Postoperative Parathyroid Hormone Levels Research Articles

Post-operative Transient Hypoparathyroidism: Incidence and Risk Factors

Background : There is limited data on the incidence and risk factors for developing postoperative hypoparathyroidism (POHP) in the South African setting. Objectives : This study aims to calculate the incidence of postoperative hypoparathyroidism in a South African tertiary setting, and to compare local risk factors for POHP to international published data. Methods : All patients who underwent a total or completion thyroidectomy at an academic referral center from January 2010 to December 2015 were included. Data reviewed included post-operative parathyroid hormone (iPTH) level, demographics, type of operation and lymphadenectomy, size of thyroid glands resected, final histology, extra capsular extension of carcinomas, number of lymph nodes resected, and the number of parathyroid excised. Results : Postoperatively, 29% of patients were diagnosed with hypoparathyroidism. Overall, there was no association between POHP and age or gender. In patients with benign histology, size was significantly associated with higher rates of POHP. In patients with thyroid carcinoma, lymphadenectomy and the number of lymph nodes resected were associated with higher rates of POHP. Conclusion : The incidence of immediate postoperative hypoparathyroidism is within international standards. Standardized postoperative follow up is necessary, and strategies to improve POPH such as auto transplantation in locally identified high-risk subgroups should be considered. Key words : Postthyroidectomy, Hypocalcaemia, Hypoparathyroidism

Parathyroidectomy decreases neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios

BackgroundSystemic inflammation has been implicated in complications and heightened mortality of patients with secondary hyperparathyroidism. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are widely available surrogate markers of inflammation. This study sought to delineate the changes in NLR and PLR after parathyroidectomy. MethodsA total of 213 patients undergoing initial parathyroidectomy from 2010 to 2015 for secondary hyperparathyroidism were identified from a prospectively maintained clinical database. Among 183 patients free of persistent or recurrent disease, follow-up NLR and PLR were available for analysis in 85 patients. ResultsIn the whole study population, the baseline NLR was positively correlated with male sex, total white blood cell count, height, serum phosphorus, and calcium–phosphorus product levels. The baseline PLR was positively correlated with platelet count, serum phosphorus, and calcium–phosphorus product levels and negatively associated with patient age. Postoperative parathyroid hormone levels were positively correlated with NLR and PLR at follow-up. For patients who had successful parathyroidectomy, there was a decrease in NLR (P = 0.0006), PLR (P = 0.0003), and platelet count (P = 0.033), whereas hemoglobin significantly increased (P = 0.0002) after surgery. Those with persistent or recurrent hyperparathyroidism had no change in NLR, PLR, hemoglobin, total white blood cell, or platelet count. ConclusionsSuccessful parathyroidectomy is associated with a decrease in NLR and PLR. The modulatory effects of parathyroidectomy on systemic inflammation may partially explain the benefits of surgery in secondary hyperparathyroidism.

Evaluation of patients who have undergone unintentional parathyroidectomy following thyroidectomy: a retrospective cohort study

Aim: We investigated the postoperative parathormone levels and the incidence of hypocalcemia in patients who had inadvertently underwent parathyroidectomy during thyroid surgery . Material and Methods: We retrospectively evaluated a total of 142 patients who had undergone thyroidectomy between January 2011 and March 2017 from their charts. The demographic feature sand pathology diagnoses of the thyroidectomy patients were evaluated. The number of excised parathyroid glands in the pathology specimens and their location were determined. The PTH level was checked after surgery. Calcium was measured on the 2nd day. Calcium replacement was provided for patients with low PTH and calcium. The level of calcium replacement was determined by referring to biochemical values. Following discharge, the calcium and PTH levels were checked during outpatient visits to determine whether the hypocalcemia was transient or permanent. Results: The 142 patients consisted of 23 males (16.2%) and 119 females (83.8%). The mean age was 49.5 years. The surgery performed was bilateral total thyroidectomy in 131, bilateral subtotal thyroidectomy in 3, left total right subtotal thyroidectomy in 3, right total leftsubtotalthyroidectomy in 2, left thyroid lobectomy in 2, and complementary thyroidectomy in 1. Unilateral neck dissection (level II, III, IV, V) was performed in 2 patients and central lymphnode dissection in 82 patients. Parathyroid tissue was found to have been excised during surgery in 35 patients, consisting of 33 females (94.2%) and 2 males (5.8%). The parathyroid tissue had been removed incidentally in 31 and not incidentally in 4. We found transient hypocalcemia in 42 patients and permanent hypocalcemia in 2 patients. Discussion: We found that some parathyroid glands had been inadvertently removed despite careful thyroid surgery. We believe that checking the PTH level postoperatively is important in determining hypocalcemia. Conclusion:

One-Hour Postoperative Parathyroid Hormone Levels Do Not Reliably Predict Hypocalcemia After Thyroidectomy.

