Intraoperative iPTH Research Articles

Management of hypocalcemia following thyroid surgery in children.

Pediatric post-thyroidectomy hypocalcemia management varies significantly from hospital to hospital. The current study has two aims: first, we evaluate demographic data in all pediatric patients submitted to thyroid surgery in our Spanish tertiary hospital over 20 years; secondly, we describe the way that hypocalcemia was diagnosed and treated in that period and present a multidisciplinary protocol for perioperative management of this condition. This is a retrospective and observational study of all patients from 0 to 16 years old who underwent thyroid surgery from 2000 to 2020 at our institution. Demographic, surgical and electrolyte data were recorded from the electronic database. From 2000 to 2016, pediatric thyroid surgery at our institution was performed on 33 patients without a consistent approach or standard electrolyte management. A protocol for perioperative management of these patients was introduced in 2017, and applied to 13 patients. In 2019, the protocol was assessed and updated following a case of symptomatic hypocalcemia. From 2000 to 2016, 47 pediatric patients in all underwent thyroid surgery. We registered eight asymptomatic hypocalcemias. One child developed symptomatic hypocalcemia. Two patients have permanent hypoparathyroidism. Our incidence of general complications following thyroidectomy was low; hypocalcemia was the most prevalent. All the cases of hypocalcemia submitted to the protocol were identified early by iPTH measurements. Intraoperative iPTH levels and percentage drop from baseline could help stratify patients according to their risk of hypocalcemia. High risk patients require immediate postoperative supplementation, including calcitriol and calcium carbonate.

Salt and pepper pot skull

A 20-year-old female presented with a 3-year history of progressive hip and leg pain at rest and on walking. X-ray showed multiple lytic lesions in the long bones of the lower and upper limb. Investigations revealed a high serum calcium 12 mg/dl (N - 8.6–10.3), alkaline phosphatase 4396 IU/L (N - 44–147), and intact parathyroid hormone (iPTH) 974 pg/ml (N - 10–55) with low serum inorganic phosphate of 2.5 mg/dl (N - 3.0–4.5). X-ray skull showed the characteristic salt and pepper pot skull [Figure 1a]. It is characterized by numerous tiny lucencies in the calvarium along with a loss of definition between the inner and outer tables of the skull giving the skull a granular appearance.[12] Dual-energy X-ray absorptiometry scan for bone mineral density revealed a low Z-score of − 5.7 at distal radius, −3.8 at femoral neck, and − 4.3 at lumbar spine. A diagnosis of primary hyperparathyroidism was made. Ultrasound of the neck was suggestive of a right parathyroid adenoma. 99m Tc sestamibi single-photon emission computed tomography SPECT-CT confirmed the location of the adenoma posterior to the right lobe of the thyroid.Figure 1: (a) Salt and pepper pot skull (b) Photomicrograph of parathyroid adenoma showing chief cell hyperplasia (arrow) H and E stain 400XShe underwent excision of the parathyroid adenoma with intra-operative iPTH estimation which showed more than 50% reduction at 10 min. Postoperatively, she suffered from a hungry bone syndrome which was appropriately managed. The histopathology of the excised adenoma showing abundant chief cells [Figure 1b, arrow] was reported as parathyroid adenoma.[3] On follow-up, her serum calcium normalized and her bone pains have subsided. A thorough skeletal survey and imaging can be useful in diagnosing metabolic bone disorders. The expanded differential diagnosis of skull demineralization includes osteoporosis associated with aging and also sickle cell anemia, thalassemia, metastatic bone disease, multiple myeloma, and the lytic phase of Paget disease, but the salt and pepper appearance due to resorption of trabecular bone of the calvaria is classically described for hyperparathyroidism.[4] Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

A case of primary hyperparathyroidism due to an intrathymic ectopic parathyroid adenoma in a 15-year-old boy

