Enhanced visualization of parathyroid glands during video-assisted neck surgery.

PURPOSE: Visualization and precise dissection of the parathyroid glands are a crucial step of thyroidectomy. Moreover, identification of parathyroid adenoma in patients with primary hyperparathyroidism can be challenging due to the possible abnormal location of the enlarged parathyroid. Near-infrared fluorescence (NIR) can be adopted during video-assisted neck surgery in addition to standard endoscopic magnification to enhance the visualization of the parathyroid tissue.

METHODS: Between July and August 2017, five patients (one male, four females) underwent video-assisted neck surgery at our hospital. One patient suffered from primary hyperparathyroidism. The four remaining patients underwent thyroidectomy for multinodular goiter or Graves' disease. The parathyroid glands were firstly identified by the video-assisted approach and then confirmed by the NIR visualization of the endogenous autofluorescence of the parathyroid tissue. Low-dose (2.5 mg/ml) indocyanine green was administered to visualize the vascular supply during and/or after the dissection. The standard dose of 2.5 mg (1 ml per injection) was used to allow repeated injection during the same procedure.

RESULTS: An endogenous parathyroid autofluorescence could be visualized by the NIR camera in all patients. The right upper parathyroid adenoma could be detected prior to fully dissection of the gland from the surrounding tissue. Twelve out of 16 parathyroid glands have been visually identified during four total thyroidectomies. Eleven glands showed an autofluorescence prior to indocyanine green (ICG) injection. Further, ICG injection has been used for guiding the dissection of the gland in three cases and for confirmation of the vascular supply at the end of the procedure in the remaining cases. There were neither intraoperative nor postoperative complications.

CONCLUSION: The 5-mm 30° NIR camera allows for enhanced visualization of the parathyroid tissue during video-assisted thyroidectomy. This promising tool can become standard for video-assisted neck surgery.