Hypoparathyroidism following total thyroidectomy: high rates at a low-volume, non-parathyroid institution.

Background: Hypoparathyroidism following total thyroidectomy is globally the most common complication to thyroid surgery. The reported complication rates vary widely and might be highly dependent on the surgical experience. In this study we aimed to evaluate the rate of hypoparathyroidism following primary total thyroidectomy at a low-volume institution that only performs thyroid surgery and does not have any experience with parathyroid surgery. Methods: Retrospective cohort study. All patients undergoing primary total thyroidectomy at the ENT-Department, Goedstrup Hospital, Denmark, over a 5-year period (2016-2020) were identified through the procedure codes for total thyroidectomy. Medical records, pathology reports, biochemical and medical histories were fully assessed for each patient. The primary endpoint was the rate of hypoparathyroidism- both immediate and permanent. Secondary outcomes were parathyroid gland identification rates, rates of parathyroid gland autotransplantation, and rates of inadvertent parathyroid gland excision. Results: A total of 89 patients were included in the final analysis. A total of 33 patients (37.1%) experienced immediate hypoparathyroidism following surgery, while 30 patients (33.7%) still were on active vitamin D two months postoperatively. One year following surgery, 28 patients (31.5%) were still on active vitamin D and were considered as having permanent hypoparathyroidism. Sixty-one percent of the parathyroid glands were identified intraoperatively, and 19% of the patients experienced parathyroid autotransplantation. Inadvertent parathyroid gland excision occurred for 21% of the patients and was associated with a significantly increased risk of permanent hypoparathyroidism (RR = 2.99; 95% CI: 1.36 - 6.62, p = 0.005). Conclusion: Both transient and permanent hypoparathyroidism following total thyroidectomy at a low-volume, non-parathyroid institution occurred with much higher frequencies than previously reported. The elevated rates were most likely due to the low-volume, non-parathyroid nature of the surgeons which in part was mirrored in low parathyroid gland identifications rates, and high rates of autotransplantation and inadvertent parathyroid gland excision.

An Alternative and Up-To-Date Recommendation for a Proper Site for Parathyroid Transplantation: The Omentum.

OBJECTIVES: Various sites have been used for parathyroid allotransplant, such as injection into the forearm, sternocleidomastoid, or deltoid muscles. However, transplant efficiency in these regions varies according to the results reported in the literature and also obtained from our previous studies. Using the omentum "as a natural incubator" for composite tissue-derived cell transplants to increase transplant success is possible. MATERIALS AND METHODS: To examine the efficiency of transplant sites for parathyroid allotransplant, we compared clinical cases from the literature and our experience with 23 cases. The omental transplant process is performed under general anesthesia by laparoscopic intervention. The abdominal cavity is visualized with an endocamera from a 5-mm trocar. With the help of a flexible catheter from another 5-mm trocar, microencapsulated or naked parathyroid cells are deposited on the omentum in approximately 30 mL of isotonic saline. The trocar sites are then sutured, and the surgery is terminated. Recipients were followed for 6 months with examination of biochemical parameters (parathormone, calcium, and phosphorus levels), medication use, and clinical scoring. RESULTS: In the 23 patients who received parathyroid allotransplants over the omentum, 7 recipients did not exhibit any changes according to the scoring system criteria. However, on average, serum calcium and phosphorus levels remained within the healthy reference range. In addition, use of oral medications among patients decreased, indicating successful transplant survival. These results were consistent with a significant decrease in hypocalcemia symptoms among patients. CONCLUSIONS: In the 23 patients, the success rate was 69.5% for the first 6-month period after transplant. Recent developments and large cohorts are needed to demonstrate the higher efficacy of parathyroid allotransplant over the omentum.

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.

Preoperative work-up and results of parathyroidectomy plus auto-transplantation for the elderly with secondary hyperparathyroidism.

