Preoperative Parathyroid Hormone Levels Research Articles

Self-assembled nanobody-DNA nanomachine conjugate for parathyroid glands intraoperative imaging and parathyroid hormone detection

During thyroidectomy, inadvertent parathyroid damage commonly occurs owing to the varying location of the parathyroid glands and their similarity to adipose tissue, lymph nodes, and thyroid nodules. Therefore, in this study, we aimed to develop a novel self-assembled nanobody-DNA nanomachine conjugate probe (PTH-Nb-HCR) for precisely identifying the parathyroid glands and monitoring parathyroid hormone (PTH) levels in patient blood. The probe consists of two components: the first component is the nanobody (Nb)-nucleic acid conjugate PTH-Nb-Trigger, acting as a recognition unit for PTH and capable of initiating the hybridization chain reaction (HCR), whereas the second component comprises the HCR hairpin probes HP1-FAM (with a modified FAM signal molecule at the 5′ end) and HP2. The assembly of the PTH-Nb-HCR fluorescent probe takes only 20 min. Using the probe, the serum PTH level was quantitatively detected in the 0.1–1000 pg/mL range, and the parathyroid glands were rapidly distinguished from adipose, lymphoid, and thyroid tissues within 5 min. We also used this probe for imaging parathyroid glands with hyperparathyroidism. Considering the strong correlation between fluorescence intensity and preoperative serum PTH levels in patients, we anticipate the use of this probe to distinguish normal and hyperfunctional tissues during hyperparathyroidism surgery.

Development of a tool to calculate the probability of hypocalcemia after total thyroidectomy: a prospective study.

This study aimed to evaluate the ability of the percentage of decrease in serum PTH level in the first 8h after total thyroidectomy (TT) to predict hypocalcemia requiring Ca supplementation and develop a tool to predict it. 97 patients who underwent TT with measurement of preoperative parathyroid hormone (PTH) levels were prospectively evaluated 1 and 8h after TT; postoperative magnesium (Mg2PO) and phosphorus levels were evaluated on the 2nd day after surgery. The percentage of decrease in PTH level 1h (%dPTH1h) and 8h (%dPTH8h) postoperatively and predictors of hypocalcemia requiring Ca supplementation were evaluated and an equation was developed to predict this outcome. %dPTH1h (p = 0.002), %dPTH8h (p = 0.001) and (Mg2PO) (p < 0.01) were isolated predictors of postoperative hypocalcemia requiring Ca supplementation. The data obtained led to the development of two tools to predict this complication. The percentage of decrease in PTH level 1h and 8h postoperatively and the magnesium level on the 2nd day after surgery were predictors of more severe hypocalcemia, and an auxiliary tool for predicting this complication was developed.

THU525 Atypical Presentation Of Parathyroid Carcinoma In The Lungs

Abstract Disclosure: J.N. Jacinto: None. O. Reyes: None. M. Cating-Cabral: None. R. Santiago: None. J. Andal: None. A 66-year-old female with a history of parathyroid adenoma underwent partial parathyroidectomy and thyroidectomy of the right lobe in 2006. She has the following comorbidities: pre-diabetes, hypertension, multiple liver cysts, medullary nephrocalcinosis and nephrolithiasis, ureterolithiasis and uterine intramural myoma. She also has a strong familial disposition of endocrine tumors. During the last quarter of 2018, parathyroid hormone and calcium levels were elevated and parathyroid imaging revealed an adenoma on the posteromedial aspect of the left thyroid lobe. Removal of the adenoma was offered but insisted on medical treatment. In 2022, she was admitted for subarachnoid hemorrhage due to fall. There was an incidental finding of a lung mass with minimal pleural effusion on the right lung lobe. PET-scan revealed five FDG-avid nodules (SUV up to 9.6) with the largest in the right middle lobe measuring 2 x 2 x 2 cm. Percutaneous needle biopsy was performed which showed a tumor with fairly uniform cells in organoid nests and solid clusters. By immunohistochemistry (IHC), the tumor cells were diffusely and strongly positive for CK and GATA-3; focally positive for chromogranin and synaptophysin; and negative for TTF-1, Pax-8, and S100. This was signed out as an epithelial tumor with neuroendocrine features; the differential diagnosis includes pulmonary neuroendocrine tumor versus metastasis from the prior parathyroid lesion. She subsequently underwent completion thyroidectomy and video-assisted thoracoscopic surgery. The lung wedge resections both showed tumors with similar morphology and IHC staining pattern as the biopsy. Additional stains were also performed to rule out other entities, which were all negative (CK7, CK20, CD56, mammaglobin, GCDFP-15, TTF-1, S100, ER, Pax-8, HSA, and SALL-4). The Ki-67 proliferation index was 17.26%. Because the overall findings were not definitive, comprehensive genomic profiling by next generation sequencing (NGS) was recommended and subsequently performed. NGS showed gene alteration in CDC73, with a variant allele frequency of 50%; this finding has been documented in parathyroid carcinoma. Pre-operative parathyroid hormone levels remained unchanged (408 to 397 pg/ml) despite surgery. Currently, there is no available targeted therapy to address her genomic alteration. Hyperparathyroidism-jaw tumor syndrome was entertained. The multidisciplinary team advised en-bloc resection of the lung tumor and additional gene testing for family members. She opted for palliative care and is on cinacalcet for her hyperparathyroidism. Presentation: Thursday, June 15, 2023

