Normocalcemia with elevated parathyroid hormone levels after surgical treatment of primary hyperparathyroidism

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

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

Ultrasound-guided microwave and radiofrequency ablation for primary hyperparathyroidism: a prospective, multicenter study

OBJECTIVES

To prospectively investigate the efficacy and safety of ultrasound (US)-guided microwave ablation (MWA) and radiofrequency ablation (RFA) for primary hyperparathyroidism (PHPT).

METHODS

We performed a prospective multicenter study of MWA and RFA for PHPT between August 2017 and October 2020 at five centers. Laboratory testing was performed pre- and post-ablation and followed for at least 6 months. The primary outcome was the cure rate. Secondary outcomes were complications and dynamic changes in serum levels of PTH, calcium, phosphorus, and ALP after ablation.

RESULTS

A total of 132 participants (mean age, 57.33 ± 13.90 years), with 141 parathyroid nodules (median maximal diameter, 1.55 cm) undergoing either MWA or RFA, were enrolled in the study. The technique success rate was 99.29% (140/141). The follow-up period was 6-36 months (median, 12 months). The cure rate was 80.30% (106/132). Pre-ablation PTH level was the independent factor associated with cure rate (Odds ratio (OR), 0.22; 95% CI, 0.07-0.69; p = 0.0090). There was no difference in cure rate between the MWA group and the RFA group (80.22% vs. 80.49%, p = 0.971). The only main complication was hoarseness (5.30%).

CONCLUSIONS

US-guided MWA and RFA for PHPT is an effective and safe procedure in the treatment of PHPT. Pre-ablation PTH level is the key factor affecting the cure rate after MWA and RFA.

KEY POINTS

• To our knowledge, this is the first prospective multicenter clinical trial with ultrasound-guided MWA and RFA for primary hyperparathyroidism. • There was no difference in cure rate between the MWA and RFA groups for primary hyperparathyroidism. The overall cure rate was 80.30%. • Pre-ablation PTH level was the independent factor associated with cure rate (odds ratio (OR), 0.22; 95% CI, 0.07-0.69; p = 0.0090).

Analysis of the cause and management of persistent laboratory abnormalities occurring after the surgical treatment of primary hyperparathyroidism

Purpose

The surgical success rate for primary hyperparathyroidism (PHPT) is currently 95%–98%. However, 3%–24% of patients show persistently elevated (Pe) parathyroid hormone (PTH) levels after parathyroidectomy (PTX). This single-center retrospective study aimed to compare the outcomes of patients with normal PTH and PePTH levels after successful PTX and to identify the factors associated with PePTH.

Methods

The normal group, defined as patients with normal serum calcium and PTH levels immediately after PTX, was compared with the PePTH group (patients with normal or low serum calcium and increased serum PTH levels up to 6 months postoperatively) to determine the causes of disease in the PePTH group.

Results

There were no significant differences in age, sex, or preoperative estimated glomerular filtration rate between the normal PTH group (333 of 364, 91.5%) and the PePTH group (31 of 364, 8.5%). However, there were significant differences in preoperative 25-hydroxyvitamin D (17.9 and 11.8 ng/mL, respectively; P = 0.003) and PTH levels (125.5 and 212.4 pg/mL, respectively; P < 0.001) between the 2 groups. Among the 31 cases of the PePTH group, 18 were attributed to vitamin D deficiency.

Conclusion

Preoperative vitamin D deficiency is a predictive factor for PePTH. Therefore, preoperative administration of vitamin D supplements may reduce the probability of postoperative disease persistence. Patients with temporary laboratory abnormalities within 6 months after successful PTX should be monitored, and appropriate vitamin D and calcium supplementation may reduce the effort and cost of various examinations or reoperations.

Primary hyperparathyroidism in adults-(Part II) surgical management and postoperative follow-up: Position statement of the Endocrine Society of Australia, The Australian & New Zealand Endocrine Surgeons, and The Australian & New Zealand Bone and Mineral Society

OBJECTIVE

To develop evidence-based recommendations to guide the surgical management and postoperative follow-up of adults with primary hyperparathyroidism.

METHODS

Representatives from relevant Australian and New Zealand Societies used a systematic approach for adaptation of guidelines (ADAPTE) to derive an evidence-informed position statement addressing eight key questions.

RESULTS

Diagnostic imaging does not determine suitability for surgery but can guide the planning of surgery in suitable candidates. First-line imaging includes ultrasound and either parathyroid 4DCT or scintigraphy, depending on local availability and expertise. Minimally invasive parathyroidectomy is appropriate in most patients with concordant imaging. Bilateral neck exploration should be considered in those with discordant/negative imaging findings, multi-gland disease and genetic/familial risk factors. Parathyroid surgery, especially re-operative surgery, has better outcomes in the hands of higher volume surgeons. Neuromonitoring is generally not required for initial surgery but should be considered for re-operative surgery. Following parathyroidectomy, calcium and parathyroid hormone levels should be re-checked in the first 24 h and repeated early if there are risk factors for hypocalcaemia. Eucalcaemia at 6 months is consistent with surgical cure; parathyroid hormone levels do not need to be re-checked in the absence of other clinical indications. Longer-term surveillance of skeletal health is recommended.

