Mechanistic Insights into Tanshinone IIA in the Amelioration of Post-Thyroidectomy Hypoparathyroidism.

BACKGROUND: Thyroidectomy causes impaired blood supply to the parathyroid glands, which leads to hypoparathyroidism. Tanshinone IIA (Tan IIA) is helpful in blood activation and cardiovascular protection. Therefore, the efficacy of Tan IIA in improving hypoparathyroidism was explored in this study. METHODS: New Zealand white rabbits were utilized to establish a unilateral parathyroid gland ischemia injury model. The model was created by selectively ligating the main blood supply vessel of one parathyroid gland, and the rabbits were then divided into three groups receiving 1, 5, and 10 mg/kg of Tan IIA. Serum calcium and parathyroid hormone (PTH) levels were measured using specialized assay kits. Immunohistochemistry was used to assess the microvessel density (MVD) in parathyroid glands. Western blotting (WB) was used to analyze protein expression related to the PI3K/AKT signaling pathway and the pathway-associated HIF-1α and VEGF. Moreover, MMP-2 and MMP-9 involved in angiogenesis were detected by WB. RESULTS: Tan IIA treatment effectively restored serum calcium and PTH levels in a dose-dependent manner. Notably, MVD in the parathyroid glands increased significantly, especially at higher doses. The Tan IIA treatment also elevated the p-PI3K/PI3K and p-AKT/AKT ratios, indicating that the PI3K/AKT pathway was reactivated. Moreover, Tan IIA significantly restored the decreased expression levels of VEGF and HIF-1α caused by parathyroid surgery. Additionally, Tan IIA increased MMP-2 and MMP-9 levels. CONCLUSION: Tan IIA activates the PI3K/AKT pathway, promotes angiogenesis by modulating VEGF, HIF-1α, MMP-2, and MMP-9, thereby further enhancing MVD within the parathyroid glands. This study demonstrates that Tan IIA improved post-thyroidectomy hypoparathyroidism.

Gallic acid pretreatment mitigates parathyroid ischemia-reperfusion injury through signaling pathway modulation.

Thyroid surgery often results in ischemia-reperfusion injury (IRI) to the parathyroid glands, yet the mechanisms underlying this and how to ameliorate IRI remain incompletely explored. Our study identifies a polyphenolic herbal extract-gallic acid (GA)-with antioxidative properties against IRI. Through flow cytometry and CCK8 assays, we investigate the protective effects of GA pretreatment on a parathyroid IRI model and decode its potential mechanisms via RNA-seq and bioinformatics analysis. Results reveal increased apoptosis, pronounced G1 phase arrest, and significantly reduced cell proliferation in the hypoxia/reoxygenation group compared to the hypoxia group, which GA pretreatment mitigates. RNA-seq and bioinformatics analysis indicate GA's modulation of various signaling pathways, including IL-17, AMPK, MAPK, transient receptor potential channels, cAMP, and Rap1. In summary, GA pretreatment demonstrates potential in protecting parathyroid cells from IRI by influencing various genes and signaling pathways. These findings offer a promising therapeutic strategy for hypoparathyroidism treatment.

Rare genetic disorders that impair parathyroid hormone synthesis, secretion, or bioactivity provide insights into the diagnostic utility of different parathyroid hormone assays.

PURPOSE OF REVIEW: Parathyroid hormone (PTH) is the major peptide hormone regulator of blood calcium homeostasis. Abnormal PTH levels can be observed in patients with various congenital and acquired disorders, including chronic kidney disease (CKD). This review will focus on rare human diseases caused by PTH mutations that have provided insights into the regulation of PTH synthesis and secretion as well as the diagnostic utility of different PTH assays. RECENT FINDINGS: Over the past years, numerous diseases affecting calcium and phosphate homeostasis have been defined at the molecular level that are responsible for reduced or increased serum PTH levels. The underlying genetic mutations impair parathyroid gland development, involve the PTH gene itself, or alter function of the calcium-sensing receptor (CaSR) or its downstream signaling partners that contribute to regulation of PTH synthesis or secretion. Mutations in the pre sequence of the mature PTH peptide can, for instance, impair hormone synthesis or intracellular processing, while amino acid substitutions affecting the secreted PTH(1-84) impair PTH receptor (PTH1R) activation, or cause defective cleavage of the pro-sequence and thus secretion of a pro- PTH with much reduced biological activity. Mutations affecting the secreted hormone can alter detection by different PTH assays, thus requiring detailed knowledge of the utilized diagnostic test. SUMMARY: Rare diseases affecting PTH synthesis and secretion have offered helpful insights into parathyroid biology and the diagnostic utility of commonly used PTH assays, which may have implications for the interpretation of PTH measurements in more common disorders such as CKD.