Hypercalcemia due to primary hyperparathyroidism (PHPT) is uncommon in children. PHPT is typically caused by a single parathyroid adenoma. Ectopic parathyroid adenomas account for 6%–16% of all parathyroid adenomas and are rare in children but should be considered in cases that present with hypercalcemia. We report the case of a 15-year-old boy with PHPT due to an intrathymic ectopic parathyroid adenoma. Neck ultrasonography and Tc-99m-sestamibi (MIBI) scanning with single-photon emission computed tomography/computed tomography (SPECT/CT) revealed ectopic parathyroid adenoma in the thymus. Video-assisted thoracoscopic surgery was performed to remove the ectopic parathyroid adenoma. Pathology showed intrathymic ectopic parathyroid adenoma. After surgery, the patient’s serum calcium level immediately normalized. Intact parathyroid hormone (iPTH) and alkaline phosphatase levels returned to normal ranges within 3 months. Delayed diagnosis of PHPT can cause end-organ damage; a timely diagnosis is especially critical to preserve bone and renal function. If ectopic parathyroid adenomas are well localized in preoperative imaging evaluation and intraoperative iPTH level decreases after resection, ectopic parathyroidectomy without bilateral neck exploration may be performed to avoid unnecessary morbidity.

SAT-377 Case Series of Ectopic Parathyroid Gland

The prevalence of mediastinal parathyroid adenoma is unknown. Embryological origin and more extensive aberrant migration of the parathyroid glands result in ectopic glands found in the mediastinum. We report herein 4 cases of ectopic parathyroid adenoma causing primary hyperparathyroidism from three public hospitals in MalaysiaCase 1.A 70 year old lady with underlying diabetes mellitus, hypertension, chronic immune thrombocytopenic purpura and liver cirrhosis presented with incidental asymptomatic hypercalcemia during an admission for pneumonia. Her blood results revealed high corrected calcium of 2.93 mmol/L (2.02-2.60) and a low phosphate of 0.66 (0.81-1.45) mmol/L with an unsuppressed intact parathyroid hormone (iPTH) of 14.56 pmol/L (1.6-6.9). She had an equivocal urinary calcium excretion ratio of 0.01. Her bone mineral density confirmed severe osteoporosis at distal radius and neck of femur with a Tscore of -3.6 and -3.1 respectively. A hyperfunctioning ectopic parathyroid gland was seen in the Technetium Sestamibi scan which corelates with a mediastinal lymphadenopathy on CECT. The largest node measured 1.6 x 1.2 cm. Parathyroid gland was confirmed on HPE of the video-assisted-thoracoscopic surgical (VATS) excision of the mediastinal mass. Intraoperative iPTH (ioPTH) serially reduced from 8.87 to 1.94 to 1.03 pmol/L and she maintained a serum calcium levels of 2.4 mmol/L post surgery. She did not require any calcium or vitamin D supplementation. Case 2. A 36 year old male presented with generalized body weakness secondary to hypokalemia. His calcium was 3.07 mmol/l, phosphate 0.64 mmol/l and iPTH 11.53 pmol/L. Increase Technetium uptake seen at mediastinum. Post operatively, calcium normalized and remained stable 1 year later. Case 3.47 year old female presented with acute gallstone pancreatitis complicated with a pancreatic pseudocyst. She was found to have hypercalcemia of 2.77 mmol/L, phosphate 0.70 mmol/l and iPTH 21.87 pmol/L. Sestamibi scan revealed hyperfunctiong parathyroid tissue posterior to the left thyroid lobe and in the mediastinum. She is awaiting surgery. Case 4.Another asymptomatic 47 year old male who has history of post Radioactive-iodine hypothyroidism had an incidental finding of serum calcium of 2.69-2.84 mmol/L, phosphate 0.71-0.91 mmol/L and iPTH 9.89 pmol/L with urinary calcium excretion ratio of 0.019. His Sestamibi scan showed uptake at the superior mediastinum. Ectopic parathyroid gland is rarely encountered. With the advent of Technetium-Sestamibi scintigraphy, ectopic parathyroid adenoma can be localized easily. However, surgery poses a challenge due the location of the adenoma which may occasionally be near large vascular structures in the mediastinum. The availability of intraoperative PTH aids the decision for surgical exploration and completion.

