Outpatient minimally invasive parathyroidectomy: a combination of sestamibi-SPECT localization, cervical block anesthesia, and intraoperative parathyroid hormone assay

The biochemical severity of primary hyperparathyroidism correlates with the localization accuracy of sestamibi and surgeon-performed ultrasound

BACKGROUND

Minimally invasive parathyroidectomy for primary hyperparathyroidism is dependent on preoperative localization, commonly with ultrasound and sestamibi imaging. This study sought to determine if preoperative serum calcium and parathyroid hormone (PTH) levels correlate with localization sensitivity and positive predictive value (PPV).

STUDY DESIGN

This is a retrospective analysis of a prospective database of 1,910 patients with primary hyperparathyroidism from 2002 to 2013, who had surgeon-performed ultrasound and/or sestamibi for preoperative localization. The sensitivity and PPV of ultrasound and sestamibi were analyzed by degree of preoperative serum calcium and parathyroid hormone level perturbation.

RESULTS

In 1,910 parathyroidectomy patients, ultrasound was localizing in 1,411 of 1,644 (86%) and sestamibi in 802 of 1,165 (69%) (p < 0.01). The PPV of ultrasound was 1,135 of 1,411 (80%) and sestamibi was 705 of 802 (88%) (p < 0.01). Using logistic regression analysis, there was statistically significant positive correlation between localization and preoperative serum calcium for both sestamibi (odds ratio [OR] 1.21 [95% CI 1.00 to 1.47; p < 0.05]) and ultrasound (OR 1.29 [95% CI 1.03 to 1.60; p < 0.05]). There was a weak, but statistically significant positive correlation of PTH with sestamibi localization (OR 1.00 [95% CI 1.00 to 1.01; p < 0.05]). There was no statistically significant correlation between the PPV and serum calcium or PTH for either study. When patients were divided into quartiles of preoperative serum calcium and PTH levels, localization rates and PPV of both ultrasound and sestamibi increased with higher calcium and PTH levels. Surgeon-performed ultrasound had higher localization rates than sestamibi, with lower calcium and PTH values. Sestamibi demonstrated higher PPV values across all quartiles.

CONCLUSIONS

Surgeon-performed ultrasound and sestamibi have higher localization rates and PPV, with increasing preoperative serum calcium and PTH levels. Surgeon-performed ultrasound may be a better initial test for patients with lower calcium (<10.5 mg/dL) and PTH (<90 pg/mL) values due to significantly higher localization rates; however, a localizing sestamibi has higher PPV.

Operative treatment of primary hyperparathyroidism: balancing cost-effectiveness with successful outcomes

Parathyroidectomy is the most cost-effective treatment for hyperparathyroidism. Randomized prospective trials have shown no difference in cure rate between focused parathyroidectomy and bilateral exploration. Costs of the two techniques differ depending on the preoperative and intraoperative localization used, speed of the operation, ability to discharge the patient on the same day as the operation, cure rate, and complications. It may be less costly and more effective to use a policy of routine 4-gland exploration without the use of preoperative or intraoperative localization studies. The potential economic impact and the expected outcome of the various strategies should be formally evaluated.

Predictors of recurrence in primary hyperparathyroidism: an analysis of 1386 cases

OBJECTIVE

The purpose of this study was to determine whether the operative approach independently influenced recurrence and to identify perioperative predictors of recurrence.

BACKGROUND

Intraoperative parathyroid hormone (IoPTH) monitoring has enabled surgeons to perform minimally invasive parathyroidectomy (MIP). Yet, the long-term durability of this approach has recently been questioned.

STUDY DESIGN

A retrospective review was performed, and cases of initial neck surgery for nonfamilial primary hyperparathyroidism were selected for analysis. Cases were classified as either open parathyroidectomy (OP) when both sides of the neck were explored or MIP when only one side was explored. Kaplan-Meier estimates were plotted for disease-free survival, and a Cox proportional hazards model was developed to evaluate factors associated with recurrence for both the entire cohort and the MIP subset. Further comparisons were made between those who recurred and those who did not recur.

RESULTS

In the past 10-year period, 1368 parathyroid operations for primary hyperparathyroidism were performed at our institution. A total of 1006 were MIP whereas 380 were OP. There were no differences in recurrence between the MIP and OP groups (2.5% vs 2.1%; P = 0.68), and the operative approach (MIP vs OP) did not independently predict recurrent disease in our multivariate analysis. The percentage decrease in IoPTH was protective against recurrence for both the entire cohort (hazard ratio = 0.96; 95% confidence interval = 0.93-0.99; P = 0.03) and the MIP subset. A higher postoperative PTH also independently predicted disease recurrence.

CONCLUSIONS

Operative approach does not independently predict recurrent hyperparathyroidism. The percentage decrease in IoPTH is one of many adjuncts the surgeon can use to determine which patients are best served by bilateral exploration whereas the postoperative PTH can guide follow-up after parathyroidectomy.