Hypocalcemia is a well-known complication after total thyroidectomy. Studies have indicated that the presence of low postoperative parathyroid hormone (PTH) levels can predict hypocalcemia. However, definitive study designs are lacking. The aim of this study was to determine whether postoperative PTH alone can accurately predict postoperative biochemical hypocalcemia. Under IRB approval, a prospective study of 218 consecutive patients who underwent total or completion thyroidectomy by two surgeons between June 2014 and June 2016 was performed. Biochemical hypocalcemia was defined as ionized calcium <1.13mmol/L or serum calcium <8.4mg/dL at any time postoperatively. Three PTH thresholds, <10, <20pg/mL, and >50% drop in PTH 1h postoperatively from baseline were examined. Postoperative PTH<10pg/mL had a sensitivity of 36.5% (95% CI 27.4-46.3%) and a specificity of 89.2% (95% CI 81.9-94.3%). Postoperative PTH<20pg/mL had a sensitivity of 66.4% (95% CI 56.6-75.2%) and a specificity of 67.6% (95% CI 58.0-76.2%). Postoperative PTH decrease >50% had a sensitivity of 63.4% (95% CI 53.2-72.7%) and a specificity of 72.5% (95% CI 62.5-81.0%). Across all PTH thresholds, the false-negative rate was 33.6-63.5% indicating that up to 64% of patients with a normal PTH level could have been discharged without appropriate calcium supplementation. The false-positive rate was 10.8-32.4% indicating that up to 32.4% of patients with low PTH could have been treated with calcium supplementation unnecessarily. Following total thyroidectomy, PTH levels are unreliable in predicting hypocalcemia. Additional prospective studies are needed to understand the true utility of PTH levels post-thyroidectomy.

Variation of Thyroidectomy-Specific Outcomes Among Hospitals and Their Association With Risk Adjustment and Hospital Performance

Current surgical quality metrics might be insufficient to fully judge the quality of certain operations because they are not procedure specific. Hypocalcemia, recurrent laryngeal nerve (RLN) injury, and hematoma are considered to be the most relevant outcomes to measure after thyroidectomy. Whether these outcomes can be used as hospital quality metrics is unknown. To evaluate whether thyroidectomy-specific outcomes vary among hospitals, whether the addition of thyroidectomy-specific variables affects risk adjustment, and whether differences in hospital performance are associated with thyroidectomy-specific care processes. In this retrospective cohort study, patients undergoing thyroidectomies from January 1, 2013, through December 31, 2015, at hospitals participating in the American College of Surgeons' National Surgical Quality Improvement Program were studied. Thyroidectomy-related care. Clinically severe hypocalcemia, RLN injury, and clinically significant hematoma within 30 days of thyroid surgery and hospital-level performance variation, change in risk adjustment, and association with processes. Overall, 14 540 patients (mean [SD] age, 52.1 [15.0] years; 11 499 [79.1%] female) underwent operations at 98 hospitals. Because operations missing thyroidectomy-specific outcomes were excluded, the numbers of operations and hospitals analyzed differed by outcome. Of 14 540 operations included, clinically severe hypocalcemia occurred in 450 patients (3.3% overall, 0.6% after partial, and 4.7% after subtotal or total thyroidectomy), RLN injury in 755 patients (5.7% overall, 4.2% after partial, and 6.6% after subtotal or total thyroidectomy), and hematoma in 175 patients (1.3%). Hospital performance varied for hypocalcemia and RLN injury but not for hematoma. Hospital performance rankings were largely unaffected by the inclusion of thyroidectomy-specific data in risk adjustment. With regard to processes, patients undergoing thyroidectomies at the best-performing vs worst-performing hospitals less frequently had their postoperative parathyroid hormone level measured (593 [19.9%] vs 457 [31.7%], P < .001) and more often were prescribed oral calcium, vitamin D, or both (2281 [76.6%] vs 962 [66.8%], P < .001). When profiled by RLN injury, use of energy devices (1517 [69.1%] vs 507 [55.2%], P < .001) and intraoperative nerve monitoring (1223 [55.7%] vs 346 [37.7%], P < .001) were more prevalent at the best- compared with the worst-performing hospitals. Postoperative hypocalcemia and RLN injury, but not hematoma, potentially could be used as thyroidectomy-specific national hospital quality improvement metrics. Strategies aimed at reducing these complications after thyroidectomy may improve the care of these patients.