Modern technologies in thyroid surgery – an overview of the benefits

Utilization of modern technologies in thyroid surgery is increasing. The aim of this paper was to present the up-to-data use of modern technologies in thyroid surgery with special emphasis put on their potential influence on minimized risk of surgeryrelated morbidity and improved quality of surgery. Authors searched PubMed database using the following search terms: modern technologies AND/OR thyroid surgery AND/ OR transoral endoscopic thyroidectomy AND/OR neuromonitoring AND/OR parathyroid preservation AND/OR energybased hemostasis. Of 1678 publications identified 826 were found to be consistent with the aim of this review. The relevant papers addressed the following issues: neuromonitoring in minimization of risk of laryngeal nerves injury (62%), intraoperative iPTH monitoring in preselection of patients for early discharge or onset of substitution with calcium (21.5%), narrow-band and near infrared imaging for identification of parathyroids (5.7%), parathyroids angiography with indcyianine green for parathyroids vascularity assessment (5.5%), transoral endoscopic thyroid surgery via vestibular approach for improvement of cosmetic effects (4.1%), energy-based devices for surgical hemostasis (1.2%). Modern technologies are primarily designed to improve the safety and quality of thyroid surgery, and only then to optimize the cosmetic effects and reduce the time of surgery.

MON-327 A Case of Parathyroid Carcinoma in a Patient with Late Stage Chronic Kidney Disease

Introduction: Parathyroid carcinoma (PC) is rare, representing 0.3-5% of primary hyperparathyroidism cases. Its pathophysiology is incompletely understood. Established predisposing factors are lacking, with the exception of known genetic mutation and possibly radiotherapy. The rarity of PC and the fact that its clinical and biochemical features overlap benign parathyroid disease make pre-operative diagnosis challenging. Often the diagnosis is made post-operatively through histopathology. It has been hypothesized that chronic kidney disease may predispose to PC, given chronic parathyroid stimulus related to hypocalcemia and hyperphosphatemia. Here we describe an unusual case of parathyroid cancer in a man with long-standing secondary hyperparathyroidism related to stage IV chronic kidney disease. Case report: A 70-year-old man with hypertension and stage IV chronic kidney disease (CKD) presented for treatment ofsuspected tertiary hyperparathyroidism. His intact parathyroid hormone (iPTH) was 384 (8-54 pg/ml) and serum calcium 11.3 (8.6-10.2 mg/dl). He initially opted not to pursue surgery. Five months later, he presented to theemergency department with shortness of breath and new onset of hoarseness. He was diagnosedwith left vocal cord paralysis. Neck ultrasound showed a 1.1 X 1.4 x 1.4 cm hypoechoic nodule posterior and inferior to the lower left thyroid gland with internal color flow, and he was referred to surgery. Pre-operative serumcalcium was 10.1 with iPTH 774. Intra operatively, the mass was adherent to the surrounding musculature, thyroid and esophagus. Biopsy suggested parathyroid cancer. He underwent an en bloc resection of the left lower parathyroid mass, left superior parathyroidectomy, and ipsilateral hemithyroidectomy. Intra-operative iPTH dropped from 747 to 245. Pathology was consistent witha 3 cm parathyroid carcinoma. The posterior margin was focally positive for tumor. PTH remained elevated post-operativelyat 249 with a corrected serum calcium of 8.6. PET CT was without evidence of metabolically active disease,and neck ultrasound was unremarkable.The patientdeclined HRPT2 mutation testing. Conclusion: The vast majority of PC cases present with primary hyperparathyroidism. The first case of PC diagnosed in secondary hyperparathyroidism was published in 1982. Most patients with long-standing CKD develop polyclonal hyperplasia. In some cases, a monoclonal form of nodular growth has been reported. This monoclonal transformation may involve somatic mutations, such as in the tumor suppressor gene WT1. Whether such cases could progress to malignancy is conceivable, although as yet unproven. Biochemical monitoring for PC recurrence in patients with underlying secondary hyperparathyroidism is challenging. PTH levels do not normalize after surgery, and PTH resistance may delay the development of recurrence-associated hypercalcemia.