CONCLUSIONS

This position statement provides up-to-date guidance on evidence-based best practice surgical and postoperative management of adults with primary hyperparathyroidism.

Recurrence after successful parathyroidectomy-Who should we worry about?

BACKGROUND

Preventing cervical reoperations is important-especially after parathyroidectomy. We sought to examine early predictors of recurrence of primary hyperparathyroidism after surgical cure.

METHODS

Adult patients with sporadic primary hyperparathyroidism treated with parathyroidectomy between September 1, 1997, and September 1, 2019, with confirmed eucalcemia at 6 months postoperatively were identified. Recurrence was defined as hypercalcemia (>10.2 mg/dL) with an elevated or nonsuppressed parathyroid hormone level on subsequent follow-up.

RESULTS

Parathyroidectomy was performed in 522 patients (median age, 62.1 years, 77% female) with the majority undergoing planned minimally invasive parathyroidectomy (85.4%, n = 446). After a median follow-up of 30.9 months, 13 patients (2.5%) recurred (median time to recurrence 50.2 months, interquartile range 27.9-66.5), all of whom underwent planned minimally invasive parathyroidectomy (n = 13/446, 2.9%). Recurrence was more common in those with higher (but still normal) 6-month calcium (10.1 vs 9.3 mg/dL, P < .001) or parathyroid hormone values (64 vs 46 pg/mL, P < .01). Multivariate analysis revealed that age >66.5 years, calcium ≥9.8mg/dL and parathyroid hormone ≥80 pg/mL at 6 months were associated with increased risk of recurrence. In addition, the presence of at least 1 preoperative imaging study that conflicted with intraoperative findings among minimally invasive parathyroidectomy patients (n = 446) was associated with increased risk of recurrence (hazard ratio 4.93, 95% confidence interval 1.25-16.53, P = .016).

CONCLUSION

Recurrence of sporadic primary hyperparathyroidism after initial surgical cure in the era of minimally invasive parathyroidectomy is 2.5%. Identification of those at risk for recurrence using 6-month serum calcium ≥9.8 mg/dL, parathyroid hormone ≥80 pg/mL, and/or potentially conflicting localization studies may inform surveillance strategies.

Persistent Elevation of Parathormone Levels after Surgery for Primary Hyperparathyroidism

BACKGROUND

Persistent elevation of serum parathyroid hormone (PTH) despite normocalcemia have been documented in 8- 40% of patients after parathyroidectomy. We hereby report our experience from different centers across India to determine clinical significance of postoperatively elevated PTH levels and review relevant literature.

METHODS

We conducted a retrospective case series study and reviewed all the patients who underwent surgery for primary hyperparathyroidism (PHPT) from April 2010 to January 2020.

RESULTS

Total of 201 patients was diagnosed as PHPT. Out of available follow-up data of 180 patients, a total of 54 patients (30%) had persistently elevated PTH (PePTH) at 1 month. Patients with PePTH were older with higher preoperative serum calcium, iPTH, alkaline phosphatase and lower serum phosphate and 25-hydroxy vitamin D3 levels. Creatinine clearance was found to be significantly lower in patients with PePTH. Multiple linear regression analysis revealed that preoperative 25-OH D3 concentration, creatinine clearance and iPTH are the factors influencing persistent elevation of PTH levels. Significantly lower serum calcium and higher alkaline phosphatase levels were observed in PePTH patients with preoperative 25-OH D3 levels <20 ng/mL. Thirty patients at 6 months, 24 patients at 1 year, 18 patients at 2 years and 9 patients at 3 years had eucalcemic PTH elevation. Nine out of 126 (7%) patients with normal initial postoperative calcium and iPTH levels developed PePTH, with none culminating into recurrent hyperparathyroidism.

CONCLUSION

Though the pathogenesis of such a phenomenon still remains to be elucidated, a multifactorial mechanism appears to play a role.

Persistently Elevated PTH After Parathyroidectomy at One Year: Experience in a Tertiary Referral Center

CONTEXT/OBJECTIVE

Increased PTH after successful parathyroid surgery represents a clinical conundrum. We aimed to determine the prevalence of persistently elevated PTH (PePTH) postsurgery, along with predisposing factors.

DESIGN

and Setting: Patients ≥ age 18 with parathyroidectomy performed at University of North Carolina Hospitals for primary hyperparathyroidism (PHPT) over a 12-year period were identified from the Carolina Data Warehouse. Clinical and demographic characteristics were collected, transformed, and analyzed.