The Impact of Postoperative Percent Change of Parathormone Level From Baseline Value on the Rate of Hypocalcemia After Total Thyroidectomy

Background The purpose of this study was to investigate the impact of the percent change of postoperative parathormone (PoPTH) level from baseline value (ΔPTH) on the rate of hypocalcemia after total thyroidectomy. Methods Assays of serum PTH and calcium (Ca) were performed preoperatively and at 24 hours postoperatively in 222 consecutive patients who underwent total thyroidectomy. Postoperative hypocalcemia was defined as serum calcium level corrected for albumin concentration (cCa) &amp;lt;8.5 mg/dL. Patients with postoperative hypocalcemia were classified as group 1 (n = 100) and those with normal Ca levels as group 2 (n = 122). The PoPTH levels and ΔPTH were compared between the 2 groups. Receiver operating characteristic analysis was performed to determine the cutoff values for PoPTH and ΔPTH. Results The mean PoPTH level was significantly lower in group 1 compared with group 2 (18.6 ± 15.3 versus 32.3 ± 15.6 pg/mL, respectively; P &amp;lt; 0.0001). PoPTH values were within the normal range in 54% of the patients with hypocalcemia and 35% of those with symptomatic hypocalcemia. PoPTH &amp;lt;28 pg/mL or ΔPTH &amp;gt;45 were significantly associated with increased risk of post-thyroidectomy hypocalcemia (P = 0.0001). A ΔPTH &amp;gt;70%, PoPTH ≤15.5 pg/mL, and postoperative serum cCa concentrations&amp;lt;8.0 mg/dL significantly predicted symptomatic hypocalcemia (P = 0.009, P = 0.006, and P = 0.0001, respectively). The sensitivities of ΔPTH, PoPTH level, and postoperative serum cCa concentration to predict symptomatic hypocalcemia were 67%, 64%, and 100%, respectively. Conclusion Although PTH decline significantly correlates with symptomatic hypocalcemia, a considerable number of patients may experience hypocalcemic symptoms despite normal PoPTH levels. Analysis of serum Ca concentrations at 24 hours postoperatively help to achieve a more precise prediction of patients who bear a high risk for developing hypocalcemic symptoms.

Risk factors for hypocalcaemia after completion hemithyroidectomy in thyroid cancer.

Hypocalcaemia (HC) is the most common complication after thyroid surgery in differentiated thyroid cancer and leads to a prolongation of the hospital stay. While risk factors for HC after total thyroidectomy (TE) are well investigated, only few studies have been published about HC risk factors after completion of thyroidectomy. Our aim was to identify potential risk factors for HC after completion of TE and to compare these incidences with figures from primary total TE. A retrospective cohort study was undertaken including patients undergoing completion of TE between 2002 and 2013 in our tertiary care centre. Patients with hypocalcaemia (group 1) after undergoing second surgery were compared to normocalcaemia patients (group 2) with respect to gender, age, type of thyroid cancer, time interval between surgeries, pre/postoperative calcium and parathyroid hormone (PTH) levels, clinical hypocalcaemia signs and calcium substitution (intravenous, oral). Hypocalcaemia was defined as <2.10 mmol/l, hypoparathyroidism as <15pg/ml. 34 (25 female, 9 male) patients were included. A total of 12 patients (33%) developed a hypocalcaemia (group 1). Three patients out of these also presented with hypoparathyroidism. One patient in each group showed clinical signs of hypocalcaemia. Calcium substitution was necessary in six cases in group 1 and in one case in group 2. There was a significant difference between the groups concerning postoperative PTH (25.1 vs 37.6 pg/ml) and calcium levels (1.87 vs 2.27 mmol/l) (p <0.05). Group comparison shows no significant relationships between all other parameters (age, gender, type of thyroid cancer and duration of interval between surgeries). Logistic regression analysis identified a low preoperative serum calcium level as the only dominant factor indicating postoperative hypocalcaemia. A hypocalcaemia rate of 33% (12/34) and a hypoparathyroidism rate of 9% (3/34) after completion of thyroidectomy in our cohort is comparable to primary total thyroidectomy. A low preoperative calcium level is a significant risk factor for postoperative hypocalcaemia after completion of thyroidectomy. The prediction of hypocalcaemia still remains difficult since it has multifactorial causes.