BACKGROUND: Total parathyroidectomy for secondary hyperparathyroidism has low morbidity and mortality rates and requires a special workup in the preoperative period. METHODS: Neck echography and technetium-99m-sestamibi scintigraphy were performed preoperatively. Cardiac echography, a thallium-201 myocardial perfusion scan, and cardiac catheterization were performed if necessary. During surgery, we removed all the parathyroid glands and the upper thymus and autotransplanted 100 mg of the smallest gland into the subcutaneous tissue of the forearm. RESULTS: The success rate in three months after total parathyroidectomy was 91.7% without mortality. In the elderly (age ≤65 years, n = 35), bone pain, skin itching, general weakness, and insomnia improved three months after surgery, and grip strength increased significantly. One year after parathyroidectomy, the serum levels of Ca, P, alkaline phosphatase, and intact parathyroid hormone were all within the normal ranges. Except for the bone mineral density (BMD) of the radial distal one-third, the BMD of the lumbar spine (L2 to L4), femoral neck, femoral global, and radial global increased significantly. Furthermore, the bone density T-scores of the lumbar spine (L2 to L4), femoral neck, femoral global, radial distal one-third, and radial global improved significantly. CONCLUSIONS: After a meticulous preoperative workup, parathyroidectomy plus autotransplantation can be performed safely for the treatment of symptomatic secondary hyperparathyroidism in the elderly to improve their quality of life and decrease their incidence of bone fractures.

Advantages of total parathyroidectomy in patients with secondary hyperparathyroidism induced by end stage renal disease.

Introduction: Secondary hyperparathyroidism, as a result of chronic kidney disease could be treated medically or surgically. When pharmacotherapy fails, patients undergo surgery - parathyroidectomy, the curative treatment of secondary hyperparathyroidism (SHPT). There are currently 3 accepted surgical techniques, each with supporters or opponents - total parathyroidectomy, subtotal parathyroidectomy and parathyroidectomy with immediate autotransplantation. Methods: In this paper we described our experience on a series of 160 consecutive patients diagnosed with secondary hyperparathyroidism who underwent surgery, in 27 cases it was totalization of the intervention (patients with previously performed subtotal parathyroidectomy or with supernumerary glands and SHPT recurrence). We routinely perform total parathyroidectomy, the method that we believe offers the best results. Results: The group of patients was studied according to demographic criteria, paraclinical balance, clinical symptomatology, pre- and postoperative iPTH (intact parathormone) values, SHPT recurrence, number of reinterventions. In 31 cases we found gland ectopy and in 15 cases we discovered supernumerary parathyroids. A percentage of 96.24% of patients with total parathyroidectomy did not show recurrence. Discussions: After analyzing the obtained results, our conclusion was that total parathyroidectomy is the intervention of choice for patients suffering from secondary hyperparathyroidism when pharmacotherapy fails in order to prevent recurrence of the disease and to correct the metabolic parameters.

Surgical management of neonatal severe hyperparathyroidism.

BACKGROUND: Neonatal severe hyperparathyroidism (NSHPT) is a rare disease that can be lethal. Most patients require parathyroidectomy. OBJECTIVE: Report experience in managing this severe disease. DESIGN: Retrospective chart review of case series. SETTING: Tertiary health care center. PATIENTS AND METHODS: We reviewed data on patients managed for NSHPT from June 2001 to January 2023. Demographic, clinical, and follow-up data were collected, and descriptive data were generated. MAIN OUTCOME MEASURES: Pre- and postoperative levels of parathyroid hormone (PTH) and serum calcium, and effect of autotransplantation. SAMPLE SIZE: 19. RESULTS: The 13 males and 6 females had a a mean age of 46 days at referral. The mean preoperative parathyroid hormone (PTH) and serum calcium levels were 996 ng/L and 4.54 mmol/L, respectively. Twelve patients underwent ultrasonography preoperatively. Of these, six had prominent glands, while no glands were seen in the other six. A Sestamibi scan was done for 15 patients, of which nine showed negative results and six showed positive results, with three glands observed in the neck and three in the sublingual area. Nineteen patients underwent renal ultrasonography, with nine showing nephrocalcinosis. The mean age at surgery was 5.2 months. Total parathyroidectomy (four glands) was performed in 17 patients, and 15 underwent concurrent auto-transplantation. One patient had three glands removed, in addition to auto-transplantation. Another underwent single gland excision as a redo-surgery after previous surgery elsewhere. The mean postoperative follow-up duration was 6 years. The mean postoperative PTH and calcium levels were 25 ng/L and 1.64 mmol/L, respectively. Ultimately, all the patients were required to initiate calcium and vitamin D supplements, except for two patients who had undergone auto-transplantation. Molecular genetic screening of the calcium-sensing receptor gene reported likely pathogenic/pathogenic mutations in 16 of 19 patients (13 were homozygous, two were heterozygous, one was negative, and data was unavailable for the remaining three patients). CONCLUSIONS: Surgical treatment of NSHPT is effective. Preoperative radiological localization studies did not impact the treatment plan. Auto-transplantation proved ineffective in maintaining independence from medical supplements. LIMITATIONS: The retrospective nature of the study may imply inaccuracybut since the data are gathered from electronic medical records, we believe it is highly accurate. The small sample size limits generalizability.