Autofluorescence-guided hemithyroidectomy in a low-volume thyroid institution with no experience in parathyroid surgery: randomized clinical trial.

BACKGROUND: Recent studies suggest that low-volume surgeons with no experience in parathyroid surgery are at increased risk of causing parathyroid gland damage during thyroid surgery. The aim of this RCT was to evaluate the impact of using autofluorescence in hemithyroidectomy on parathyroid gland identification and preservation in a low-volume institution with no experience in parathyroid surgery. METHODS: Patients referred for hemithyroidectomy were randomized 1 : 1 to either autofluorescence-guided hemithyroidectomy (the near-infrared autofluorescence group) or conventional hemithyroidectomy (the control group). The primary outcome was parathyroid gland identification rate. Secondary outcomes were the rate of parathyroid gland autotransplantation and the rate of inadvertent parathyroid gland excision. RESULTS: A total of 170 patients were randomized to either autofluorescence-guided hemithyroidectomy (84 patients) or conventional hemithyroidectomy (86 patients). In the near-infrared autofluorescence group, 81.0% of parathyroid glands were identified, compared with 57.0% in the control group (P < 0.001). Autofluorescence enabled parathyroid gland visualization before the naked eye in 46.3% of cases. Surgeons had lower confidence in the parathyroid gland identification process in the control group than in the near-infrared autofluorescence group (59.1% versus 87.5% respectively; P < 0.001). In the near-infrared autofluorescence group, the parathyroid gland autotransplantation rate was initially high, but declined over time. There was no difference in the rate of inadvertent parathyroid gland excision. CONCLUSION: Autofluorescence guidance significantly improved the parathyroid gland identification rate in hemithyroidectomy in a low-volume institution with no experience in parathyroid surgery and provided an increase in surgical confidence. The pattern of parathyroid gland autotransplantation in autofluorescence-guided surgery indicates the presence of a learning curve. REGISTRATION NUMBER: NCT05044351 (http://www.clinicaltrials.gov).

Damage to the parathyroid glands is common during thyroid surgery. The main reason for that is that they can be difficult to see during surgery. The aim of this study was to see if the use of a new near-infrared camera during thyroid surgery could make it easier to see the parathyroid glands. Patients, where removal of part of their thyroid gland was planned, were randomly assigned to one of two groups. In the first group, the near-infrared camera was used, whereas it was not used in the other group. When the near-infrared camera was used, more parathyroid glands were found and the surgeons felt more secure in their handling of parathyroid glands.

Thoracoscopic treatment of mediastinal ectopic parathyroid adenomas: a Latinamerica experience case series and literature review.

BACKGROUND: Hyperparathyroidism (HPT) is a disease caused by hypersecretion of one or more parathyroid glands, it can be associated with ectopic mediastinal parathyroid glands (MEPA) in 2% of cases. The use of video-assisted thoracoscopic surgery (VATS) for the surgical resection of these glands is a safe, cost-effective, and low morbidity option for patients with MEPA. We report a case series of patients with this disease managed with VATS, the first in Mexico and Latinamerica. METHODS: From 2008 to 2022, a retrospective study involving patients with MEPA and treated by VATS approach was performed in a tertiary hospital in Mexico city. Relevant biochemical and clinical variables such as imaging studies, pre and postoperative laboratory results, surgical strategy, outcomes and pathological analysis were analyzed. RESULTS: Four cases of mediastinal parathyroid adenomas causing HPT were included. All patients were female with a median age of 52.5 years-old (range 46-59 years), half of the patients had primary HPT and the others tertiary HPT after kidney transplant. 75% of cases had a MEPA in the medium mediastinum, all had a preoperative positive SPECT-CT 99mTc Sestamibi scan. Mean preoperative PTH was 621.3pg/mL (182-1382pg/mL). All patients successfully underwent parathyroidectomy with a VATS approach, no deaths were reported. CONCLUSIONS: VATS is a minimally invasive surgery that provides adequate access to mediastinal located glands, optimal visualization of mediastinal structures and has a high resection success rate with less complications and morbidity than open approaches.