Variational Quantum Circuit Topology Grid Search for Hypocalcemia Following Thyroid Surgery

Quantum computing’s potential to revolutionise medical applications has spurred interest in leveraging quantum algorithms for healthcare challenges. In this research, the authors explored the application of variational quantum circuits to predicting hypocalcemia risk following thyroid surgery. Hypocalcemia, resulting from hypoparathyroidism, is a common post-surgical complication. This novel approach includes a topology grid search of the variational quantum circuits. To execute the grid search, our research employed a classical optimiser that guided the adjustment of different circuit topologies, assessing their impact on predictive performance. Our research used, as relevant features, an intra-operative PTH (parathyroid hormone) at 10 min post-removal and percentage decrease of pre-operative and intra-operative PTH levels. The findings revealed insights into the interplay between variational quantum circuit topologies and predictive accuracy for hypocalcemia risk assessment.

WTP2.4 Can we predict parathyroid adenoma size preoperatively with biochemical markers?

Abstract Aim In primary hyperparathyroidism, parathyroidectomy remains the mainstay of treatment. However, localising abnormal parathyroid glands can often prove challenging, and re-operations may be necessary. We aim to evaluate any correlation that might exist between parathyroid hormone (PTH) levels, preoperative peak corrected calcium levels and cinacalcet use with adenoma size. Methods We retrospectively reviewed consecutive parathyroidectomies performed for primary hyperparathyroidism by two experienced upper gastrointestinal surgeons (VS and PT) in a teaching hospital between April 2013 and December 2022. Hospital database was accessed to obtain data for biochemical markers, operation notes and histopathology reports. Spearman correlation coefficient was computed to evaluate linear relationship between PTH, peak calcium levels and adenoma size. Mann-Whitney-U test was used to compare cinacalcet use and adenoma sizes. P-value&amp;lt;0.05 was statistically significant. Results 170 parathyroidectomies for primary hyperparathyroidism were performed during the study period. Patient cohort was predominantly female (n=131, 77.1%). Mean age of study population was 58±12 years. There were positive correlations between adenoma size and preoperative peak corrected calcium levels (R=0.25, p=0.001) and PTH levels (R=0.4, p&amp;lt;0.001) respectively. In patients who took cinacalcet preoperatively (n=46, 27.1%), there was an association with larger adenoma size (18±8mm vs 22±12mm, p=0.009). Conclusion Higher preoperative PTH levels and peak corrected calcium levels along with cinacalcet use may be associated with larger adenoma sizes. Further studies are required to validate these findings.

Diagnostic Value of Four-Dimensional Dynamic Computed Tomography for Primary Hyperparathyroidism in Patients with Low Baseline Parathyroid Hormone Levels.

Low baseline levels of parathyroid hormone (PTH) are associated with a higher rate of multiglandular disease, lower localization rates of preoperative imaging modalities, and a higher rate of unsuccessful minimally invasive parathyroidectomies. The objective of this study is to assess the diagnostic value of four-dimensional dynamic computed tomography (4D-CT) in localizing primary hyperparathyroidism (pHPT) in patients with low baseline PTH levels, compared to patients with high baseline PTH levels. Patients with pHPT who received a 4D-CT scan as part of their standard diagnostic evaluation were divided into two groups based on the following criteria: (1) preoperative PTH levels less than 100 pg/mL and (2) patients with preoperative PTH levels greater than 100 pg/mL. All patients underwent parathyroidectomy based on 4D-CT findings, with intraoperative parathyroid hormone monitoring. The lesion-based sensitivity of 4D-CT was 88% in patients with low baseline PTH levels and 94.7% in patients with high baseline PTH levels (p = 0.33). However, the success rate of image-guided resection based on 4D-CT findings was 71.4% in the low baseline PTH group compared to 90.6% in the high baseline PTH group (p = 0.06). Our study demonstrated that 4D-CT has a high lesion-based sensitivity in patients with pHPT and low baseline PTH levels but led to a relatively low rate of successful image-guided resection in patients with low baseline PTH levels. Therefore, it is important to exercise increased caution during 4D-CT-guided surgical exploration of patients with low baseline PTH levels to ensure successful surgical resection of all parathyroid lesions.