Impact of pre-operative serum 25-hydroxyvitamin D on post-operative serum calcium in patients undergoing total thyroidectomy for benign goitre: retrospective study of 246 patients.

To determine whether pre-operative serum 25-hydroxyvitamin D has an impact on post-operative parathyroid hormone and serum calcium levels in patients undergoing total thyroidectomy for benign goitre. This single-centre, retrospective study comprised 246 unselected surgical patients who had undergone total thyroidectomy for bilateral, benign, multinodular goitre. The correlation between pre-operative serum 25-hydroxyvitamin D and post-operative serum parathyroid hormone and serum calcium was studied to determine whether low pre-operative serum 25-hydroxyvitamin D was predictive of post-operative hypocalcaemia. Seventy-nine patients (32 per cent) had post-operative hypocalcaemia. Eighteen patients (7.32 per cent) experienced unintentional parathyroidectomy (1 parathyroid gland in 15 patients, 2 parathyroid glands in 3 patients). In univariate analysis, pre-operative serum 25-hydroxyvitamin D was not correlated with post-operative serum calcium (p = 0.69) or post-operative serum parathyroid hormone (p = 0.5804). Furthermore, in multivariate analysis, which took into account unintentional parathyroidectomy, no correlation was found (p = 0.33). Bilateral unintentional parathyroidectomy was statistically associated with post-operative hypocalcaemia (p = 0.032). Pre-operative serum 25-hydroxyvitamin D did not appear to have any impact on post-operative serum calcium in patients undergoing total thyroidectomy for benign goitre.

Prophylactic oral calcium supplementation therapy to prevent early post thyroidectomy hypocalcemia and evaluation of postoperative parathyroid hormone levels to detect hypocalcemia: A prospective randomized study

BackgroundPostoperative hypocalcemia is the most common complication after total thyroidectomy. Postoperative parathyroid hormone (PTH) measurement is one of the methods to detect or prevent postoperative hypocalcemia. Prophylactic oral calcium supplementation is another method to prevent early postoperative hypocalcemia. The aim of this study is to detect the accurate timing of PTH and evaluate efficacy of routine oral calcium supplementation for postoperative hypocalcemia. MethodsA total of 106 patients were performed total thyroidectomy. Rotuine oral calcium supplementation was given to group 1 and no treatment to group 2 according to randomization. Serum calcium and PTH level of patients in group 2 at postoperative 6, 12 and 24 h and patients in both groups at postoperative day 7 were evaluated. Patients were compared according to age, sex, operation findings, serum calcium and PTH levels and symptomatic hypocalcemia. ResultsHalf of the patients (50%) were in group 1. Most of the patients were female (83%). The most common etiology of thyroid disease was multinodular goiter (64.1%). Oral calcium supplementation was given to 18 (33.9%) patients in group 2. Symptomatic hypocalcemia for group 1 and 2 was found to be 1.9 and 33.9% respectively (p < 0.05). No statistical difference can be observed regarding the timing of serum biomarkers. ConclusionSerum PTH levels at postoperative 12 and 24 h can predict early post-thyroidectomy hypocalcemia. Prophylactic oral calcium supplementation therapy can prevent early post-thyroidectomy hypocalcemia with advantages of being cost effective and safe.

