Parathyroidectomy for solitary parathyroid adenoma via trans-areola single site endoscopic approach: Results of a case-match study.

BACKGROUND: This study aimed to establish the standardized procedure of trans-areola single site endoscopic parathyroidectomy (TASSEP), and to compare the performance of TASSEP with that of conventional open parathyroidectomy (COP). METHODS: This study enrolled 40 patients with primary hyperparathyroidism (PHPT) who underwent TASSEP, and included 40 of 176 PHPT patients who underwent COP based on propensity score matching. The retrospective analysis was conducted based on prospectively collected data. Perioperative outcomes, including surgical profile, surgical burden and cosmetic results and follow-up were reported. The learning curve was described using a cumulative sum (CUSUM) analysis. RESULTS: 40 TASSEPs were completed successfully without conversions or severe complications. There was no statistically significant difference in operation time between TASSEP and COP groups (80.83 ± 11.95 vs. 76.95 ± 7.30 min, p = 0.084). Experience of 17 cases was necessitated to reach the learning curve of TASSEP. Postoperative pain score and traumatic index (C-reactive protein and erythrocyte sedimentation rate) in TASSEP were apparently lower than those in COP group (p < 0.05). During the proliferation and stabilization phases, TASSEP was associated with significantly better incision recovery and cosmetic scores. Postoperative serum calcium and PTH levels throughout the follow-up period indicated satisfactory surgical qualities in both groups. CONCLUSION: Based on precise preoperative localization and intraoperative planning facilitated by three-dimensional (3D) virtual modeling, TASSEP can be feasibly performed on selected patients with satisfactory success rates and low complication rates, providing preferable cosmetic results and alleviating the surgical burden to a certain extent.

Ultrasonographic Detective Flow Imaging for Evaluating Parathyroid Adenoma in Patients with Primary Hyperparathyroidism.

BACKGROUND: Detective flow imaging (DFI) is a new imaging technology that displays low-velocity blood flow, which is difficult to visualize on conventional color Doppler ultrasonography (CDU). In this study, we compared the usefulness of DFI with that of CDU and methoxy-isobutyl-isonitrile (MIBI) scintigraphy for detecting parathyroid adenoma (PA) in patients with primary hyperparathyroidism (PHPT). METHODS: From March 2021 to March 2023, 87 PHPT patients underwent surgery, and 66 had a single PA. We performed preoperative conventional ultrasonography with CDU, MIBI scintigraphy, and DFI for 42 patients (5 males and 37 females; mean age: 61.6 ± 15.4 years). RESULTS: MIBI scintigraphy detected PA in 85.7% (36/42) patients, and both CDU and DFI detected PA in all patients. The rates of vascularity in PA detected by CDU and DFI were 71.4% (30/42) and 85.7% (36/42), respectively. Vascularity was detected by DFI in 6 patients who were negative for vascularity on MIBI scintigraphy. Furthermore, DFI detected blood supply in 6 of the 12 patients with undetectable blood supply on CDU. Fisher's exact test revealed that high or low blood flow, as determined by DFI, was significantly associated with detection of feeding vessels in PA by CDU (P < 0.001). CONCLUSIONS: DFI was useful for preoperative detection of PA blood flow.

Emerging pattern of asymptomatic hyperparathyroidism in South India - a six-year retrospective study.

INTRODUCTION: Primary hyperparathyroidism (PHPT) is a common endocrine disease with a variable presentation. There is a recent increase in the number of asymptomatic cases due to the use of multichannel automated analyzers.

Operative management of primary hyperparathyroidism in Europe.

BACKGROUND: Multicentre studies have previously reported on national outcomes of surgery for primary hyperparathyroidism, but not investigated whether management and outcome are uniform among countries. This study investigated whether there are differences among European countries in operative management and outcome of surgery for primary hyperparathyroidism. METHODS: Using data from Eurocrine®, a pan-European registry for endocrine surgeries, a retrospective observational cross-sectional multicentre study with 99 participating centres in 14 European countries was performed. Data on age, sex, calcium levels, operative strategy, conversion rate and rate of failed exploration were analysed for patients who underwent initial surgery for sporadic primary hyperparathyroidism. Primary outcome measures were intention to perform limited parathyroidectomy and the rate of hypercalcaemia at first follow-up. RESULTS: A total of 9548 patients were registered between 2015 and 2020. There were 7642 (80%, range 74.5-93.2%) females. There was intention to perform limited parathyroidectomy in 7320 of 9548 (76.7%) operations, ranging from 498 of 1007 (49.5%) to 40 of 41 (97.6%) among countries. Hypercalcaemia at first follow-up (median time to follow-up 15 days) was found in 416 of 9548 (4.4%) operations, ranging from 0 of 119 (0%) to 3 of 38 (7.9%) among countries. CONCLUSION: This study demonstrated large differences in the intention to perform limited parathyroidectomy for primary hyperparathyroidism among European countries, as well as differences in the rate of postoperative hypercalcaemia. Future studies are needed to evaluate the impact of these different healthcare practices on patient outcomes.