RESULTS

Five hundred seventy patients met initial criteria for PHPT, and of those 407 had postoperative values. One hundred forty-four had laboratory results within 3 to 18 months post operatively. There was no clinical difference between those with and without long-term laboratory follow-up. Presurgery, patients had average calcium of 11 mg/dL and PTH 125.4 pg/mL. Ninety-seven percent of patients had normalized calcium after surgery, but 30% had PePTH, which can be predicted at 3 months. Patients with PePTH (persistent elevation of PTH) after surgery did not differ from those with normalized PTH in terms of sex, age, body mass index, or excised gland weight; presurgery 25-vitamin D was slightly lower, but not abnormal (26 ± 15 vs 36 ± 11). The presurgical PTH was significantly higher (P < 0.001) in those with PePTH (156.5 pg/mL compared with presurgical level of 102.5 in those whose PTH normalized).

CONCLUSIONS

Nearly one-third of PHPT patients have elevated PTH levels postsurgery in a tertiary hospital setting. At presentation, patients with PePTH tend to have higher PTH relative to calcium levels. Whether PePTH after surgical treatment of PHPT has pathological consequences is unknown.

Percutaneous ultrasound-guided ethanol ablation for treatment of primary hyperparathyroidism in a cat

Case summary

A 9-year-old male neutered European Shorthair cat was presented owing to vomiting and mild weight loss. Clinical examination was normal, but biochemistry results showed increased concentrations of total calcium (4.05 mmol/l; reference interval [RI] 2.20-2.90 mmol/l) and ionised calcium (iCa) (2.19 mmol/l; RI 1.12-1.40 mmol/l), as well as hypophosphataemia (2.5 mg/dl; RI 3.1-7.5 mg/dl). Parathyroid hormone (PTH) concentration (>1000 pg/ml) was markedly increased, while parathyroid hormone-related protein concentration (<0.8 pmol/l) was normal. Neck ultrasound showed a large left parathyroid mass (13 × 7 × 6 mm). Under general anaesthesia and with ultrasonographic guidance, a fine-needle aspiration of the mass followed by chemical ablation with 2 ml 96% ethanol was performed. The cat was re-evaluated and iCa concentration measured 24 h, 72 h, 5 days, 4 weeks and 4 months post-ablation. Normocalcaemia was reached within 24 h, remained stable throughout the whole evaluation period and the concentration of PTH normalised 4 months later. Vomiting stopped promptly after chemical ablation and a slight change in voice, as well as a mild prolapse of the nictitating membrane, were the only side effects after the treatment but resolved some weeks later.

Relevance and novel information

To our knowledge, this is the first report of successful chemical ablation of a parathyroid mass in a cat with primary hyperparathyroidism. Chemical ablation might therefore be a possible alternative to parathyroidectomy in cats.

A retrospective study of elevated post-operative parathormone in primary hyperparathyroid patients

We retrospectively analyzed the relationship between normocalcemic parathormone elevation (NPE) and recurrence of primary hyperparathyroidism (pHPT) after surgery, as well as the risk factors of NPE. Out of 309 patients with pHPT that underwent parathyroidectomy. Six months after surgery, 75 patients exhibited NPE with high preoperative serum levels of alkaline phosphatase, calcium and intact parathyroid hormone (iPTH), postoperative day 1 iPTH, and large parathyroid volume. 15 exhibited NPE at 2 years after surgery with low serum vitamin D levels. Postoperative serum iPTH levels gradually normalized in most patients. Multivariate analysis showed that male patients were at greater risk for postoperative NPE (p<0.05). Only 3 of 309 patients showed recurrence during the follow-up period. NPE may not predict recurrent hyperparathyroidism or incomplete parathyroidectomy for benign parathyroid lesions. Postoperative NPE thus appears to be a response to severe hyperparathyroidism and vitamin D deficiency.

Persistent and recurrent hyperparathyroidism

Despite remarkable progress in imaging modalities and surgical management, persistence or recurrence of primary hyperparathyroidism (PHPT) still occurs in 2.5-5% of cases of PHPT. The aim of this review is to expose the management of persistent and recurrent hyperparathyroidism. A literature search was performed on MEDLINE using the search terms "recurrent" or "persistent" and "hyperparathyroidism" within the past 10 years. We also searched the reference lists of articles identified by this search strategy and selected those we judged relevant. Before considering reoperation, the surgeon must confirm the diagnosis of PHPT. Then, the patient must be evaluated with new imaging modalities. A single adenoma is found in 68% of cases, multiglandular disease in 28%, and parathyroid carcinoma in 3%. Others causes (<1%) include parathyromatosis and graft recurrence. The surgeon must balance the benefits against the risks of a reoperation (permanent hypocalcemia and recurrent laryngeal nerve palsy). If surgery is necessary, a focused approach can be considered in cases of significant imaging foci, but in the case of multiglandular disease, a bilateral neck exploration could be necessary. Patients with multiple endocrine neoplasia syndromes are at high risk of recurrence and should be managed regarding their hereditary pathology. The cure rate of persistent-PHPT or recurrent-PHPT in expert centers is estimated from 93 to 97%. After confirming the diagnosis of PHPT, patients with persistent-PHPT and recurrent-PHPT should be managed in an expert center with all dedicated competencies.

