assay as a gold standard for cure. If parathyroid hormone blood levels do not drop more than 50% after resection of the first parathyroid tumor, the surgeon continues to search for more abnormal parathyroid tissue in other likely locations.
At Ft. Lauderdale Endocrine Surgery, we place a strong emphasis on the use of out-patient Sestamibi and high resolution ultrasound (performed by Dr. Harrell, our endocrinologist) to locate enlarged glands prior to surgery. Then, in the operating room, we combine Dr. Norman’s and Dr. Irvin’s approaches to maximize our surgical success rate.
As with all neck surgeries, complications of minimally invasive parathyroidectomy may include vocal chord paralysis due to accidental damage to the recurrent laryngeal nerve (which lies close to the parathyroids), bleeding and low blood calcium if too much parathyroid tissue is removed. If all the abnormal parathyroid tissue is not removed, the blood calcium will remain high after the surgery and the patient will not be cured from his/her hyperparathyroidism. In Dr. Bimston’s capable hands the risk for the complications mentioned above is less than 1% and the risk for non-cure is less than 5%.
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