Selective parathyroid venous sampling in reoperative parathyroid surgery: A key localization tool when noninvasive tests are unrevealing.

BACKGROUND: Preoperative localization studies are essential for parathyroid re-exploration. When noninvasive studies do not regionalize the abnormal parathyroid gland, selective parathyroid venous sampling may be employed. We studied the utility of parathyroid venous sampling in reoperative parathyroid surgery and the factors that may affect parathyroid venous sampling results. METHODS: Patients with hyperparathyroidism and previous cervical surgery undergoing evaluation for reoperative parathyroidectomy over a 20-year period were identified. Patients with indeterminate or negative noninvasive studies underwent parathyroid venous sampling. Parathyroid hormone values were mapped with a ≥2-fold increase above peripheral signifying positive parathyroid venous sampling. These results were correlated with reoperative findings. RESULTS: Parathyroid venous sampling was positive in 113 of 140 (81%). Re-exploration occurred in 75 (66%). Parathyroid venous sampling correctly detected the region of abnormal glands in 58 (77%). With 1 gradient, 1 abnormal gland was found in 81%. With multiple gradients, 1 abnormal gland was found in 78%, most often at the site with the largest gradient. Eighty percent of patients who underwent reoperative parathyroidectomy were biochemically cured. CONCLUSION: Parathyroid venous sampling can guide parathyroid re-exploration when noninvasive localizing studies are indeterminate. Expectation of 1 versus multiple remaining glands was key in interpreting the results.

Autofluorescence imaging of parathyroid glands: An assessment of potential indications.

BACKGROUND: The aim of this study was to determine both the accuracy of near infrared fluorescence imaging to detect parathyroid glands and the potential indications of near infrared fluorescence imaging in thyroid and parathyroid surgery by correlating the autofluorescence signature with the pathologic specimen. METHODS: This was an institutional review board-approved, prospective study of patients undergoing thyroidectomy and parathyroidectomy with near infrared fluorescence imaging. Each specimen sent to pathology was inspected with near infrared fluorescence imaging and predicted to be either parathyroid or non-parathyroid tissue by its autofluorescence signature and then correlated with the pathologic findings. RESULTS: Autofluorescence was demonstrated to be present in 98% of the parathyroid glands, with 23% identified correctly with infrared based on the autofluorescence signature before visual identification by the surgeon. There were 550 specimens that were imaged with autofluorescence and then sent to pathology. For these samples, sensitivity, specificity, and positive and negative predictive values to predict parathyroid tissue were 98.5%, 97.2%, 95.1%, and 99.1%. In 5% of the total thyroidectomy specimens, incidentally resected parathyroid glands were identified with autofluorescence, leading to their subsequent reimplantation. In patients with parathyroid disease and negative preoperative localization, 21% of abnormal glands were recognized with autofluorescence before visual identification by the surgeon. CONCLUSION: Although the ability of infrared autofluorescence to confirm the presence of parathyroid tissue within surgical specimens was high, its power to find parathyroid glands in situ before visual recognition by surgeons was low. These advantages and limitations should be kept in mind when incorporating this technology into an endocrine surgical practice. Once a parathyroid seems to have been identified by the surgeon or tissue that looks like a parathyroid gland is identified, the autofluorescence signature is a very accurate assurance of parathyroid tissue.

Impact of fluorescence and autofluorescence on surgical strategy in benign and malignant neck endocrine diseases.

Fluorescence and autofluorescence have been shown by several recent studies to be valuable adjuncts in identifying parathyroid glands during thyroidectomy and parathyroidectomy. The aim of this chapter is to review the impact of this new technology on surgical strategy concerning identification and preservation of parathyroid glands during thyroidectomy, identification of parathyroid glands in hyperparathyroidism, and the potential role in thyroid cancer surgery.

Analysis of a thyroid nodule care pathway: Opportunity to improve compliance and value of care.

