Hypoparathyroidism is a common complication of thyroid surgeries, affecting as many as 30% of these patients (J Clin Med. 2020;9:830), and it can occur during central compartment lymph node surgery as well. Patients may develop either temporary or permanent hypocalcemia. Recent advances in intraoperative, near-infrared imaging technology, such as devices that harness the glands’ natural autofluorescence to illuminate them during surgery, may offer effective tools for surgeons to help avoid these negative outcomes.
Explore This IssueFebruary 2021
“The ability to better identify and preserve normal parathyroid glands during this surgery could reduce patient morbidity, length of hospitalization, and overall cost of care,” said Mark Zafereo, MD, associate professor, department of head and neck surgery, and section chief, head and neck endocrine surgery at The University of Texas MD Anderson Cancer Center in Houston. “In recent years, intraoperative techniques for better identification of parathyroid glands have centered around the natural autofluorescence of parathyroid tissue, as well as the use of fluorophores, such as indocyanine green [ICG]. Unfortunately, neither of these techniques is without challenges.”
Head and neck surgeons say they’re excited about the possibilities of both ICG, which involves intravenous injection of a contrast green dye, and even newer near-infrared autofluorescence imaging systems to reduce the incidence of these outcomes. Some have begun to provide feedback to manufacturers, so the devices may be modified to make them easier to use. Potential concerns include up-front costs for a new technology (see “Cost: When to Invest?” on page 16) and the optimal scenarios for using it, they say.
Protect the Parathyroids
It’s important to clearly image and identify the parathyroid glands, which are about the size of a grain of rice and often blend in with other tissues nearby. Surgeons found that older technologies like ultrasound and sestamibi scans were inadequate: They were used mostly preoperatively and only identified abnormal parathyroids, not healthy glands, according to researchers exploring more effective imaging modalities (J Biomed Opt. 2011;16:067012). In 2018, the American Thyroid Association (ATA) published a statement emphasizing the need for better strategies to manage or minimize hypoparathyroidism and included advanced imaging modalities as one way to achieve that goal (Thyroid. 2018;28:830-841).
“Hypoparathyroidism may cause long-term symptoms such as muscle spasms, weakness, brain fog, anxiety, skeletal disease, or renal dysfunction, and it dramatically impacts a patient’s quality of life,” said Brendan C. Stack Jr., MD, professor and chairman, otolaryngology–head and neck surgery at Southern Illinois University School of Medicine in Springfield, Ill., and a co-author of the ATA’s statement. “Look at the condition from another perspective. About 70,000 people in the U.S. are estimated to have hypothyroidism—overall, a very low prevalence. Out of those 70,000 people, about three-quarters are postoperative surgery patients. The condition can exist for other reasons, but it’s largely caused by central neck surgery.”