MANAGEMENT OF ENDOCRINE DISEASE: Postsurgical hypoparathyroidism: current treatments and future prospects for parathyroid allotransplantation

A prospective cross-sectional study on hypocalcemia after total thyroidectomy in patients with Graves' disease: insights on secondary hyperparathyroidism

PURPOSE

To investigate the parathyroid function and calcium (Ca) levels in the secondary hyperparathyroidism (SHPT) state in patients with Graves' disease.

METHODS

We examined 31 consecutive patients with Graves' disease without chronic kidney disease, who were treated with total thyroidectomy. The patients were divided into a normal parathyroid hormone (PTH) group (NPTH group; n = 19) with a PTH level ≤ 65 pg/mL, and a secondary hyperparathyroidism group (SHPT group; n = 12), with a PTH level > 65 pg/mL. The PTH and Ca-related parameters were examined and the risk factors for postoperative hypocalcemia were analyzed.

RESULTS

The preoperative Ca level was significantly lower (2.24 ± 0.06 vs. 2.31 ± 0.07 mmol/L, p < 0.05) in the SHPT group than in the NPTH group. The reduction in PTH, 1,25-dihydroxyvitamin D (1,25(OH)2D), and Ca levels from the preoperative day to the next morning was significantly greater in the SHPT group than in the NPTH group (p < 0.05). When intraoperative factors were included, the decrease in the PTH level alone was significant. SHPT was a significant factor in determining the extent of PTH reduction.

CONCLUSIONS

Hyperfunctioning parathyroid glands in the SHPT state were more susceptible to postoperative PTH reduction, which, combined with low preoperative Ca levels, increased the risk of postoperative hypocalcemia in patients with Graves' disease.

Advances in the selection and timing of postoperative radioiodine treatment in patients with differentiated thyroid carcinoma

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy. Patients who receive systematic care typically have a better prognosis. RAI treatment plays a key role in eradicating any remaining thyroid lesions in DTC patients, hence decreasing the risk of distant metastases and cancer recurrence. As research continues to advance, RAI treatment is becoming more and more individualized. Because of the excellent prognosis for DTC patients, there is a relatively broad window for RAI treatment, making it easy to overlook when to receive RAI treatment. However, research on this issue can help patients with varying recurrence risk stratification make better decisions about when to begin RAI treatment following surgery, and physicians can schedule patients based on the severity of their disease. This will improve patient prognosis and lessen needless anxiety in addition to helping solve the problems of unjust healthcare resource distribution. In this review, we will mainly discuss the target population of RAI treatment as well as studies that examine the impact of RAI treatment timing on patient outcomes. In an effort to discourage DTC patients and physicians from selecting RAI therapy at random, we also review the possible negative effects of this treatment.

The outcomes of parathyroid gland autotransplantation during thyroid surgery: a systematic review, meta-analysis and trial sequential analysis

PURPOSE

Thyroidectomy is the treatment of choice for malignant thyroid diseases as well as for benign conditions who cannot be treated medically. The most common complication following thyroidectomy is hypocalcaemia and hypoparathyroidism that usually results from accidental damage or removal of one or more parathyroid glands. Parathyroid gland autotransplantation has been one of the most common intraoperative strategies applied to tackle this problem. The aim of this study is to assess whether parathyroid auto trasnplantation is associated with a decrease in postoperative hypoparathyroidism following thyroidectomy.

METHODS

We conducted a thorough systematic review and meta-analysis of relevant studies published up to February 2024 in MEDLINE, Scopus, Embase and Cochrane Library databases. We compared the incidence of postoperative hypoparathyroidism between the group of patients who underwent autotransplantation and the patients were the parathyroid glands were preserved in situ. A trial sequential analysis was performed subsequently to confirm the findings.

RESULTS

Eighteen studies fulfilled all the inclusion criteria and were ultimately included in our study. The total number of patients was 8,182 with 4,029 receiving parathyroid gland autotransplantation. Autotransplantation was associated with a higher incidence of immediate (within 24 h) and transient hypoparathyroidism (RR 1.58, 1.45-1.73, CI 95%, p < 0.00 and RR 1.60, 1.47-1.76, CI 95%, p < 0.001, respectively). However, it did not affect the rate of permanent postoperative hypoparathyroidism (RR 0.85, 0.51-1.41, CI 95%, p = 0.54). The subsequent trial sequential analysis confirmed these findings.