[Clinical application of parathyroid autofluorescence imaging in endoscopic thyroid surgery].

Objective:To investigate the application value of near-infrared autofluorescence imaging in identifying and protecting parathyroid glands in endoscopic thyroid surgery. Methods:From May 2022 to February 2023, 158 patients who underwent endoscopic thyroid surgery in the Department of Thyroid and Breast Vascular Surgery of Guilin People's Hospital were selected. The endoscopic fluorescence camera system was used to monitor the parathyroid glands under autofluorescence during endoscopic thyroid surgery. A total of 214 pieces were collected, among which the first 15 cases that could not be preserved in situ during the operation needed to be autotransplanted or the tissue clamped parts that could not be clearly identified as parathyroid glands were sent to fast-frozen pathology to determine whether they were parathyroid glands. Results:Among the first 15 patients who could not be preserved in situ during the operation or whose anatomy could not be clearly defined, 23 parathyroid glands were detected by autofluorescence imaging, 21 parathyroid glands were confirmed by pathology, and 2 were adipose tissue, with an accuracy rate of 91.30%; 158 patients underwent surgery Blood calcium decreased 2 hours after operation compared with preoperative blood calcium（P<0.05）, decreased blood calcium 5 days after operation compared with preoperative blood calcium（P<0.01）, and increased slightly 5 days after the operation compared to blood calcium 2 hours after the operation, but the difference was not statistically significant（P>0.05）; while comparing parathyroid hormone（PTH）, PTH at 2 hours after operation decreased significantly compared with PTH before operation（P<0.01）, and PTH at 5 days after operation compared with PTH before operation PTH also decreased（P<0.01）, but increased compared with PTH 2 hours after operation（P=0.001）. Conclusion:In laparoscopic thyroid surgery, the application of near-infrared autofluorescence imaging technology can help surgeons quickly identify and protect parathyroid glands, and reduce the incidence of permanent hypoparathyroidism. Combining autofluorescence imaging, visual anatomy recognition under magnification of laparoscope, and intraoperative frozen pathological examination "trinity" method can improve the success rate of parathyroid gland recognition.

Accidental parathyroidectomy during total thyroidectomy and hypoparathyroidism in a large series of 766 patients: incidence and consequences in a referral center.

PURPOSE: Transient hypoparathyroidism is the most common complication after total thyroidectomy, and accidental parathyroidectomy (AP) may be a cause. The aim of this study was to investigate the incidence of AP and its impact on postoperative calcemia. MATERIALS AND METHODS: From February 2016 to May 2018, 766 patients undergoing total thyroidectomy were prospectively included. Surgical indications, hormonal status, definitive histology, and postoperative calcium and PTH levels were analyzed. RESULTS: 578/(75.45%) were women and 188/(24.55%) men with mean age of 53.4 years. Parathyroid tissue on the thyroid specimen was observed in 40 (5.2%) patients: 30 APs and 10 parathyroid fragments. Among the 30 APs, 12 glands were intrathyroid and 18 (2.3%) in eutopic location. 97 (12.6%) patients were treated for postoperative hypocalcemia: 90 (11.7%) had transient and 5 (0.6%) definitive hypoparathyroidism; 2 were lost in follow-up. 13/30 (43.3%) with AP had transient hypoparathyroidism. A strong correlation was found (p < 0.0001) between AP and postoperative hypocalcemia. 1/30 (3.3%) patient with APs had definitive hypoparathyroidism. Transient and persistent nerve palsies were found in 10 (1.3%) and 3 (0.4%) patients, respectively. DISCUSSION: A careful examination of the thyroid gland after resection help to identify an AP that could be autotransplanted. Surgeon and hospital activity volume per years seem to reduce the risk of hypoparathyroidism. CONCLUSION: Total thyroidectomy and intrathyroid localization of parathyroid glands are risk factors for the AP. The incidence of AP was 2.3%, and this remains low due to our longstanding experience in thyroid and parathyroid surgery.

Efficacy of parathyroid autotransplantation in endoscopic total thyroidectomy with CLND.

