Near-infrared Autofluorescence Probe Versus Visual Identification for Parathyroid Detection and Functional Preservation During Total Thyroidectomy

OBJECTIVE: To assess whether PTeye-guided identification increases the number of parathyroid glands (PGs) preserved in situ and reduces hypoparathyroidism compared with visual identification alone. BACKGROUND: Injury or inadvertent removal of PGs during thyroidectomy is the main cause of postoperative hypoparathyroidism. Reliance on visual inspection makes intraoperative PG identification difficult. Probe-based near-infrared autofluorescence (NIRAF) systems such as PTeye provide real-time, tissue-specific feedback that may enhance PG detection and preservation. METHODS: In this single-center, prospective, randomized trial, patients undergoing first-time total thyroidectomy were allocated to PTeye-assisted or visual PG identification. Procedures were performed by 2 senior and 3 junior surgeons. The primary outcome was the number of PGs identified. Secondary outcomes included inadvertent parathyroidectomy, autotransplantation, and transient and last follow-up hypoparathyroidism. RESULTS: Among 154 randomized patients (77 per group; mean age 53.4±14.3 y; 84.4% female), PTeye increased the mean number of PGs identified (3.81 vs. 2.73; P<0.001) and the proportion with 3-4 PGs preserved in situ (98.7% vs. 87.0%; P=0.004). Inadvertent parathyroidectomy was less frequent with PTeye (5.2% vs. 20.8%; P=0.004). Junior surgeons performed more autotransplantations than senior surgeons when using PTeye (33.3% vs. 10.5%; P=0.015). Female sex (P=0.047), ≤2 PGs preserved (P=0.008), and autotransplantation (P=0.010) predicted low postoperative day-1 parathormone serum level. Among junior surgeons, transient hypoparathyroidism was lower with PTeye (20.5% vs. 55.2%; P<0.001), with no difference among senior surgeons. Permanent hypoparathyroidism rates were similar between groups. CONCLUSIONS: PTeye-guided NIRAF improves PG identification and in situ preservation and reduces transient hypoparathyroidism, particularly for junior surgeons, without affecting permanent hypoparathyroidism.