CONCLUSION

Parathyroid autotransplantation does not lead to a decrease in the rate of permanent post-thyroidectomy hypoparathyroidism. The most important factor to decrease its incidence remains the accurate identification and preservation of the parathyroid glands intraoperatively.

Risk factors of transient and permanent hypoparathyroidism after thyroidectomy: a systematic review and meta-analysis

BACKGROUND

Postoperative hypoparathyroidism (hypoPT) is a common complication following thyroid surgery. However, current research findings on the risk factors for post-thyroid surgery hypoPT are not entirely consistent, and the same risk factors may have different impacts on transient and permanent hypoPT. Therefore, there is a need for a comprehensive study to summarize and explore the risk factors for both transient and permanent hypoPT after thyroid surgery.

MATERIALS AND METHODS

Two databases (PubMed and Embase) were searched from inception to 2024. The Newcastle-Ottawa Scale was used to rate study quality. Pooled odds ratios were used to calculate the relationship of each risk factor with transient and permanent hypoPT. Subgroup analyses were conducted for hypoPT with different definition-time (6 or 12 months). Publication bias was assessed using Begg's test and Egger's test.

RESULTS

A total of 19 risk factors from the 93 studies were included in the analysis. Among them, sex and parathyroid autotransplantation were the most frequently reported risk factors. Meta-analysis demonstrated that sex (female vs. male), cN stage, central neck dissection, lateral neck dissection, extent of central neck dissection (bilateral vs. unilateral), surgery [total thyroidectomy (TT) vs. lobectomy], surgery type (TT vs. sub-TT), incidental parathyroidectomy, and pathology (cancer vs. benign) were significantly associated with transient and permanent hypoPT. Preoperative calcium and parathyroid autotransplantation were only identified as risk factors for transient hypoPT, while preoperative PTH was a protective factor. Additionally, node metastasis and parathyroid in specimen were associated with permanent hypoPT.

CONCLUSION

The highest risk of hypoPT occurs in female thyroid cancer patients with lymph node metastasis undergoing TT combined with neck dissection. The key to preventing postoperative hypoPT lies in the selection of surgical approach and intraoperative protection.

Significant role of 1,25-dihydroxyvitamin D on serum calcium levels after total thyroidectomy: a prospective cohort study

Introduction

Although active vitamin D (VD) has been used both preoperatively and postoperatively to prevent hypocalcemia risk in patients undergoing total thyroidectomy, the role of 1,25-dihydroxyvitamin D (1,25(OH)2D) has not been examined. This study comprehensively investigated the effects of 1,25(OH)2D on calcium (Ca) concentrations after total thyroidectomy.

Methods

Serum Ca, parathyroid hormone (PTH), and 1,25(OH)2D levels were measured in 82 patients with thyroid disease before and after surgery.

Results

Serum Ca, PTH, and 1,25(OH)2D levels decreased significantly on the morning of the first postoperative day. Notably, the decrease in 1,25(OH)2D concentration was significantly lower than that of PTH concentration (10.5 ± 33.4% vs. 52.1 ± 30.1%, p<0.0001), with 28% of patients showing increases in 1,25(OH)2D. The only factor predicting a postoperative 1,25(OH)2D decrease was a high preoperative 1,25(OH)2D concentration. Postoperative 1,25(OH)2D concentrations, as well as the magnitude and rate of decrease from preoperative levels, showed strong positive correlations with preoperative 1,25(OH)2D concentrations (p<0.0001 for all three variables) but not with PTH concentrations. These findings suggest that 1,25(OH)2D concentrations after thyroidectomy were more strongly dependent on preoperative concentrations than on the effect of PTH decrease and were relatively preserved, possibly preventing sudden severe postoperative hypocalcemia. A high 1,25(OH)2D level was the most important preoperative factor for hypocalcemia (<2 mmol/L; p<0.05) on the first postoperative day; however, only PTH decrease was statistically significant (p<0.001) when intraoperative factors were added. In the PTH >10 pg/mL group, the decrease in 1,25(OH)2D levels was significantly associated with postoperative hypocalcemia (p<0.05). Similarly, in the PTH levels >15 pg/mL group, a decrease in 1,25(OH)2D concentration was a significant factor, and the amount of PTH decrease was no longer significant.

