Impact of near-infrared fluorescence imaging plus indocyanine green fluorescence on postoperative hypoparathyroidism rates after total thyroidectomy and central neck lymph node dissection

Background: Patients with thyroid carcinoma often undergo cervical lymph node dissection, which is associated with high rates of both transient and permanent postoperative hypoparathyroidism. The impact of near-infrared fluorescence imaging + indocyanine green (ICG) fluorescence on postoperative hypoparathyroidism rates after total thyroidectomy and central neck lymph node dissection was evaluated.

Methods: All patients undergoing surgery between January 2019 and March 2023 were included and divided into three groups: a control group (parathyroid glands identified visually), a near-infrared fluorescence imaging alone group, and a near-infrared fluorescence imaging + ICG fluorescence group. The primary outcome was the transient and permanent postoperative hypoparathyroidism rates. Secondary outcomes were: length of surgery and number of parathyroid glands identified, inadvertently resected, and autotransplanted.

Results: A total of 131 patients were included in the study (47 in the control group, 45 in the near-infrared fluorescence imaging alone group, and 39 in the near-infrared fluorescence imaging + ICG fluorescence group). The transient hypoparathyroidism rate was 48.9% in the control group, 37.8% in the near-infrared fluorescence imaging alone, and 5.1% in the near-infrared fluorescence imaging + ICG fluorescence group (P < 0.0001), while the permanent hypoparathyroidism rate was 8.5% in the control group, 2.2% in the near-infrared fluorescence imaging alone group, and 0% in the near-infrared fluorescence imaging + ICG fluorescence group (P = 0.096). The number of parathyroid glands identified was 159 of 188 in the control group, 165 of 180 in the near-infrared fluorescence imaging alone group, and 149 of 156 in the near-infrared fluorescence imaging + ICG fluorescence group (P = 0.002). Inadvertent resection of parathyroid glands occurred for 29 of 188 in the control group, 15 of 180 in the near-infrared fluorescence imaging alone group, and 7 of 156 in the near-infrared fluorescence imaging + ICG fluorescence group (P = 0.002), with subsequent parathyroid gland autotransplantation for 2 of 29 in the control group, 2 of 15 in the near-infrared fluorescence imaging alone group, and 3 of 7 in the near-infrared fluorescence imaging + ICG fluorescence group (P = 0.040). There was no difference in the median operating time between groups.

Conclusion: The use of near-infrared fluorescence imaging + ICG fluorescence decreased both transient and permanent hypoparathyroidism rates in patients undergoing total thyroidectomy and central neck lymph node dissection.