Atypical parathyroid adenoma with severe bone manifestations in early adolescence.

This is a case of primary hyperparathyroidism in a female teenager with multiple fractures and severe bone manifestations. The histopathology revealed atypical parathyroid adenoma, an exceedingly rare form of hyperparathyroidism; its main differential diagnosis is parathyroid carcinoma, as it shares both clinical and histological characteristics with it, in addition to its still uncertain malignant potential.

TRPC3 Is Downregulated in Primary Hyperparathyroidism.

Transient receptor potential canonical sub-family channel 3 (TRPC3) is considered to play a critical role in calcium homeostasis. However, there are no established findings in this respect with regard to TRPC6. Although the parathyroid gland is a crucial organ in calcium household regulation, little is known about the protein distribution of TRPC channels-especially TRPC3 and TRPC6-in this organ. Our aim was therefore to investigate the protein expression profile of TRPC3 and TRPC6 in healthy and diseased human parathyroid glands. Surgery samples from patients with healthy parathyroid glands and from patients suffering from primary hyperparathyroidism (pHPT) were investigated by immunohistochemistry using knockout-validated antibodies against TRPC3 and TRPC6. A software-based analysis similar to an H-score was performed. For the first time, to our knowledge, TRPC3 and TRPC6 protein expression is described here in the parathyroid glands. It is found in both chief and oxyphilic cells. Furthermore, the TRPC3 staining score in diseased tissue (pHPT) was statistically significantly lower than that in healthy tissue. In conclusion, TRPC3 and TRPC6 proteins are expressed in the human parathyroid gland. Furthermore, there is strong evidence indicating that TRPC3 plays a role in pHPT and subsequently in parathyroid hormone secretion regulation. These findings ultimately require further research in order to not only confirm our results but also to further investigate the relevance of these channels and, in particular, that of TRPC3 in the aforementioned physiological functions and pathophysiological conditions.

5-year Follow-up of Reimplanted Parathyroid Glands in Forearm Subcutaneous Tissue During Thyroidectomy. A Confirmation of Graft Vitality in a Large Series of Patients.

INTRODUCTION: The aim of this study is to assess the outcomes of parathyroid gland reimplantation with PR-FaST technique in patients undergoing thyroid surgery, focusing on graft functionality over a 5-year follow-up period. MATERIALS AND METHODS: We analyzed data from 131 patients who underwent parathyroid reimplantation using the PR-FaST technique during thyroid surgery due to inadvertent parathyroid removal or evident vascular damage. Postoperative evaluations included serum calcium (Ca), magnesium (Mg), and phosphorus (P) analyses on the 1st and 2nd postoperative days, at 10 days, and at 1, 3, 6 months, 1 year, and 5 years of follow-up. Additionally, the mean values of serum intact parathyroid hormone (iPTH) concentration were measured from blood samples collected from both the reimplanted arm (iPTH RA) and non-reimplanted arm (iPTH NRA) within the same period. RESULTS: Among 131 patients, at 10 days post-surgery, only 46 patients (35.1%) out of 131 exhibited graft viability (iPTH ratio >1.5). This percentage increased to 72.8% (94 patients) after 1 month and further to 87.8% (108 patients) after 3 months post-surgery. At 1 year, 84.7% of patients showed good graft functionality. After 5 years, the percentage remained stable, with graft viability observed in 81.3% of patients. Only 91 of the initial 131 patients completed follow-up up to 5 years, with a dropout rate of 30.5 %. CONCLUSIONS: Parathyroid reimplantation using the PR-FaST technique is a viable option for patients undergoing thyroidectomy and has been shown to be a reproducible and effective technique in most patients, with sustained graft functionality and parathyroid hormone production over a 5-year follow-up period.