Conclusion

1,25(OH)2D plays an important role in preventing sudden, severe hypocalcemia due to decreased PTH levels after total thyroidectomy, whereas high preoperative 1,25(OH)2D levels are a significant risk factor for postoperative hypocalcemia. Optimizing preoperative protocols to adjust Ca, PTH, and 1,25(OH)2D levels to improve the management of patients undergoing total thyroidectomy and to prevent extreme intraoperative PTH decreases may reduce the risk of hypocalcemia.

Parathyroid Allotransplantation: Report of Outcomes in 3 Patients

BACKGROUND

Hypoparathyroidism is a relatively rare endocrine disorder defined as inadequate parathyroid hormone (PTH) secretion leading to a clinical syndrome characterized by hyperphosphatemia and hypocalcemia. This condition has high morbidity; patients present with a heterogeneous range of emotional, mental, and physical symptoms. We present our experience with PTH transplantation, using parathyroid glands surgically removed in the setting of secondary hyperparathyroidism, with a description of the clinical course, immunosuppressive management, and surgical technique.

METHODS

Between 2017 and 2021, 3 patients underwent parathyroid allotransplantation at the University of Illinois at Chicago. The 2 outcomes of interest were (1) symptomatic relief and improvement in calcium levels and (2) time to graft failure, defined as the presence of undetectable PTH levels.

RESULTS

All 3 patients experienced dramatic improvement in their debilitating symptoms, even though 2 patients required repeated PTH transplantation procedures. One patient had a remarkable course with symptom resolution, normalization of PTH levels, and a great reduction in calcium supplementation.

CONCLUSION

The use of hyperplastic glands from patients with secondary hyperparathyroidism undergoing 4-gland parathyroidectomy with autotransplantation represents an important source. However, a uniform definition of graft viability and prospective studies with long follow-ups are needed to address how much parathyroid tissue is optimally transplanted and the need for immunosuppression. Most patients affected by hypoparathyroidism are successfully managed by medical treatment; however, some do not respond to therapy and present debilitating symptoms related to hypocalcemia. This subgroup may benefit from parathyroid allotransplantation. Our 3 patients had remarkable improvement in their symptoms with the adoption of hyperplastic glands. Two out of 3 patients required multiple procedures to sustain symptom control.

[A case of severe hyperparathyroidism in clinical practice. Case report]

Disorders of the mineral balance often determine the symptoms, the severity of the course and the prognosis of many diseases. Primary hyperparathyroidism (PHPT) is a common endocrine disease caused by increased secretion of parathyroid hormone as a result of primary damage to the parathyroid glands. Diagnosis of PHPT is often difficult. Clinical signs of PHPT appear months or years after the onset of the disease, however, the presence of hypercalcemia serves as an early indication of the disease of the thyroid gland. Often, patients are observed for a long time by related specialists (rheumatologists, traumatologists-orthopedists, oncologists), which gives rise to a lot of problems consisting in the lack of adequate treatment and its result, the progression of the disease, disability, and a decrease in the quality of life. Often, patients are observed for a long time by related specialists (rheumatologists, orthopedic traumatologists, oncologists) under the "masks" of various pathologies (osteoporosis, recurrent urolithiasis, etc.), which gives rise to a lot of problems, consisting in an erroneous diagnosis, lack of adequate treatment and its result, progression of the disease, disability, and a decrease in the quality of life. Late diagnosis of PHPT leads to the development of severe complications (osteoporetic fractures, renal failure) and an increased risk of premature death. A clinical case of late diagnosis of PHPT at the stage of pronounced bone complications of the disease, which proceeded under the guise of osteoarthritis, is considered. According to the results of laboratory and instrumental studies, the following were revealed: hypercalcemia, a significant increase in the concentration of PTH, adenoma of the left lower parathyroid gland, hyperparathyroid osteodystrophy, and a decrease in bone mineral density. Surgical treatment was performed - selective parathyroidectomy with the development of hypocalcemia in the early postoperative period, which was stopped by taking calcium supplements and active vitamin D metabolites and is designed to help practitioners of various specialties to understand the issues of diagnosis of PHPT and effective care for patients.