Eucalcemic parathyroid hormone elevation after parathyroidectomy for primary sporadic hyperparathyroidism: risk factors, trend, and outcome

BACKGROUND

Patients with eucalcemic parathyroid hormone elevation (ePTH) after parathyroidectomy for primary hyperparathyroidism (HPT) may be at risk of recurrence. We aimed to examine risk factors, trend of PTH level, and outcome of patients with ePTH 6 months after parathyroidectomy.

METHODS

A total of 161 primary HPT were analyzed. The 6-month postoperative calcium and PTH levels were obtained. ePTH was defined as an elevated PTH level in the presence of normocalcemia. At 6 months, 98 had eucalcemic normal PTH and 63 (39.1%) had ePTH. Perioperative variables, PTH trend, and outcome were compared between 2 groups. Multivariable analyses were performed to identify independent preoperative and operative/postoperative risk factors for ePTH.

RESULTS

Among preoperative factors, advanced age (odds ratio [OR] = 1.042, P = .027) and low 25-hydroxyvitamin D(3) (25OHD(3)) (OR = 1.043, P = .009) were independently associated with ePTH, whereas among operative/postoperative factors, high 10-min intraoperative PTH level (OR = 1.015, P = .040) and high postoperative 3-month PTH (OR = 1.048, P < .001) were independently associated with ePTH. After a mean follow-up of 38.7 months, recurrence rate was similar between the 2 groups (P = 1.00). In the first 2 postoperative years, 75 (46.6%) had ePTH on at least 1 occasion and 8 (5.0%) had persistently ePTH on every occasion.

CONCLUSIONS

Advanced age, low 25OHD(3), high 10-min intraoperative PTH, and high postoperative 3-month PTH were independently associated with ePTH at 6-month. Although 39.1% of patients had ePTH at 6 months, more than 50% had at least 1 ePTH within the first 2 years of follow-up. Recurrence appeared similar between those with or without ePTH at 6 months.

[Primary hyperparathyroidism. Postoperative normocalcemic hyperparathyrinemia after curative parathyroidectomy]

INTRODUCTION

Normocalcemic hyperparathyrinemia, i.e. elevated parathyroid hormone (PTH) levels after parathyroidectomy in patients with primary hyperparathyroidism (pHPT) may occur in the course of postoperative recovery without the development of persistence or relapse.

MATERIALS, METHODS AND RESULTS

Intraoperative and long-term (7 year) postoperative PTH and calcium levels after curative parathyroidectomy are demonstrated on the basis of a case report of a 62-year-old female patient with severe pHPT and pronounced osseous and renal manifestations. The intraoperative PTH gradient displayed a decrease from 1072 pg/ml to 13 pg/ml (normal range 11-67 pg/ml) followed by an increase of up to 287 pg/ml. The hyperparathyoid values decline to subnormal levels on administration of calcium and vitamin D and increase again after tapering these medications. The inverse calcium/PTH correlation in the course of the 7-year observation period suggests an intact feed-back mechanism. Preoperative PTH screening was performed in 316 consecutive normocalcemic thyroid patients to evaluate the rate of incidental hyperparathyroidism in patients with normal serum calcium levels. Of these patients 31 (9.8%) with normocalcemia (average 2.28 mmol/l, normal range 2.1-2.7 mmol/l) exhibited increased PTH levels averaging 84.2 pg/ml. A parathyroid adenoma was found intraoperatively as the cause for normocalcemic pHPT in only 1 of these 31 patients.

DISCUSSION AND CONCLUSIONS

A review of the literature revealed that late postoperative elevated parathyroid hormone levels after successful pHPT surgery occur in 21.5%. Multiple causes are discussed, e.g. reactive hyperparathyroidism in cases of relative hypocalcemia, hungry bone syndrome, vitamin D deficiency, renal dysfunction and ethnic or lifestyle differences. In mild cases of postoperative hyperparathyrinemia observation of the patient may be sufficient. In cases of reactive hyperparathyroidism due to hypocalcemia, administration of calcium is indicated, in symptomatic patients, additional administration of vitamin D or calcitriol is necessary. Vitamin D deficiency per se needs adequate substitution. In cases of ongoing hyperparathyrinemia an interdisciplinary diagnostic and therapeutic approach is required.

