VALUE OF THE INDOCYANINE GREEN FLUORESCENCE SCORE IN PREDICTING POSTOPERATIVE HYPOPARATHYROIDISM IN THYROID SURGERY - A PROSPECTIVE OBSERVATIONAL STUDY.

Abstract

Context: Postoperative hypoparathyroidism is the most frequent complication of total thyroidectomy (transient form, 19-38%). Indocyanine green (ICG) fluorescence imaging is validated for parathyroid perfusion assessment; its predictive value combined with strict in situ preservation has not been reported in Romania.

Objective: To evaluate the predictive performance of the Vidal Fortuny ICG score for transient postoperative hypoparathyroidism.

Design: Prospective observational single-centre study (February 2024 - February 2025) at the National Institute of Endocrinology "C.I. Parhon", Bucharest.

Subjects and methods: Twenty-four consecutive adults received intraoperative ICG (5 mg IV; Karl Storz IMAGE1 S™ Rubina^®) during thyroid surgery. Each parathyroid gland (PG) was assigned an ICG score (0/1/2) and a signal-to-background ratio versus the common carotid artery. Primary endpoint: biochemical hypoparathyroidism at 24 hours (PTH < 15 pg/mL or total Ca < 8.0 mg/dL).

Results: Twenty-one women and 3 men; mean age 55.2 ± 14.1 years. All four PGs were identified in every patient (96/96, 100%). Score distribution (score 2/ 1/ 0): 63.5%/ 32.3%/ 4.2%. Transient hypoparathyroidism: 25.0%; dysphonia at 6 weeks: 0%. Sensitivity 66.7%, specificity 100%, PPV 100%, NPV 90%; LR- 0.33 (LR+ undefined: specificity 100%).

Conclusions: As an adjunct to careful anatomical dissection, the ICG score reliably identifies devascularized parathyroid glands (specificity and PPV both 100%). In situ preservation without autotransplantation was safe. ICG complements anatomical dissection and warrants routine integration.