Effect Of Laparoscopic Sleeve Gastrectomy On Vitamin D, Parathormone Hormone, And Serum Calcium Levels.

To evaluate the effect of laparoscopic sleeve gastrectomy on vitamin D status, parathyroid hormone,serum calcium and the effectiveness of vitamin D supplementation. The prospective study was conducted at the General Surgery Department of Kafrelsheikh University Hospital, Egypt, in November 2019, and comprised morbidly obese patients of either gender who were managed with laparoscopic sleeve gastrectomy. Serum levels of vitamin D, calcium and parathyroid hormone were assessed at baseline and at 6 and 12 months after the surgery. All subjects were given 400 IU/day of vitamin D. If the level of vitamin D was <30ng/ml, further doses of calcifediol 200,000 IU were added every two weeks. Data was analysed using SPSS 22. Of the 40 patients, 28(70%) were females and 12(30%) were males. The overall mean age was 33.9±10.8, mean weight was 136±18.29kg and mean body massindex was 50±4.9kg/m2 . The mean operative time was 64.5±13.6 minutes, and the mean hospitalstay was 1.8±1.1 days. There wassignificant reduction in body massindex values after the surgery (p<0.05). Vitamin D level was 19.2±3.2 ng/ml at baseline, which rose to 21.4±2.7 ng/ml at 6 months and 26.6±2.8 ng/ml at 12 months post-surgery (p<0.05). Preoperative parathyroid hormone level was 58.3±7.8 pg/ml , which went down to 48.6±7.4 pg/ml at 6 months, and 41.3±6.5 pg/ml at 12 months postoperatively (p<0.05). The mean serum calcium level at baseline was 9±0.4mg/dL, which rose to 9.2 ±0.3mg/dL and 9.5±0.4 mg/dL at 6 and 12 months post-surgery (p<0.05). Low vitamin D complications could be decreased postoperatively by administering vitamin D as a routine treatment. Postoperative monitoring of vitamin D, parathyroid hormone and serum calcium levels is essential.

Clinical characteristics of primary parathyroid adenoma and its relationship with coexisting papillary thyroid carcinoma: a clinical retrospective study.

Parathyroid adenoma (PA) is a common but relatively poorly understood endocrine tumor. A significant number of PA patients also have papillary thyroid carcinoma (PTC). The clinicopathological characteristics of PA and its relationship with PTC need further study. The clinical data of 99 PA patients were reviewed and the clinicopathologic features of PA were analyzed. PTC occurred in 22 PA patients. The clinicopathologic features of 22 patients with PA + PTC and 77 patients with PA alone were compared. According to age, gender and thyroid surgery methods, 22 PA + PTC patients were matched with 1,123 patients with PTC alone during the same period. The pathological characteristics of the two groups of patients were compared. All data analysis was performed using SPSS23.0, variables were compared by t-test, chi square test or Mann Whitney U-test as appropriate. Ninety-nine PA patients (21 males, 78 females) with a median age of 51 [10-80] years were included. The preoperative parathyroid hormone (PTH) (P=0.007) and preoperative blood calcium (P=0.036) of male patients were higher than those of female patients, and the proportion of asymptomatic patients (P=0.008) and postoperative PTH level (P=0.013) were lower. The preoperative PTH level (P=0.002), preoperative blood calcium level (P=0.004), preoperative alkaline phosphatase (ALP) level (P=0.018) and postoperative PTH levels (P=0.023) in PA + PTC group were lower than those in PA group. The asymptomatic rate was higher in PTC + PA group than that in PA group (P<0.001). There was no statistical difference between PA + PTC group and PTC group in multifocal tumor, capsule invasion, lymph node metastasis (P>0.05). The lymph node metastasis rate in PA + PTC group (9/215) was significantly lower than that in PTC group (37/337) (P=0.005). PA exhibited the following characteristics: occurred in all age groups; more common in women but more severe in men; more located in the lower pole. The coexistence of PTC and PA did not promote the progression of PA, nor did it increase the aggressiveness of PTC. Conversely, their co-existence may lead to early diagnosis of the disease. PA patients (22.2%) also have PTC, so surgeons should pay attention to thyroid disease to prevent the need for reoperation.