BACKGROUND: Care pathways facilitate standardized, evidence-based treatment to improve outcomes and value of care. Care pathways consist of multiple nodes representing decision points. Few studies investigate care pathway compliance. We demonstrate nodal care pathway analysis by reviewing compliance with our institutional multidisciplinary, evidence-based care pathways on the treatment of thyroid nodule to generate strategies to increase care pathway adherence and value of care. METHODS: Patients undergoing workup and treatment of structural thyroid disease between January 2018 and June 2018 were included in a retrospective analysis of enterprise-wide compliance with the following 3 care pathway nodes: (1) laboratory testing: only patients with abnormal results from thyroid-stimulating hormone testing should have T3/T4 measured. (2) imaging: neck computed tomography, magnetic resonance imaging, and positron emission tomography ordered for the workup of nodules were reviewed to determine clinical appropriateness. (3) operative treatment: the first 200 thyroid resections conducted in 2018 were reviewed to determine whether the indication and extent of the operation complied with the care pathway. Medicare fee schedules were used for financial calculations. RESULTS: Care pathway nonadherence occurred in 48% of the thyroid-stimulating hormone studies and 38% of the imaging studies obtained, with annual costs exceeding $120,000. Substantial care pathway nonadherence occurred in 3% of nodule-related operations. CONCLUSION: Care pathway nodal analysis can identify areas of care pathway nonadherence. Nodal analysis should be considered for care pathway maintenance and generation of strategies of quality improvement.

Primary Hyperparathyroidism: Redefining Cure.

Primary hyperparathyroidism is the most common cause of hypercalcemia. Follow-up can be resource-intensive and costly. The aim of this study was to determine if there is a subset of patients who can be defined cured earlier than six months. This was a retrospective study of patients who underwent parathyroidectomy between January 2012 and March 2014. Patients with a history of multiple endocrine neoplasia syndrome, and secondary or tertiary hyperparathyroidism were excluded. Patients with normal preoperative calcium and parathyroid hormone (PTH) and those without six months follow-up were excluded. Patients were divided into two groups: cured and not cured. Data analysis was performed between the two groups. A total of 509 patients were screened, and 214 met our inclusion criteria: 202 in the cured category and 12 in the not cured category (94% cure rate). There was no significant difference between age, gland weight, or preoperative PTH. There was a statistically significant difference between final intraoperative PTH (IOPTH) (37 vs 55, P = 0.008) and per cent PTH decrease (69 vs 43%, P < 0.0001). There was a significant difference between intraoperative cure rate (P < 0.0006), imaging concordance (P = 0.0115), and solitary versus multiglandular disease (P = 0.0151). Subgroup analysis in patients with concordant imaging, solitary parathyroid adenoma, and IOPTH decrease by 50 per cent to normal or near-normal correlated with a six-month cure rate of 97 per cent. Patients with primary hyperparathyroidism with concordant imaging, single-adenoma pathology, and IOPTH decrease by 50 per cent to normal or near-normal levels (15-65 pg/mL) can be considered cured and may need less frequent follow-up.

Evaluation of Parathyroid Glands with Indocyanine Green Fluorescence Angiography After Thyroidectomy.

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.

Flat Epithelial Atypia on Core Biopsy and Upgrade to Cancer: a Systematic Review and Meta-Analysis.

BACKGROUND: No consensus exists on whether flat epithelial atypia (FEA) diagnosed percutaneously should be surgically excised. A systematic review and meta-analysis of the frequency of upgrade to cancer or an atypical ductal hyperplasia (ADH) at surgical excision of FEA was performed. METHODS: Embase, MEDLINE, Scopus, and Web of Science databases from January 2003 to November 2015 were searched. The inclusion criteria required a manuscript in English with original data on FEA diagnosed percutaneously, data including the presence or absence of other concurrent high-risk lesions, and data including outcome of cancer at surgical excision. Studies were assessed for quality, and two reviewers extracted data. Random-effects meta-analysis was used to pool estimates. The impact of study-level characteristics was assessed by stratified meta-analysis and meta-regression. RESULTS: The inclusion criteria was met by 32 studies. A total of 1966 core needle biopsies showed pure FEA, and 1517 (77%) showed surgical excision. The proportions of patients with upgrade to cancer varied from 0 to 42%, with an overall pooled estimate of 11.1%. Heterogeneity was observed, with the greatest impact based on whether a study included cases of FEA diagnosed before 2003. With restriction of the investigation to 16 higher-quality studies, the cancer upgrade pooled estimate was 7.5% (95% confidence interval [CI], 5.4-10.4%), and the rate of invasive cancer was 3% (95% CI 1.9-4.5%). For upgrade to ADH, data from 22 studies including 937 patients were analyzed. The proportion of patients upgraded to ADH ranged from 0 to 60%, with a pooled estimate of 17.9% overall and 18.6% among high-quality studies. CONCLUSIONS: With patient management change potential for approximately 25% of patients, this analysis supports a general recommendation for surgical excision of FEA diagnosed by core biopsy.