Incidence of post-surgical hypoparathyroidism (POSH) after total thyroidectomy

Post-surgical hypoparathyroidism (POSH) is a recognised complication of total thyroidectomy, leading to hypocalcaemia and its associated adverse effects. This retrospective study aimed to determine the incidence of POSH and identify perioperative predictors for its development. Data from patients who underwent total or completion thyroidectomy between January 2017 and July 2022 were retrospectively analysed. The incidence of POSH was assessed, and patients were categorised into transient or prolonged POSH at six months postoperatively. Potential predictors for POSH were investigated including gender, histological diagnosis, and preoperative thyroid function. A total of 133 adult patients were included in the study. The incidence of patients recovering from transient POSH within six months was 15%, and 5% had prolonged POSH beyond six months of surgery. Parathyroid hormone (PTH) levels normalised in 83% of prolonged POSH patients within 14-33 months, reducing the incidence of persistent POSH to 0.75%. Despite normal PTH levels, overall, 3% had persistent marginally low calcium levels (mean 2.11 mmol/L) in keeping with relative parathyroid insufficiency. Histological diagnosis of malignancy was the only significant risk factor for both transient and prolonged POSH (RR 2.95, CI 1.54 to 5.67, p = 0.001) in this cohort. Cautious capsular dissection during thyroidectomy and protection of the parathyroid glands and vascular supply produce a low incidence of POSH. Although the vast majority of patients with POSH recover after six months, hypocalcaemia may persist due to relative parathyroid insufficiency, requiring long-term calcium supplementation. Further research is needed to determine the best strategies for preventing and treating this condition.

Post-Thyroidectomy Development of Posterior Reversible Encephalopathy Syndrome (PRES) Due to Calcium Over-Replacement

Posterior reversible encephalopathy syndrome (PRES) represents a distinct neurological entity characterized by a range of neurological signs and symptoms (seizures, headache, visual abnormalities, altered consciousness, and/or focal neurological signs) and typical neuroimaging findings reflecting reversible subcortical vasogenic edema, usually in the setting of blood pressure fluctuations, cytotoxic drugs, autoimmune disorders, and eclampsia. Here we present a case of a 61-year-old woman, with a history of recent total thyroidectomy and postoperative hypoparathyroidism, who was admitted to the Emergency Department with generalized seizures. Although in this clinical setting, hypocalcemia is expected as the most possible underlying pathogenic factor for triggering seizures, the patient was diagnosed with iatrogenic hypercalcemia and milk-alkali syndrome. A brain magnetic resonance imaging (MRI) demonstrated cortical swelling and fluid-attenuated inversion recovery (FLAIR) signal abnormalities in both occipital, parietal, and right frontal lobes, consistent with PRES. The patient's encephalopathy resolved after resolution of hypercalcemia; she had no neurological deficits on discharge, while she was restarted on lower doses of calcium for hypoparathyroidism. This case illustrates the challenges imposed by postoperative hypoparathyroidism and highlights that PRES is a rare but serious complication of hypercalcemia of which endocrinologists should be aware.

Neuroendocrine Parathyroid Tumors: Quality of Life in Patients with Primary Hyperparathyroidism