Use of dual energy computed tomography versus conventional techniques for preoperative localization in primary hyperparathyroidism: Effect of preoperative calcium and parathyroid hormone levels

BackgroundWe aimed to investigate the association of preoperative calcium and parathyroid hormone (PTH) levels with sensitivity and accuracy of dual energy computed tomography (DECT), single-photon emission CT with 99mTc-sestamibi (CT-MIBI), and ultrasound (US) for pre-operative localization primary hyperparathyroid (PHP) patients. MethodsPatients undergoing parathyroidectomy for PHP at a tertiary care facility who underwent DECT, CT-MIBI and US between 2012 and 2021 were stratified by preoperative calcium and PTH levels. ResultsOf 278 patients, those with high calcium and PTH levels had a higher sensitivity and accuracy with DECT (87.7%, 85.2%) compared to CT-MIBI (82.3%, 79.0%), and US (61.7%, 53.1%). DECT was more sensitive and accurate than other preoperative localization techniques in subgroups with normal PTH (DECT sensitivity 60.9%, accuracy 52.1%) and normal calcium levels (41.7%, 33.3%). ConclusionPreoperative calcium and PTH were associated with sensitivity and accuracy of pre-operative localization in PHP. DECT was sensitive and accurate for preoperative localization compared to other first-line imaging techniques.

Correlation between preoperative calcium and parathormone levels with parathyroid gland volume.

Objective. Hyperparathyroidism is a prevalent disease with parathyroid adenomas being the most common cause. Surgical excision remains the standard treatment for parathyroid adenoma. Successful preoperative localization of the parathyroid adenoma could facilitate the decision regarding the extent of surgical exploration. The aim of the current study was to assess the correlation between the preoperative values of parathyroid hormone and ionized calcium with the adenoma weight and volume in patient with primary hyperparathyroidism caused by single-gland adenoma. Patients and Methods. We did this retrospective review for all patients who were diagnosed with primary hyperparathyroidism due to a solitary parathyroid adenoma in our general surgery department over 4 years. SPSS software was used to get the correlation coefficient between the peak preoperative levels of calcium and parathyroid hormone with the parathyroid adenoma weight and volume. Results. Ninety-nine patients were included into the study. The average age at surgery was 62.65±12.00 years. The correlation coefficient between the adenoma volume and weight with the preoperative ionized calcium level was weakly positive (r=0.329, p<0.01) and (r=0.281, p=0.019), respectively, while the correlation with the preoperative parathyroid hormone level was stronger (r=0.708, p<0.01) and (r=0.650, p<0.01), respectively. Conclusions. The strong positive relationship between the preoperative parathyroid hormone and calcium levels with the parathyroid adenoma size and weight can help the surgeon to predict the volume of the involved gland and avoid an unnecessary dissection.

Laboratory and Imaging Profile of Primary Hyperparathyroidism: A Record Based Retrospective Study

Introduction: Primary Hyperparathyroidism (PHPT) is an uncommonly diagnosed symptomatic disease that occurs in India. Unlike the Western countries where the disease is asymptomatic, the various manifestations that occur are skeletal, muscular, and renal. Studies on PHPT from developing countries like India, have shown that symptomatic PHPT is still common as compared to developed countries. Data on PHPT from Kerala (a state with health indices comparable to the Western world) are lacking. Aim: To compare the preoperative and postoperative calcium and Parathyroid Hormone (PTH) levels among the participants. Materials and Methods: A record-based retrospective study was conducted at Amrita Institute of Medical Sciences, Cochin, in the Department of Endocrinology. All 116 patients who had PHPT from January 2013 to December 2019 were included in the study. The data available in the hospital records were analysed for various laboratory values and imaging diagnoses. The preoperative and postoperative calcium and PTH levels were compared. Data were analysed by paired sample t-test. (Wilcoxon sign-rank test). The data analysis was done using coGuide. Results: The mean age was 53.42±14.89 years in the study population. Among 116 subjects, (46 (39.66%) were males and 70 (60.34%) were females) eighty-three (71.55%) had the symptomatic disease. The majority, 80 (68.97%) participants underwent single parathyroidectomy. The difference between pre-operative and post-operative calcium and PTH was statistically significant (p-value &lt;0.001). Conclusion: PHPT largely occurs in the fifth decade of life, and the majority were symptomatic. Females were more affected compared to males in the present study. Preoperative imaging is recommended in routine practice.

The value of intraoperative parathyroid hormone monitoring in patients with primary hyperparathyroidism and varying baseline parathyroid hormone levels.

