Assessment of functional status of auto-transplanted parathyroid glands after total thyroidectomy.

First described in the Indian rhinoceros in the year 1862 [1], the parathyroid glands are intimately related to the thyroid gland. Normal parathyroid function is integral to the calcium homeostasis in the body. However, thyroid surgery in general and total thyroidectomy in particular is associated with a significant risk of parathyroid injury, post-operative hypoparathyroidism and hypocalcemia. While acute hypocalcemia has various dramatic clinical features ranging from paresthesias to seizures and even death, chronic hypocalcemia can result in crippling complications including heart failure and cardiomyopathy. Generally, post-operative hypocalcemia and hypo-parathyroidism are transient phenomena which resolve spontaneously over time. Definitive hypo-parathyroidism and chronic hypocalcemia occur as a result of irreversible loss of function of the parathyroids, invariably due to inadvertent removal or ischemic necrosis of the parathyroid glands. So, definitive hypo-parathyroidism is a complication that can be prevented with better intra-operative care. The best approach to prevent definitive hypo-parathyroidism is to identify the parathyroids and their blood supply during surgery. Should the gland be inadvertently removed or rendered ischemic due to vascular compromise, it can be auto-transplanted to a heterotopic site. The parathyroid tissue has certain unique properties, by virtue of which auto transplantation is a viable option in order to prevent chronic hypoparathyroidism and hypocalcemia. This study was conducted in the Department of Endocrine Surgery, Madras Medical College with an objective to assess the functionality of the auto-transplanted gland during thyroidectomy and parathyroid autotransplantation. In summary, while the rate of functionality of the parathyroid grafts after autotransplantation was 72.9%, the grafts in the remaining patients might be non-functional according to this study due to the following causes – absence of parathyroid tissue in the harvested sample, prolonged cold ischemia time, seroma or hematoma formation in the graft bed, misrepresentative samples due to anatomical variations in the pattern of venous drainage of the forearm and issues with sample stability. In this study, the overall rate of transient post-operative hypocalcemia was 37.5%. None of the patients included in this study developed permanent post-operative hypoparathyroidism