EIS in Thyroid and Parathyroid Surgery

Parathyroid glands are involved in calcium metabolism and their damage during neck surgery results in 'hypoparathyroidism', a condition characterized by 'low blood calcium' levels; this is associated with significant short and long term morbidity. There are four parathyroid glands in the neck which can vary in size and location. They can be mistaken for lymph nodes, fat or thyroid nodules. A normal parathyroid gland is the size of a small pea and is often difficult to recognize during surgery; making it susceptible to inadvertent injury or removal. Thyroid and parathyroid surgery are commonly performed in the UK. Prompt and accurate identification of parathyroid tissue during surgery reduces the likelihood of hypoparathyroidism. However, this complication is still common. Research exploring the use of intraoperative technologies to enable early identification and preservation of normal parathyroid glands during surgery is ongoing. Electrical impedance spectroscopy (EIS) is one such technology. ZedScanTM is a handheld device that measures electrical impedance of tissues. It is currently used as a adjunct during colposcopy in cervical cancer screening. The device has a CE mark for this purpose and is safe to use in humans. We have already demonstrated that electrical impedance spectroscopy can detect differences in cellular structure and differentiate between tissues in the rabbit neck. We now aim to demonstrate the feasibility of using this technology (ZedScanTM) in humans. This has potential to be used in thyroid and parathyroid surgery to differentiate parathyroid glands from other structures; thereby decreasing their damage and the risk of post surgical hypothyroidism.