Postoperative Hypoparathyroidism

Postoperative hypoparathyroidism (POH) is the most common complication after bilateral thyroid surgery and it is characterized by low serum calcium levels with inappropriately low parathyroid hormone (PTH) level. Several risk factors have been described, including technical issues (inadvertent gland excision or devascularization) and patient- or disease-related factors (sex, type of thyroid disease). Surgical strategies to minimize POH have been implemented, including careful preservation of parathyroid blood supply. The spectrum and the severity of symptoms depend on the severity of hypocalcemia; the most common symptoms of POH concern neuromuscular irritability and may range from tingling in the fingertips and circumoral region to paresthesias of the upper and lower extremities, bronchospasm, laryngospasm or tetany. The measurement of serum calcium and postoperative PTH levels following thyroidectomy is critical to detect and promptly manage POH and avoid symptomatic hypocalcemia. In general, a postoperative PTH level < 15 pg/mL indicates an increased risk for POH. Symptomatic hypocalcemia is generally well controlled by oral calcium and vitamin D supplementation or by intravenous calcium supplementation. Long-term consequences of hypoparathyroidism, including nephrolithiasis, nephrocalcinosis, basal ganglia calcification, ectopic soft tissue calcification, cataracts, and defects in bone metabolism, should be prevented by adequate management.