Contribution of CT scan to patient's radiation exposure in parathyroid SPECT/CT scintigraphy.

INTRODUCTION: Dual phase technetium-99mTc-methoxy isobutyl isonitrile (MIBI) single-photon emission computed tomography with computed tomography (SPECT/CT) may be the most accurate conventional imaging approach for localization of enlarged parathyroid gland (EPG). The imaging is based on the radiopharmaceutical (RP) retention in EPG compared to washout from normal thyroid and normal parathyroid glands. This study aimed to estimate and optimize the contribution of computed tomography (CT) scan and scan range to effective dose (ED) in dual-phase MIBI SPECT/CT parathyroid scintigraphy. METHODS: The study included seventy-four patients; thirty-seven with reduced and thirty-seven with extended CT scan range. The ED caused by the CT scan was calculated using Dose Length Product (DLP) data and estimated using the Imaging Performance Assessment of CT scanners (ImPACT) calculator. RESULTS: For all patients, the contribution of CT to the ED in a combined SPECT/CT examination was 2.62 ± 0.29 mSv (48%). The contribution of CT to the total ED was 1.8 ± 0.18 mSv (33%) when using reduced and 3.44 ± 0.23 mSv (64%) when using extended scan range. The DLP and ED were statistically significantly different between the reduced and extended CT scan range (p < 0.001) in the first and second phases. The individual organ dose was reduced from 8% to 94%. CONCLUSION: The hybrid SPECT/CT improves the interpretation of nuclear medicine images and also increases the radiation dose to the patient. An adequately defined CT scan range on SPECT/CT imaging, can significantly reduce a patient's ED. IMPLICATIONS FOR PRACTICE: The research findings showed that knowledge of anatomy, pathology and technology can provide optimising diagnostic procedures and reduce patient ED after SPECT/CT scans.

Real-time imaging of ipsilateral parathyroid glands by retrograde injection of methylene blue into the superior thyroid artery: a new intraoperative parathyroid protection method.

BACKGROUND: Postoperative hypoparathyroidism caused by parathyroid injury is a problem faced by thyroid surgeons. The current technologies for parathyroid imaging all have some defects. METHODS: Patients with differentiated thyroid carcinoma (DTC) who underwent unilateral thyroidectomy plus ipsilateral central lymph node dissection were recruited. We dissected the main trunk of the superior thyroid artery entering the thyroid gland and placed the venous indwelling tube into the artery. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated. RESULTS: A total of 132 patients enrolled in this single-arm clinical trial, 105 of them completed retrograde catheterization via the superior artery. The sensitivity was 69.23 and 83.33% respectively. The specificity was 72.91 and 64.89%. The accuracy was 72.91 and 64.89%. The PPV was 85.71 and 81.08%. The NPV was 22.58 and 45.45%. There were no patients with allergic reactions to the methylene blue, or methylene blue toxicity. CONCLUSIONS: Retrograde injection of methylene blue via the superior thyroid artery is an effective and safe method to visualize parathyroid glands. This method can accurately locate the target organ by ultraselecting the blood vessel and injecting the contrast agent while avoiding background contamination and reducing the amount of contrast agent. TRIAL REGISTRATION: Clinical trial registration numbers and date of registration: ChiCTR2300077263、02/11/2023.

Thoracoscopic resection of paraesophageal ectopic mediastinal parathyroid adenoma in the superior posterior mediastinum: a case report.

