Methylene Blue Spray for Identification of Recurrent Laryngeal Nerve and Parathyroid Gland

"After ligation of the middle thyroid vein and the upper pole of the thyroid, the thyroid lobe was retracted medially and diluted methylene blue (0.5 ml methylene blue 2% was diluted by 5ml normal saline) was sprayed over the lower thyroid pole and the perilobar area. This area contains structures including recurrent laryngeal nerve, parathyroid glands, and inferior thyroid vessels which were observed After spraying.~The vocal cord mobility was assessed intraoperatively by the anesthesiologist at time of extubation. The serum calcium was measured on the 2nd postoperative day. There was no routine use of postoperative calcium supplementation. Hypocalcemia was defined when the serum calcium level was less than 8 mg/dl."