Parathyroid conditions in childhood

This review of parathyroid surgery in children will briefly discuss parathyroid gland embryology and anatomy before focusing on the pathophysiology, clinical presentation, and treatment of hyperparathyroidism in children. Hyperparathyroidism (HPT) is the overproduction of PTH and it is rare in children, with an incidence of 2-5 per 100,000. This rarity means that the principles of caring for children with parathyroid disease are largely extrapolated from the richer adult experience; however, the unique pediatric aspects of parathyroid problems and their surgical treatment, including presentation, imaging, operative approach, and complications, will be considered.

Three-dimensional sonography in the evaluation of primary hyperparathyroidism

Three-dimensional sonography is useful in the preoperative evaluation of patients with primary hyperparathyroidism. In this pictorial essay, we review the characteristic spectrum of grayscale and Doppler appearances of parathyroid glands on 2-dimensional sonography and demonstrate the additional benefits of 3-dimensional scanning.

Recurrent and persistence primary hyperparathyroidism occurs more frequently in patients with double adenomas

INTRODUCTION

The incidence of recurrent primary hyperparathyroidism (PHPT) had been reported to be between 1% and 10%. The purpose of this study was to examine if patients with multigland disease have a different recurrence rate.

METHODOLOGY

A retrospective analysis of a prospectively collected database was performed on patients with PHPT who underwent parathyroidectomy at one institution between 2001 and 2013. Patients who underwent initial parathyroidectomy with at least 6 mo of follow-up were included and were divided into three groups according to operative notes: single adenoma (SA), double adenoma (DA), and hyperplasia (HP). An elevated postoperative serum calcium level within 6 mo of surgery was defined as a persistent disease, whereas an elevated calcium after 6 mo was defined as a recurrence.

RESULTS

In total, 1402 patients met inclusion criteria, and the success rate of parathyroidectomy was 98.4%. The mean age was 60±14 y and 78.5% were female. Among them, 1097 patients (78%) had SA, 124 patients (9%) had DA, and 181 patients had HP (13%). The rate of persistent PHPT was higher among patients with DA (4%) versus SA (1.3%) and HP (2.2%) (P=0.0049). Moreover, the recurrence rate was higher among patients with DA (7.3%) versus SA (1.7%) and HP (4.4%) (P=0.0005) with identical median follow-up time. The median of the follow-up was 11 mo for patients with SA, 12.5 for patients with DA, and 12 for patients with HP (P=0.1603).

CONCLUSIONS

Recurrent and persistent PHPT occur more frequently in patients with DA. These data suggest that DA in some cases could represent asymmetric or asynchronous hyperplasia. Therefore, patients with DA may warrant more rigorous intraoperative scrutiny and more vigilant monitoring after parathyroidectomy.

Strategy of operative treatment of hyperparathyroidism using US scan and (99m)Tc-MIBI SPECT/CT

We evaluated the efficacy of technetium-sestamibi ((99m) Tc-MIBI) SPECT/CT for planning parathyroidectomy in cases with primary hyperparathyroidism (pHPT), comparing with planar scintigraphy and ultrasound (US), in an aim to establish the proper surgical strategy according to the preoperative imaging studies. A retrospective review of consecutive 75 pHPT patients who had been operated on was conducted. The results of preoperative imaging modalities and the operative finding were analyzed. Seven cases were found to have multiple hyperplastic glands, and no responsible gland was found in three cases. Four cases underwent only US scan for preoperative imaging. Remaining 61 cases were found to have single adenoma, and were included in the evaluation of localization imaging. US scan, (99m) Tc-MIBI planar scan and (99m) Tc-MIBI SPECT/CT showed accurate localization in 77.0% (47/61), 75.4% (46/61) and 88.5% (46/52) of the evaluable cases, respectively. US and (99m) Tc-MIBI planar scan demonstrated consistent result in 42 cases (68.9%), and those cases showed accurate localization in 90.5% (38/42). When both US and (99m) Tc-MIBI SPECT/CT was consistent, all 37 lesions had been correctly indicated. No clinico-pathological features were suggested to influence in demonstrating the localization, other than only (99m) Tc-MIBI SPECT/CT exhibited 100% sensitivity in ectopic glands. Combination of US and (99m) Tc-MIBI SPECT/CT certainly contributes to the planning of minimally invasive operation in cases with pHPT by indicating correct localization of single adenoma.

Factors in conversion from minimally invasive parathyroidectomy to bilateral parathyroid exploration for primary hyperparathyroidism

BACKGROUND

Ongoing experience has documented equivalence of minimally invasive parathyroidectomy (MIP) and standard bilateral parathyroid exploration (BPE) for primary hyperparathyroidism in most patients; however, intraoperative conversion of MIP to BPE is required for multiple indications. This study analyzes the factors, predictors, and cure rates in converted MIP.

METHODS

We retrospectively analyzed a database of 1,002 patients undergoing initial parathyroidectomy for primary hyperparathyroidism from 2008 to 2011 for rate of successful MIP, converted MIP, planned BPE, and factors leading to conversion from MIP to BPE.