BACKGROUND: The ectopic superior parathyroid in the tracheoesophageal groove and paraesophageal region is rare. Hyperparathyroidism results when these glands become hyperfunctioning. That may necessitate surgical intervention in the form of parathyroidectomy, which requires a transsternal or transthoracic approach due to a deeply seated mediastinal parathyroid gland. Minimally invasive strategies have emerged recently as an alternative approach with less morbidity. CASE PRESENTATION: We present a case of the paraesophageal ectopic parathyroid gland in the superior posterior mediastinum, which was successfully treated with thoracoscopic resection. CONCLUSION: The current imaging tools improve the thoracoscopic management of mediastinal parathyroid glands. Video-assisted thoracoscopic surgery (VATS) can provide access and exposure to ectopic parathyroid adenoma with low morbidity and financial burden.

The value of ultrasound in combination with 99mTc-MIBI imaging department of ultrasound medicine, for the diagnosis of ectopic parathyroid glands in the thyroid gland in patients with secondary hyperparathyroidism.

To investigate the value of preoperative ultrasound combined with 99mTc-MIBI imaging for the diagnosis of ectopic intrathyroid parathyroid gland (ETPG) in patients with secondary hyperparathyroidism (SHPT). One hundred and eleven patients with SHPT who underwent total parathyroidectomy plus forearm transplantation from January 2015 to January 2022 in the Third Hospital of Hebei Medical University were selected. All patients underwent routine preoperative ultrasonography and 99mTc-MIBI imaging, and with pathological diagnosis as the gold standard, the clinical data of ETPG patients were selected, including clinical manifestations, laboratory tests, preoperative ultrasonography and 99mTc-MIBI imaging for localization and diagnosis, intraoperative exploration and postoperative pathology, and postoperative follow-up. To analyze the ultrasound manifestations of preoperative parathyroid hyperplasia and the results of 99mTc-MIBI imaging in patients with ETPG. Among 111 patients with SHPT, there were 5 patients with ETPG, 1 male and 4 females with a mean age of (45.00 ±â€…5.05) years, and 6 ectopic parathyroid glands were located in the thyroid gland. The incidence of ETPG was 4.5% (5/111), 4 were detected by ultrasound, 2 were not detected with a diagnostic accuracy of 66.7% (4/6), 3 were positive for 99mTc-MIBI imaging, 3 were negative with a diagnostic accuracy of 50.0% (3/6). Among them, one was not detected by ultrasound, but was positive for 99mTc-MIBI imaging, 2 with negative 99mTc-MIBI imaging, but all were detected by ultrasound, and one with negative 99mTc-MIBI imaging was detected by ultrasound but misdiagnosed as a thyroid nodule. A total of 5 ETPGs were detected by ultrasound combined with 99mTc-MIBI imaging, with a diagnostic accuracy of 83.3% (5/6). Patients' postoperative serum calcium and serum parathyroid hormone (PTH) levels were normalized or significantly decreased from preoperative levels. Ultrasound combined with 99mTc-MIBI imaging can achieve higher accuracy than either examination alone in the preoperative localization and diagnosis of ETPG in SHPT patients.

The application of autofluorescence system contributes to the preservation of parathyroid function during thyroid surgery.

PURPOSE: The purpose of this study was to investigate the impact of autofluorescence technology on postoperative parathyroid function and short-term outcomes in patients undergoing thyroid surgery. METHODS: A total of 546 patients were included in the study, with 287 in the conventional treatment group and 259 in the autofluorescence group. Both groups underwent central lymph node dissection, which is known to affect parathyroid function. Short-term outcomes, including rates of postoperative hypocalcemia and parathyroid dysfunction, serum calcium and PTH levels on the first postoperative day, as well as the need for calcium supplementation, were analyzed. A multivariable analysis was also conducted to assess the impact of autofluorescence on postoperative parathyroid dysfunction, considering factors such as age, BMI, and preoperative calcium levels. RESULTS: The autofluorescence group demonstrated significantly lower rates of postoperative hypocalcemia and parathyroid dysfunction compared to the conventional treatment group. The autofluorescence group also had better serum calcium and PTH levels on the first postoperative day, and a reduced need for calcium supplementation. Surprisingly, the use of autofluorescence technology did not prolong surgical time; instead, it led to a shorter hospitalization duration. The multivariable analysis showed that autofluorescence significantly reduced the risk of postoperative parathyroid dysfunction, while factors such as age, BMI, and preoperative calcium levels did not show a significant correlation. CONCLUSION: This study provides evidence that autofluorescence technology can improve the preservation of parathyroid function during thyroid surgery, leading to better short-term outcomes and reduced postoperative complications. The findings highlight the potential of autofluorescence as a valuable tool in the management of parathyroid hypofunction. Further research and validation are needed to establish the routine use of autofluorescence technology in the thyroid.