Contribution of early SPECT/CT to 99mTc-MIBI double phase scintigraphy in primary hyperparathyroidism: Diagnostic value and correlation between uptake and biological parameters

AimTo evaluate the value of 99mTc-MIBI double-phase scintigraphy (DPS) and early SPECT/CT in the pre-surgical assessment of patients with primary hyperparathyroidism (PHPT). Also, to calculate the correlation between uptake and some biological parameters. Material and methodsForty patients with PHPT were included: 37 solitary adenomas, 1 hyperplasia, and 2 double adenomas. Fifteen patients had ectopic glands.DPS and early SPECT/CT were acquired in all patients. Ultrasound was performed in 31/40. All patients underwent surgery, intra-operative iPTH measurements, and histopathological examinations.Qualitative DPS uptake was assessed and correlated to pre-surgical calcium, iPTH levels, gland weight, and maximum diameter. ResultsIn the planar study, there were 23 positive cases, 8 doubtful, and 9 negatives. With the SPECT/CT, 8/9 negatives cases were located. All doubtful cases were confirmed as positives. Gland location improved in 16 cases (12 ectopic).DPS+SPECT/CT failed to detect a solitary adenoma and at least one gland in three cases of multiglandular disease (MGD). The sensitivity by patient was: DPS 72.5%, DPS+SPECT/CT 90%, and ultrasound 42%.Ultrasound and scintigraphy (DPS+SPECT/CT) were concordant in 16/31 patients. For the rest of them, scintigraphy proved correct in 14/15, and both techniques failed in one case.There was a significant correlation between level of uptake and iPTH level, gland weight, and maximum diameter. ConclusionEarly SPECT/CT improves sensitivity and the locating of parathyroid pathological glands and increases diagnostic confidence. iPTH level, glandular size, and weight are related to the qualitative assessment of 99mTc-MIBI uptake in early DPS.

Contribution of early SPECT/CT to 99mTc-MIBI double phase scintigraphy in primary hyperparathyroidism: Diagnostic value and correlation between uptake and biological parameters.

To evaluate the value of 99mTc-MIBI double-phase scintigraphy (DPS) and early SPECT/CT in the pre-surgical assessment of patients with primary hyperparathyroidism (PHPT). Also, to calculate the correlation between uptake and some biological parameters. Forty patients with PHPT were included: 37 solitary adenomas, 1 hyperplasia, and 2 double adenomas. Fifteen patients had ectopic glands. DPS and early SPECT/CT were acquired in all patients. Ultrasound was performed in 31/40. All patients underwent surgery, intra-operative iPTH measurements, and histopathological examinations. Qualitative DPS uptake was assessed and correlated to pre-surgical calcium, iPTH levels, gland weight, and maximum diameter. In the planar study, there were 23 positive cases, 8 doubtful, and 9 negatives. With the SPECT/CT, 8/9 negatives cases were located. All doubtful cases were confirmed as positives. Gland location improved in 16 cases (12 ectopic). DPS+SPECT/CT failed to detect a solitary adenoma and at least one gland in three cases of multiglandular disease (MGD). The sensitivity by patient was: DPS 72.5%, DPS+SPECT/CT 90%, and ultrasound 42%. Ultrasound and scintigraphy (DPS+SPECT/CT) were concordant in 16/31 patients. For the rest of them, scintigraphy proved correct in 14/15, and both techniques failed in one case. There was a significant correlation between level of uptake and iPTH level, gland weight, and maximum diameter. Early SPECT/CT improves sensitivity and the locating of parathyroid pathological glands and increases diagnostic confidence. iPTH level, glandular size, and weight are related to the qualitative assessment of 99mTc-MIBI uptake in early DPS.