RESULTS

Of 989 included parathyroidectomies, 647 (65%) were successful MIP, 186 (19%) were converted MIP, and 156 (16%) were planned BPE. The most common indication for conversion included intraoperative parathyroid hormone (IOPTH) criteria not met (46%), localization incorrect (36%), and evidence of multigland disease (17%). Converted MIP had lower preoperative calcium and PTH and lower baseline IOPTH compared with successful MIP. Complication rates were similar; however, rates of persistent hyperparathyroidism were highest in converted MIPs (6%) versus planned BPEs (3%) and successful MIPs (2%; P < .01).

CONCLUSION

Patients requiring conversion of MIP to BPE have lower preoperative serum calcium and PTH levels, a less dramatic decrease in IOPTH, and a greater rate of persistent disease than successful MIP.

Predictors of accuracy in preoperative parathyroid adenoma localization using ultrasound and Tc-99m-Sestamibi: a 4-quadrant analysis

PURPOSE

To compare the accuracy of preoperative parathyroid adenoma localization in patients with primary hyperparathyroidism (pHPT) due to a single adenoma using a detailed 4-quadrant analysis and to identify patient and tumor characteristics associated with accurate preoperative localization.

MATERIALS AND METHODS

Retrospective review of 203 patients who underwent parathyroidectomy for pHPT due to a single adenoma between 2008 and 2011. Results from preoperative ultrasound and Tc-99m-sestamibi were compared to operative findings to determine accuracy of localization studies. Associations between clinicopathologic features and accurate preoperative adenoma localization were evaluated.

RESULTS

Ultrasound was performed on 198 patients, sestamibi on 177 patients, and both on 172 patients. Accurate localization occurred significantly more often for ultrasound than sestamibi (63% vs. 41%, P<0.001). For ultrasound, accurate localization was found in patients with larger or heavier adenomas, those with adenomas located inferiorly, patients not having a reoperative procedure, and patients with higher post-operative serum calcium levels. For sestamibi, greater adenoma size or weight, adenomas located inferiorly, and patients with associated thyroid cancer on pathology were most predictive of accurate preoperative localization.

CONCLUSIONS

Our results provide evidence that ultrasound is more accurate in localizing parathyroid adenomas in patients with pHPT due to a single adenoma when compared to sestamibi scan using 4-quadrant location analysis and may be the preferred preoperative imaging modality in these patients. No significant preoperative patient factors were associated with accurate localization by ultrasound or sestamibi, but adenoma size, weight, and location in an inferior position were predictive of accurate preoperative localization.

Accuracy and clinical utility of a point-of-care HbA1c testing device

BACKGROUND

Point-of-care testing (POCT) is widely used to measure blood glucose levels in people with diabetes, although its use in measuring glycated hemoglobin (HbA1c) levels is less common, perhaps due to perceived performance issues and access to the technology.

METHODS

Forty blood samples were analyzed in duplicate using Bayer's A1CNow + ® Multi-Test A1C system (A1CNow + ) with 3 different reagent lots; HbA1c levels of the samples spanned the clinically relevant range of 4% to 10%. Corresponding samples were sent to a National Glycohemoglobin Standardization Program (NGSP) secondary reference laboratory (University of Missouri Secondary Reference Laboratory #9), which analyzed the samples with a Tosoh Automated Glycohemoglobin Analyzer HLC-723G8 (Tosoh G8; Tosoh Bioscience, Inc).

RESULTS

Glycated hemoglobin levels measured with the A1CNow + aligned with measurements obtained using the laboratory method, with correlation coefficients of 0.985, 0.987, and 0.989 for the 3 lots, respectively. The 95% CIs for the differences between the A1CNow + levels and the mean HbA1c levels were within -0.55% to +0.50% for the 3 reagent lots, which is well within the currently acceptable limits of ±0.75% HbA1c required by the NGSP. Results were further analyzed per the new tighter NGSP performance criteria effective September 1, 2012, requiring that 37 of 40 results be within ±7% (relative bias) of the NGSP reference laboratory measures. All 3 lots met the tighter NGSP criteria.

CONCLUSION

The A1CNow + provides accuracy and precision when performing POCT of HbA1c as an aid in diabetes management. Ongoing improvements in this and other HbA1c POCT devices may lead to a greater global acceptance of the role of POCT of HbA1c in diabetes management.

Minimal benefit to subsequent intraoperative parathyroid hormone testing after all four glands have been identified

BACKGROUND

Modern tools, such as intraoperative parathyroid hormone (IoPTH) assay, reduce operative time and extent of parathyroidectomy. However, the utility of a subsequent final set of IoPTH after all four glands are visualized remains questionable. This study was designed to determine the added value of IoPTH assay following parathyroidectomy with four-gland visualization in patients with primary hyperparathyroidism (PHPT).

METHODS

A retrospective review of patients who underwent parathyroidectomy for PHPT between July 2001 and February 2012 by two experienced endocrine surgeons was performed. Included were patients with operative reports indicating that all four parathyroid glands were identified. Following four-gland visualization a subsequent final set of IoPTH was measured to confirm cure. Cure was defined as at least 50 % fall by 5, 10, or 15 min postexcision compared with preincision levels.

