Teaching parathyroid-sparing thyroidectomy: Clinical and educational impact of near-infrared autofluorescence. Results of a retrospective case-control study

Abstract

Background: To evaluate the impact of near-infrared autofluorescence on both postoperative parathyroid function and the learning curve of surgeons performing total thyroidectomy.

Methods: We conducted a retrospective case-control study including 335 adult patients undergoing total thyroidectomy for primary thyroid disease (181 with intraoperative near-infrared autofluorescence guidance [near-infrared autofluorescence positive] and 154 under conventional standard approach [near-infrared autofluorescence negative]). Primary endpoints were transient hypocalcemia, transient hypoparathyroidism, and parathyroid gland identification rate. To specifically explore learning dynamics, we evaluated the influence of near-infrared autofluorescence on the surgeons' performance over time, comparing outcomes and parathyroid gland identification rate across 2 consecutive near-infrared autofluorescence utilization periods. Multivariate logistic regression was used to identify independent predictors of postoperative parathyroid gland dysfunction.

Results: Near-infrared autofluorescence significantly increased parathyroid gland identification rate (90.7% vs 70.5%) and was associated with lower rates of transient hypocalcemia (46.3% vs 60.2%, P = .011) and transient hypoparathyroidism (45.5% vs 57.7%, P = .041). On multivariate analysis, near-infrared autofluorescence remained an independent protective factor for transient hypocalcemia (odds ratio, 0.554; P = .009) and transient hypoparathyroidism (odds ratio, 0.606; P = .040). Along the near-infrared autofluorescence adoption timeline, parathyroid gland identification rate under white-light visualization progressively improved, suggesting a possible perceptual calibration effect that may contribute to shortening the learning curve for parathyroid gland-sparing thyroidectomy. Finally, short-term postoperative calcium levels were significantly higher in the near-infrared autofluorescence-positive group.

Conclusion: Near-infrared autofluorescence improves intraoperative parathyroid gland identification and reduces early postoperative parathyroid dysfunction after total thyroidectomy. Beyond its technical utility, fluorescence guidance may act as an educational scaffold, potentially enhancing visual discrimination of parathyroid tissue. Whether near-infrared autofluorescence independently accelerates the surgical learning curve remains to be confirmed in prospective, surgeon-stratified studies.