Surgical treatment for patients with hyperparathyroidism

Although parathyroid surgery is not a complicated surgical procedure, enough knowledge of the surgical anatomy and accurate information for localization of involved gland are required from the fact of the variation in the number and the location of the parathyroid gland. Surgical treatment for patients with hyperparathyroidism has been in the transition state from the era of both sides exploration to minimally invasive surgery. In addition, intraoperative radio guide method, intraoperative iPTH measurement, and intraoperative neuromonitoring have been introduced for the safe and reliable operation.

Subtotal parathyroidectomy for secondary renal hyperparathyroidism: a 20-year surgical outcome study.

AimThe aim of this study was to evaluate the outcomes of surgery for patients with secondary renal hyperparathyroidism (rHPT).MethodsThis is a retrospective cohort study. Our institutional database was searched for eligible patients treated in 1995–2014. The inclusion criterion was initial parathyroidectomy for rHPT. Clinical and follow-up data were analyzed to estimate the cure rate (primary outcome), and morbidity (secondary outcome).ResultsThe study group comprised 297 patients (154 females, age 44.5 ± 13.7 years, follow-up 24.6 ± 10.5 months), including 268 (90.2 %) patients who had underwent subtotal parathyroidectomy, and 29 (9.8 %) who had had incomplete parathyroidectomy. Intraoperative iPTH assay was utilized in 207 (69.7 %) explorations. Persistent rHPT occurred in 12/268 (4.5 %) patients after subtotal parathyroidectomy and 5/29 (17.2 %) subjects after incomplete parathyroidectomy (p = 0.005). The patients operated on with intraoperative iPTH assay had a higher cure rate than non-monitored individuals, 201/207 (97.1 %) vs. 79/90 (87.8 %), respectively (p = 0.001). In-hospital mortality occurred in 1/297 (0.3 %) patient. The hungry bone syndrome occurred in 84/268 (31.3 %) patients after subtotal parathyroidectomy and 2/29 (6.9 %) subjects after incomplete parathyroidectomy (p = 0.006). Transient recurrent laryngeal nerve paresis occurred in 14/594 (2.4 %) and permanent in 5/594 (0.8 %) nerves at risk.ConclusionsSubtotal parathyroidectomy is a safe and efficacious treatment for patients with rHPT. Utilization of intraoperative iPTH assay can guide surgical exploration and improve the cure rate.

The current status of intraoperative iPTH assay in surgery for primary hyperparathyroidism.

Intraoperative intact parathyroid hormone (iPTH) monitoring has been accepted by many centers specializing in parathyroid surgery as a useful adjunct during surgery for primary hyperparathyroidism. This method can be utilized in three discreet modes of application: (I) to guide surgical decisions during parathyroidectomy in one of the following clinical contexts: (i) to confirm complete removal of all hyperfunctioning parathyroid tissue, which allows for termination of surgery with confidence that the hyperparathyroid state has been successfully corrected; (ii) to identify patients with additional hyperfunctioning parathyroid tissue following the incomplete removal of diseased parathyroid/s, which necessitates extended neck exploration in order to minimize the risk of operative failure; (II) to differentiate parathyroid from non-parathyroid tissue by iPTH measurement in the fine-needle aspiration washout; (III) to lateralize the side of the neck harboring hyperfunctioning parathyroid tissue by determination of jugular venous gradient in patients with negative or discordant preoperative imaging studies, in order to increase the number of patients eligible for unilateral neck exploration. There are many advantages of minimally invasive parathyroidectomy guided by intraoperative iPTH monitoring, including focused dissection in order to remove the image-indexed parathyroid adenoma with a similar or even higher operative success rate, lower prevalence of complications and shorter operative time when compared to conventional bilateral neck exploration. However, to achieve such excellent results, the surgeon needs to be aware of hormone dynamics during parathyroidectomy and carefully choose the protocol and interpretation criteria that best fit the individual practice. Understanding the nuances of intraoperative iPTH monitoring allows the surgeon for achieving intraoperative confidence in predicting operative success and preventing failure in cases of unsuspected multiglandular disease, while safely limiting neck exploration in the majority of patients with sporadic primary hyperparathyroidism. Thus, parathyroidectomy guided by intraoperative iPTH monitoring for the management of sporadic primary hyperparathyroidism is an ideal option for the treatment of this disease entity. However, the cost-benefit aspects of the standard application of this method still remain a matter of controversy.

