Total Parathyroidectomy with Subcutaneous Parathyroid Forearm Autotransplantation in the Treatment of Secondary Hyperparathyroidism: A Single-Center Experience

Single-cell analysis reveals transcriptional dynamics in healthy primary parathyroid tissue

Studies on human parathyroids are generally limited to hyperfunctioning glands owing to the difficulty in obtaining normal human tissue. We therefore obtained non-human primate (NHP) parathyroids to provide a suitable alternative for sequencing that would bear a close semblance to human organs. Single-cell RNA expression analysis of parathyroids from four healthy adult M. mulatta reveals a continuous trajectory of epithelial cell states. Pseudotime analysis based on transcriptomic signatures suggests a progression from GCM2 hi progenitors to mature parathyroid hormone (PTH)-expressing epithelial cells with increasing core mitochondrial transcript abundance along pseudotime. We sequenced, as a comparator, four histologically characterized hyperfunctioning human parathyroids with varying oxyphil and chief cell abundance and leveraged advanced computational techniques to highlight similarities and differences from non-human primate parathyroid expression dynamics. Predicted cell-cell communication analysis reveals abundant endothelial cell interactions in the parathyroid cell microenvironment in both human and NHP parathyroid glands. We show abundant RARRES2 transcripts in both human adenoma and normal primate parathyroid cells and use coimmunostaining to reveal high levels of RARRES2 protein (also known as chemerin) in PTH-expressing cells, which could indicate that RARRES2 plays an unrecognized role in parathyroid endocrine function. The data obtained are the first single-cell RNA transcriptome to characterize nondiseased parathyroid cell signatures and to show a transcriptomic progression of cell states within normal parathyroid glands, which can be used to better understand parathyroid cell biology.

Intraoperative Parathyroid Hormone Monitoring Is of Limited Usefulness in Guiding Autotransplantation in Reoperative or Subtotal Parathyroidectomy for Primary Hyperparathyroidism

INTRODUCTION

Patients with primary hyperparathyroidism (1HPT) undergoing reoperative or subtotal parathyroidectomy (PTX) may undergo autotransplantation (ATX) when the viability of remaining tissue is unknown. This study aims to identify whether intraoperative parathyroid hormone levels (IOPTH) can determine ATX candidacy.

METHODS

Patients with 1HPT who underwent PTX with ATX at our institution were identified. IOPTH and PTH values within 24 h, 2-4 weeks, and >1 month postoperative were analyzed. Patients were classified as either a candidate for ATX (low PTH after 2-4 weeks) or not a candidate based on postoperative PTH (normal PTH after 2-4 weeks). Associations of ATX candidate status with demographic and clinical attributes were studied.

RESULTS

268 had a reoperative (49%) or subtotal PTX with ATX. 151 had data for PTH analysis, and 21 (14%) were identified as candidates for ATX. The mean % decline in IOPTH from baseline to 20 min post-excision was 51% in noncandidates vs 73% in candidates (P = .002). The mean change in IOPTH from baseline to final was 52% in noncandidates and 83% in candidates (P = .009). A decrease in IOPTH from baseline to 20 min post-excision of 23.4% or greater or a final PTH of 52 pg/mL or less would be an indication for ATX. Of the 21 who needed an ATX, it failed in 10.

CONCLUSION

Parathyroid ATX is frequently unnecessary, and the viability is less than expected. While candidates for ATX have a greater IOPTH % decline at all points during surgery and a lower final IOPTH, the clinical practicality of using IOPTH to determine ATX candidacy is limited.

Surgical treatment of tertiary hyperparathyroidism: does one fit for all?

BACKGROUND

Tertiary hyperparathyroidism (3HPT) is defined as a condition of excessive autonomous excretion of intact parathyroid hormone (iPTH) with persistent hypercalcemia (>10.5 mg/dL) that lasts for more than 12 months after a successful kidney transplantation, in the context of a long course secondary hyperparathyroidism (2HPT). The chronic high levels of iPTH cause a worsening of graft function, accompanied by systemic symptoms of hypercalcemia. The only curative therapy is parathyroidectomy (PTX). It remains unclear whether total parathyroidectomy with autotransplantation (TPTX-AT) or subtotal parathyroidectomy (SPTX) lead to better outcomes.

