To identify or not to identify parathyroid glands during total thyroidectomy

Abstract

Hypoparathyroidism is one of the most common complications after total thyroidectomy and may impose a significant burden to both the patient and clinician. The extent of thyroid resection, surgical techniques, concomitant central neck dissection, parathyroid gland (PG) autotransplantation and inadvertent parathyroidectomy have long been some of the risk factors for postoperative hypoparathyroidism. Although routine identification of PGs has traditionally been advocated by surgeons, recent evidence has suggested that perhaps identifying fewer number of in situ PGs during surgery (i.e., selective identification) may further lower the risk of hypoparathyroidism. One explanation is that visual identification may often lead to subtle damages to the nearby blood supply of the in situ PGs and that may increase the risk of hypoparathyroidism.However, it is worth highlighting the current literature supporting either approach (i.e., routine vs. selective) remains scarce and because of the significant differences in study design, inclusions, definitions and management protocol between studies, a pooled analysis on this important but controversial topic remains an impossible task. Furthermore, it is worth nothing that identification of PGs does not equal safe preservation, as some studies demonstrated that it is not the number of PGs identified, but the number of PG preserved in situ that matters. Therefore a non-invasive, objective and reliable way to localize PGs and assess their viability intra-operatively is warranted. In this aspect, modern technology such as the indocyanine green (ICG) as near-infrared fluorescent dye for real-time in situ PG perfusion monitoring may have a potential role in the future.

Post-operative hypocalcaemia following open thyroidectomy for benign multinodular goiters using FOCUS harmonic scalpel versus conventional suture ligation technique for hemostasis - a prospective, single-blind, randomized controlled trial

“…Visual identification of all four (or 3-4) in situ PGs for preservation during total thyroidectomy has traditionally been advocated by surgeons to lower the risk of hypoparathyroidism and hypocalcaemia (5,10). However, this approach may not guarantee…”

“…Injury to RLNs, which provide motor innervation to the intrinsic muscles of the larynx, can lead to unilateral vocal cord paralysis characterized by inadequate coughing, inability to clear secretions, and aspiration in the postoperative setting (4) and may cause life-threatening airway obstruction. (3) Inadvertent damage or removal of the PGs during thyroid surgery can result in acute and chronic parathyroid insufficiency syndromes, especially postoperative hypocalcaemia, protracted hypoparathyroidism, and permanent hypoparathyroidism (5,6).…”

“…Post-operative hypocalcaemia is clinically defined as a serum calcium of less than 8 mg/ dL (80%) in post-operative patients with permanent hypoparathyroidism (5,7,8). Untreated post-operative hypocalcaemia can result in renal and neurological dysfunction (2,9), with clinical manifestations ranging from mild (numbness and tingling in the arms or hands and around the mouth) to severe (severe muscle cramping of the entire body and sometimes convulsions).…”

“…Effective vessel hemostasis during thyroidectomy is the key to intra-operative prevention of post-thyroidectomy hypocalcaemia and hypoparathyroidism (5,10). Conventional techniques, such as LigaSure and clamp-and-tie techniques, have been demonstrated to have comparable efficacy and safety for achieving hemostasis in total thyroidectomy (11).…”

Hypocalcemia after Total Thyroidectomy – A Prospective Study

“…It has been reported that the rate of postoperative transient hypocalcemia ranges from 6% to 30%, although there is ≤2% incidence of persistent dysfunction. 7 The nadir of hypocalcemia often appears within 48 hours after thyroidectomy. 8 Symptoms are severe and, requiring calcium replacement therapy.…”