Can the use of intraoperative intact parathyroid hormone monitoring be abandoned in patients with hyperparathyroidism?

BackgroundUltrasound (US) and technetium-99m sestamibi scintigraphy (MIBI) are used to determine the localization of abnormal glands in cases of primary hyperparathyroidism (PHPT). Intraoperative intact parathyroid hormone (iPTH) monitoring is a reliable examination used to cure PHPT. The aim was to assess the necessity of intraoperative iPTH monitoring. MethodsSixty patients were examined using preoperative MIBI and US. iPTH was measured at 3 time points: (1) at the start of surgery; (2) 10 minutes after gland resection; and (3) more than 60 minutes after surgery. We defined a decreased iPTH level as an iPTH measured 10 minutes after resection that was less than 50% of the preoperative level. ResultsThe iPTH of 55 patients with concordant lesions decreased to within the normal range more than 60 minutes after surgery. ConclusionsIt is not necessary to monitor intraoperative iPTH when single concordant lesions are preoperatively identified on both MIBI and US.

Could the eZ-SCOPE AN Gamma Camera Replace Intraoperative Measurement of iPTH for PHPT?

Intraoperative intact parathyroid hormone (iPTH) measurements have been proposed as an effective assay in surgery for primary hyperparathyroidism (PHPT). We have demonstrated the efficiency of the use of a hand-held gamma camera, eZ-SCOPE AN, with technetium-99m sestamibi (Tc-MIBI) scintigraphy for navigation surgery for PHPT. The aim of this preliminary study was to assess the possibility that the eZ-SCOPE AN can replace the measurement of intraoperative iPTH in surgery for PHPT. Sixteen consecutive patients with documented primary hyperparathyroidism underwent surgery using this compact camera. iPTH was routinely measured preoperatively and 10 minutes after the complete removal of adenoma. All patients had a well-defined parathyroid lesion identified on preoperative Tc-MIBI. The eZ-SCOPE revealed hyperfunctioning parathyroid glands in all cases. iPTH levels were decreased in all cases after the removal of adenomas. Our results suggest that this gamma camera is useful for confirming complete resection of endocrinologically active tissue in surgery for PHPT. In selective patients with scan-positive cases identified by preoperative Tc-MIBI, the eZ-SCOPE may replace the intraoperative iPTH assay in surgery for PHPT.

Evaluation of the ‘putative’ role of intraoperative intact parathyroid hormone assay during parathyroidectomy for secondary hyperparathyroidism. A retrospective study on 35 consecutive patients