Tumors of the parathyroid glands, when associated with PTH (parathyroid hormone) excess, display a large area of complications; in addition to the classical clinical picture of primary hyperparathyroidism (PHP), a complex panel of other symptoms/signs can be identified, including memory and cognitive impairment, chronic asthenia/fatigue, reduced muscle functionality, depressive mood, non-specific bone pain, and loss of sleep quality. The perception of quality of life (QoL) can be supplementarily enhanced by their progressive onset, which makes many patients not be fully aware of them. Their improvement was reported very early after parathyroidectomy (PTx), yet the level of statistical evidence does not qualify these non-classical elements as standalone indications for PTx. Our objective is introducing an up-to-date on QoL scores with regards to the patients diagnosed with PHP, particularly taking into consideration PHP management from baseline to post-operatory outcome, including in cases with multiple endocrine neoplasia. This is a narrative review of literature. We revised full-length papers published in English through PubMed research conducted between January 2018 and May 2023 by using the key words "quality of life" and "primary hyperparathyroidism". We particularly looked at data on self-reported QoL (through questionnaires). We excluded from the search the studies focused on non-PTH related hypercalcemia, secondary, and/or renal/tertiary hyperparathyroidism, and vitamin D supplementation. Overall, we identified 76 papers and selected for the final analysis 16 original studies on QoL and PHP (a total of 1327 subjects diagnosed with syndromic and non-syndromic PHP). The studies with the largest number of individuals were of 92, 104, 110, 134, 159, as well as 191. A few cohorts (n = 5) were of small size (between 20 and 40 patients in each of them). Concerning the study design, except for 2 papers, all the mentioned studies provided longitudinal information, particularly the timeframe from baseline (before PTx) and after surgery. The post-operatory follow-up was of 3-6 months, but mostly between 1 and 3 years (maximum a decade of surveillance). The age of the patients varies between medians of 56, 62, 64, and 68 years. Most frequent questionnaires were SF-36, PHPQoL, and PAS. Despite not being unanimously similar, an overall reduced score of QoL in patients with PHP versus controls was registered, as well as general improvement following PTx. Variations of QoL results might have a multifactorial background from different comorbidities, studied populations, technical aspects of collecting the data, etc. QoL scores in PHP represents a complex heterogeneous picture, from their correlation with clinical features and lab assays (e.g., the level of serum calcium), the associated comorbidities (such as multiple endocrine neoplasia syndromes), up to the assessment of the QoL improvement after parathyroidectomy (PTx). While current studies do not unanimously agree on each QoL domain, the assessment of QoL might represent a supplementary argument to consider when deciding for PTx, especially in asymptomatic cases and in patients who do not fit into well-known categories of surgery candidates, according to current guidelines, thus assessing QoL in PHP is part of a current research gap. QoL evaluation in PHP remains an open issue, towards which awareness should be cultivated by both endocrinologists and surgeons. The introduction of a routine evaluation of the QoL scores in patients, as well as the selection of the most appropriate questionnaire(s), represents an open chapter thus awareness in mandatory.

Is parathyroid allotransplantation a viable option in the treatment of permanent hypoparathyroidism? A review of the literature

BACKGROUND

The standard clinical treatment for hypoparathyroidism, replacement of calcium and vitamin metabolites (calcitriol), has been used for decades; however, evidence points to its inefficiency in acting on the pathophysiology of the disease, which may precipitate or aggravate conditions already related to hypoparathyroidism. Therapies based on recombinant human parathyroid hormone have emerged in recent years but still have low availability due to their high cost. Parathyroid allotransplantation (Pt-a) has been reported as a strategy for treating more severe cases.

METHODS

This narrative review highlights relevant aspects of conventional permanent hypoparathyroidism treatment and provides a comprehensive and critical review of the reports of applications of Pt-a, especially those carried out in recent years. Particular focus is placed on the following key points: parathyroid immunogenicity, immunosuppression regimens (short-term or chronic), techniques to reduce the expression of immunogenic molecules, follow-up time, and reductions in calcium and vitamin D supplementation.

CONCLUSION

Pt-a has been considered a safe and relatively low-cost therapy and is believed to have the potential to cure the disease, in addition to treating symptoms. However, there is considerable heterogeneity in treatment protocols; therefore, more studies are required to improve the standardization of the procedure and thus improve the consistency of outcomes.

The Effect of Pre-Thyroidectomy Calcitriol Prophylaxis on Post-Thyroidectomy Hypocalcaemia in Children

INTRODUCTION

Transient or persistent hypoparathyroidism is one of the most well-known complications of total thyroidectomy and may lead to symptomatic hypocalcaemia. In children, treatment of post-thyroidectomy hypocalcaemia usually consists of postoperative calcium and/or vitamin D supplementation. In 2013, we implemented prophylactic pre-thyroidectomy calcitriol supplementation for all children undergoing total thyroidectomy at the Amsterdam UMC. The objective of this study was to evaluate the efficacy of this prophylactic calcitriol supplementation in preventing post-thyroidectomy hypocalcaemia in children.

METHODS

In a retrospective case study, we included all children (age <18 years), who underwent a total or completion thyroidectomy in the Amsterdam UMC, between 2000 and 2020. Patients were divided into two groups, patients with preoperative calcitriol supplementation and those without (controls). Hypocalcaemia was defined as total serum calcium concentration of <2.0 mmol/L. The primary outcome measure was the occurrence of hypocalcaemia in the first 72 h after surgery. Secondary outcome measures were occurrence of symptomatic hypocalcaemia, need for medical intervention within the first 72 h after surgery, and length of hospitalization.