When applying intraoperative parathyroid hormone monitoring (IOPTH) to patients with primary hyperparathyroidism (PHPT), there are established criteria predicting biochemical cure in patients with basal parathyroid hormone (PTH) levels in the medium range (100-400 pg/ml); however, there is a challenge concerning patients with low (less than 100 pg/ml) or high (more than 400 pg/ml) basal PTH levels. The aim of this study was to investigate the value of the 'Vienna criterion' applied during IOPTH in patients with PHPT and various basal PTH concentrations. Consecutive patients between 1999-2009 with a biochemical diagnosis of PHPT who underwent surgical parathyroidectomy were included. Based on preoperative PTH levels they were divided into three groups: group 1 (low) (<100 pg/ml), group 2 (medium) (100-400 pg/ml) and group 3 (high) (>400 pg/ml) basal PTH. PTH was measured at the start of the operation, when the gland was excised and then at 5, 10 and 15 min after. Calcium and PTH levels were measured at 7 days and 12 months postoperatively. Sensitivity, specificity, positive and negative predictive value, as well as accuracy of IOPTH were calculated for the different groups postoperatively. 675 patients with PHPT were analysed. Sensitivity and specificity were 83.7 per cent and 66.7 per cent in group 1 (n = 187), 90.7 per cent and 69.2 per cent in group 2 (n = 433), and 94.4 per cent and 100 per cent in group 3 (n = 55) to predict cure. Preoperative creatinine (p = 0.002) showed significant statistical difference between the groups but was not related to intraoperative PTH decline. At 12 months follow-up normocalcaemia was documented in 98.9 per cent in group 1, 99.0 per cent group 2, and 98.0 per cent of group 3 patients. Normocalcaemia was predicted intraoperatively by applying the 'Vienna criterion' in 98 to 100 per cent and was confirmed after 12 months follow-up in up to 99.0 per cent of patients. Low specificity and a high false-negative rate in patients with low basal PTH show that other criteria might be better suited for this group.

Differences in the Clinical Presentation and Biochemical Profile of the Patients with Primary Hyperparathyroidism with regard to their Serum Vitamin D Levels: a Single-center Experience.

The association between vitamin D deficiency and primary hyperparathyroidism (PHPT) is common and has clear implications. Vitamin D deficiency is commonly seen in PHPT population and exacerbates its severity with skeletal and metabolic effects. Retrospective data collection and review were done in patients who underwent surgery for PHPT at a tertiary care hospital in India between January 2011 and December 2020. A total of 150 subjects were included in the study and were divided into group 1 (vitamin D < 20ng/ml, deficient), group 2 (vitamin D 21-29ng/ml, insufficient), and group 3 (vitamin D > 30ng/ml, sufficient). There was no difference in the duration of symptoms or the symptomatology between the three groups. Mean pre-operative serum calcium and serum phosphorous levels were also comparable in all the three groups. Mean pre-operative parathyroid hormone (PTH) levels in the three groups were 703 ± 996 vs 343.6 ± 396 vs 343.6 ± 396pg/ml, respectively (P = 0.009). There was a statistically significant difference in group 1 vs groups 2 and 3 in their mean weight of the parathyroid gland (P = 0.018) and high alkaline phosphatase (ALP) levels (P = 0.047). Post-operative symptomatic hypocalcemia was observed in 17.3% of patients. Post-operative hungry bone syndrome occurred in 4 patients, all in group 1. PHPT in patients with low serum vitamin D was associated with higher serum PTH levels, increased frequency of high serum ALP levels, and higher weight of the excised gland, with no difference in the serum calcium and phosphorous.

Parathyroidectomy for Normocalcemic Tertiary Hyperparathyroidism: A 19-Year Experience.

Parathyroidectomy is the standard management for patients with tertiary hyperparathyroidism (THPT) and hypercalcemia. However, a subset of patients with THPT have normal or mildly-elevated serum calcium levels in the setting of significantly elevated parathyroid hormone (PTH). The purpose of this study is to determine the effectiveness and safety of parathyroidectomy in normocalcemic THPT. Retrospective review of 212 consecutive patients with THPT who subsequently underwent parathyroidectomy between 2001 and 2020 was performed. Patients were categorized as normocalcemic, "mild" (Ca ≤ 10.4mg/dL) or hypercalcemic, "classic" THPT (Ca ≥ 10.5mg/dL) and clinical data are compared. 71 of 212 (34%) were normocalcemic with median pre-operative Ca and PTH levels of 9.7mg/dL and 225pg/mL, respectively and 141 of 212 (67%) were hypercalcemic with median preoperative Ca and PTH levels of 11mg/dL and 211pg/mL, respectively. The mean length of stay was shorter in normocalcemic patients (0.33 versus 0.50d; P=0.03). 10 of 71 (14%) normocalcemic patients underwent reoperative parathyroidectomy, more than double that of hypercalcemic patients (5.6%; P=0.06). Concomitant thymectomy was performed in 28.1% and 22.1% of normocalcemia and hypercalcemic patients, respectively (P=0.44). No patient in either group required intravenous calcium or had undetectable PTH levels, but permanent hypocalcemia was more frequent in normocalcemic compared to hypercalcemic patients (11.2% versus 1.4%; P=0.03). Parathyroidectomy for normocalcemic tertiary hyperthyroidism (HPT) can be performed safely. These data can help guide multidisciplinary discussions for earlier surgical referral and intervention. Future investigations are needed to evaluate the impact of parathyroidectomy on the renal allograft, bone health, and cardiovascular disease.

