Utility of Indocyanine Green Fluorescence Imaging for Intraoperative Localization in Reoperative Parathyroid Surgery.

Background. Due to the variations in anatomic location, the identification of parathyroid glands may be challenging. Although there have been advances in preoperative imaging modalities, there is still a need for an accurate intraoperative guidance. Indocyanine green (ICG) is a new agent that has been used for intraoperative fluorescence imaging in a number of general surgical procedures. Its utility for parathyroid localization in humans has not been reported in the literature. Results. We report 3 patients who underwent reoperative neck surgery for primary hyperparathyroidism. Using a video-assisted technique with intraoperative ICG fluorescence imaging, the parathyroid glands were recognized and removed successfully in all cases. Surrounding soft tissue structures remained nonfluorescent, and could be distinguished from the parathyroid glands. Conclusions. This report suggests a potential utility of ICG imaging in intraoperative localization of parathyroid glands in reoperative neck surgery. Future work is necessary to assess its benefit for first-time parathyroid surgery.

The utility of repeat sestamibi scans in patients with primary hyperparathyroidism after an initial negative scan.

BACKGROUND: We analyzed the utility of repeated sestambi scans in patients with primary hyperparathyroidism and its effects on operative referral. METHODS: We carried out a retrospective review of patients with primary hyperparathyroidism who underwent repeated sestambi scans exclusively within our health system between 1996-2015. Patient demographic, presentation, laboratory, imaging, operative, and pathologic data were reviewed. Univariate analysis with JMP Pro v12 was used to identify factors associated with conversion from an initial negative to a subsequent positive scan. RESULTS: After exclusion criteria (including reoperations), we identified 49 patients in whom 59% (n = 29) of subsequent scans remained negative and 41% (n = 20) converted to positive. Factors associated with an initial negative to a subsequent positive scan included classic presentation and second scans with iodine subtraction (P = .04). Nonsurgeons were less likely to order an iodine-subtraction scan (P < .05). Fewer patients with negative imaging were referred to surgery (33% vs 100%, P = .005), and median time to operation after the first negative scan was 25 months (range 1.4-119). Surgeon-performed ultrasonography had greater sensitivity and positive predictive value than repeated sestamibi scans. CONCLUSION: Negative sestambi scans decreased and delayed operative referral. Consequently, we identified several process improvement initiatives, including education regarding superior institutional imaging. Combining all findings, we created an algorithm for evaluating patients with primary hyperparathyroidism after initially negative sestamibi scans, which incorporates surgeon-performed ultrasonography.

Intraoperative tumor localization and tissue distinction during robotic adrenalectomy using indocyanine green fluorescence imaging: a feasibility study.

BACKGROUND: To investigate the feasibility of a method for intraoperative tumor localization and tissue distinction during robotic adrenalectomy (RA) via indocyanine green (ICG) imaging under near-infrared light. METHODS: Ten patients underwent RA. After exposure of the retroperitoneal space, but before adrenal dissection was started, ICG was given intravenously (IV). Fluorescence Firefly™ imaging was performed at 1-, 5-, 10-, and 20-min time points. The precision with which the borders of the adrenal tissue were distinguished with ICG imaging was compared to that with the conventional robotic view. The number and the total volume of injections for each patient were recorded. RESULTS: There were six male and four female patients. Diagnosis was primary hyperaldosteronism in four patients and myelolipoma, adrenocortical neoplasm, adrenocortical hyperplasia, Cushing's syndrome, pheochromocytoma, and metastasis in one patient each. Procedures were done through a robotic lateral transabdominal approach in nine and through a robotic posterior retroperitoneal approach in one patient. Dose per injection ranged between 2.5 and 6.3 mg and total dose per patient 7.5-18.8 mg. The adrenal gland took up the dye in 1 min, with contrast between adrenal mass and surrounding retroperitoneal fat becoming most distinguished at 5 min. Fluorescence of adrenal tissue lasted up to 20 min after injection. Overall, ICG imaging was felt to help with the conduct of operation in 8 out of 10 procedures. There were no conversions to open or morbidity. There were no immediate or delayed adverse effects attributable to IV ICG administration. CONCLUSION: In this pilot study, we demonstrated the feasibility and safety of ICG imaging in a small group of patients undergoing RA. We described a method that enabled an effective fluorescence imaging to localize the adrenal glands and guide dissection. Future research is necessary to study how this imaging affects perioperative outcomes.

Robotic parathyroidectomy.

Robotic parathyroidectomy has recently been described. Although the procedure eliminates the neck scar, it is technically more demanding than the conventional approaches. This report is a review of the patients' selection criteria, technique, and outcomes.