Ultrafast intraoperative parathyroid hormone monitoring system: prospective, multicentre, clinical validity study.

BACKGROUND: Intraoperative parathyroid hormone (PTH) monitoring is a proven and reliable adjunct to parathyroid surgery, able to improve the outcomes and efficiency of the diagnostic and therapeutic pathway for patients with primary hyperparathyroidism. This study evaluated the innovative, compact, fully automated NBCL CONNECT Analyzer, which can measure whole-blood PTH in 5 min. METHODS: A prospective multicentre study was conducted in stages: results reviews, recommendations, and implementation of improvements to the mechanical design, components of cartridges, calibration, and sampling protocols. Patients undergoing parathyroidectomy had PTH levels measured on the Analyzer and main laboratory platforms, either Roche or Abbott. The Miami criterion of a 50% drop in PTH concentration was used to define biochemical cure during surgery, and normal postoperative calcium level as cure of primary hyperparathyroidism. Measurements on the Analyzer were done by laboratory staff in London and nurses in Stuttgart. The Pearson coefficient (R) and Wilcoxon test were used for statistical analysis. RESULTS: Some 234 patients (55 male, 179 female) with a median age of 58.5 (age full range 15-88) years underwent parathyroidectomy (195 minimally invasive, 38 bilateral neck exploration, 1 thoracoscopic; 12 conversions) for primary hyperparathyroidism between November 2021 and July 2022. Primary hyperparathyroidism was cured in 225 patients (96.2%). The sensitivity, specificity, and overall accuracy of the Analyzer assay in predicting biochemical cure were 83.9, 100, and 84.8% in phase 1; 91.2, 100, and 91.3% in phase 2; and 98.6, 100, and 98.6% in phase 3. There were no false-positive results (positive predictive value 100%). Correlations between Analyzer measurements and those obtained using the Roche device were very strong (R = 0.98, P < 0.001 in phase 1; R = 0.92, P < 0.001 in phase 2; R = 0.94, P < 0.001 in phase 3), and correlations for Analyzer readings versus those from the Abbott platform were strong (R = 0.82, P < 0.001; R = 0.89, P < 0.001; R = 0.91, P < 0.001). The Analyzer showed continued good mechanical performance, with stable and repeatable operations (calibrations, quality controls). Introducing a stricter sampling protocol and improvements in the clot-detecting system led to a decrease in the number of clotted samples and false-negative results. Outcomes were not affected by measurements performed either by nurses or laboratory staff. CONCLUSION: Intraoperative PTH monitoring during parathyroid surgery can be done accurately, simply, and quickly in whole blood using the Analyzer.

Primary hyperparathyroidism in pregnancy: a case report highlighting uncommon complication.

Primary hyperparathyroidism (PHPT) is characterized by elevated levels of calcium and parathyroid hormone (PTH). However, the interpretation of diagnostic tests, such as serum calcium and PTH levels, is complex in pregnant women. The aim of this report is to present a case of PHTP in a pregnant adolescent, with a special emphasis on an uncommon complication, as well as diagnostic and treatment strategies. A 17-year-old pregnant female presented with hyperemesis gravidarum and neurological symptoms, leading to the diagnosis of cerebral venous thrombosis. Further investigations revealed hypercalcemia and persistently elevated PTH levels, consistent with PHPT. After localization studies, the patient underwent an emergency parathyroidectomy with a diagnosis of parathyroid adenoma. During follow-up, intrauterine growth restriction and severe preeclampsia developed, necessitating an emergency cesarean section. Both the mother and neonate had favorable outcomes. PHPT is an infrequent condition in the pregnant population, and its diagnosis can be challenging due to the overlap of symptoms with normal physiological changes during pregnancy. The occurrence of uncommon complications, such as thrombotic phenomena, highlights the need for a comprehensive approach to ensure early detection and management. In most cases, parathyroidectomy is the treatment of choice.