Management of Completion and Total Thyroidectomy Patients Based on 1-Hour Postoperative Parathyroid Hormone

After thyroid surgery, protocols based on postoperative parathyroid hormone (PTH) levels may prevent symptoms of hypocalcemia, while avoiding unnecessary prophylactic calcium and/or vitamin D supplementation. We examined the value of an initial management protocol based solely on a single PTH level measured one hour after completion or total thyroidectomy to prevent symptomatic hypocalcemia by conducting a retrospective review of 697 consecutive patients treated from July 2003 to April 2015. The proportion of patients who developed symptomatic hypocalcemia was similar between those treated before (n = 155) and after (n = 542) implementation of this 1-hour PTH protocol (16.8% vs 15.9%; P = 0.786). Those in the 1-hour PTH groups had lower overnight observation rates (97.4% vs 53.7%; P < 0.001) and length of stay (1.98 ± 2.61 vs 0.89 ± 1.87 days; P < 0.001), and required less calcium (3.9% vs 0.8%; P = 0.015) and vitamin D (2.6% vs 0%; P = 0.002) supplementation one year after surgery. Less than 1 per cent of patients discharged on the day of surgery in accordance with the 1-hour PTH guidelines returned to the emergency room for symptomatic hypocalcemia; none experienced significant morbidity. This protocol facilitates early discharge of low-risk patients and results in a similar or improved postoperative course compared with traditional overnight observation.

Persistently elevated parathyroid hormone after successful parathyroid surgery.

Explore potential causes of persistently elevated parathyroid hormone levels after curative parathyroidectomy in patients with primary hyperparathyroidism due to single gland disease. Case series with planned data collection. An analysis was undertaken of 314 patients with primary hyperparathyroidism undergoing parathyroid surgery in a tertiary academic practice between January 2009 and April 2013. There were 187 patients with single-gland disease; 68 failed to meet inclusion criteria, resulting in a study population of 119 patients. Preoperative parathyroid hormone, calcium, ionized calcium, 25-OH-vitamin D, creatinine, and glomerular filtration rate values were determined, along with postoperative calcium, ionized calcium, and parathyroid hormone levels. Patients were divided into two groups based on their postoperative parathyroid hormone values: elevated parathyroid hormone and normal parathyroid hormone. Thirty (25.2%) patients achieved postoperative normocalcemia but had elevated parathyroid hormone levels. This group had significantly higher preoperative levels of parathyroid hormone (P =.002) and creatinine (P =.007), and a lower glomerular filtration rate (P =.002) than patients with normal postoperative parathyroid hormone levels. The preoperative 25-OH-vitamin D level was not significantly associated with an elevated parathyroid hormone (odds ratio [OR]: 1.56). Preoperative impaired renal function, specifically an abnormal glomerular filtration rate (OR: 12.8), was significantly associated with an elevated parathyroid hormone. Parathyroid hormone remains elevated in 25% of patients who are cured (eucalcemic) after surgery for primary hyperparathyroidism. This phenomenon was associated with higher preoperative parathyroid hormone levels and impaired renal function rather than low 25-OH-vitamin D levels. 4. Laryngoscope, 127:1720-1723, 2017.

Next-day Parathyroid Hormone as a Predictor of Post-thyroidectomy Hypocalcemia

ABSTRACT Aims Total thyroidectomy is significantly complicated by parathyroid dysfunction and hypocalcemia. These aspects impact the decision regarding the timing of discharge and quantum of calcium supplementation required. Therefore, we aimed at evaluating the accuracy of next-day parathyroid hormone (PTH) level as a predictor of post-thyroidectomy hypocalcemia. Secondly, we aimed at establishing our institution's postoperative PTH level, which can accurately predict the development of post-thyroidectomy hypocalcemia to help us ensure the safe and early discharge of patients. Materials and methods A prospective observational study of 50 continuous patients undergoing thyroidectomy was conducted at a tertiary hospital in South India. Postoperative blood samples were collected for estimation of PTH, calcium, albumin, and phosphorous. The data were collated and results analyzed using Stata I/C 10.1. Results A total of 30% (15/50) of the patients had postoperative hypocalcemia (serum calcium &lt;8 mg/dL). Postoperative PTH was low (&lt;8 pg/mL) in 40% (20/50) of patients. There was a significant association between PTH &lt; 8 pg/mL and the presence of postoperative hypocalcemia (p = 0.029). The area under the receiver operating characteristic (ROC) curve was 0.7, and a next-day PTH of &lt;6 pg/mL showed the highest sensitivity and specificity (83 and 60% respectively) for the development of postoperative hypocalcemia, with a positive predictive value (PPV) and negative predictive value (NPV) of 83 and 60 respectively. Conclusion The PTH assessment performed the day after surgery is an acceptable test to predict post-thyroidectomy hypocalcemia; PTH &lt;6 pg/mL can be used as our institution's cutoff value. Department protocols for calcium and vitamin D supplementation following total thyroidectomy may be formulated based on the appropriately timed local postoperative PTH value to assist safe and early discharge of patients. Clinical significance Discharge protocols for patients undergoing thyroidectomy may be formulated based on the postoperative PTH values, thus enabling safe and early discharge of patients. How to cite this article Cherian AJ, Ramakant P, Paul TV, Abraham DT, Paul MJ. Next-day Parathyroid Hormone as a Predictor of Post-thyroidectomy Hypocalcemia. World J Endoc Surg 2016;8(3):203-207.