RESULTS

A total of 51 patients were included; 26 with calcitriol prophylaxis and 25 controls. There was no significant difference in occurrence of hypocalcaemia (17/26 prophylaxis group; 18/25 control group). Median postoperative calcium concentrations in the first 72 h were significantly higher in the group with prophylaxis at 30-35 h (2.26 vs. 2.01 mmol/L) and 36-41 h (2.17 vs. 1.92 mmol/L). Occurrence of symptomatic hypocalcaemia, need for medical intervention, and length of hospitalization were not significantly different between the groups.

CONCLUSION

Calcitriol prophylaxis resulted in somewhat higher postoperative calcium concentrations but did not reduce the occurrence of hypocalcaemia or affect clinical outcome measures such as occurrence of symptomatic hypocalcaemia and length of postoperative hospitalization.

Kidney Complications and Hospitalization in Patients With Chronic Hypoparathyroidism: A Cohort Study in Sweden

CONTEXT

Kidney complications may be considerably higher in patients with chronic hypoparathyroidism (hypoPT) treated with activated vitamin D and calcium supplementation.

OBJECTIVE

We aimed to investigate the risk of chronic kidney disease (CKD), urolithiasis, and hospitalization in patients with chronic hypoPT.

METHODS

In this population-based cohort study in Sweden, national registries (Swedish National Patient Register, Swedish Prescribed Drug Register, and Total Population Register, 1997-2018) were used to identify patients with chronic hypoPT and controls matched by sex, age, and county of residence. We determined time to CKD and urolithiasis diagnosis, and incidence rates of hospitalization.

RESULTS

A total of 1562 patients with chronic hypoPT without preexisting CKD and 15 620 controls were included. The risk of developing CKD was higher in patients with chronic hypoPT compared with controls (hazard ratio [HR] 4.45; 95% CI, 3.66-5.41). In people without prior urolithiasis (n = 1810 chronic hypoPT and n = 18 100 controls), the risk of developing urolithiasis was higher in patients with chronic hypoPT (HR 3.55; 95% CI, 2.84-4.44) compared with controls. Patients with chronic hypoPT had higher incidence rates for all-cause hospitalization (49.59; 95% CI, 48.50-50.70, per 100 person-years vs 28.43; 95% CI, 28.15-28.71, respectively) and for CKD (3.46; 95% CI, 3.18-3.76, per 100 person-years vs 0.72; 95% CI, 0.68-0.77, respectively), compared with controls. Men with hypoPT appear to have a higher risk of CKD than women.

CONCLUSION

Patients with chronic hypoPT had an increased risk of CKD, urolithiasis, and hospitalization compared with controls.

Teriparatide administration by the Omnipod pump: preliminary experience from two cases with refractory hypoparathyroidism

CONTEXT

Hypoparathyroidism (hypoPTH) in adults is mainly due to total thyroidectomy. Conventional therapies (calcium, active vitamin D) can fail to normalize calcemia, expose the patient to hypercalciuria and impact quality-of-life. Human parathormone (PTH) replacement therapy is a suitable option in these cases, although few clinical reports have been published so far.

METHODS

We describe two cases of patients with refractory postsurgical hypoPTH, in whom subcutaneous infusion of recombinant PTH (teriparatide) through the Omnipod® pump was initiated after failure of all other therapeutic options. Besides, we performed a review of literature of hypoPTH cases treated by continuous infusion of teriparatide.

RESULTS

Two women aged 46 and 61 years old failed to normalize calcemia either with conventional treatments (calcium 8 g/day + calcitriol 9 mcg/day and calcium 5 g/day + calcitriol 12 mcg/day) or with thrice daily subcutaneous injections of teriparatide. As a last resort, teriparatide infusion via Omnipod® device normalized their calcemia and allowed calcium/vitamin D withdrawal, with average teriparatide dose of 23 and 32 mcg/day, respectively. The flow of teriparatide was adapted according to a protocol based on measured calcemia, under medical supervision. In the literature, 15 adult cases (13 women, mean age 44.5 ± 5.2 years old) are reported. HypoPTH was consecutive to surgery in all of them. Mean dose of teriparatide administered was 25 ± 6 mcg/day with improvement of calcemia level and quality-of-life in all patients.

CONCLUSIONS

Continuous administration of teriparatide through Omnipod® appears as an efficient therapeutic option in refractory hypoPTH, whose administration to the patient can be assisted by medically-supervised protocol.