Purpose: To evaluate the safety and efficacy of autologous parathyroid transplantation in laparoscopic total thyroidectomy combined with central lymph node dissection (CLND). Methods: Retrospective analysis of clinical data of 152 patients admitted to the General Surgery Department of Gansu Provincial People's Hospital who underwent endoscopic total thyroidectomy combined with CLND from June 2018 to December 2021. The intraoperative parathyroid glands were divided into the orthotopic preservation group (non-transplantation group) and the immediate active autologous transplantation group (transplantation group) according to the different treatment management of parathyroid glands during operation. The levels of Ca2+ in parathyroid blood and the incidence of hypoparathyroidism were compared between the two groups before operation and 1 day, 3 day, 1 week, 1 month, 3 months and 6 months after operation. Results: There was no significant difference in PTH between the preoperative transplantation group compared and the non-transplantation group (P>0.05); The PTH in the transplantation group was lower than that of the non-transplantation group 1 and 3 d after surgery, and the difference was statistically significant (P<0.05); No statistically significant difference in PTH between patients in the transplantation group compared with those in the non-transplantation group at 1 week postoperatively (P>0.05); PTH was significantly higher in the transplant group than in the non-transplant group at 1, 3 and 6 months after surgery, with statistically significant differences (P<0.05); there was no statistically differences (P>0.05) in serum Ca2+ between the preoperative, 1d, 3d and 1 week postoperative transplantation group and the non-transplantation group; Blood Ca2+ was significantly higher in the transplant group than in the non-transplant group at 1, 3 and 6 months after surgery, with statistically significant differences (P<0.05); The rate of temporary hypoparathyroidism in the transplantion group was higher than that in the non-transplantion group, and the rate of permanent hypoparathyroidism was lower than that in the non-transplantion group (P=0.044); There was no significant difference in the concentration of PTH in the cephalic vein of the elbow between the transplanted side and the non-transplanted side at 1 day and 3 days postoperatively (P>0.05); the concentration of PTH in cephalic vein of the elbow was significantly higher than that in non-transplanted side at 1 week, 1 month, 3 months and 6 months postoperatively (P<0.001); the number central area dissection and metastasis dissection in the transplantation group were significantly higher than those in the non-transplantation group (P<0.05). Conclusions: Most autologous parathyroid glands, having functional parathyroid autograft, is helpful to the occurrence of hypoparathyroidism after endoscopic total thyroidectomy with CLND, and it is an effective strategy to prevent permanent hypoparathyroidism, and more thorough area dissection is beneficial to the disease prognosis.

Preservation of parathyroid glands during thyroid and neck surgery.

The parathyroid glands are situated in close proximity to the thyroid gland. They have an important endocrine function maintaining calcium and phosphate homeostasis in the body by the secretion of parathormone (PTH), which is responsible for this function. The parathyroid glands are commonly damaged during thyroid surgeries. This could lead to transient or permanent hypoparathyroidism in 30% of cases. Preservation of the parathyroid glands, is an important and integral part of thyroidectomy and other surgical interventions in the neck. The main principle underlying this is a thorough understanding of parathyroid anatomy in relation to the thyroid gland and other important structures in the area. There can also be significant variation in the anatomical location of the glands. Various techniques and methods have been described for parathyroid preservation. They include intraoperative identification utilizing indocyanine green (ICG) fluorescence, carbon nanoparticles, loupes, and microscopes. The techniques of surgery (meticulous capsular dissection), expertise, central compartment neck dissection, preoperative vitamin D deficiency, extent and type of thyroidectomy are the risk factors associated with damaged thyroids, inadvertent parathyroidectomy and subsequent hypoparathyroidism. Parathyroid Autotransplantation is a treatment option for inadvertent parathyroidectomy. Ultimately, the best way to assure normal parathyroid function is to preserve them in situ intraoperatively undamaged.

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.

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.

Autologous parathyroid gland in left-brachioradialis transplantation: A single-center study and long-term follow-up.