Intraoperative PTH Assay during Minimally Invasive Parathyroidectomy May Be Helpful in the Detection of Double Adenomas and May Minimise the Risk of Recurrent Surgery

Background. Minimally invasive parathyroidectomy (MIP) is increasingly replacing the traditional bilateral neck exploration in the treatment of primary hyperparathyroidism (PHP). Intraoperative PTH (IOPTH) measurement has recently been introduced as a useful adjunct in confirming successful excision of abnormal parathyroid gland. Aims. We evaluate the safety, efficacy, and clinical usefulness of IOPTH measurement during MIP in a district general hospital. Methods. Retrospective review of eleven consecutive patients with PHP who underwent MIP with IOPTH, following preoperative assessment with ultrasound and sestamibi scans. Results. All patients had successful removal of the abnormal parathyroid gland. The concordance rate between ultrasound and sestamibi scan in localising the parathyroid adenoma was 82%. IOPTH measurement confirmed the removal of adenoma in all cases and, in one case, led to identification of a second adenoma, not localised preoperatively. The median hospital stay was 2 days (range 1-7 days). All patients remained normocalcaemic after a median of 6 months (range 1-10 months). Conclusions. Minimally invasive parathyroidectomy is a feasible, safe, and effective method for treatment of PHP. The use of IOPTH monitoring potentially offers increased sensitivity in detecting multiglandular disease, can minimise the need and risk associated with recurrent operations, and may facilitate cost-effective minimally invasive surgery.

Ectopic thymic parathyroid adenoma and vitamin D deficiency rickets: a 5-year-follow-up case report and review of literature

Sixteen patients with primary hyperparathyroidism presenting as rickets have so far been reported in the English literature. However, no report of an ectopic thymic parathyroid adenoma presenting as rickets has been published. We report a 14-year-old Caucasian American, wheelchair-ridden male who presented with signs and symptoms suggestive of vitamin D deficiency rickets subsequently confirmed by laboratory and radiological findings. Following the intramuscular administration of 125,000 U ergocalciferol (vitamin D2), he developed hypercalcemia with persistently elevated parathyroid hormone (PTH) levels suggestive of primary hyperparathyroidism. Sestamibi scan demonstrated significant uptake in the superior chest, without uptake at the normal parathyroid glands location. Surgical exploration revealed normal parathyroid glands and a thymic mass, which was removed and confirmed by pathology to be a parathyroid adenoma. With subsequent oral ergocalciferol solution and calcium carbonate therapies, the patient's symptoms resolved, blood chemistries normalized, and radiological evidence of rickets significantly improved. To our knowledge, this is the first case of an ectopic thymic parathyroid adenoma in a patient presenting with rickets. Our patient demonstrates that hyperparathyroidism-induced hypercalcemia may be masked by severe vitamin D deficiency. Prolonged treatment with ergocalciferol after removal of the parathyroid adenoma was necessary to normalize iPTH and replenish vitamin D store.

Vitamin D deficiency and primary hyperparathyroidism

Temporally associated with the improvement in vitamin D nutrition in many Western countries in the mid-20th century, there was a change in many characteristics of primary hyperparathyroidism. Osteitis fibrosa cystica became a rare manifestation of what is now frequently an asymptomatic disease. At the same time, in patients with the disease, levels of PTH and parathyroid adenoma weights have fallen dramatically. In view of these observations and others, an association between vitamin D deficiency and severity of primary hyperparathyroidism has been proposed. Data support an association on two distinct levels. First, regardless of the clinical severity of primary hyperparathyroidism, the disease seems to be more severe in those with concomitant vitamin D deficiency. Second, vitamin D deficiency and insufficiency seem to be more prevalent in patients with primary hyperparathyroidism than in geographically matched populations. The association between vitamin D deficiency and primary hyperparathyroidism has clear implications. Co-existing vitamin D deficiency may cause the serum calcium level to fall into the normal range, which can lead to diagnostic uncertainty. With regard to management, preliminary data on vitamin D repletion in patients with mild primary hyperparathyroidism suggest that, in some cases, correction of vitamin D deficiency may be accomplished without worsening the underlying hypercalcemia. Vitamin D-deficient patients undergoing parathyroidectomy are also at increased risk of postoperative hypocalcemia and "hungry bone syndrome," which underscores the importance of preoperative assessment of vitamin D status in all patients with primary hyperparathyroidism.

Oral vitamin D supplementation reduces the incidence of eucalcemic PTH elevation after surgery for primary hyperparathyroidism

BACKGROUND

As many as 43% of patients will have normocalcemic intact parathyroid hormone (PTH) elevation after undergoing curative parathyroidectomy for primary hyperparathyroidism. This phenomenon may be due in part to an absolute or relative deficiency of vitamin D, which is under-recognized in patients with primary hyperparathyroidism.

METHODS

From September 1, 2004, to September 30, 2005, 86 consecutive patients underwent parathyroidectomy for primary sporadic hyperparathyroidism (psHPT). The patients were segregated into 2 groups based on postoperative management. Group 1 was composed of 26 patients who received routine oral calcitriol and calcium carbonate postoperatively. The 60 patients in the second group (group 2) received calcium carbonate postoperatively at the discretion of the primary surgeon.