RESULTS

Of 1,838 patients that underwent parathyroidectomy, four glands were visualized in 238 cases (13 %). Of those patients meeting inclusion criteria with four glands visualized, the final set of IoPTH fell to cure criteria in 235 patients (98 %). An inadequate drop was documented in three (2 %) patients all of which were found to have multigland disease. Only in one patient (0.4 %) was a fifth parathyroid gland identified and resected. In all three cases, the subsequent final IoPTH did not affect the ultimate outcome or cure rate.

CONCLUSIONS

When experienced surgeons visualize all four parathyroid glands, drawing a subsequent final set of IoPTH rarely changes the operative course and therefore serves a limited role.

Preoperative Localization of Parathyroid Adenomas Using 4-Dimensional Computed Tomography: A Pictorial Essay

Accurate preoperative localization is the key to successful parathyroid surgery in the era of minimally invasive parathyroid surgery. This article presents and discusses the embryologic basis of parathyroid gland and ectopic location and different imaging modalities helpful in diagnosing and localizing parathyroid adenomas and/or hyperplasia. We also aim to review the current surgical concepts in treatment of parathyroid adenomas and/or hyperplasia, the utility of 4-dimensional computed tomography for accurate preoperative localization of hyperfunctioning parathyroid glands, imaging classification of adenomas and/or hyperplasia, and, finally, present some of the limitations of 4-dimensional computed tomography.

Preoperative localization strategies for primary hyperparathyroidism: an economic analysis

BACKGROUND

Strategies for localizing parathyroid pathology preoperatively vary in cost and accuracy. Our purpose was to compute and compare comprehensive costs associated with common localization strategies.

METHODS

A decision-analytic model was developed to evaluate comprehensive, short-term costs of parathyroid localization strategies for patients with primary hyperparathyroidism. Eight strategies were compared. Probabilities of accurate localization were extracted from the literature, and costs associated with each strategy were based on 2011 Medicare reimbursement schedules. Differential cost considerations included outpatient versus inpatient surgeries, operative time, and costs of imaging. Sensitivity analyses were performed to determine effects of variability in key model parameters upon model results.

RESULTS

Ultrasound (US) followed by 4D-CT was the least expensive strategy ($5,901), followed by US alone ($6,028), and 4D-CT alone ($6,110). Strategies including sestamibi (SM) were more expensive, with associated expenditures of up to $6,329 for contemporaneous US and SM. Four-gland, bilateral neck exploration (BNE) was the most expensive strategy ($6,824). Differences in cost were dependent upon differences in the sensitivity of each strategy for detecting single-gland disease, which determined the proportion of patients able to undergo outpatient minimally invasive parathyroidectomy. In sensitivity analysis, US alone was preferred over US followed by 4D-CT only when both the sensitivity of US alone for detecting an adenoma was ≥ 94 %, and the sensitivity of 4D-CT following negative US was ≤ 39 %. 4D-CT alone was the least costly strategy when US sensitivity was ≤ 31 %.

CONCLUSIONS

Among commonly used strategies for preoperative localization of parathyroid pathology, US followed by selective 4D-CT is the least expensive.

Is minimally invasive parathyroidectomy associated with greater recurrence compared to bilateral exploration? Analysis of more than 1,000 cases

BACKGROUND

The durability of minimally invasive parathyroidectomy (MIP) has been questioned, and some advocate for routine open parathyroidectomy (OP). This study compared outcomes between patients treated with MIP compared with OP for primary hyperparathyroidism (PHPT).

METHODS

A retrospective review was performed to identify cases of PHPT with single adenomas (SA) between 2001 and 2011. Operations were classified as OP when both sides were explored. Kaplan-Meier estimates were plotted and compared by the log-rank test.

RESULTS

We analyzed 1,083 patients with PHPT with SA; 928 (85.7%) were MIP and 155 (14.3%) were OP. There was no difference in the rates of persistence (0.2% MIP vs 0% OP, P = .61) or recurrence (2.5% MIP vs 1.9% OP, P = .68) between the 2 groups. The Kaplan-Meier estimates did, however, began to separate beyond 8 years' follow-up. The OP group did experience a greater incidence of transient hypocalcemia postoperatively (1.9% vs 0.1%, P = .01).

CONCLUSION

MIP appears equivalent to OP in single-gland disease. Although patients undergoing OP experienced more transient hypocalcemia, patients undergoing MIP appear to have a greater long-term recurrence rate. Therefore, proper patient selection and counseling of these risks is necessary for either approach.

Superiority of minimally invasive parathyroidectomy

Because greater than 80% of spontaneous cases of primary hyperparathyroidism are caused by a single adenoma, BCE of the neck, which has long been the approach of choice, is being replaced. Focused parathyroidectomy has been made possible by advances in preoperative parathyroid localization and IOPTH monitoring, which allows confirmation of cure and confirmation of the absence of MGD without visualizing all 4 parathyroids. Several techniques for focused parathyroidectomy exist, but open MIP through an incision of 2 to 3 cm with surgeon-administered locoregional anesthesia seems to improve on the already high success rate and low morbidity associated withimproe on bilateral exploration. In addition, MIP is associated with numerous secondary benefits such as decreased hospital cost, improved patient satisfaction, decreased operative time, and same-day discharge. Bilateral exploration will remain the standard of care for most patients with multigland or syndromic disease. Most patients with sporadic PHPT are candidates for MIP.