In the surgical treatment of secondary hyperparathyroidism (2HPT) of chronic kidney disease (CKD), a parathyroidectomy (PTx) of 4 glands can only be presumed as 'total', and indications for autoimplantation are complex. Intraoperative rapid parathyroid hormone assay could be useful to predict a radical resection. We evaluated iPTH levels 20 min and 24 h after a 4-gland PTx in 35 patients to determine the predictive value of intraoperative iPTH assay. We analysed retrospectively 35 patients affected by 2HPT of CKD, 13 undergoing total parathyroidectomy (TP) and 22 TP + autoimplantation (TPai), after removing 4 glands in 33 cases and 5 glands in 2. Intact PTH assays were acquired after 40 min before induction of anaesthesia, after removing both ipselateral glands, at 20 min after surgery and on postoperative day 1. 20 min after 4-gland PTx, a decrease of iPTH levels >80 % of the preoperative value was observed in 27 of 35 cases (77.1 %) and <80 % in 8 of 35 cases (22.8 %). In 6 of these 8 patients, iPTH levels were within the normal range 24 h after surgery. Although the intraoperative iPTH assays are of interest in the treatment of 2HPT, the predictive value of this method is not entirely satisfactory. In fact, a 4-gland PTx ensures euparathyroidism in most cases, even when intraoperative iPTH assays are not trustworthy; however, intraoperative iPTH assay, although not a perfect 'tool', is a proved aid for the surgeon in making his decision.

Completion Thyroidectomy for Well-differentiated Thyroid Cancer

Completion thyroidectomy should be offered to those patients for whom a near-total or total thyroidectomy would have been recommended had the diagnosis been available before the initial surgery. This includes all patients with thyroid cancer except those with small (<1 cm), unifocal, intrathyroidal, node-negative, low-risk tumors. Therapeutic central neck lymph node dissection should be included if the lymph nodes are clinically involved. Ablation of the remaining lobe with radioactive iodine has been used as an alternative to completion thyroidectomy. It is unknown whether this approach results in similar long-term outcomes. Consequently, routine radioactive iodine ablation in lieu of completion thyroidectomy is not recommended. Although reoperative thyroid surgery carries a higher risk of operative complications than initial thyroid surgery, experience has demonstrated that it can be performed safely by several different techniques. Nevertheless, thyroid surgeon in their practice should be aware of how to minimize the need for reoperative thyroid surgery and strictly adhere to detailed preoperative work-up and individual risk assessment before initial operation. Nothing less than a unilateral lobectomy with isthmusectomy should be performed as well as the surgeon must make every effort to preserve all encountered parathyroid glands and protect the recurrent laryngeal nerve at initial operation. Several adjuncts to thyroid surgery like intraoperative nerve monitoring or intraoperative iPTH assay may be of help in improving outcomes of individual performance. Such a strategy plays an ever increasing role in improving quality of thyroid surgery worldwide.

Primary Hyperaparathyroidism due to Cystic Parathyroid Adenoma not Detected on99mTc-Sestamibi Scan

99m Tc-sestamibi) parathyroid scan is a sensitive diagnostic tool for the localization, although it sometimes shows a false-negative result. Here we report a case of presumed cystic parathyroid adenoma based on clinical findings and analysis of cystic fluid with negative findings in a parathyroid scan. A 44-year-old male patient visited the hospital due to leg pain and compressive symptoms (dysphagia, hoarseness) that had started 4-5 months before. His serum calcium level was 14.4 mg/dL and his intact parathyroid hormone (iPTH) had increased to 478.1 pg/mL. On neck computed tomography, a cystic nodule measuring 6.2 cm was detected in the inferior part of the right thyroid gland. Sestamibi uptake for this nodule was not detected on 2-h delayed imaging, and fluorodeoxyglucose positron emission tomography showed only subtle uptake. Fine-needle as piration was performed and intracystic iPTH had increased to 61,600 pg/mL. Focused parathyroidectomy guided by intraoperative iPTH monitoring led to successful enucleation of the right inferior parathyroid gland. A parathyroid adenoma was confirmed, and his laboratory results had normalized. This study shows that cystic parathyroid adenoma can sometimes be difficult to detect on a 99m Tc-sestamibi parathyroid scan. (Endocrinol Metab 27:83-88, 2012)

A profile of patients with hyperparathyroidism undergoing lithium therapy for affective psychiatric disorders

