Preservation of Parathyroid Glands during Thyroid Surgery

Abstract

Hypoparathyroidism after thyroidectomy occurs as a result of devascularization or unintentional resection of the parathyroid glands. To preserve parathyroid glands, surgeons have to know well about their embryology and anatomy. The parathyroid glands vary in number, size, shape, and color. Because of more variable migration path in the neck, the inferior parathyroid glands are more widely distributed than the superior glands. The upper parathyroid glands are dorsal and the lower parathyroid glands are ventral to the coronal plane of recurrent laryngeal nerve path. Positional symmetry of superior or inferior parathyroid glands is found in approximately 70-80%. Each parathyroid gland has its own end-artery. Both the superior and inferior parathyroid glands most frequently receive blood supply from the inferior thyroid artery. Parathyroid exploration requires a meticulous and bloodless dissection with help of surgical loupes. During the superior pole dissection, every attempt should be made to dissect the gland posteriorly off the thyroid with preserving the posterior branch of the superior thyroid artery. Dissection of the lateral lobe is best achieved by capsular dissection. The tertiary branches of the inferior thyroid artery lying on the thyroid capsule are individually ligated and divided. The surgeon can also utilize positional symmetry of the parathyroid glands. If the parathyroid gland is clearly devascularized or turns deep black, it should be biopsied, confirmed as normal parathyroid tissue, and reimplanted. It is useful to search for unintentionally resected parathyroid tissue in the surgical specimen for autotransplantation at the end of the operation.