El hiperparatiroidismo primario (HPTP) se caracteriza por niveles elevados de calcio y hormona paratiroidea (PTH). Sin embargo, la interpretación de pruebas diagnósticas, como los niveles de calcio sérico y PTH, es compleja en mujeres embarazadas. El objetivo de este reporte es presentar un caso de HPTP en una adolescente embarazada, con especial hincapié en una complicación infrecuente, así como en las estrategias diagnósticas y de tratamiento. Una mujer embarazada de 17 años presentó hiperémesis gravídica y síntomas neurológicos, lo que llevó al diagnóstico de trombosis venosa cerebral. Posteriores investigaciones revelaron hipercalcemia y niveles persistentemente elevados de PTH, consistentes con HPTP. Tras la realización de estudios de localización, la paciente fue sometida a una paratiroidectomía de emergencia con diagnóstico de adenoma de paratiroides. Durante el seguimiento, se desarrolló restricción del crecimiento intrauterino y preeclampsia grave, lo que resultó en la necesidad de realizar una cesárea de emergencia. Tanto la madre como el neonato evolucionaron favorablemente. El HPTP es una condición infrecuente en la población embarazada y su diagnóstico puede ser desafiante por la superposición de síntomas con los cambios fisiológicos normales del embarazo. La aparición de complicaciones infrecuentes, como fenómenos trombóticos, resalta la necesidad de un abordaje integral para garantizar la detección y el manejo temprano. En la mayoría de los casos, la paratiroidectomía es el tratamiento de elección.

Surgical strategy in lithium-associated hyperparathyroidism: A population-based study.

BACKGROUND: The extent of parathyroidectomy (PTX) recommendation in patients with lithium-associated hyperparathyroidism (LAH) remains controversial. The primary objectives of this study were to analyze extent of surgery, complications, and long-term outcomes. METHODS: A population-based study, including all primary hyperparathyroidism (PHPT) patients who underwent PTX in Sweden between 2008 and 2017. Data on exhibited lithium prescriptions, morbidity, surgical approach, and outcomes were collected from relevant national registers and the Scandinavian Quality Register of Thyroid, Parathyroid, and Adrenal Surgery. Patients with lithium exposure before PTX were defined as having LAH. Descriptive summary statistics and regression models were used to evaluate differences in comorbidities, surgical approach, and outcomes between LAH and PHPT not exposed to lithium (non-LAH). RESULTS: Lithium exposure was significantly more common among PHPT (n = 202, 2.3%) than in controls (n = 416, 0.5%); OR 5.0 (95% CI 4.2-5.9). The risk of LAH correlated to the length of lithium exposure. In the LAH-group, the surgical procedures were more extensive and associated with a higher risk of postoperative bleeding, wound infections, persistent hypercalcemia, and hypocalcemia that remained after adjustment for the higher percentage of multiglandular disease. However, the cumulative risk of re-admission for PHPT was similar the first years after PTX and primarily elevated for patients with >5 years duration of lithium exposure prior to surgery. CONCLUSIONS: The findings support the perception of LAH as a complex entity. We recommend a functionally oriented approach, aimed to obtain and maintain normocalcemia for as long as possible, minimizing the risk of permanent hypoparathyroidism, and accepting some risk of recurrence.

Management of surgical diseases of Primary Hyperparathyroidism: indications of the United Italian Society of Endocrine Surgery (SIUEC).

A task force of the United Italian society of Endocrine Surgery (SIUEC) was commissioned to review the position statement on diagnostic, therapeutic and health­care management protocol in parathyroid surgery published in 2014, at the light of new technologies, recent oncological concepts, and tailored approaches. The objective of this publication was to support surgeons with modern rational protocols of treatment that can be shared by health-care professionals, taking into account important clinical, healthcare and therapeutic aspects, as well as potential sequelae and complications. The task force consists of 12 members of the SIUEC highly trained and experienced in thyroid and parathyroid surgery. The main topics concern diagnostic test and localization studies, mode of admission and waiting time, therapeutic pathway (patient preparation for surgery, surgical treatment, postoperative management, management of major complications), hospital discharge and patient information, outpatient care and follow-up, outpatient initial management of patients with pHPT.

Characteristics, management and outcomes of primary hyperparathyroidism from 2009 to 2021: a single centre report from South Africa.

