Characterization of fluorescence patterns exhibited by different adrenal tumors: Determining the indications for indocyanine green use in adrenalectomy.

ABSTRACT

BACKGROUND: A number of small studies have reported the use of indocyanine green imaging during adrenalectomy. Nevertheless, imaging properties of different tumors and the indications for indocyanine green imaging use in adrenalectomy have not been defined. METHODS: This is an Institutional Review Board-approved retrospective review of a prospectively maintained database. Consenting patients underwent indocyanine green imaging fluorescence-guided robotic adrenalectomy. Fluorescence patterns of adrenal tumors were assessed. Multivariate logistic regression was performed to determine the best clinical applications. RESULTS: One hundred patients with Cushing syndrome (n = 29), pheochromocytoma (n = 24), primary hyperaldosteronism (n = 23), nonsecreting adrenocortical adenoma (n = 9), and other tumors (n = 15) underwent robotic adrenalectomy through lateral transabdominal (n = 77) and posterior retroperitoneal (n = 23) approaches. Mean tumor size was 3.6 cm and mean body mass index 33. A total of 74% of the tumors were hyperfluorescent compared with the surrounding retroperitoneal tissues, whereas the remaining 26% were nonfluorescent. Hyperfluorescence was predicted by adrenocortical tissue origin but not by demographic characteristics or tumor size. The contrast distinction between the tumor and the retroperitoneum was better, similar, or inferior on indocyanine green fluoresced compared with the nonfluoresced view in 41%, 27%, and 32% of patients, respectively. The utility was best for adrenocortical adenomas removed through a lateral transabdominal approach. Indocyanine green fluorescence imaging was used to confirm remnant viability in all 4 patients undergoing cortical-sparing adrenalectomy for pheochromocytoma (n = 2), adrenal cyst (n = 1), and lymphatic malformation (n = 1). CONCLUSION: Adrenal tumors have different patterns of indocyanine green fluorescence based on histologic origin. Indocyanine green confers the highest utility for adrenocortical tumors removed through a lateral transabdominal approach and cortical-sparing adrenalectomy.