MO812: Risk Factors of Long-Term Hypocalcemia After Parathyroidectomy in Dialysis-Dependent Patients

Abstract BACKGROUND AND AIMS Surgical treatment of secondary hyperparathyroidism (SHPT) is often followed by long-term hypocalcemia, also known as a hungry bone syndrome. We aimed to evaluate the prevalence and risk factors of prolonged hypocalcemia after parathyroidectomy (PTx) for SHPT in dialysis-dependent patients. METHOD The retrospective study included 1711 analyses for total serum calcium (Ca) obtained from 372 patients who underwent PTx (either subtotal or total PTx with autotransplantation of parathyroid tissue) for SHPT between 2011 and 2019 in a tertiary care centre of endocrine surgery. The median age of the patients was 50 (IQR 40–57) years, and the median dialysis duration was 82 (IQR 48–134) months. Preoperative parathyroid hormone level was 136 pmol/L (IQR 99.4–210.4), total serum Ca was 2.43 mmol/L (IQR 2.26–2.57) and alkaline phosphatase (AP) was 183 IU/L (IQR 129–395). Follow-up period after surgery ranged from 3 months to 6 years. Postoperative hypocalcemia was defined as a total serum Ca level &amp;lt;2.1 mmol/L, severe hypocalcemia—&amp;lt;1.9 mmol/L. To identify possible risk factors, we took total serum Ca level &amp;lt;2.1 mmol/L after 12 months from PTx as the endpoint. RESULTS Hypocalcemia was registered at least once in 81.5% (n = 303), severe hypocalcemiain 59.1% (n = 224) of the patients in the postoperative period. The prevalence of hypocalcemia and severe hypocalcemia gradually decreased from 3 to 24 months post-PTx and remained relatively stable thereafter (Figure 1). The fraction of patients with moderate hypocalcemia (total serum Ca 1.9–2.1 mmol/L) varied from 17% to 41% during 3–60 months of follow-up. Twelve months after surgery, 53.2% (150 of 282) of the patients had a total Ca level &amp;lt;2.1 mmol/L. Univariate analysis showed no association of hypocalcemia with age (P = .997), sex (P = .17), dialysis vintage (P = .32), modality of treatment (HD/PD, P = .74), type of surgery (P = .29) or use of calcimimetics before surgery (P = .89). Pre-operative parathyroid hormone (P = .55), total Ca (P = .089) and β-crosslaps (P = .69) levels were not associated with an increased risk of hypocalcemia as well. However, low preoperative (P = .037) and postoperative (P = .0092) ionized Ca and high preoperative AP (P = 0.014) levels were associated with an increased risk of long-term postoperative hypocalcemia. Multivariate analysis discovered postoperative ionized Ca as the only independent predictor of prolonged postoperative hypocalcemia [OR = 0.022 (95% confidence interval 0.001–0.356); P = 0.007]. CONCLUSION We identified a high prevalence of moderate and severe hypocalcemia in the long-term period after PTx in dialysis-dependent patients. Total serum Ca levels return to a normal range at 24 months post-PTx in approximately half of the patients. Patients with low preoperative and postoperative serum ionized Ca and high preoperative AP levels are more likely to have persistent hungry bone syndrome after PTx. Immediate postoperative ionized calcium level is the only independent predictor of long-term hypocalcemia after PTx for SHPT.

MO815: Cinacalcet Does not Prevent Severe Hypocalcemia After Parathyroidectomy in Dialysis-Dependent Patients