RESULTS

A total of 85 patients (99%) achieved postoperative cure with sustained reduction in serum calcium. Within 30 days postoperatively, mean serum PTH levels normalized in both groups (41 +/- 31 vs 39 +/- 31 pg/ml; P = .91). However, at 1 to 3 months postoperatively, mean serum calcium levels remained similar (9.5 +/- 0.7 vs 9.3 +/- 0.5 mg/dl; P = .39) whereas mean serum PTH levels in groups 1 and 2 were 43 +/- 25 pg/ml and 67 +/- 45 pg/ml (P = .02), respectively. At 4 to 6 months postoperatively, mean PTH was again higher in group 2 (36 +/- 22 vs 67 +/- 35; P = .03), whereas mean serum calcium levels were normal (9.2 +/- 0.8 vs 9.6 +/- 0.4 mg/dl; P = .18). The incidence of postoperative normocalcemic PTH elevation was significantly higher in group 2 at 1 to 3 months (14% vs 39%; P = .04) and at 7 to 12 months (22% vs 83%; P = .04).

CONCLUSIONS

Vitamin D supplementation following parathyroidectomy for primary hyperparathyroidism reduces the incidence of postoperative eucalcemic PTH elevation.

The role of parathyroid hormone measurements after surgery for primary hyperparathyroidism

BACKGROUND

During parathyroidectomy for primary hyperparathyroidism (pHPT), intraoperative parathyroid hormone (IOPTH) levels are used to confirm removal of all hyperfunctioning parathyroid tissue. The phenomenon of elevated parathyroid hormone (PTH) levels with normocalcemia after curative parathyroidectomy, seen in up to 40% of patients, continues to be an unexpected and unexplained finding. We therefore investigated whether postoperative PTH levels are as reliable as IOPTH levels in predicting cure after surgery for pHPT.

METHODS

We reviewed our prospective database of consecutive patients undergoing surgery for pHPT between December 1999 and November 2004. Curative parathyroidectomy was defined as normocalcemia 6 months or longer postoperatively.

RESULTS

A total of 328 patients who underwent 330 operations for pHPT had IOPTH measurements and serum follow-up calcium levels at 6 months or longer. Surgery was curative in 315 (95.5%) operations. IOPTH levels correctly predicted operative success in 98.2% (positive predictive value [PPV]. Postoperatively, the PPV of a normal PTH level at 1 week, 3 months, and 6 months was 97.1%, 97.3%, and 96.5%, respectively. Of all patients with an elevated postoperative PTH level at 1 week, 3 months, or 6 months, only 13.7%, 14.3%, and 14%, respectively, were not cured.

CONCLUSIONS

Normal postoperative PTH levels reliably predict operative success. However, they do not improve upon results predicted by IOPTH levels. Elevated postoperative PTH levels do not predict operative failure in most patients. We propose that PTH measurements after surgery for pHPT may be misleading, costly, and not indicated in normocalcemic patients.

25-hydroxyvitamin D deficiency is a risk factor for symptoms of postoperative hypocalcemia and secondary hyperparathyroidism after minimally invasive parathyroidectomy

BACKGROUND

Patients with primary hyperparathyroidism who undergo minimally invasive parathyroidectomy (MIP) may have postoperative symptoms of hypocalcemia or secondary hyperparathyroidism. This study sought to identify factors predictive of these events.

METHODS

Between 1998 and 2004, 190 patients with primary hyperparathyroidism underwent MIP with excision of a single adenoma. Age, gender, race, prior head and neck surgery, use of preoperative thyroid hormone or calcium-channel blockers, preoperative levels of calcium, 25-hydroxyvitamin D (25[OH]D) and intact parathyroid hormone (iPTH), the presence of osteopenia or osteoporosis, intraoperative iPTH levels, and adenoma weight were evaluated by univariate analysis as predictors of postoperative symptoms of hypocalcemia and secondary hyperparathyroidism.

RESULTS

None of the following were predictors of postoperative symptoms of hypocalcemia: age, gender, race, prior head and neck surgery, preoperative medications, preoperative calcium and iPTH levels, osteopenia or osteoporosis, intraoperative iPTH levels, or adenoma weight. However, patients with postoperative symptoms of hypocalcemia had significantly lower preoperative 25[OH]D levels (P = .01). Further, higher preoperative iPTH levels (P < .01) and lower preoperative 25[OH]D levels (P = .05) were associated with secondary hyperparathyroidism postoperatively.

CONCLUSIONS

A low preoperative 25[OH]D level is associated with postoperative symptoms of hypocalcemia and secondary hyperparathyroidism in patients undergoing MIP. One might consider instituting empiric calcium supplementation postoperatively in patients with low 25[OH]D levels.

Persistently elevated parathyroid hormone levels after parathyroid surgery

BACKGROUND

Persistent elevation of serum parathyroid hormone (PTH), despite normocalcemia, occurs in 8% to 40% of patients after parathyroidectomy. Explanations have included hypocalcemia owing to vitamin D deficiency or bone remineralization, and persistent hyperparathyroidism.

METHODS

A retrospective chart review of 816 consecutive patients who underwent surgery for primary hyperparathyroidism was conducted.

