A comparison of the quantitative evaluation of in situ parathyroid gland perfusion by indocyanine green fluorescence angiography and by visual examination in thyroid surgery

The most vital complications of thyroidectomy are recurrent nerve damage and hypocalcaemia. We aimed to compare the tissue perfusion scores (PS) of IG fluorescence angiography (IGFA) and visual examination by the surgeon after total thyroidectomy. Forty-three patients were accepted into the study. Localisation of the parathyroid gland (PG) was determined by the naked eye and scored in terms of tissue perfusion. The averages of fluorescent light intensities for each IGFA were calculated, the perfusions were scored and compared with the PS given by the surgeon. Biochemical parameters were noted. 37.2% of patients had autotransplanted PGs, according to their visual scores. The means of IGFA-PS for PGs scored as 0, 1 or 2 on visual inspection were 48.58 ± 4.49 [30-70], 89.65 ± 8.93 [36-144] and 158.76 ± 8.93 [70-253], respectively, which correlated with the visual PSs in a statistically significant manner (P < 0.0001). The predictive cut-off value for IGFA-PS was determined to be 70, given a visual PS of 0 (95% CI [0.72-0.85]), and this was interpreted to be a candidate cut-off point for the autotransplantation of PGs. IGFA scoring may be considered as an operative predictor, providing objective criteria to evaluate the tissue and blood perfusion of PGs after thyroidectomy. IGFA scoring may be considered to have value in minimising postoperative permanent hypoparathyroidism in patients.