Sestamibi imaging for primary hyperparathyroidism: the impact of surgeon interpretation and radiologist volume

BACKGROUND

Preoperative localization is the first step towards minimally invasive targeted parathyroidectomy. While there are data emphasizing that surgeon experience optimizes operative outcomes, the role of the radiologist's experience in successful preoperative imaging is unclear. We hypothesized that the accuracy of sestamibi scanning for primary hyperparathyroidism is dependent upon surgeon interpretation and radiologist volume.

METHODS

Between January 2000 to August 2009, 1,255 patients underwent parathyroidectomy for hyperparathyroidism at our institution. Of these, 763 had sestamibi scans for primary hyperparathyroidism. All scans were reviewed by surgeons and radiologists blinded, and were correlated with the operative findings and pathological reports. Radiologists were grouped into high volume (>50 cases/year, HV-RAD) or low volume (<50 cases/year, LV-RAD) based upon a database of >6,000 parathyroid cases reported by 89 regional hospitals.

RESULTS

Of the 763 patients, 77 % were female and the mean age was 60 years. Mean baseline calcium and parathyroid hormone levels were 11.2 ± 0.03 mg/dl and 133 ± 3.27 pg/ml, respectively. The sensitivity of the surgeon (93 %) was higher than both HV (83 %) and LV (72 %) radiologists. Importantly, the positive predictive values were similar: 96 % for surgeon, 93 % for HV-RAD, and 98 % for LV-RAD. As a result, out of 99 scans which were correctly read by the surgeon but not by radiologist, 84 were read as negative by radiologist, 11 on the wrong side of the neck, and 4 on the same side but the wrong gland.

CONCLUSIONS

Surgeon interpretation and radiologist volume increase the likelihood of successful preoperative sestamibi parathyroid localization for primary hyperparathyroidism. We recommend that imaging be reviewed by experienced parathyroid surgeons rather than relying on radiological interpretation alone.

General or local anaesthesia in one-day thyroid surgery-does it matter?

OBJECTIVE

We aimed to determine the safety and feasibility of general anaesthesia (GA) compared with local anaesthesia + Monitored Anaesthesia Care (LA+MAC) for One-Day Thyroid Surgery (ODTS); to assess patient and operator satisfaction with either of the anesthetic approaches.

MATERIAL AND METHODS

We reviewed prospectively 130 patients who underwent ODTS from 2008 to 2011. 64 patients were operated on under GA and 62 - under LA+MAC. All variables of patient demographic characteristics, duration and type of operation, postoperative complications, difficulty in airway management and postoperative opiate consumption were recorded and analyzed.

RESULTS

There is no difference in respect to length of stay, discharge time and major/minor complications rate between two groups, but in the LA+MAC group, pain appears earlier and is more severe (56min; VAS 6, 5) than in GA patients (223 min; VAS 1, 5; p<0.001). Patient satisfaction was similar but the operator preference was greater for GA.

CONCLUSION

In experienced hands LA with MAC for Thyroidectomy is a safe and wise choice, but GA is even more so!

Outpatient Parathyroid Surgery Data from the University Health System Consortium

Objective

To determine demographics and cost for outpatients undergoing parathyroid surgery at hospitals belonging to the University Health System Consortium (UHC).

Study Design

UHC data were accessed in 2011 and reflected data collected from 2005 through 2010 (24 quarters). Searching strategy was based on diagnoses of parathyroid disease and patients undergoing parathyroidectomy across all UHC member facilities. Complications evaluated in this analysis included: hypocalcemia, hypoparathyroidism, aspiration pneumonia, hematoma, wound infection, stroke, myocardial infarction, deep venous thrombosis/pulmonary embolism (PE), and death.

Setting

The University Health System Consortium, Oak Brook, Illinois, was formed in 1984 and consists of 112 academic medical centers and 250 of their affiliated hospitals. This represents 90% of the nonprofit academic medical centers in the United States ( www.uhc.edu ).

Subjects and Methods

Patients enrolled in the UHC database were studied retrospectively. Data were compiled from discharge summaries into a secure, interactive, Web-based database. The outpatient data collection set has been a recent addition to the originally established UHC inpatient discharge database.

Results

There were 21,057 patients who had outpatient parathyroid surgery. The average age was 59.0 (0.8-96.2) yrs. Seventy-six percent of patients were female. Outpatient parathyroidectomy had lower charges than inpatient surgery ($12,738 and $14,657, respectively; P = 0.004, Wilcoxon signed-rank test). Complications were low but were likely underreported.

Conclusion

Parathyroid surgery is increasingly being done in the outpatient setting in the United States. By virtue of omitting inpatient hospitalization, the outpatient approach becomes a more economical way to manage parathyroid disease. This is the largest known series reporting experience with outpatient parathyroid surgery.

