Transient and/or permanent hypoparathyroidism is the most frequent complication after total thyroidectomy. The identification of the parathyroid glands and a correct dissection during thyroidectomy have been postulated as key factors for their preservation and, consequently, to prevent hypoparathyroidism. The use of indocyanine green (ICG) fluorescence has reliably predicted parathyroid glands functionality in the immediate postoperative period. Recently, it is proposed that showing the vascular map of the parathyroid glands before performing the thyroidectomy by means of ICG angiography prevent the development of postoperative hypoparathyroidism.

The goal of this multicentric study is to demonstrate that the preservation of the function of parathyroid glands is greater with use of arteriography than without.

Patients will be divided in two groups. In the study group, the vascular map with ICG of parathyroid glands will be showed before performing the lobectomy. Once the lobectomy is done, the function of the glands will be assessed. Whereas in the control group, arteriography with ICG will only be carried out in order to check their function at the end of the lobectomy.

Researchers will compare the study group and the control group to see which one present the lowest taxes of postoperative hypoparathyroidism.

To assess the appearance of postoperative hypoparathyroidism, a systematic determination of PTH and corrected calcium values will be carried out the morning after the intervention.

It will be considered that there is hypoparathyroidism when the patient presents symptoms of hypocalcaemia, when he has required the administration of calcium and/or vitamin D prior to this determination or when he presents corrected calcium values < 1.8 mmol/L.

Inclusion Criteria:

• Patients ≥ 18 years of age with a surgical indication for total thyroidectomy with or without central cervical lymph node dissection due to thyroid pathology.
• The patient or their guardian, where applicable, has the capacity to understand the study and agrees to participate in it, signing the corresponding informed consent document.

Exclusion Criteria:

• Previous surgical intervention on the thyroid or parathyroid gland.
• Associated hyperparathyroidism that requires associating a parathyroidectomy in the same surgical act.
• Patients with contraindications for the administration of ICG.
• Current drug use or alcohol abuse that could interfere with compliance with the study requirements.
• Participation in any other drug trials in the month prior to randomization.