BACKGROUND: There has been a notable shift towards the diagnosis of less severe and asymptomatic primary hyperparathyroidism (PHPT) in developed countries. However, there is a paucity of recent data from sub-Saharan Africa (SSA), and also, no reported data from SSA on the utility of intra-operative parathyroid hormone (IO-PTH) monitoring. In an earlier study from Inkosi Albert Luthuli Central Hospital (IALCH), Durban, South Africa (2003-2009), majority of patients (92.9%) had symptomatic disease. The aim of this study was to evaluate the clinical profile and management outcomes of patients presenting with PHPT at IALCH. METHODS: A retrospective chart review of patients with PHPT attending the Endocrinology clinic at IALCH between July 2009 and December 2021. Clinical presentation, laboratory results, radiologic findings, surgical notes and histology were recorded. RESULTS: Analysis included 110 patients (87% female) with PHPT. Median age at presentation was 57 (44; 67.5) years. Symptomatic disease was present in 62.7% (n:69); 20.9% (n:23) had a history of nephrolithiasis and 7.3% (n:8) presented with previous fragility fractures. Mean serum calcium was 2.87 ± 0.34 mmol/l; median serum-PTH was 23.3 (15.59; 45.38) pmol/l, alkaline phosphatase 117.5 (89; 145.5) U/l and 25-hydroxyvitamin-D 42.9 (33.26; 62.92) nmol/l. Sestamibi scan (n:106 patients) identified an adenoma in 83.02%. Parathyroidectomy was performed on 84 patients with a cure rate of 95.2%. Reasons for conservative management (n:26) included: no current surgical indication (n:7), refusal (n:5) or deferral of surgery (n:5), loss to follow-up (n:5) and assessed as high anaesthetic risk (n:4). IO-PTH measurements performed on 28 patients indicated surgical success in 100%, based on Miami criteria. Histology confirmed adenoma in 88.1%, hyperplasia in 7.1% and carcinoma in 4.8%. Post-operative hypocalcaemia developed in 30 patients (35.7%), of whom, 14 developed hungry bone syndrome (HBS). In multivariate analysis, significant risk factors associated with HBS included male sex (OR 7.01; 95% CI 1.28, 38.39; p 0.025) and elevated pre-operative PTH (OR 1.01; 95% CI 1.00, 1.02; p 0.008). CONCLUSIONS: The proportion of asymptomatic PHPT has increased at this centre over the past decade but symptomatic disease remains the dominant presentation. Parathyroidectomy is curative in the majority of patients. IO-PTH monitoring is valuable in ensuring successful surgery.

TRPC3 Is Downregulated in Primary Hyperparathyroidism.

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

Comparative Analysis of Transoral Endoscopic Parathyroidectomy Vestibular Approach and Focused Open Surgery for Primary Hyperparathyroidism Treatment: A Single Center Experience.

BACKGROUND Primary hyperparathyroidism is one of the most common endocrine disorders, for which the definitive treatment is surgical parathyroidectomy. Generally, surgical exploration is performed as open focused neck surgery. The vestibular route is a new approach to minimally invasive endoscopic parathyroidectomy. This retrospective study from a single center in Turkey aimed to compare surgical outcomes from the transoral endoscopic vestibular approach (TOEPVA) vs direct open parathyroidectomy in 57 patients. MATERIAL AND METHODS Our study included data from 57 patients. TOEPVA was performed in 20 of these patients who did not want a cervical scar, and focused surgery was performed in the remaining 37 patients. The variables we analyzed were size, volume, and localization of the adenoma, operative time, presence of bleeding, presence of the recurrent laryngeal nerve damage, preoperative, short-term, and long-term postoperative PTH levels, use of drain, presence of postoperative hypocalcemia, and short-term and long-term calcium levels. RESULTS No laryngeal nerve and mental nerve damage was observed in either group. The mean operative time in focused open surgery was 80.54±33.1 min, while the mean operative time in TOEPVA was 128.21±30.88 (p: 0.794) min. The mean hospitalization period of patients who underwent open surgery was 3.29±1.9 days, while the mean discharge days of patients who underwent endoscopic surgery was 2.40±1.2. (p>0.05). CONCLUSIONS TOEPVA is a safe method in patients who underwent parthyroid surgery to avoid cervical scarring.

Parathyroid fine needle aspiration with PTH washout: Can it lead to parathyroid cell seeding in primary hyperparathyroidism?