Parathyroid Allotransplantation: A Systematic Review

Background: To date, there is no satisfactory treatment for patients with calcium and vitamin D supplementation refractive hypoparathyroidism. Parathyroid allotransplantation by design is a one-time cure through its restoration of the parathyroid function and, therefore, could be the solution. A systematic literature review is conducted in the present paper, with the aim of outlining the possibilities of parathyroid allotransplantation and to calculate its efficacy. Additionally, various transplantation characteristics are linked to success. Methods: This review is carried out according to the PRISMA statement and checklist. Relevant articles were searched for in medical databases with the most recent literature search performed on 9 December 2021. Results: In total, 24 articles involving 22 unique patient cohorts were identified with 203 transplantations performed on 148 patients. Numerous types of (exploratory) interventions were carried out with virtually no protocols that were alike: there was the use of (non-) cryopreserved parathyroid tissue combined with direct transplantation or pretreatment using in vitro techniques, such as culturing cells and macro-/microencapsulation. The variability increased further when considering immunosuppression, graft histology, and donor–recipient compatibility, but this was found to be reported in its entirety by exception. As a result of the large heterogeneity among studies, we constructed our own criterium for transplantation success. With only the studies eligible for our assessment, the pooled success rate for parathyroid allotransplantation emerged to be 46% (13/28 transplantations) with a median follow-up duration of 12 months (Q1–Q3: 8–24 months). Conclusions: Manifold possibilities have been explored around parathyroid allotransplantation but are presented as a double-edged sword due to high clinical diverseness, low expertise in carrying out the procedure, and unsatisfactory study quality. Transplantations carried out with permanent immunosuppression seem to be the most promising, but, in its current state, little could be said about the treatment efficacy with a high quality of evidence. Of foremost importance in pursuing the answer whether parathyroid allotransplantation is a suitable treatment for hypoparathyroidism, a standardized definition of transplantation success must be established with a high-quality trial.

Thyroidectomy for Cancer: The Surgeon and the Parathyroid Glands Sparing

BACKGROUND

The diagnosis of thyroid cancer is continuously increasing and consequently the amount of thyroidectomy. Notwithstanding the actual surgical skill, postoperative hypoparathyroidism still represents its most frequent complication. The aims of the present study are to analyze the rate of postoperative hypoparathyroidism after thyroidectomy, performed for cancer by a single first operator, without any technological aid, and to compare the data to those obtained adopting the most recent technological adjuncts developed to reduce the postoperative hypoparathyroidism.

METHODS

During the period 1997-2020 at the Endocrine Surgery Unit of the Department of Clinical and Experimental Medicine of the University of Florence, 1648 consecutive extracapsular thyroidectomies for cancer (401 with central compartment node dissection) were performed. The percentage of hypoparathyroidism, temporary or permanent, was recorded both in the first period (Group A) and in the second, most recent period (Group B). Total thyroidectomies were compared either with those with central compartment dissection and lobectomies. Minimally invasive procedures (MIT, MIVAT, some transoral) were also compared with conventional. Fisher's exact and Chi-square tests were used for comparison of categorical variables. p < 0.01 was considered statistically significant. Furthermore, a literature research from PubMed® has been performed, considering the most available tools to better identify parathyroid glands during thyroidectomy, in order to reduce the postoperative hypoparathyroidism. We grouped and analyzed them by technological affinity.

RESULTS

On the 1648 thyroidectomies enrolled for the study, the histotype was differentiated in 93.93 % of cases, medullary in 4% and poorly differentiated in the remaining 2.06%. Total extracapsular thyroidectomy and lobectomy were performed respectively in 95.45% and 4.55%. We recorded a total of 318 (19.29%) cases of hypocalcemia, with permanent hypoparathyroidism in 11 (0.66%). In regard to the literature, four categories of tools to facilitate the identification of the parathyroids were identified: (a) vital dye; (b) optical devices; (c) autofluorescence of parathyroids; and (d) autofluorescence enhanced by contrast media. Postoperative hypoparathyroidism had a variable range in the different groups.

CONCLUSIONS

Our data confirm that the incidence of post-surgical hypoparathyroidism is extremely low in the high volume centers. Its potential reduction adopting technological adjuncts is difficult to estimate, and their cost, together with complexity of application, do not allow immediate routine use. The trend towards increasingly unilateral surgery in thyroid carcinoma, as confirmed by our results in case of lobectomy, is expected to really contribute to a further reduction of postsurgical hypoparathyroidism.