AIMS

The aim of this retrospective, single-institution cohort study is to evaluate the rate of persistent or recurrent disease and postoperative calcium/iPTH disturbances in patients treated with TPTX-AT or SPTX for 3HPT.

METHODS

A single-center retrospective analysis of 3HPT patients submitted to TPTX-AT or SPTX between 2007-2020 with at least 24 months follow-up was conducted. The outcome parameters included persistence/recurrence of disease, incidence of transitory hypocalcemia, and temporary/permanent hypoparathyroidism.

RESULTS

A cohort of 52 patients was analyzed and divided in two groups: 38 (73%) were submitted for TPTX-AT, and 14 patients (27%) were submitted for SPTX. The TPTX-AT population showed lower plasmatic calcium concentrations compared with the SPTX group during the entire follow-up period (p<0.001). There were eight cases (21%) of transitory hypocalcemia in the TPTX-AT group and none in the SPTX group, with p=0.065. Two cases (5%) of temporary hypoparathyroidism occurred in the TPTX-AT group and none in the SPTX group, with p= 0.530. There were no cases of permanent hypoparathyroidism and no cases of persistent disease. No statistical difference was assessed for the recurrence of 3HPT between the TPTX-AT group and the SPTX group (N=1, 3% vs N=1, 7%) (p=0.470).

CONCLUSION

No significative difference was registered between the TPTX-AT and SPTX groups in terms of persistence/recurrence of disease, incidence of transitory hypocalcemia, and temporary/permanent hypoparathyroidism. Mean calcium levels iPTH values were statistically lower among the TPTX-AT group compared with the SPTX group while remaining always in the range of normality.

[Special features of the diagnostics and treatment of hereditary primary hyperparathyroidism]

Between 2% and 10% of patients with primary hyperparathyroidism (pHPT) are diagnosed with hereditary forms of primary hyperparathyroidism (hpHPT). They are more prevalent in younger patients before the age of 40 years, in patients with persistence or recurrence of pHPT and pHPT patients with multi-glandular disease (MGD). The various forms of hpHPT diseases can be classified into four syndromes, i.e., hpHPT associated with diseases of other organ systems, and four diseases that are confined to the parathyroid glands. Approximately 40% of patients with hpHPT suffer from multiple endocrine neoplasia type 1 (MEN-1) or show germline mutations of the MEN‑1 gene. Currently, germline mutations that lead to a specific diagnosis in patients with hpHPT have currently been described in 13 different genes, which enables a clear diagnosis of the disease; however, a clear genotype-phenotype correlation does not exist, even though the complete loss of a coded protein (e.g. due to frame-shift mutations in the calcium sensing receptor, CASR) often leads to more severe clinical consequences than merely a reduced function of the protein (e.g. due to point mutation). As the various hpHPT diseases require different treatment approaches, which do not correspond to that of sporadic pHPT, a clear definition of the specific form of hpHPT must always be strived for. Therefore, before surgery of a pHPT with clinical, imaging or biochemical suspicion of hpHPT, genetic proof or exclusion of hpHPT is necessary. The differentiated treatment approach for hpHTP can only be defined by taking the clinical and diagnostic results of all the abovenamed findings into account.

Efficacy and safety of total parathyroidectomy with autotransplantation vs. subtotal parathyroidectomy for secondary hyperparathyroidism: A retrospective study

Background

No consensus has been reached on the best surgical approach for secondary hyperparathyroidism (SHPT). We evaluated the short-term and long-term efficacy and safety of total parathyroidectomy with autotransplantation (TPTX + AT) and subtotal parathyroidectomy (SPTX).

Methods

We retrospectively analyzed the data of 140 patients undergoing TPTX + AT and 64 undergoing SPTX between 2010 and 2021 in Second Affiliated Hospital of Soochow University, and carried out follow-up. We compared the differences in symptoms, serological examinations, complications and mortality between the two methods, and explored the independent risk factors of secondary hyperparathyroidism recurrence.

Results

In short time after surgery, serum intact parathyroid hormone and calcium level was lower in TPTX + AT group than that in SPTX group (both P < 0.05). Severe hypocalcemia was more common in TPTX group (P = 0.003). The recurrent rate was 17.1% for TPTX + AT and 34.4% for SPTX (P = 0.006). There was no statistical difference in all-cause mortality, cardiovascular events, cardiovascular mortality between the two methods. Higher preoperative serum phosphorus level (HR: 1.929 95% CI 1.045-3.563, P = 0.011) and the SPTX surgical method (HR: 2.309, 95% CI 1.276-4.176, P = 0.006) were found to be independent risk factors for SHPT recurrence.

