Prospectives and surgical usefulness of perioperative parathyroid hormone assay in thyroid surgery

Abstract

Hypocalcemia is the most frequent complication after thyroid surgery. The incidence varies and has been reported as ranging from 1.2 to 40%. Permanent hypoparathyroidism occurs in less than 3% of patients, whereas transient postoperative hypocalcemia is much more common. Postoperative hypoparathyroidism is traditionally detected by serial measurement of serum calcium concentrations and requires multiple venepunctures and, potentially, several days of hospitalization following the procedure. The parathyroid hormone (PTH) molecule is a polypeptide composed of an 84-amino acid sequence with an active amino terminal on one end and an inactive carboxyl unit on the other. Measurement of the intact PTH (iPTH) is an accurate representation of the true parathyroid state. In recent years, iPTH assay has been under investigation for thyroid surgery in many centers as an early iPTH measurement may be of value for prediction of postoperative symptomatic hypocalcemia, guiding the surgeon for parathyroid autotransplatation, and selection of patients requiring onset of calcium substitution or safe discharge home. This paper reviews the relevant medical literature published regarding the influence of PTH assay technology on the quality of thyroid surgery, as well as on the prevention of postoperative symptomatic hypocalcemia. Searches were last updated in April 2008.

Indocyanine green-enhanced fluorescence for assessing parathyroid perfusion during thyroidectomy

“…Postoperative hypocalcemia is a common complication of thyroidectomy performed by either conventional or endoscopic methods (35)(36)(37)(38)(39)(40)(41). Decreased serum calcium, secondary to hypoparathyroidism, may present clinically with muscle cramps, perioral and peripheral paresthesias, carpopedal spasm or tetany, and/or confusion.…”

“…Decreased serum calcium, secondary to hypoparathyroidism, may present clinically with muscle cramps, perioral and peripheral paresthesias, carpopedal spasm or tetany, and/or confusion. Symptomatic patients often require extended hospitalization after thyroid surgery, which increases healthcare costs (35)(36)(37)(38)(39)(40)(41). Depending on the extent of parathyroid gland damage, hypocalcemia may be transient and resolve within several few months or may be permanent.…”

“…Permanent hypocalcemia requires lifelong oral calcium and vitamin D supplementation. Although ambulatory thyroid surgery enables early discharge of patients, postoperative hypocalcemia is a particularly important consideration (35)(36)(37)(38)(39)(40)(41). In fact, some surgeons advocate indiscriminate postoperative calcium supplementation.…”

“…However, this approach has been contested. On result of the increased interest in outpatient and short-stay thyroid surgery is the improved ability of surgeons to identify patients at risk for hypocalcemia (35)(36)(37)(38)(39)(40)(41). Therefore, accurate and standardized data for thyroidectomy outcomes are essential.…”

“…For example, some studies analyze not only patients who have received total thyroidectomy, but also patients who have received less invasive procedures such as thyroid lobectomy, which has a relatively low hypocalcemia risk. Such reports can underestimate the incidence of hypocalcemia and are subject to misinterpretation (35)(36)(37)(38)(39)(40)(41).…”