Abstract BACKGROUND AND AIMS Surgical treatment of secondary hyperparathyroidism (SHPT) is often followed by the rapid development of hypocalcemia, which is also known as hungry bone syndrome. We aimed to evaluate if preoperative use of cinacalcet may help to prevent severe hypocalcemia after parathyroidectomy (PTx) for SHPT in dialysis-dependent patients during the early postoperative period. METHOD The retrospective analysis included 616 patients who underwent PTx (either subtotal or total PTx with autotransplantation of parathyroid tissue) for SHPT between 2011 and 2019 in the single tertiary care center of endocrine surgery. Data on severe hypocalcemia development were available for 559 of the patients, 172 of them received cinacalcet before surgery. The median age of the patients was 49 (IQR 40–56) years and the median dialysis duration was 94 (IQR 56–142) months. Preoperative parathyroid hormone level was 153 pmol/L (IQR 105–223), total serum Ca was 2.44 mmol/L (IQR 2.24–2.61) and alkaline phosphatase was 283 IU/l (IQR 157–645). Severe postoperative hypocalcemia was defined as a serum ionized Ca level &amp;lt;0.9 mmol/L on the second or third day post-PTx. We also assessed need for intravenous (IV) calcium supplementation and the duration of in-hospital stay (≤7 days or &amp;gt;7 days) as surrogate markers of hungry bone syndrome severity. RESULTS Among patients treated with cinacalcet, 55.8% (n = 96) received 30 mg/day, 33.1% (n = 57)received 60 mg/day, 10.5% (n = 18) received 90 mg/day and 0.6% (n = 1) received 120 mg/day. Prevalence of severe hypocalcemia was less in patients who received 90 or more mg of cinacalcet a day, although this difference did not reach statistical significance (P = .1038) (Figure 1A). Use of cinacalcet (yes/no) was not associated with the risk of severe postoperative hypocalcemia: RR = 1.047 [95% confidence interval (95% CI) 0.946–1.146], OR = 1.229 (95% CI 0.801–1.886), P = .3837. A total of 54% of the patients were administered with IV calcium. Preoperative use of cinacalcet did not reduce the risk of IV calcium supplementation need: RR = 0.93 (95% CI 0.79–1.09), OR = 0.86 (95% CI 0.61–1.21); P = .3749. Among patients supplemented with IV calcium, medians of total Ca amount did not differ between those who received pre-PTx cinacalcet and those who did not: 6 (IQR 3–15) g versus 6 (IQR 4–10) g, respectively, P = .3981. Patients who received 60 mg of cinacalcet a day or more were more likely to require higher amounts of total IV Ca (Figure 1B), but this was not statistically significant [RR = 1.4 (95% CI 0.83–2.4); P = .2138]. In terms of length of hospital stay, we did not find differences between patients received 30, 60 and ≥ 90 mg of cinacalcet a day (P = .1285) (Figure 1C). Use of cinacalcet was not associated with prolonged (&amp;gt;7 days) in-hospital stay: RR = 0.863 (95% CI 0.708–1.04), OR = 0.765 (95% CI 0.546–1.081); P = .1417. CONCLUSION We found no evidence of a protective effect of preoperative cinacalcet use, neither on the prevalence nor on the severity of hypocalcemia development after PTx for SHPT in dialysis patients.

Shifting from open to video-assisted parathyroidectomy: effect of the adjustment period on safety, clinical outcomes and cost.

Bilateral neck exploration (BNE) has been the gold standard for the treatment of primary hyperparathyroidism (PHPT). Minimally invasive parathyroidectomy (MIP) has emerged as an alternative procedure for localised solitary adenomas. The most popular MIP techniques are the open MIP (OMIP) and the minimally invasive video-assisted parathyroidectomy (MIVAP). This study aims to assess whether we achieved a smooth transition from OMIP to MIVAP without compromising the results or increasing the cost. A parathyroid adenoma was successfully localised preoperatively in 77/86 patients with PHPT. MIP was contraindicated in 27/86 cases. For MIVAP, a 5mm, 30 degree camera was employed, along with special instruments. Median preoperative parathyroid hormone (PTH) level was 145.9pg/dl (59-2,151) and median calcium (Ca) was 10.8mg/dl (9.3-19). Comparing MIVAP (N=31) with OMIP (N=28), there was no significant difference in the age, sex, location of the adenoma, preoperative PTH and Ca levels as well as in all the other factors compared, apart from the size of adenomas, which were bigger in the OMIP group (1.85cm vs 1.4cm, p=0.032). Moreover, cure rates, operating time, hospital stay and rates of postoperative normocalcaemia were similar between the two groups. Despite the learning curve, MIVAP was not found to be inferior to OMIP for localised adenomas. The final cost was no higher for MIVAP than OMIP with the use of common reusable instruments. This, along with surgeons' experience in parathyroid and endoscopic surgery facilitates a smooth and cost-effective transition from OMIP to MIVAP.

Histopathological Features of Parathyroid Adenoma and 18F-Choline Uptake in PET/MR of Primary Hyperparathyroidism.

