Intra-operative parathyroid identification using methylene blue in parathyroid surgery.

The objective of this study was to determine the value of intra-operative methylene blue (MB) during parathyroid surgery. We did a retrospective study of 473 patients after initial exploration for previously untreated symptomatic primary hyperparathyroidism. Procedural and post procedural data were collected on four groups of patients: minimally invasive parathyroidectomy with MB (n = 147), and without MB (n = 205), bilateral parathyroid exploration with intra-operative parathormone assay with MB (n = 56), and without MB (n = 65). Length of surgery was shorter for patients explored with MB (P = 0.026). For the minimally invasive parathyroidectomy group, the difference between the MB and non-MB groups was seven minutes. Twelve minutes was the difference between the MB and non-MB intra-operative parathormone assay groups. Length of stay, local complications, and correction of hypercalcemia after parathyroidectomy were not significantly affected by the use of MB. Systemic complications were lower in the MB groups. Aside from a statistically significant, but quantitatively minimal decrease in the length of surgery, no consistent benefit was identified with the use of MB for intra-operative parathyroid identification.