Our objective was to evaluate whether lithium-induced hyperparathyroidism (LIHPT) is caused by single-gland versus multigland disease. Medical records of 7 patients who underwent parathyroidectomy for LIHPT were reviewed. The mean preoperative calcium was 11.1 ± 0.7 mg/dL. Six of 7 patients were rendered eucalcemic with surgery. Of the 6 patients successfully treated with surgery, 4 had single-gland disease, 1 had double adenomas, and 1 had 4-gland hyperplasia. Intraoperative intact serum parathyroid hormone (iPTH) accurately predicted resolution of hyperparathyroidism in 6 of 7 patients. One patient then subsequently developed persistent hyperparathyroidism refractory to further surgery. Localization studies defined the extent of disease in 5 of 7 patients. LIHPT presents with a spectrum of disease ranging from single-gland to multigland disease. The utility of preoperative localization studies and intraoperative iPTH in this population is uncertain. Bilateral exploration may be best to achieve a resolution of LIHPT.

Validity and limits of intraoperative parathyroid hormone monitoring during minimally invasive parathyroidectomy: a 10-year experience

The availability of intraoperative intact parathyroid hormone monitoring allows the success of minimally invasive parathyroidectomy to be ensured during the operation. However, false-negative results leading to unnecessary explorations and difficulties in interpreting the data raise concern about the effectiveness of the method. Patients with primary hyperparathyroidism (pHPT) and one unequivocally enlarged parathyroid gland on preoperative ultrasound or (99m)Tc-SestaMIBI scintigraphy underwent minimally invasive video-assisted parathyroidectomy according to the technique initially described by Miccoli. Intraoperatively, rapid electrochemiluminescence immunoassay was used to measure intact parathyroid hormone (iPTH) levels before the operation, after complete mobilization of the adenoma (preexcision value), and 5, 10, and 15 min after the excision. The operation was considered successful when more than a 50% decrease in preexcision iPTH levels and subsequent attainment of the normal range within 15 min were observed. Between November 1999 and November 2009, 235 (43%) of 546 patients with pHPT were eligible for a minimally invasive approach. Intraoperative iPTH monitoring showed 221 true-positive, 1 false-positive, 6 false-negative, and 7 true-negative results. This calculated to a sensitivity of 97% and a specificity of 88%. Despite the availability of high-resolution ultrasound and (99m)Tc-SestaMIBI scintigraphy, the presence of multiple glandular disease cannot be ruled out completely. Although the authors observed six false-negative results, they believe that intraoperative iPTH monitoring represents a valuable asset for minimally invasive parathyroidectomy because it identifies sporadic hyperplasia.

A Case of Parathyroidectomy of Supernumerary Parathyroid Glands Using Intraoperative IPTH Monitoring

The incidence of hyperparathyroidism has slowly increased recently with routine measurement of serum calcium and increasing awareness of the disease by the public. Despite the availability of expert surgeons and preoperative imaging investigations, some patients are re-operated for persistent or recurrent hyperparathyroidism. The main cause of re-operation is the presence of ectopic parathyroid gland or supernumerary parathyroid gland. Supernumerary parathyroid glands are more frequently described in the secondary hyperparathyroidism than in the primary hyperparathyroidism cases, especially in surgery for renal hyperparathytroidism. The intraoperative measurement of intact parathyroid hormone (iPTH) provides the surgeon with a quantitative test that predicts the postoperative serum calcium level and can justify early closure or further exploration for hyperfunctioning parathyroid gland. We present a case of parathyroidectomy of supernumerary parathyroid glands by monitoring intraoperative iPTH in patients with secondary hyperparathyroidism. Korean J Otorhinolaryngol-Head Neck Surg 2010;53:190-3 Key WordsZZParathyroid gland·Parathyroid hormone·Secondary hyperparathyroidism.

Bilateral Neck Exploration with Intraoperative iPTH Assay in the ERA of Minimaly Invasive Parathyroidectomy

Bilateral Neck Exploration with Intraoperative iPTH Assay in the ERA of Minimaly Invasive Parathyroidectomy