Is focused parathyroidectomy appropriate for patients with primary hyperparathyroidism?

PurposeThe aim of this study was to determine whether focused or complete parathyroidectomy was more appropriate and to compare follow-up data in primary hyperparathyroidism (PHPT).MethodsWe retrospectively analyzed 225 operations for PHPT at Yonsei University Health System between 2000 and 2012. After excluding 93 patients, the remaining 132 were divided into 2 groups: those who underwent focused parathyroidectomy (FP) and those who underwent conventional parathyroidectomy (CP). We compared clinicopathological features; preoperative calcium, parathyroid hormone (PTH), phosphorus, vitamin D, 24-hour urine calcium, and alkaline phosphatase levels; postoperative calcium and PTH levels; pathologic diagnosis; multiplicity; and results of a localization study between the 2 groups.ResultsThere was no significant difference in the rates of development of postoperative persistent hyperparathyroidism (1/122 FP patients and 1/10 CP patients) between the 2 groups due to a technical reason (FP 0.8% vs. CP 10.0%, P = 0.146). Multiglandular disease (MGD) was uncommon in all cases (6 of 132, 4.5%). All MGD cases were diagnosed using a preoperative localization study. Sestamibi scan and ultrasonography sensitivity were 94.2% and 90.2%, respectively.ConclusionWe suggest that FP is appropriate in PHPT, except in cases of MGD if detected before the operation using preoperative imaging. Knowledge of hereditary PHPT and improved preoperative localization studies, such as high-resolution ultrasonography, contributed to the decision to perform FP rather than CP in all cases of unilateral results of the localizing study.

Parathyroid carcinoma: A report of six cases with a brief review of the literature.

Parathyroid carcinoma (PC) is an uncommon endocrine malignancy and constitutes a rare cause of hyperparathyroidism. The current study presents the clinical features, laboratory findings, sensitivity of imaging modalities, surgical treatment and the long-term outcome of six patients, who were diagnosed with PC and treated in the Department of Head and Neck Surgery, Zhejiang Province Cancer Hospital (Hangzhou, China) over 13 years (February 1999-January 2012). Pre-operative recognition and intraoperative identification of this rare endocrine malignancy is extremely important, but require a high index of clinical suspicion. The primary treatment is surgical en bloc resection of the tumor and any involved surrounding structures, and it is of great importance, as the prognosis depends on the initial surgery. Radiation therapy and chemotherapy showed no evidence of effectiveness on PC, although certain data show a decreased risk of localized disease recurrence with the addition of radiation therapy. The prognosis of PC is variable and post-operative parathyroid hormone levels that do not decrease often indicate a poor prognosis or presence of other metastases.

Algorithm for early discharge after total thyroidectomy using PTH to predict hypocalcemia: prospective study.

Hypocalcemia is the most common complication after total thyroidectomy. The aim of this study was to determine whether postoperative parathyroid hormone (PTH) levels predict hypocalcemia in order to design an algorithm for early discharge. We present a prospective study including patients who underwent total thyroidectomy. Hypocalcemia was defined as serum ionized calcium < 1.09 mmol/L or clinical evidence of hypocalcemia. PTH measurement was performed preoperatively and at 1, 3, and 6 h postoperatively. The percent decline of preoperative values was calculated for each time point. One hundred and six patients were included. Thirty-six (33.9%) patients presented hypocalcemia. A 50% decline in PTH levels at 3 h postoperatively showed the highest sensitivity and specificity to predict hypocalcemia (91 and 73%, respectively). No patients with a decrease <35% developed hypocalcemia (100% sensitivity), and all patients with a decrease >80% had hypocalcemia (100% specificity). PTH determination at 3 h postoperatively is a reliable predictor of hypocalcemia. According to the proposed algorithm, patients with less than 80% drop in PTH levels can be safely discharged the day of the surgery.