Although parathyroid fine-needle aspiration (P-FNA) with parathyroid hormone (PTH) washout is effective in detecting preoperative parathyroid lesions, it also presents risks such as fibrosis, hematoma, and, in rare cases, tumor seeding. This study aimed to investigate whether P-FNA with PTH washout leads to the seeding of parathyroid cells along the path of the needle. A retrospective analysis was conducted on patients undergoing minimally invasive parathyroidectomy guided by preoperative PTH washout. Permanent pathology reports, imaging data, and postoperative serum parathyroid hormone and calcium levels were assessed to determine the effectiveness and safety of the procedure. Complications following P-FNA with PTH washout were also reviewed using data from the patient registration system of Bulent Ecevit University. The procedure accurately localized parathyroid adenomas in 87 patients who underwent ultrasound-guided parathyroidectomy following preoperative P-FNA and PTH washout. Postoperatively, 75 patients showed normal parathyroid hormone and calcium levels. Two patients required secondary surgery for contralateral adenomas. Critically, there was no evidence of P-FNA with PTH washout-induced parathyromatosis or seeding during the follow-up. Effective adenoma localization is crucial for successful minimally invasive surgery of hyperparathyroidism. Our study indicates that combining preoperative P-FNAB with PTH washout and imaging enhances adenoma detection, especially when intraoperative PTH measurements are not available, thus improving surgical outcomes. Notably, we found no evidence of cell implantation after P-FNA, suggesting the safety and efficacy of this method for preventing parathyroid cell seeding.

Patient-reported outcome measures for primary hyperparathyroidism: a systematic review of measurement properties.

BACKGROUND: The quality of patient-reported outcome measures (PROMs) used to assess the outcomes of primary hyperparathyroidism (PHPT), a common endocrine disorder that can negatively affect patients' health-related quality of life due to chronic symptoms, has not been rigorously examined. This systematic review aimed to summarize and evaluate evidence on the measurement properties of PROMs used in adult patients with PHPT, and to provide recommendations for appropriate measure selection. METHODS: After PROSPERO registration (CRD42023438287), Medline, EMBASE, CINAHL Complete, Web of Science, PsycINFO, and Cochrane Trials were searched for full-text articles in English investigating PROM development, pilot studies, or evaluation of at least one PROM measurement property in adult patients with any clinical form of PHPT. Two reviewers independently identified studies for inclusion and conducted the review following the Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN) Methodology to assess risk of bias, evaluate the quality of measurement properties, and grade the certainty of evidence. RESULTS: From 4989 records, nine PROM development or validation studies were identified for three PROMs: the SF-36, PAS, and PHPQoL. Though the PAS demonstrated sufficient test-retest reliability and convergent validity, and the PHPQoL sufficient test-retest reliability, convergent validity, and responsiveness, the certainty of evidence was low-to-very low due to risk of bias. All three PROMs lacked sufficient evidence for content validity in patients with PHPT. CONCLUSIONS: Based upon the available evidence, the SF-36, PAS, and PHPQoL cannot currently be recommended for use in research or clinical care, raising important questions about the conclusions of studies using these PROMs. Further validation studies or the development of more relevant PROMs with strong measurement properties for this patient population are needed.

The Role of Demographic and Clinical Factors in Germline Mutation Testing for Patients with Primary Hyperparathyroidism.

INTRODUCTION: Guidelines recommending genetic counseling in primary hyperparathyroidism (PHPT) vary. To further delineate current recommendations, this study examined genetic counseling referral patterns and rates of mutations in surgical patients with PHPT. PATIENTS AND METHODS: A single-institution review was performed of adult patients who underwent parathyroidectomy for presumed sporadic PHPT. Genetic testing indications of hypercalcemia onset ≤ 40 years, multigland disease (MGD), family history (FHx) of PHPT, or other clinical indications suspicious for a PHPT-related endocrinopathy were examined by demographics and mutation detection rates. RESULTS: Genetic counseling was performed in 237 (37.9%) of 625 patients. Counseling was discussed but not performed in 121 (19.4%) patients. No evidence was noted of genetic referral discussion in the remaining 267 (42.7%). Of these groups, patients who received genetic counseling were youngest, p < 0.001 [median age 55.3 (IQR 43.2, 66.7) years]. The majority of patients with indications of age ≤ 40 years (65.7%), FHx (78.0%), and other clinical indications (70.7%) underwent genetic counseling, while most with MGD (57.0%) did not. Eight mutations were detected in 227 patients (3.5%). Mutations included: MEN1 (n = 2), CDC-73 (n = 4), and CASR (n = 2). Detection was most common in patients with FHx (4/71, 5.6%), then age ≤ 40 years (3/66, 4.5%), and other clinical indications (3/80, 3.8%). No mutations were identified in 48 patients tested solely for MGD. CONCLUSIONS: Most patients with onset of hypercalcemia age ≤ 40 years, positive FHx, or other clinical concerns underwent genetic counseling, while most with MGD did not. As no germline mutations were identified in patients with MGD alone, further investigation of MGD as a sole indication for genetic counseling may be warranted.