RESULTS

One hundred fourteen patients (15%) had persistently elevated PTH levels (PPTH). Patients with PPTH had higher preoperative PTH levels than those with normal PTH levels postoperatively. They also had lower postoperative Ca(++) and vitamin D levels. Multiple gland enlargement was identified in fewer patients with PPTH than in those with normal postoperative PTH levels. In patients with PPTH and a postoperative Ca(++) less than 9.6 mg/dL (group I), there was a greater decrease in IOPTH, a higher initial postoperative PTH level, and a lower postoperative vitamin D level than in PPTH patients whose postoperative Ca(++) was > or =9.6 mg/dL (group II). Postoperative Ca(++) and vitamin D levels were also lower in patients whose PPTH did not ultimately resolve. Three patients in group II had recurrent disease.

CONCLUSIONS

Persistent elevation of postoperative serum PTH levels in normocalcemic patients is associated with mild hypocalcemia, probably owing to vitamin D deficiency. In some patients it may also be indicative of mild persistent hyperparathyroidism.

Reelevation of parathyroid hormone level after parathyroidectomy in patients with primary hyperparathyroidism: importance of decreased renal parathyroid hormone sensitivity

BACKGROUND

We hypothesized that impaired peripheral sensitivity to parathyroid hormone (PTH) may play a role in reelevation of PTH after successful operation for primary hyperparathyroidism (pHPT).

METHODS

Factors affecting reelevation of PTH were determined in 90 patients who underwent parathyroidectomy for pHPT. PTH/nephrogenous cyclic adenosine monophosphate ratio, as an index of renal resistance to PTH, was examined in relation to factors shown to influence reelevation of PTH.

RESULTS

Serum PTH levels were elevated above the upper limit of normal in 23 patients (26%) at 1 week and in 39 patients (43%) at 1 month after parathyroidectomy. These 39 normocalcemic patients with elevated serum PTH at 1 month after parathyroidectomy had a higher preoperative serum level of PTH and lower serum phosphate and 25-hydroxyvitamin D (25OHD) concentrations than those with normal PTH (n = 59). Elevated PTH and low 25OHD were shown by multivariate analysis to be significant predictors of reelevation of PTH. Renal resistance to PTH was higher in patients with vitamin D deficiency or renal insufficiency than in patients with normal serum vitamin D concentrations or normal renal function, and it increased according to increases in levels of PTH.

CONCLUSIONS

The mechanism of PTH reelevation in patients with pHPT after successful parathyroidectomy appears to be renal resistance to PTH.

Surgical management of primary hyperparathyroidism: the case for giving up quick intraoperative PTH assay in favor of routine PTH measurement the morning after

OBJECTIVE

To analyze the utility of quick intraoperative parathyroid hormone (PTH) measurement in the surgical management of primary hyperparathyroidism.

BACKGROUND DATA

The use of intraoperative PTH monitoring is well established in the surgery of primary hyperparathyroidism. However, some false-negative predictions lead to unnecessary explorations; furthermore, surgeons are becoming increasingly dependent on hormone measurement for intraoperative decisions, which raises concerns about the cost-effectiveness of the method.

METHODS

A retrospective analysis of 268 neck explorations performed for primary hyperparathyroidism using intraoperative PTH monitoring from April 2001 to February 2003 was done. We used the criterion of "biologic recovery" of hyperfunctioning tissue, defined as a more than 50% decrease in PTH level from baseline value at 5 minutes after excision to predict the outcome of successful parathyroidectomy documented by normal postoperative serum calcium level. Additionally, we also sampled PTH at 10 minutes, 30 minutes, and the morning after surgery to compare the predictive value of delayed sampling. Patients were classified according to the prediction being concordant or discordant with the outcome. The data were analyzed using a 2 x 2 table construct for each of the sampling times, therefore providing sequential sensitivity, specificity, positive and negative predictive values, and overall accuracy of the predictions.

RESULTS

Concordance or overall accuracy of prediction (true positives and negatives) was obtained in 229 cases (85.4%), and discordance or failure of prediction (false positives and negatives) was obtained in 34 cases (12.7%) at T5. On analyzing the iPTH prediction at T10, T30, and D1 among the group of 33 false negatives, we found that 28 (10.4%) patients reached the concordance at 30 minutes, while by the first day 32 patients (12.3%) had achieved concordance. Thus, there was a progressive increase in sensitivity and overall accuracy, but more importantly, in the negative predictive value reaching 88.9% on the day after surgery.

CONCLUSIONS

The method of sampling PTH intraoperatively at 5 minutes has a high positive predictive value (99.5%) but a low negative predictive value (19.5%), which can lead to unnecessary explorations and a delay in the operative procedure. The negative predictive value increases substantially at 30 minutes and is best on the day after surgery. We suggest giving up the intraoperative measurement of PTH to adopt the first day postoperative measurement of PTH as a predictor of successful parathyroidectomy.

