Near-Infrared Fluorescence Imaging Useful in Locating Parathyroid Glands in Thyroidectomy Specimens

by Linda Kossoff •

How effective is near-infrared fluorescence imaging (NIFI) compared with a surgeon’s visual inspection in identifying parathyroid glands (PGs) among histologically proven PG/non-PG specimens and detecting incidentally resected PGs from thyroidectomy specimens?

BOTTOM LINE

NIFI is comparable to the experienced surgeon’s visual inspection in identifying PGs and may be useful in helping experienced surgeons to locate incidentally resected PGs within thyroidectomy specimens for autotransplantation.

BACKGROUND: In thyroid surgery, especially total thyroidectomy, failure to identify and preserve the PGs can lead to postoperative hypocalcemia. Intraoperative PG identification has conventionally relied on the surgeon’s experience. However, the evidence has shown that NIFI can be applied to detect PGs, which have intrinsic autofluorescence (AF), at a high sensitivity.

STUDY DESIGN: Prospective study.

SETTING: Department of Otolaryngology–Head and Neck Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.

SYNOPSIS: Thirty-six patients (10 males, 26 female, mean age 36 years) undergoing total thyroidectomy or thyroid lobectomy for thyroid disease between July and December 2019 were enrolled. Surgeries were performed by five experienced head, neck, and thyroid surgeons. If the PGs had a questionable blood supply, they were removed and autotransplanted after confirming their histology by frozen sections. Possible PGs and lymph nodes were identified by the experienced surgeon’s visual inspection. Using NIFI, 15 PGs were further identified from thyroidectomy specimens. For these 75 specimens, the surgeon’s judgments (PG vs non-PG) were recorded. Results from examining these specimens showed no significant differences in sensitivity, specificity, positive predictive value, and negative predictive value between the surgeon’s visual inspection and NIGI in identifying PGs, suggesting that NIGI would not provide additional benefit to experienced surgeons but could benefit novice surgeons. NIGI sensitivity (82.9%) for PG detection from thyroidectomy specimens was significantly higher than that of the surgeon’s visual inspection (61.0%), suggesting that NIFI could be a useful navigation tool to detect incidentally resected PGs from thyroidectomy specimens for autotransplantation purposes. Limitations within this study included dependency on the surgeon’s subjective impression regarding AF presence/absence.

CITATION: Takahashi T, Yamazaki K, Ota H, et al. Near-infrared fluorescence imaging in the identification of parathyroid glands in thyroidectomy. Laryngoscope. 2021;131:1188-1193.