Screening for asymptomatic nephrolithiasis in primary hyperparathyroidism patients is warranted.

BACKGROUND: We aimed to investigate the prevalence, characteristics, and management of nephrolithiasis in primary hyperparathyroidism (PHPT) patients. METHODS: Medical records of patients who underwent parathyroidectomy at a tertiary care hospital in British Columbia from January 2016 to April 2023 were retrospectively reviewed. Demographic data, laboratory results, imaging reports, and urologic consultations were examined. Descriptive statistics and relevant statistical tests, including logistic regressions, were utilized for data analysis. RESULT: Of the 413 PHPT patients included in the study population, 41.9% harbored renal stones, and nearly half (48.6%) required urological interventions. Male sex, elevated preoperative serum ionized calcium (iCa) and 24-h urinary calcium (24 â€‹h urine Ca) levels were independent risk factors for stone formation. Additionally, male sex, younger age, and lower preoperative serum 25-hydroxyvitamin D (25(OH)D) level were associated with higher odds of requiring urological intervention for stones. CONCLUSIONS: This study identified significant prevalence of asymptomatic renal calcifications in PHPT patients, with a substantial proportion necessitating urological intervention. These findings emphasize the importance of incorporating screening and treatment of renal stones into the management of PHPT patients.

[Association between preoperative cholecalciferol therapy and hypocalcemia after parathyroidectomy in patients with primary hyperparathyroidism].

BACKGROUND: Primary hyperparathyroidism (PHPT) is a endocrine disorder characterized by excessive secretion of parathyroid hormone (PTH) from parathyroid gland tumors. Parathyroidectomy (PTE) is the main treatment for PHPT, but it can lead to hypocalcemia in up to 46% of cases. Hypocalcemia is associated with seizures and life-threatening cardiac arrhythmias, and vitamin D deficiency can exacerbate PHPT severity and contribute to «hungry bones syndrome,¼ resulting in severe and persistent postoperative hypocalcemia. AIM: To evaluate the association and determine the strength of the relationship between preoperative cholecalciferol therapy and the occurrence of hypocalcemia within 1-3 days after PTE in patients with PHPT. MATERIALS AND METHODS: The study was conducted at the Endocrinology Research Centre, during the periods of 1993-2010 and 2017-2020. The inclusion criteria consisted of patients diagnosed with PHPT who required PTE, had a serum 25-hydroxyvitamin D (25(OH)D) level below 20 ng/mL, and a serum total calcium level below 3 mmol/L. The exclusion criterion was the use of medications that affect calcium-phosphorus metabolism, including cinacalcet, denosumab, or bisphosphonates, either as monotherapy or as part of combination therapy. RESULTS: There were 117 patients, including 110 (94%) females and 7 (6%) males. The median age and interquartile range were 58 [49; 65] years. Among the participants, 21 (18%) received cholecalciferol supplementation for a duration of 2 weeks to 2 months prior to PTE, aiming to address vitamin D deficiency. The remaining 96 (82%) participants did not receive -cholecalciferol supplementation. Both groups, i.e., participants receiving cholecalciferol and those who did not, were similar in terms of anthropometric factors (sex and age at the time of surgery), preoperative clinical characteristics (BMD decrease), and laboratory parameters (PTH, total calcium, phosphorus, ALP, OC, CTX-1, and 25(OH)D levels). The occurrence of postoperative hypocalcemia was significantly lower in participants who received cholecalciferol supplementation (10% vs. 63%, p<0,001, FET2). Cholecalciferol intake showed a negative association with hypocalcemia development (RR=0,15, 95% CI (0,03; 0,51)). CONCLUSION: Preoperative cholecalciferol supplementation for 2 weeks to 2 months before PTE reduces the risk of postoperative hypocalcemia in patients with PHPT by 2-33 times.