Intraoperative PTH monitoring
Intraoperative intact PTH assay is adjunct used in minimal invasive or focused parathyroid surgery. PTH is hormone secreted by the parathyroid gland and in hyperparathyroidism it is increased several folds in majority of our patients. Pre-requisite for minimal invasive or focussed parathyroid surgery is that the disease should be localized (i.e tumour should be picked up on pre-operative anatomical and functional imaging like Ultrasound, Sestamibi etc.) to one out of four parathyroid glands. Combined positive predictive value (i.e to detect the correct site of tumour) of these preoperative imaging modalities is more that 90% but there are cases which may be missed out. By adding intraoperative PTH assay we can further decrease the chance of missing those ectopic parathyroid tumour and similarly chances of surgical failure.
In this we take five PTH samples: Pre-incision, pre-excision of tumour, 5, 10, 15 minute post excision of tumour and usually more than 50 % drop in PTH level is reflective of surgical cure i.e the culprit gland has been taken out.