Indocyanine green fluorescence-guided parathyroidectomy for primary hyperparathyroidism

Abstract

Background: Our aim was to evaluate the ease and utility of using indocyanine green fluorescence angiography for intraoperative localization of the parathyroid glands.

Methods: Indocyanine green fluorescence angiography was performed during 60 parathyroidectomies for primary hyperparathyroidism during a 22-month period. Indocyanine green was administered intravenously to guide operative navigation using a commercially available fluorescence imaging system. Video files were graded by 3 independent surgeons for strength of enhancement using an adapted numeric scoring system.

Results: There were 46 (77%) female patients and 14 (23%) male patients whose ages ranged from 17 to 87 (average 60) years old. Of the 60 patients, 43 (71.6%) showed strong enhancement, 13 (21.7%) demonstrated mild to moderate vascular enhancement, and 4 (6.7%) exhibited little or no vascular enhancement. Of the 54 patients who had a preoperative sestamibi scan, a parathyroid adenoma was identified in 36, while 18 failed to localize. Of the 18 patients who failed to localize, all 18 patients (100%) had an adenoma that fluoresced on indocyanine green imaging. The operations were performed safely with minimal blood loss and short operative times.

Conclusion: Indocyanine green angiography has the potential to assist surgeons in identifying parathyroid glands rapidly with minimal risk.

Fig. 1.

ICG fluorescence angiography in a patient with a single parathyroid adenoma. (A) The bright light image of the operating field. Arrows indicate parathyroid gland and asterisk indicates the thyroid gland in all. (B) Same field in the greyscale fluorescent mode. (C) Fluorescent mode with computer-generated overlay where green color saturation is proportional to the intensity of the fluorescent signal.

Fig. 2.

ICG fluorescence angiography in a patient with 4 gland hyperplasia. (A) The bright light image of the operating field. Arrows indicate 2 parathyroid glands and asterisk indicates the thyroid gland in all. (B) Same field in the greyscale fluorescent mode. (C) Fluorescent mode with computer-generated overlay where green color saturation is proportional to the intensity of the fluorescent signal.

Fig. 3.

ICG fluorescence angiography modified grading scale for parathyroid adenomas. Computer-generated fluorescent overlay as well as the black and white modes of 3 separate patients. A and B have almost no fluorescent enhancement and receive a score of 0 on our modified scale. C and D demonstrate some uptake and receive a score of 1. E and F are greatly enhanced as evidenced by the strong green signal in E and the bright white area of demarcation in F and receive a score of 2.