Parathyroid gland transplantation into the sternocleidomastoid muscle is effective, but it is not possible to confirm transplant survival with this method. In this study, we evaluated parathyroid autotransplantation into the brachioradialis muscle and its survival rate. OBJECTIVES: To evaluate autologous parathyroid gland left forearm brachioradial muscle transplantation and its survival rate. SUMMARY BACKGROUND DATA: The most commonly used transplantation site is the sternocleidomastoid muscle, but transplant survival cannot be confirmed using this method. Autologous parathyroid gland left forearm brachioradial muscle transplantation solves this problem, and we evaluate the transplant survival using this method. METHODS: We followed-up patients who underwent thyroidectomy and autologous parathyroid left forearm brachioradial muscle transplantation in our center from September 2013 to January 2018. The last follow-up date was January 2021; all enrolled patients underwent at least 3 years of follow-up. We calculated the transplant survival rate at several time points. RESULTS: We evaluated 238 transplanted cases, for which the long-term survival rate was 85.7% (204/238), and the short-term survival rate was 86.1% (205/238). Sixty-five cases had two parathyroid glands transplanted into the left forearm brachioradialis muscle. The long-term survival rate was 92.3% (60/65), and the short-term survival rate was 95.4% (62/65). CONCLUSIONS: Autologous parathyroid gland left brachioradialis transplantation is a reliable, measurable method with good survival rate, and we recommend this method for consideration for transplanting parathyroid glands in thyroidectomy.

Near-Infrared Autofluorescence Imaging in Thyroid Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVE: This meta-analysis aimed to assess the position of near-infrared autofluorescence (NIRAF) imaging in the recognition and protection of the parathyroid gland (PG) during thyroidectomy. METHODS: The PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Library databases were searched up to June 2021. The primary outcome was to evaluate the rates of postoperative hypocalcemia, inadvertent PG resection, and autotransplantation of PG when adopting NIRAF imaging compared with standard naked-eye (N-E) surgery. RESULTS: Eight studies with 2,889 patients were enrolled in the analysis. Our analysis showed that the incidence of transient hypocalcemia was 7.11% (60/844) in the NIRAF group and 22.40% (458/2045) in the N-E group (p < 0.0001) and the rate of transient hypoparathyroidism was 28.31% (126/445) and 33.36% (496/1487) in the NIRAF and N-E groups (p = 0.0008). The rate of inadvertent resection of PGs was 7.65% (55/719) in the NIRAF group and 14.39% (132/917) in the N-E group (p < 0.0001). No significant difference was observed in other indexes including the pooled proportion of permanent hypocalcemia and rate of PG autotransplantation. CONCLUSIONS: The application of NIRAF imaging in thyroidectomy can help lower the incidence of inadvertent PG resection and reduce the risk of postoperative hypocalcemia and hypoparathyroidism compared with N-E recognition.

Effects of Multi-stage Procurement on the Viability and Function of Human Donor Parathyroid Glands.

INTRODUCTION: Parathyroid allotransplantation is an emerging treatment for severe hypoparathyroidism. Ensuring the viability and functional integrity of donor parathyroid glands following procurement is essential for optimal transplantation outcomes. METHODS: Cellular viability, calcium-responsive hormone secretion, and gland xenograft survival were assessed in a series of deceased donor parathyroid glands following a two-stage procurement procedure recently developed by our group (en bloc cadaveric dissection with subsequent gland isolation after transport to the laboratory). RESULTS: Parathyroid glands resected in this manner and stored up to 48 h in 4°C University of Wisconsin (UW) media retained in vitro viability with no induction of hypoxic stress (HIF-1α) or apoptotic (caspase-3) markers. Ex vivo storage did not significantly affect parathyroid gland calcium sensing capacity, with comparable calcium EC50 values and suppression of parathyroid hormone secretion at high ambient calcium concentrations. The isolated glands engrafted readily, vascularizing rapidly in vivo following transplantation into mice. CONCLUSIONS: Parathyroid tissue retains viability, calcium-sensing capacity, and in vivo engraftment capability after en bloc cadaveric resection, ex vivo dissection, and extended cold storage.

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.

A preoperative parathyroid scan is important for the total removal of the transplanted parathyroid tissue in recurrent secondary hyperthyroidism: A case report and literature review.

