Evaluation of Parathyroid Glands with Indocyanine Green Fluorescence Angiography After Thyroidectomy

Abstract

Background Indocyanine green fluorescence angiography (ICGA) is a new adjunct that has been used in surgical procedures to assess blood flow. This study evaluated the utility of ICGA compared to visual inspection to predict parathyroid function, guide autotransplantation and potentially decrease permanent hypoparathyroidism. Methods This was a retrospective study of patients who underwent total or near‐total thyroidectomy (T‐NT) between January 2015 and March 2018. Patients with preoperative hyperparathyroidism and those undergoing reoperation were excluded. Patients who had ICGA were compared to T‐NT patients without ICGA. Data were analyzed to assess the frequency of autotransplantation and incidence of hypoparathyroidism between groups. Results In total, 210 patients underwent T‐NT: 86 with ICGA and 124 without. Autotransplantation was more common in the ICGA group at 36% compared to 12% in the control (p = 0.0001). There was no correlation with at least one normal parathyroid gland on ICGA and postoperative PTH levels (p = 0.75). There was a difference in having normal postoperative PTH when there were at least two normal parathyroid glands (n = 50) compared to patients with less than two normal ICGA glands (n = 36, p = 0.044). Visual assessment and ICGA assessment of vascularity were in agreement, 245/281 (87%). There were 19 glands (6.8%) that would have undergone autotransplant based on visual inspection that had adequate blood supply on ICGA. Transient hypoparathyroidism was present in 45 out of 124 controls (36%) and 32 out of 86 (37%) in the ICG group. Conclusions ICGA is a novel technique that may improve the assessment of parathyroid gland blood supply compared to visual inspection. ICGA can guide more appropriate autotransplantation without compromising postoperative parathyroid function. At least two vascularized glands on ICGA may predict postoperative parathyroid gland function.

Preoperative and Intraoperative Methods of Parathyroid Gland Localization and the Diagnosis of Parathyroid Adenomas

“…This property enables a charge-coupled device camera to record the fluorescence of ICG molecules [78]. Thus, this characteristic has been applied in the visualization of PGs since the fluorescence intensity of the glands can be measured by the ICG fluorescence angiography (ICGA) [74,126,127]. ICG is a nonselective agent, which constitutes a limitation of its intraoperative application in PGs detection since it does not target parathyroid parenchyma specifically.…”

“…Further studies reported that ICG can apply to humans in many broad specialties like cholangiography, perfusion assessment of gastrointestinal anastomoses, adrenalectomy, or real-time lymph node mapping [79]. Further, ICG can be used in assessing blood perfusion within the PGs, but also in other cases including skin flaps, bowel anastomosis or lower limbs [126]. Several studies reported that ICG can be used in the intraoperative localization of parathyroid adenomas.…”

Intraoperative Autofluorescence and Indocyanine Green Angiography for the Detection and Preservation of Parathyroid Glands

“…In addition, ICG has most recently emerged as a technique for assessing the vascularization of the parathyroid glands, which seems to be closely correlated with parathyroid function, after thyroid resection [22,[32][33][34][35][36]. From a technical point of view, the protocols and doses of dye used for ICG angiography differ from center to center, with the best dosage still under debate.…”

“…Rudin et al [34] 2019 210 TT At least two vascularized glands on ICGA may predict postoperative parathyroid gland function.…”

“…The authors declare no conflicts of interest. In contrast, some studies report fewer positive results regarding the prediction of parathyroid function using ICG angiography [34,38], although this difference could be related to the subjective visual interpretation of gray scale imaging (i.e., ICG score) [32] during angiography in the absence of a standardized numerical criterion (Table 3). Table 3.…”