The effect of bovine parathyroid hormone withdrawal on MC3T3-E1 cell proliferation and phosphorus metabolism.

Hypocalcemia and hypophosphatemia are common complications after parathyroidectomy (PTX). Sudden removal of high circulating levels of parathyroid hormone (PTH) causes decreased osteoclastic resorption resulting in a decreased bone remodeling space. These phenomena are likely due to an increased influx of calcium and phosphorus into bone. However, there are currently no data to support this hypothesis. In this study, we found that PTX significantly reduced levels of PTH, calcium and phosphate. Compared with preoperative levels, after 1 year, postoperative PTH, calcium and phosphate levels were 295.6 ± 173.7 pg/mL (P < 0.05), 86.62 ± 15.98 mg/dL (P < 0.05) and 5.56 ± 2.03 mg/dL (P < 0.05), respectively. We investigated continuous bovine PTH administration as well as withdrawal of bovine PTH stimulation in the mouse osteoblast precursor cell line MC3T3-E1. MC3T3-E1 cells were cultured with continuous bovine PTH treatment for 20 days or with transient bovine PTH treatment for 10 days. High doses of continuous bovine PTH exposure strongly reduced cell proliferation, alkaline phosphatase activity and the number of mineralized calcium nodules. However, withdrawal of bovine PTH (100 ng/mL) significantly increased the number of mineralized calcium nodules and caused a rapid decline in calcium and phosphorus content of culture medium. In conclusion, continuous exposure to bovine PTH inhibited osteoblast differentiation and reduced the formation of mineralized nodules. However, this inhibition was removed and mineralized nodule formation resumed with withdrawal of bovine PTH. According to the results of our clinical examinations and in vitro experiments, we hypothesize that the sudden removal of high levels of PTH may cause an increased influx of calcium and phosphorus into bone after PTX.

Pedicled Parathyroid Autotransposition in Surgical Management of Secondary Hyperparathyroidism

Objectives: In this study, we report a new, less invasive surgical technique in managing preserved parathyroid tissue in patients with secondary hyperparathyroidism who undergo bilateral parathyroid exploration and excision of all 4 parathyroid glands. We report this technique in 4 patients and evaluate their postoperative parathyroid hormone (PTH) levels as a marker to evaluate efficacy. Methods: All 4 glands were first exposed. Superior glands are not possible to transpose and were excised while the inferior glands were mobilized on their pedicles. Once identified, the inferior glands were kept intact until it was determined which gland can be best preserved on its vascular pedicle with adequate length for transposition. This gland was then mobilized through an incision made in the strap muscles, placing it superficial and ventral to the muscles. The majority of the hyperplastic gland was then resected distal to its vascular pedicle. The portion of the gland that was preserved was secured over the strap muscle, making it easily accessible for future exploration and debulking if needed and avoiding a second operative site in the forearm. Results: Rapid intraoperative PTH assay confirmed adequate removal of hypersecreting parathyroids and was indicative of a curative outcome. All patients exhibited a greater than 90% initial reduction in the PTH level from their baseline and a sustained decrease in postoperative PTH levels well below their preoperative baselines at one month. The percentage mean reduction in PTH at longest follow-up was 94.57%. Importantly, none of the patients exhibited postoperative PTH levels indicative of hypoparathyroidism. Conclusions: None provided.