Conclusions

Compared with SPTX, TPTX + AT is more effective in reducing the recurrent risk of SHPT without increasing the risk of all-cause mortality and cardiovascular events.

Treatment for secondary hyperparathyroidism focusing on parathyroidectomy

Secondary hyperparathyroidism (SHPT) is a major problem for patients with chronic kidney disease and can cause many complications, including osteodystrophy, fractures, and cardiovascular diseases. Treatment for SHPT has changed radically with the advent of calcimimetics; however, parathyroidectomy (PTx) remains one of the most important treatments. For successful PTx, removing all parathyroid glands (PTGs) without complications is essential to prevent persistent or recurrent SHPT. Preoperative imaging studies for the localization of PTGs, such as ultrasonography, computed tomography, and 99mTc-Sestamibi scintigraphy, and intraoperative evaluation methods to confirm the removal of all PTGs, including, intraoperative intact parathyroid hormone monitoring and frozen section diagnosis, are useful. Functional and anatomical preservation of the recurrent laryngeal nerves can be confirmed via intraoperative nerve monitoring. Total or subtotal PTx with or without transcervical thymectomy and autotransplantation can also be performed. Appropriate operative methods for PTx should be selected according to the patients' need for kidney transplantation. In the case of persistent or recurrent SHPT after the initial PTx, localization of the causative PTGs with autotransplantation is challenging as causative PTGs can exist in the neck, mediastinum, or autotransplanted areas. Additionally, the efficacy and cost-effectiveness of calcimimetics and PTx are increasingly being discussed. In this review, medical and surgical treatments for SHPT are described.

Improving management of severe hypoparathyroidism: a case series

INTRODUCTION

Hypoparathyroidism is considered a rare endocrine disease. Despite being a deficiency of parathyroid hormone, the standard therapy is based on oral calcium and active vitamin D supplementation. This approach provides satisfactory management in most cases but may be inadequate for patients in the most complex spectrum of the disease. Other therapies are being explored, and among them, the use of recombinant human parathyroid hormone (PTH) has proved to decrease the requirements of calcium and active vitamin D to reach adequate therapeutic goals.

OBJECTIVE

We aimed to provide information on the effectiveness of the current recombinant parathyroid hormone analogs in the clinical management of difficult to control cases of hypoparathyroidism.

METHOD AND MATERIALS

We report our experience using teriparatide and PTH (1-84) through five complex cases of hypoparathyroidism of diverse etiologies. We describe each case and report the effectiveness of treatment in clinical practice.

RESULTS

Four patients with postsurgical hypoparathyroidism and one patient with autoimmune hypoparathyroidism, all of them with suboptimal control under the standard treatment with calcium and calcitriol supplements or calcium gluconate infusion, are presented. They were all started on teriparatide or PTH (1-84), and all of them showed a diminishment of symptoms and were able to maintain normocalcemia without parenteral calcium despite a reduction of oral treatment.

CONCLUSION

This article highlights the effectiveness and safety of hormonal replacement treatment in difficult to manage hypoparathyroidism and provides evidence which justifies its off-label prescription in the case of teriparatide. We consider that this treatment should be considered in cases in which standard treatment fails to reach adequate therapeutic goals.

Diagnostic Accuracy of Intraoperative Intact Parathyroid Hormone Monitoring for Surgical Outcomes of Secondary Hyperparathyroidism