Primary hyperparathyroidism in older people: surgical treatment with minimally invasive approaches and outcome

Introduction. Elderly patients with primary hyperparathyroidism (pHPT) are often not referred to surgery because of their associated comorbidities that may increase surgical risk. The aim of the study was to review indications and results of minimally invasive approach parathyroidectomy in elderly patients to evaluate its impact on outcome. Materials and Methods. All patients of 70 years of age or older undergoing minimally approach parathyroidectomy at our Department from May 2005 to May 2011 were reviewed. Data collected included patients demographic information, biochemical pathology, time elapsed from pHPT diagnosis to surgical intervention, operative findings, complications, and results of postoperative biochemical studies. Results and Discussion. 37 patients were analysed. The average length of stay was 2.8 days. 11 patients were discharged within 24 hours after their operation. Morbidity included 6 transient symptomatic postoperative hypocalcemias while one patient developed a transient laryngeal nerve palsy. Time elapsed from pHPT diagnosis to first surgical visit evidences that the elderly patients were referred after their disease had progressed. Conclusions. Our data show that minimally invasive approach to parathyroid surgery seems to be safe and curative also in elderly patients with few associated risks because of combination of modern preoperative imaging, advances in surgical technique, and advances in anesthesia care.

Does the final intraoperative PTH level really have to fall into the normal range to signify cure?

BACKGROUND

Intraoperative parathyroid hormone (IOPTH) helps shorten the duration of surgery and increase the likelihood of surgical cure. Although general consensus agrees that the IOPTH should fall by 50%, there is much debate as to whether the IOPTH needs to fall into the normal range.

METHODS

We retrospectively reviewed a prospective database of patients undergoing surgery for treatment of primary hyperparathyroidism. We included all patients with an IOPTH that fell by >50% by 10 or 15 min, but that did not fall into the normal range (parathyroid hormone remained ≥ 60 pg/ml). We excluded patients who had undergone prior neck surgery or had known multiple endocrine neoplasia 1 or 2.

RESULTS

A total of 1,231 patients underwent a parathyroidectomy, 155 of whom met the study's inclusion/exclusion criteria (12.6%). A total of 117 patients had an IOPTH fall by 50% by 10 min, and 38 patients' IOPTH fell by 50% by 15 min. Overall surgical cure rate was 98.7%. One patient from the 10-minute group and one patient from the 15-minute group had persistent disease on follow-up. One patient in the 15-minute group had recurrent disease. With a mean ± SEM 18.1 ± 2.1 months' follow-up, the recurrence rate in this cohort was 0.6%. The average calcium at last follow-up was 9.4 ± 0.0 mg/dl.

CONCLUSIONS

Allowing the IOPTH to fall by 50% by 15 min, regardless of whether the IOPTH falls into the normal range, results in a high success rate when performed by experienced surgeons. This helps reduce intraoperative time used waiting for additional parathyroid hormone levels and the risks associated with unnecessary bilateral neck exploration.

Sestamibi (99mTc) scan as a single localization modality in primary hyperparathyroidism and factors impacting its accuracy

Background

The proper localization of a hypersecreting parathyroid gland is of vital importance for successful unilateral neck exploration (UNE) and parathyroidectomy.

Aim:

In this study we aim to evaluate the (99mTc) sestamibi parathyroid scan as a single localizing modality, and we also assess its relation to the weight of the gland and to the preoperative parathyroid hormone (PTH) levels.

Patients and Methods:

We reviewed 170 patients from our hospital (Notre-Dame hospital) from 2005 to 2008, with a mean age of 56.6 years and a female to male ratio of 3.3:1. With primary hyperparathyroidism, all of them had (99mTc) sestamibi parathyroid scan for the localization of the parathyroid adenoma. Preoperative and postoperative PTH levels were recorded. The histopathology reports confirmed the diagnosis and weight of the diseased gland, which were recorded every time. The results were analyzed and correlated with the sestamibi results, to evaluate its accuracy.

Results:

Seventy-eight patients (41%) of the 170 had an exact match (EM) sestamibi results, 81 (51.6%) had a partial match, and only 11 patients were reported as mismatch. Analyzing the mean weight of the gland in each group between matching (EM, PM) versus mismatch resulted in a mean difference of 0.823 g (1.05 and 0.247 g, respectively) P = 0.045. Hyperplasia to adenoma ratio was more in the partial matching group (18.5%) versus the exact matching group (7.6%). Finally the mean PTH level was higher in the EM group (28.8 pmol/L) compared to the mismatch group (10.1 pmol/L) P = 0.02. Overall sensitivity and specificity for the (99 mTc) sestamibi in our data was 98.1 and 97%, respectively.

Conclusion:

(99mTc) sestamibi is a highly accurate test that can be employed as a single localizing modality for identifying a hypersecreting parathyroid, a UNE, or a parathyroidectomy. The weight of the gland plays an important role in the accuracy of the test, as also the preoperative PTH levels.

Rapid intraoperative parathyroid hormone assay in the surgical management of hyperparathyroidism

CONTEXT

Historically, successful surgical management of primary hyperparathyroidism has required bilateral exploration of the neck. By confirming complete removal of hypersecreting tissue, an intraoperative parathyroid hormone (IO-PTH) assay allows use of a more limited procedure.