Predictors of the development of postoperative hypocalcemia following thyroidectomy in the patients presenting with non-toxic multinodular goiter

Postoperative hypocalcemia is a most frequent complication following thyroidectomy in the patients presenting with non-toxic multinodular goiter. It may require long-term hospitalization, additional treatment, a large number of analyses, and frequent visits to outpatient facilities. The objective of the present study was to identify the predictors of postoperative hypoparathyroidism for the prevention of the development of hypocalcemia and its medicamental correction. The clinical data were collected prospectively during the period from October 2011 till May 2013. A total of 140 patients were available for the observation after thyroidectomy performed for the management of non-toxic multinodular goiter. Indications for the surgical intervention included cervical compression syndrome and a cosmetic defect. The patients were divided into two groups depending on the serum calcium level in the postoperative period. Group 1 (n=45) was comprised of the patients having the serum calcium level 2.00 mmol/l or lower, group 2 (n=95) included the patients showing the serum calcium level above 2.00 mmol/l. In addition, serum 25(OH) vitamin D and parathyroid hormone (PTH) levels were measured in all the patients pre- and postoperatively. The preoperative 25(OH)D level and postoperative calcium and PTH levels in the patients of group 1 were significantly lower than in group 2 (p=0.001). It was shown that the main prognostic factors of postoperative hypocalcemia are the preoperative 25(OH)D level below 15 ng/ml (p&lt;0.001), postoperative PTH level below 10 pg/ml (p=0.01), and the age above 50 years (p=0.01). It is concluded that in the majority of the patients the age, the low serum 25(OH)D level in the preoperative period, and the low postoperative PTH level are significantly related to the development of postoperative hypocalcemia.

Parathyroid Hormone Levels Predict Posttotal Thyroidectomy Hypoparathyroidism

We hypothesized that parathyroid hormone (PTH) determination would be the most effective strategy to identify posttotal thyroidectomy hypoparathyroidism (PTTHP) compared with other clinical and laboratory parameters. We retrospectively reviewed our recent experience with total thyroidectomy. We recorded demographics, malignancy, thyroid weight, parathyroid autotransplantation, hospital stay, use of postoperative calcium and hormonally active vitamin D3 (calcitriol), and postoperative serum calcium and PTH levels. Patients were divided into two groups depending on whether supplemental calcitriol was required to maintain eucalcemia and therefore reflecting the diagnosis of PTTHP. From October 2010 to June 2013, a total of 202 total thyroidectomies were performed. Twenty-four patients (12%) developed PTTHP and required calcitriol replacement. Logistic regression analysis revealed that only postoperative calcium levels (P = 0.02) and PTH levels (P < 0.0001) statistically significantly predicted PTTHP. Twenty-two of 29 patients with PTH 13 pg/mL or less had PTTHP. Only two of 173 patients with a PTH level greater than 13 pg/mL were diagnosed with PTTHP. We recommend using PTH levels after total thyroidectomy to determine which patients will have hypoparathyroidism requiring calcitriol therapy. An early determination of PTTHP allows for prompt management that can shorten hospital stay and improve outcomes.

Postoperative PTH monitoring of hypocalcemia expedites discharge after thyroidectomy

PurposeHypocalcemia is the most common complication after total thyroidectomy. Some patients need to stay in the hospital for monitoring of hypocalcemic symptoms and serum calcium levels for several days. We investigated the efficacy and safety of using early postoperative parathyroid hormone (PTH) results for early discharge after thyroidectomy. Materials and MethodsA retrospective cohort study of 2 sequential groups of patients undergoing total thyroidectomy between January 2010 and March 2013 was undertaken. Patients were divided into 2 groups. In Group 1 (before June 2011), patients had daily monitoring of serum calcium level and hypocalcemic symptoms. They were discharged when calcium level was static and asymptomatic. Postoperative PTH was not utilized for discharge plan. In Group 2 (after June 2011), postoperative PTH and calcium level on day 1 were utilized to dictate subsequent management and discharge plan. ResultsOf the 107 patients reviewed, 54 (50.5%) were in Group 1 and 53 (49.5%) were in Group 2. A total of 51 (47.7%) patients developed hypocalcemia. The two groups were comparable in demographic data, early postoperative PTH value, rate of hypocalcemia, the need for oral calcium and vitamin D supplements and rate of permanent hypoparathyroidism. Fewer patients in Group 2 experienced hypocalcemic symptoms, p=0.005. None of the patients in Group 2 needed intravenous calcium supplement (p=0.003). The median postoperative hospital stay for Group 1 was 4days and for Group 2 was 1day (p<0.0001). ConclusionsPostoperative PTH level after total thyroidectomy facilitates early supplementation therapy and abates symptomatic hypocalcemia. It also allows early and safe patient discharge.