BACKGROUND Intraoperative intact parathyroid hormone (IO-iPTH) monitoring has not reached a consensus in predicting surgical outcomes of secondary hyperparathyroidism. Here, we explore the predictive effect of IO-iPTH monitoring on surgical outcomes of secondary hyperparathyroidism as a potentially effective standard. MATERIAL AND METHODS We enrolled 119 patients who underwent total parathyroidectomy with autotransplantation from January 2016 to August 2019. Intact parathyroid hormone (iPTH) levels were tested 1 day before surgery (iPTHpre), 10 min after glands resection (iPTH10min), and 1 and 7 days after the operation (iPTHd1, iPTHd7). According to iPTHpre levels, patients were divided into a <2000 pg/ml group and a ≥2000 pg/ml group, and the cutoff values were compared. In patients with successful parathyroidectomy, the value of iPTHpre minus iPTH10min (iPTHdec) and relative-iPTH10min were compared between groups. RESULTS Using cutoff values, the predictive criterion was defined as iPTH10min ≤314.5 pg/ml or relative-iPTH10min ≤12.4%. In the iPTHpre ≥2000 pg/ml group, iPTH10min had a higher predictive value (318 pg/ml vs 218 pg/ml) whereas relative-iPTH10min had a lower predictive value (12.1% vs 20.3%). In patients with successful PTX, the iPTHdec value of the iPTHpre ≥2000 pg/ml group was significantly higher than that of the <2000 pg/ml group. Additionally, the relative-iPTH10min was significantly lower in the ≥2000 pg/ml group than in the <2000 pg/ml group. CONCLUSIONS An intraoperative predictive criterion of iPTH10min ≤314.5 pg/ml or relative-iPTH10min ≤12.4% is associated with effectively predicting surgical success of secondary hyperparathyroidism. The predictive value is affected by iPTHpre level; therefore, a variable prediction standard based on iPTHpre levels shall be established.

Use of 99mTc-sestamibi SPECT/CT imaging in predicting the degree of pathological hyperplasia of the parathyroid gland: semi-quantitative analysis

Background

Previous studies have demonstrated that ^99mTc-sestamibi (^99mTc-MIBI) Single-Photon Emission Computed Tomography/ Computed Tomography (SPECT/CT) imaging is an effective isotopic technique for locating the parathyroid in secondary hyperparathyroidism (SHPT). This study aimed to explore further the correlation between ^99mTc-MIBI SPECT/CT imaging and SHPT to demonstrate the value of ^99mTc-MIBI SPECT/CT in evaluating the degree of pathological hyperplasia of the parathyroid gland (PG).

Methods

The demographics, surgical records, and follow-up information of 91 patients were recorded and analyzed. A total of 216 paraffin-embedded PGs of 54 patients were obtained and analyzed.

Results

Patients with ^99mTc-MIBI negative PG(s) had significantly lower preoperative serum phosphorus and higher serum calcium levels at 6 months postoperatively compared to those with ^99mTc-MIBI positive PG(s) (P<0.05). We also found a higher total uptake ratio of the region of interest (URRI) and higher URRI max in the hypocalcemia group than in the non-hypocalcemia group. Both URRI total (P=0.003) and URRI max (P=0.028) were independent risk factors for hypocalcemia 6 months postoperatively. The URRI values of the PGs were significantly positively correlated with glandular weight (R²=0.343, P<0.001), glandular volume (R²=0.240, P<0.001), and degree of pathological hyperplasia (P<0.001). However, the URRI value of the PGs exhibited a notably weak correlation with proliferating cell nuclear antigen (PCNA) (R²=0.035, P=0.006). The area under the receiver operating characteristic curve showed a URRI evaluative value of 0.771 for diffuse and nodular types in 216 PGs (P<0.001). We further evaluated 167 nodular-type PGs, distinguishing between nodular hyperplasia and a single nodule; the URRI evaluative value reached 0.819, which was higher than the volume or weight (P<0.001).

Conclusions

The ^99mTc-MIBI SPECT/CT scintigraphy results were related to serum calcium levels at 6 months after total parathyroidectomy with autotransplantation (TPTX+AT), suggesting the occurrence of hypocalcemia (6 months after TPTX+AT). More importantly, this technique effectively evaluated the pathological hyperplasia of PGs preoperatively, and therefore, could assist surgeons in selecting the PGs with the lowest degree of hyperplasia intraoperatively.