Factors affecting the rates of incidental parathyroidectomy during thyroidectomy.

BACKGROUND: The most important factors affecting the development of postoperative hypocalcaemia (PH) include intraoperative trauma to the parathyroid glands, incidental parathyroidectomy (IP), and the surgeon's experience. In this study, we aimed to determine the incidence of IP, evaluate its effect on postoperative calcium levels and investigate the effect of surgeon experience and volume on IP incidence and postoperative calcium levels. METHODS: This retrospective study included 645 patients who underwent thyroid surgery at the Department of General Surgery, Kütahya Health Sciences University between September 2016 and March 2020. All patients underwent surgery at a single clinic by general surgeons experienced in thyroid surgery and their residents (3-5 years). RESULTS: Normal parathyroid glands were reported in 58 (8.9%) of 645 patients. In 5 (8.6%) of 58 patients the parathyroid gland was detected in the intrathyroidal region. PH developed in ten patients (17.2%) with incidental removal of the parathyroid glands. A statistically significant difference was found between the number of incidentally removed parathyroid glands and the development of hypocalcaemia (p<0.05). Normal parathyroid glands were reported in the pathology of 37 (7.9%) patients operated on by general surgeons and 22 (12.6%) patients operated on by their residents. PH developed in 39 (8.2%) patients operated on by general surgeons and in 8 (4.5%) patients operated on by their residents. CONCLUSIONS: We found that the complication rate during the resident training process was the same as that of experienced general surgeons. A thyroidectomy can be safely performed by senior residents during residential training.

Evaluating the effectiveness of dual dye combination of indocyanine green and carbon nanoparticles with parathyroid hormone test in preserving parathyroid gland during papillary thyroid cancer surgery: a single-center retrospective cohort study.

Preserving the integrity of parathyroid glands is crucial in papillary thyroid cancer (PTC) surgery to avoid hypoparathyroidism. In recent years, two novel dyes, activated carbon nanoparticles (CNP) and indocyanine green (ICG), have been utilized to assist in parathyroid gland identification. However, the use of CNP or ICG alone can result in extravasation of dye or excessive fluorescence of non-parathyroid tissue, which can affect the accuracy of surgical outcomes by yielding false negative or false positive results. Therefore, it is important to further optimize the application of these two dyes in surgery. We analyzed case files of 124 PTC patients who underwent routine total or near-total thyroidectomy with bilateral lymph node dissection in the central region at the Affiliated People's Hospital of Ningbo University from January to November 2022. The patients were randomly divided into three groups based on the type of intraoperative dye used. The CNP group (n = 38) received an intra-thyroidal injection of CNP dye. The ICG group (n = 42) used the ICG near-infrared fluorescence endoscopy system to show parathyroid fluorescence. The group that received a combined approach of ICG and CNP (n = 44) leveraged the advantages of both methods that allow for positive development of ICG and negative development of CNP to identify and preserve the parathyroid gland during operation. The parathyroid hormone detection reagent (PTH test method) was employed to verify the highly suspected parathyroid tissue in all three groups. We analyzed intraoperative data pertaining to intraoperative parathyroid identification, misexcision, number of autotransplantation, and postoperative hypoparathyroidism among the three groups. Compared with the ICG group and the CNP group, the combined group demonstrated more prominent advantages in identifying average the number of lower parathyroid glands (1.93 ± 0.26, p = 0.015), reducing the average numberrate of misexcision (0.45 ± 0.5, p = 0.004), and reducing the incidence of postoperative temporary hypothyroidism (3/44, p = 0.015). The combined use of ICG and CNP dual-dye with PTH test method appears to be more effective in both identifying and protecting parathyroid glands during PTC surgery.