Elevated serum parathyroid hormone concentration in eucalcemic patients after parathyroidectomy for primary hyperparathyroidism and its relationship to vitamin D profile

Elevation of serum parathyroid hormone (PTH) level in eucalcemic patients after parathyroidectomy for primary hyperparathyroidism has been described in up to 40% of patients, but little is known about its etiology or clinical significance. To better understand the cause of this phenomenon, we studied 49 patients without renal dysfunction or osteomalacia who underwent parathyroidectomy for primary hyperparathyroidism. Patients were categorized into 2 groups based on their serum PTH and calcium levels after parathyroidectomy: (1) elevated PTH with eucalcemia (n = 21), (2) normal PTH with eucalcemia (n = 28). Elevation of serum PTH with eucalcemia after parathyroidectomy occurred in 43% of patients. Patients in group 1 had significantly higher preoperative and postoperative mean serum PTH levels and significantly lower postoperative serum levels of 1,25(OH)(2)D(3), 1,25(OH)(2)D(3)/25(OH)D(3) ratio, and 1,25(OH)(2)D(3)/PTH ratio compared with patients in group 2. Serum PTH in group 1 patients normalized as early as 3 months, but remained elevated in some patients for more than 4 years, and was not associated with development of recurrent hypercalcemia. Normalization of serum PTH in group 1 patients was associated with significant increase in 1,25(OH)(2)D(3) and 1,25(OH)(2)D(3)/PTH ratio. Our data suggest that elevation of serum PTH in eucalcemic patients after parathyroidectomy is a frequently reversible state of resistance of the kidneys to PTH-mediated 1-alpha hydroxylation of 25(OH)D(3) and does not signify subsequent recurrence of hyperparathyroidism.

Molecular classification of parathyroid neoplasia by gene expression profiling

The current classification of sporadic parathyroid neoplasia, specifically the distinction of adenoma from multiple gland neoplasia (double adenoma and nonfamilial primary hyperplasia) is problematic and results in a relatively high rate of clinical error. Oligonucleotide microarrays (Affymetrix U133A) were used to evaluate parathyroid samples from 61 patients; 35 adenomas, 10 nonfamilial multiple gland neoplasia, 3 familial primary hyperplasia, 8 renal-induced hyperplasia, and 5 from patients without parathyroid disease (normals). A multiclass comparison using supervised clustering identified distinct gene signatures for each class of parathyroid samples. We developed a predictor model that correctly identified 34 of 35 cases of adenoma, 9 of 10 cases of nonfamilial multiple gland neoplasia, and identified a minimum set of 11 genes for the distinction of adenoma versus multiple gland neoplasia. All methods of unsupervised clustering showed two related but different types of parathyroid adenomas that we have arbitrarily designated as type 1 and type 2 adenomas. Multiple gland parathyroid neoplasia, which represents either synchronous or asynchronous autonomous growth in two, three, or all four parathyroid glands, is a distinct molecular entity and does not represent the molecular pathogenesis of adenoma occurring in multiple glands.

Trends in surgical techniques

SUMMARY At present surgery is the only effective treatment for primary hyperparathyroidism. For many years bilateral cervical exploration has been the preferred surgical approach and has been limited to those patients with symptoms or complications of the disease. Recent improvement in preoperative localization techniques, combined with the feasibility of intraoperative parathyroid hormone measurement, has increased the opportunity to perform minimally invasive or unilateral surgery. There are now several minimally invasive procedures, including unilateral neck exploration, video assisted and complete endoscopic techniques. This review provides an overview of the different surgical approaches currently used for the management of primary hyperparathyroidism and discusses the indications, advantages and disadvantages of each technique.

Elevated serum parathormone level after "concise parathyroidectomy" for primary sporadic hyperparathyroidism

BACKGROUND

Cure after parathyroid exploration is traditionally assessed by serum calcium concentration 6 months postoperatively. Postoperative normocalcemic elevation of serum parathormone (PTH) level has been described but is of unclear significance.

METHODS

In a 6-year prospective study of outcomes in 380 patients undergoing initial parathyroidectomy for primary sporadic hyperparathyroidism, we measured intact serum PTH and calcium levels at more than 5 months. Those with normocalcemic high PTH levels were begun on oral calcium + vitamin supplements and monitored.

RESULTS

At more than 5 months postoperatively, normocalcemic elevation in serum PTH level occurred in 28% of patients, was more common after resection of double adenomas (P =.01), and predated the onset of recurrent hypercalcemia in 3 of 3 patients with unrecognized multiglandular disease. Although delayed treatment with calcium and vitamin supplements produced no clear benefit, patients who took such supplements from the date of surgery were much less likely to have an elevated serum PTH level more than 5 months later (P =.0005).

CONCLUSIONS

After successful parathyroid surgery, compensatory normocalcemic elevation in serum PTH level is frequent and may arise from dietary deficiency. Monitored supplemental intake of calcium and vitamin D appears to prevent or to normalize the condition in most patients. Patients with normocalcemic elevation in serum PTH level should receive evaluation for dietary deficiencies as well as follow-up for possible residual disease.