OBJECTIVE

Our objective was to evaluate the utility of IO-PTH assay used in 32 parathyroid explorations versus conventional bilateral exploration used before the advent of IO-PTH assays.

METHODS

Minimally invasive parathyroidectomy (MIP) was used. Plasma samples were obtained at several intervals and were analyzed for IO-PTH by use of a rapid immunochemiluminescent assay (ICMA). Outcomes were assessed by univariate inferential testing, yielding one-tailed t-test results.

RESULTS

The study group had a mean plasma IO-PTH level decrease of 87% at ten minutes after excision. All 32 patients who underwent MIP using IO-PTH monitoring had successful surgery. At last postoperative follow-up examination, all 32 patients were normocalcemic. There were statistically significant decreases in duration of surgery, length of hospital stay, and surgery cost.

CONCLUSIONS

IO-PTH levels predicted the postoperative outcome for all patients studied, can provide valuable information to surgeons, and can decrease the duration of surgery and hospital stay.

The superiority of minimally invasive parathyroidectomy based on 1650 consecutive patients with primary hyperparathyroidism

OBJECTIVE

To compare the results of minimally invasive parathyroidectomy (MIP) and conventional parathyroid surgery.

BACKGROUND

Primary hyperparathyroidism is a common endocrine disorder often treated by surgical intervention. Outpatient MIP, employing image-directed focused exploration under cervical block anesthesia, has replaced traditional surgical approaches for many patients with primary hyperparathyroidism. This retrospective review of a prospective database compared MIP with conventional parathyroid surgery.

METHODS

One thousand six hundred fifty consecutive patients underwent surgery for primary hyperparathyroidism by a single surgeon between 1990 and 2009 at 2 tertiary care academic hospitals. Conventional bilateral cervical exploration under general anesthesia was performed in 613 patients and MIP was performed in 1037 cases. Cure rates, complication rates, pathologic findings, length of hospital stay, and total hospital costs were compared.

RESULTS

Minimally invasive parathyroidectomy is associated with improvements in the cure rate (99.4%) and the complication rate (1.45%) compared to conventional exploration with a cure rate of 97.1% and a complication rate of 3.10%. In addition, the hospital length of stay and total hospital charges were also improved compared to conventional surgery.

CONCLUSIONS

Minimally invasive parathyroidectomy is a superior technique and should be adopted for the majority of patients with sporadic primary hyperparathyroidism.

Minimally Invasive Parathyroid Surgery, The Norman 20% Rule: Is It Valid?

The 20 per cent rule proposed by Norman established a guideline using radioactivity in the minimally invasive radioguided parathyroidectomy (MIRP) technique to localize and confirm removal of an abnormal parathyroid gland in patients with primary hyperparathyroidism. If radioactivity in the resected gland was at least 20 per cent of excision site/background radioactivity, the 20 per cent rule was satisfied. Patients meeting these criteria underwent unilateral MIRP without intraoperative parathyroid hormone assay or intraoperative frozen section. The study aim was to independently evaluate the 20 per cent rule in MIRP patients with primary hyperparathyroidism. Using the University of Louisville Parathyroid Database from January 1, 1999 to December 31, 2007, 216 MIRP patients with complete radioguided and postoperative management data were identified. The average percentage of ex vivo parathyroid gland radioactivity compared with excision site/background radioactivity was 107 per cent with a range from 14 to 388 per cent. For 99 per cent (196/198) radioactivity recorded from the excised gland was at least 20 per cent of radioactivity recorded from the excision site. Normocalcemia was documented in 98.5 per cent (195/198) at 12 month follow-up. Our data supports the 20 per cent rule in that in 99 per cent of MIRP patients the resected gland radioactivity was at least 20 per cent of excision site radioactivity allowing localization and confirmation of an overactive gland without intraoperative parathyroid hormone monitoring or tissue analysis.

Financial and clinical implications of low-energy CT combined with 99m Technetium-sestamibi SPECT for primary hyperparathyroidism

BACKGROUND

(99m)Technetium-sestamibi hybrid SPECT/CT has been favored over conventional SPECT in preoperative evaluation of primary hyperparathyroidism (PHPT) patients. However, the financial implications of CT-image acquisition have never before been published. This prompted us to perform a cost analysis of the aforementioned nuclear procedures.

METHODS

A total of 55 PHPT patients operated on between 2004 and 2009 were studied. Overall, 27 patients underwent SPECT and 28 SPECT/CT. Localization results, as well as diagnostic and clinical cost variations between SPECT and SPECT/CT patients, were compared.

RESULTS

SPECT/CT revealed higher sensitivity than SPECT (96.7 vs 79.3%; P = .011), as well as higher specificity (96.4 vs 82.4%; P = .037) and positive predictive value (PPV) (96.7 vs 83%; P = .038) for correctly identifying the neck-side affected by PHPT. Likewise, SPECT/CT disclosed higher sensitivity (86.7 vs 61.1%; P < .0001), specificity (97.4 vs 90%; P = .022), and PPV (86.7 vs 65.7%; P = .0001) for correct neck-quadrant identification. The mean operative time decreased from 62 min following SPECT to 36 min following SPECT/CT (P < .0001), yielding a mean surgical expense saving of 109.9 <euro>/patient (updated at 2009/2010 billing database). SPECT/CT actually ensures a mean expenditure reduction of 98.7 <euro>/patient (95% CI: 47.96 <euro>-149.42 <euro>), diagnostic costs variation amounting to 11.2 <euro>/procedure.