The aim of this study was to assess the relationship between the histopathological properties of hyperfunctioning parathyroids and parathyroid 18F-choline uptake. A total of 31 parathyroid adenomas were retrospectively analyzed in patients with primary hyperparathyroidism and preoperative 18F-choline PET/MR. PET/MR parameters of parathyroid glands (SUVmax and target-to-background ratio in early-phase [EP] and late-phase [LP]), MRI volume, preoperative parathyroid hormone (PTH) serum concentration, and postoperative histopathology (predominant cell type and growth pattern of adenoma cells, location and size of adenoma) were assessed. The relationship of PET/MR parameters, PTH, and histological parameters was determined using linear regression, Spearman correlation and Kruskal-Wallis test. The median volume of parathyroid adenoma was 421.78 ± 142.46 mm3 (46.39-4412.69). Adenomas were predominantly composed of chief, water-clear, and oncocytic/oxyphilic cells in 27/31, 2/31, and 2/31 cases, respectively. The growth pattern was predominantly solid, follicular, and trabecular in 18/31, 8/31, and 5/31, respectively. The SUVmax was 6.71 ± 3.39 in EP and 6.91 ± 3.97 in LP. Follicular growth pattern had slightly higher EP SUVmax (trabecular: 4.12 ± 0.56; solid: 6.62 ± 3.19; follicular: 8.56 ± 3.96; P = 0.046). Spearman correlation showed strong positive correlation between volume and both EP and LP SUVmax (0.626; P = 0.0001 and 0.576; P = 0.0001, respectively). Linear regression analysis revealed significant correlation between PTH level and EP and LP SUVmax (both P = 0.001); in contrast, no correlation was found between PTH level and both cell type and growth pattern. Our findings suggest that 18F-choline uptake of parathyroid adenomas might be associated both with the histological growth pattern and adenoma volume, but not with a specific cell type.

Comparisons Between Normocalcemic Primary Hyperparathyroidism and Typical Primary Hyperparathyroidism.

BackgroundNormocalcemic primary hyperparathyroidism (NPHPT) was first described in 2008. It is defined as consistently elevated serum parathyroid hormone (PTH) levels with normal serum calcium (sCa) concentration, after excluding secondary causes of PTH elevation. However, the exact definition and management strategy for NPHPT remain controversial. We retrospectively investigated the clinicopathological features and short-term outcomes of NPHPT patients.MethodsA total of 280 patients who were surgically indicated for primary hyperparathyroidism (PHPT) at the Yonsei Severance Medical Center between 2015 and 2019 were included. Patients were classified according to preoperative PTH, corrected sCa, and ionized calcium (iCa) levels as follows: typical primary hyperparathyroidism (TPHPT, elevated PTH, sCa, and iCa, n = 158) and NPHPT (elevated PTH, normal sCa, n = 122).ResultsNPHPT was commonly seen in younger individuals (aged < 50 years, P = 0.025); nephrolithiasis and bone fractures were common. Preoperative PTH level was higher in the TPHPT group (P < 0.001). The NPHPT group had higher numbers of multiple parathyroid lesions (P = 0.004) that were smaller (P = 0.011). NPHPT patients were further divided into two subgroups according to iCa levels: the elevated (n = 95) and normal iCa (n = 27) groups. There was no significant difference between the two subgroups regarding symptoms and multiplicity of lesions.ConclusionWe found that NPHPT may be a heterogeneous disease entity of PHPT with high rates of multi-gland disease, which appears to be biochemically milder but symptomatic. Intraoperative PTH monitoring might help increase the surgery success rate. Moreover, the short-term outcomes of NPHPT after surgery did not differ from that of TPHPT.

Preventing calcium and vitamin D deficiencies following weight loss and metabolic surgery

IntroductionUncertain nutritional outcomes following common metabolic surgical techniques are concerning given the long-term potential for postoperative metabolic bone disease. This study aims to investigate the variations in serum calcium, vitamin D, and parathyroid hormone (PTH) levels following Roux-en-Y Gastric bypass (RYBP) and Sleeve Gastrectomy (SG).MethodsA retrospective analysis of 370 patients who underwent metabolic surgery at a single-centre group practice in Melbourne, Australia, over 2 years.ResultsPatients underwent SG (n = 281) or RYGP (n = 89), with 75% and 87% of the cohort being female, respectively. Postoperative mean serum calcium levels and median serum vitamin D levels improved significantly by 24 months within both cohorts. Serum PTH levels within the RYBP group were significantly higher than the SG group across all time points. PTH levels significantly fell from 5.7 (IQR 4.2–7.4) to 5.00 (4.1–6.5) pmol/L by 24 months following SG. However, PTH levels following RYBP remained stable at 24 months, from 6.1 (IQR 4.7–8.7) to 6.4 (4.9–8.1) pmol/L. Furthermore, we failed to notice a significant improvement in PTH levels following RYBP among those with higher PTH levels preoperatively.ConclusionHigher PTH levels following RYBP, compared to SG, may imply we are undertreating patients who are inherently subjected to a greater degree of malabsorption and underlying nutritional deficiencies. This finding calls for a tailored supplementation protocol, particularly for those with high preoperative PTH levels undergoing RYBP, to prevent deficiencies.