A Rare Ectopic Parathyroid Adenoma in the Prevertebral Space.

Ectopic parathyroid adenomas are an uncommon etiology of primary hyperparathyroidism. We present a case of a patient admitted to the hospital with severe hypercalcemia and elevated parathyroid hormone levels, in whom imaging revealed two distinct parathyroid masses in the prevertebral space, representing a rare and atypical location for parathyroid tissue. This case highlights the importance of considering ectopic parathyroid adenomas as a potential cause of hyperparathyroidism and discusses the diagnostic challenges and management strategies associated with such cases.

The effect of carbon nanoparticles vs. immune colloidal gold technique test strips on parathyroid protection in total thyroidectomy: A randomized clinical trial study.

BACKGROUND: The long-term effect of intraoperative usage of carbon nanoparticles (CN) and parathyroid hormone (PTH) test strip using immune colloidal gold technique (ICGT) is unclear. This study aims to compare the effect of intraoperative usage of CN and ICGT test strips on PG function. METHODS: This randomized clinical study involved adult patients who underwent total thyroidectomy. They were randomly allocated into three groups (control, CN, and ICGT group). Clinical data were analyzed. RESULTS: Each group involved 98 patients. Serum calcium and PTH concentrations at 24 h postoperatively (PTH24h) were higher in CN group. The parathyroid function recovered quicker in CN group. Use of CN increased in situ PG preservation and PTH24h. Mediation analysis indicated that 23.05% of the total effect of CN on PTH24h was attributed to PGRIS. CONCLUSION: CN holds promise to improve in situ PG preservation and protect PG vasculature, thereby reducing the incidence of early hypoparathyroidism. The value of ICGT test strips for PG protection is dubious.

Cost-Effectiveness of Parathyroid Cryopreservation and Autotransplantation.

Importance: Delayed autotransplantation of cryopreserved parathyroid tissue (DACP) is the only surgical treatment for permanent postoperative hypoparathyroidism. Studies suggest that only a small minority of cryopreserved samples are ultimately autotransplanted with highly variable outcomes. For these reasons, many have questioned the economic utility of the process, although, to the authors' knowledge, this has never been formally studied. Objective: To report the clinical outcomes of parathyroid cryopreservation and DACP at a large academic institution and to determine the cost-effectiveness of this treatment. Design, Setting, and Participants: An institutional review board-approved, retrospective review of patients at a single institution who underwent DACP over a 17-year period was conducted with a median follow-up of 48.2 months. A forward-looking cost-utility analysis was then performed to determine the economic utility of cryopreservation/DACP vs usual care (monitoring and supplementation). Patients who had parathyroid tissue in cryopreserved storage between August 2005 to September 2022 at a single-center, academic, quaternary care center were identified. Exposure: Parathyroid cryopreservation and DACP. Main Outcomes and Measures: Graft functionality, clinical outcomes, and cost utility using a willingness-to-pay threshold of $100 000 per quality-adjusted life-year (QALY). Results: A total of 591 patients underwent cryopreservation. Of these, 10 patients (1.7%; mean [SD] age, 45.6 [17.9] years; 6 male [60%]) underwent DACP. A minority of autografts (2 [20%]) were subsequently fully functional, one-half (5 [50%]) were partially functional, and 3 (30%) were not functional. The cost-utility model estimated that at a large academic center over 10 years, the additional cost of 591 patients undergoing cryopreservation and 10 patients undergoing autotransplantation would be $618 791.64 (2022 dollars) and would add 8.75 QALYs, resulting in a cost per marginal QALY of $70 719.04, which is less than the common willingness-to-pay threshold of $100 000/QALY. Conclusions and Relevance: The reimplantation rate of cryopreserved tissue was low (<2%), but when implanted, autografts were at least partially functional 70% of the time. In the first-ever, to the authors' knowledge, formal cost analysis for this treatment, results of the current model suggest that cryopreservation and autotransplantation were cost-effective compared with the usual care for hypoparathyroidism at a large, academic institution. It is recommended that each surgical center consider whether the economic and logistical commitments necessary for cryopreservation are worthwhile for their individual needs.