Hypoparathyroidism: State of the Art on Cell and Tissue Therapies

Hypoparathyroidism is an endocrine disorder characterized by low serum calcium levels, high serum phosphorus levels, and by inappropriate or absent secretion of the parathyroid hormone (PTH). The most common therapeutic strategy to treat this condition is hormone replacement therapy with calcium and vitamin D but, unfortunately, in the long term this treatment may not be sufficient to compensate for the loss of endocrine function. Glandular autotransplantation is considered the most effective technique in place of replacement therapy. Although it leads to excellent results in most cases, autotransplantation is not always possible. Allograft is a good way to treat patients who have not been able to undergo autograft, but this technique has limited success due to side effects related to tissue rejection. This therapy is supported by systemic immunosuppression, which leads to the onset of serious side effects in patients, with a risk of endocrine toxicity. Today, research on endocrine disorders is focused on discovering alternative graft therapies that can allow optimal results with the fewest possible side effects. In this review, we will make an update on the current state of the art about the cell and tissue therapy as treatment for hypoparathyroidism, to identify which type of therapeutic strategy could be valid for a future clinical use.

Atypical parathyroid adenoma: clinical and anatomical pathologic features

BACKGROUND

Primary hyperparathyroidism is an endocrine pathology that affects calcium metabolism. Patients with primary hyperparathyroidism have high concentrations of serum calcium or high concentrations of parathyroid hormone, or incorrect parathyroid hormone levels for serum calcium values. Primary hyperparathyroidism is due to the presence of an adenoma/single-gland disease in 80-85%. Multiple gland disease or hyperplasia accounts for 10-15% of cases of primary hyperparathyroidism. Atypical parathyroid adenoma and parathyroid carcinoma are both responsible for about 1.2-1.3% and 1% or less of primary hyperparathyroidism, respectively.

METHODS

We performed a retrospective cohort study and enrolled 117 patients with primary hyperparathyroidism undergoing minimally invasive parathyroidectomy. Histological and immunohistochemical examination showed that 107 patients (91.5%) were diagnosed with typical adenoma (group A), while 10 patients (8.5%) were diagnosed with atypical parathyroid adenoma (group B). None of the patients were affected by parathyroid carcinoma.

RESULTS

Significant statistical differences were found in histological and immunohistochemical parameters as pseudocapsular invasion (p <  0.001), bands of fibrosis (p <  0.001), pronounced trabecular growth (p <  0.001), mitotic rates of > 1/10 high-power fields (HPFs) (p <  0.001), nuclear pleomorphism (p = 0.036), thick capsule (p <  0.001), Ki-67+ > 4% (p <  0.001), galectin-3 + (p = 0.002), and protein gene product (PGP) 9.5 + (p = 0.038).

CONCLUSIONS

Atypical parathyroid adenoma is a tumor that has characteristics both of typical adenoma and parathyroid carcinoma. The diagnosis is reached by excluding with strict methods the presence of malignancy criteria. Atypical parathyroid adenoma compared to typical adenoma showed significant clinical, hematochemical, histological, and immunohistochemical differences. We did not find any disease relapse in the 10 patients with atypical parathyroid adenoma during 60 months of follow-up time.

Effectiveness of the Gamma Probe in Childhood Parathyroidectomy: Retrospective Study

Background There are few reports about parathyroidectomy due to secondary hyperparathyroidism in patients with end-stage renal failure in the literature. We aimed to evaluate the surgical treatment methods and the results of patients who were operated for secondary hyperparathyroidism with end-stage renal disease in our center. Method Sixteen patients with the diagnosis of secondary hyperparathyroidism were treated surgically in our center. Demographical data, laboratory findings, and imagining methods were all examined. The effect of the Technetium 99m methoxyisobutylisonitrile (Tc-99m-MIBI) probe sensitive to gamma rays detection was also evaluated to locate and identify all the parathyroid glands during the operation. Results Eleven of the patients underwent intravenous (IV) Tc-99m MIBI preoperatively and a gamma probe was detected during surgery. The gamma probe was not used in five patients. Four parathyroid glands were removed in eight (72.7%) out of 11 patients with gamma probes and three parathyroid glands were found in three patients. Total parathyroidectomy and parathyroid autoimplantation were made to eight patients who had removed four glands, subtotal parathyroidectomy was done for the other patients. On a comparison of laboratory findings before and after the surgery, there was a significant relationship between the decrease of serum parathyroid hormone and calcium levels (p<0.05). Conclusion Total parathyroidectomy and parathyroid autoimplantation is the most efficient and safe mode of management for secondary parathyroidism patients. During the surgery, using a probe sensitive to gamma rays detection may also help the surgeon. Thus, unnecessary dissections to prevent the presence of atypical parathyroid glands are prevented.