Methods for the identification and preservation of parathyroid glands in thyroid surgery: a narrative review

Background and Objective: Accurate intraoperative identification and viability assessment of the parathyroid glands (PGs) has always been a crucial but challenging aspect of thyroid surgery. The traditional method, naked-eye (NE) assessment, is significantly associated with the experience of the surgeon. Therefore, various methods have been developed to help surgeons protect PGs, with some benefits and limitations. Recently, near-infrared autofluorescence (NIRAF) and indocyanine green fluorescence imaging (ICGFI) have been demonstrated to be promising in the identification and viability assessment of PGs. Herein, we provide an overview of the methods of intraoperative identification and viability assessment of PGs, focusing on the application of NIRAF and ICGFI. Methods: We performed a systematic literature search of PubMed, Medline, Cochrane Library databases, Web of Science, and EMBASE to identify all relevant studies published up to March 2023. The keywords were ((autofluorescence) OR (indocyanine green)) AND (parathyroid gland). Key Content and Findings: In this narrative review, we summarized the benefits and limitations of intraoperative methods for PG identification and viability assessment, focusing on the application of NIRAF and ICGFI. Conclusions: Intraoperative parathyroid protection methods have developed from traditional subjective identification of PGs to the latest near-infrared (NIR) fluorescence imaging technology. The discovery, development, and application of NIRAF and ICGFI have provided better ways for surgeons to protect PGs intraoperatively.