RATIONALE: Secondary hyperparathyroidism was one of mineral and bone disorders owing to chronic kidney disease. Patients who suffer from secondary hyperparathyroidism would receive medical treatment or parathyroidectomy with or without autotransplantation (AT). However, some patients receiving parathyroidectomy with AT have recurrent hyperparathyroidism, which impacts their lives. Patients with recurrent hyperparathyroidism may present persistent hypercalcemia and hyperphosphatemia, which would cause cardiovascular disease, like atherosclerosis. PATIENT CONCERNS: A 63-year-old female of Asian descent with chronic kidney disease who suffered from recurrent hyperparathyroidism for twice. The patient underwent parathyroidectomy with AT in the left thigh when secondary hyperparathyroidism happened. After 3 months, recurrent hyperparathyroidism happened. DIAGNOSIS: The patient was diagnosed with recurrent hyperparathyroidism due to chronic kidney disease with hyperparathyroidism status post parathyroidectomy with AT in the left thigh. Our patient also suffered from mineral and bone disorder. INTERVENTION: Two parathyroid adenoma in the left thigh were found. However, one of them was too small to found in the operation. Therefore, autograftectomy of the large one was performed. However, hyperparathyroidism happened again. This time, the autograftectomy was performed under dual phase Tc-99m MIBI (99m Tc-methoxy isobutyl isonitrile) parathyroid scintigraphy and it succeeded. OUTCOMES: After secondary autograftectomy, the value of intact parathyroid hormone was surveyed immediately and dropped by two-third followed by gradual reduction in the following weeks. The calcemia and phosphatemia were back to normal gradually. LESSONS: In our case, importance of scintigraphy in the parathyroidectomy was confirmed.

Evaluation of risk factors, long-term outcomes, and immediate and delayed autotransplantation to minimize postsurgical hypoparathyroidism in multiple endocrine neoplasia type 1 (MEN1): A retrospective cohort study.

BACKGROUND: Postoperative hypoparathyroidism from inadequate parathyroid hormone is of concern after multigland resections in multiple endocrine neoplasia type 1-related primary hyperparathyroidism. We evaluated risk factors, long-term outcomes, and roles of autotransplantation and cryopreservation in postoperative hypoparathyroidism in multiple endocrine neoplasia type 1. METHODS: Retrospective cohort study of patients with multiple endocrine neoplasia type 1 and parathyroidectomy who were evaluated at MD Anderson from 1990 to 2020. RESULTS: We included 206 patients. Median follow-up after the last operation (index 65%, reoperation 35%) was 8 years. Index parathyroidectomy was subtotal in 47%, less than subtotal in 42%, and total in 12%; hypoparathyroidism was more frequent after total parathyroidectomy. Forty-seven patients (23%) had hypoparathyroidism ≥6 months; odds were significantly higher when cumulative ≥4 glands were resected (odds ratio 6 [2.96-12.24]) or when immediate postoperative parathyroid hormone was <15 pg/mL (odds ratio 13.10 [3.61-47.47]). After median 26 months postoperatively, 30% recovered parathyroid function spontaneously; this was less likely when ≥4 glands were resected (odds ratio 0.19 [0.05-0.72]). None of the 4 patients who were aparathyroid (parathyroid hormone undetectable or ≤3 pg/mL) at 6 months postoperatively recovered parathyroid function. Immediate autotransplantation success rate was 72%. Cryopreservation was performed in 96 operations with delayed autotransplantation in 10 patients (10% utilization), of whom 5 recovered parathyroid function (time to recovery 12-93 months). CONCLUSION: Odds of prolonged hypoparathyroidism are higher when cumulative ≥4 glands are resected or postoperative parathyroid hormone is <15 pg/mL. Spontaneous recovery occurred but was less likely when ≥4 glands were resected or patients were aparathyroid at 6 months postoperatively. Cryopreservation should be sparingly used, but there is value in select high-risk patients such as reoperative parathyroidectomy/cervical surgery.

Parathyroid allotransplantation for the treatment of permanent hypoparathyroidism: A systematic review.

BACKGROUND: Hypoparathyroidism is the most common complication of bilateral operations in the central neck. No formal guidelines exist for the management of permanent hypoparathyroidism. Current treatment involving medical supplementation increases resource utilization and patient morbidity while decreasing quality of life. Parathyroid allotransplant (PA) offers a promising therapy; however, the optimal technique and role of immunosuppression (IS) in PA remain unclear. METHODS: We performed a systematic search of the Embase, MEDLINE, and Cochrane Library databases to identify studies investigating PA for treatment of hypoparathyroidism. RESULTS: A total of 24 studies including 186 individual allograft transplants in 146 patients were identified. Pooled graft survival for allotransplants in transplant-naïve vs prior transplant recipients was 29.9% and 80%, respectively. CONCLUSIONS: PA using normocellular, fresh parathyroid donor tissue that is ABO-compatible, with induction and, at minimum, short-term maintenance IS presents a potentially safe and effective therapeutic option for permanent hypoparathyroidism in patients tolerating IS.

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.