CONCLUSIONS

SPECT/CT ensures better focus for the surgical exploration, shortens surgical times, and eventually cuts costs when used for localization of parathyroid adenomas.

Intraoperative adjuncts for parathyroid surgery

In recent years, parathyroid surgery has evolved from traditional bilateral neck exploration to minimal invasive parathyroidectomy. This trend became possible due to preoperative localization imaging that guides the surgeon in the search for a parathyroid adenoma. Intraoperative adjuncts are complementary to preoperative localization and assist in localizing parathyroid glands, confirming parathyroid tissue and establishing a cure. Institutions and surgeons utilize different intraoperative adjuncts in different protocols with varying results. The purpose of this article is to review the available intraoperative adjuncts to parathyroid surgery and critically evaluate their utility, accuracy and their added value to the surgeon.

Intraoperative Parathyroid Hormone Assay

Objectives. The aims were to: (1) evaluate whether failure of intraoperative parathyroid hormone (ioPTH) to decrease by the Miami criterion is a more specific indicator of multiglandular disease (MGD) than sestamibi scan and (2) determine an adequate cutoff value for decrease in ioPTH in MGD.

Study Design. Case series with chart review.

Setting. Louisiana State University Health Sciences Center–Shreveport.

Subjects and Methods. Review of subjects undergoing parathyroidectomy using ioPTH and sestamibi for suspected parathyroid adenoma between 2005 and 2009. Patients with MGD were identified by pathology and operative reports.

Results. Eighty-three subjects were identified (68 single adenomas, 11 double adenomas, and 4 multiple-gland hyperplasias). Sestamibi predicted MGD in only 4 of 15 cases (27%). Five of the 11 double adenomas (DAs) were identified during initial surgery; the rest required reoperation for cure. ioPTH was useful in predicting MGD in 7 of 10 cases (70%) when a postexcisional value was drawn after removal of the first enlarged gland. Using the Miami criterion of 50% decrease in ioPTH over 15 minutes would have resulted in 1 unnecessary neck exploration and 3 missed DAs. Requiring both a 50% decrease in ioPTH over 15 minutes and normalization of the postexcisional value would have missed only 1 DA and resulted in a single unnecessary neck exploration.

Conclusion. Sestamibi alone fails to identify MGD 73% of the time, but the success rate increases significantly when combined with ioPTH. The “50% and normal” criterion worked best to increase the success rate in our study population, but larger trials are needed to confirm the utility of this criterion.

Minimally invasive parathyroidectomy

Minimally invasive parathyroidectomy (MIP) is an operative approach for the treatment of primary hyperparathyroidism (pHPT). Currently, routine use of improved preoperative localization studies, cervical block anesthesia in the conscious patient, and intraoperative parathyroid hormone analyses aid in guiding surgical therapy. MIP requires less surgical dissection causing decreased trauma to tissues, can be performed safely in the ambulatory setting, and is at least as effective as standard cervical exploration. This paper reviews advances in preoperative localization, anesthetic techniques, and intraoperative management of patients undergoing MIP for the treatment of pHPT.

A rising ioPTH level immediately after parathyroid resection: are additional hyperfunctioning glands always present? An application of the Wisconsin Criteria

OBJECTIVE

This study was designed to determine if a rising intraoperative parathyroid hormone (ioPTH) level following parathyroid resection indicates multiple hyperfunctioning glands and to determine the appropriate intraoperative management.

SUMMARY BACKGROUND DATA

IoPTH monitoring is commonly used to guide parathyroid surgery. A significant rise in the ioPTH immediately after resection of a single parathyroid is often perceived to be indicative of the presence of additional hyperfunctioning glands.

METHODS

A total of 797 consecutive patients underwent parathyroidectomy for primary hyperparathyroidism with ioPTH monitoring. Patients with an elevated 5 minute ioPTH were extensively studied. Operative success was defined as normocalcemia 6 months after surgery.

RESULTS

Of the 797 patients, 108 (14%) had a rising ioPTH 5 minutes after resection of a single parathyroid. Of these 108 patients, 36 (33%) continued to have elevated ioPTH levels and further exploration revealed additional hyperfunctioning glands. Importantly, in the majority of patients (n = 72 or 67%), the ioPTH started to fall after an additional 5 minutes (10 minutes after resection). The ioPTH declined by more than 50% from the 5 minute elevated value in 30%, 89%, and 99% of patients at 10, 15, and 20 minutes after resection, respectively. Importantly, this fall correctly predicted operative success in 100% of patients after removal of a single abnormal gland.

CONCLUSIONS

A rising ioPTH level immediately after parathyroidectomy is observed in 14% of patients. The majority of these patients do not have additional hyperfunctioning glands. Most of patients fell below 50% of the 5 minute elevated value within 20 minutes of gland resection and in all cases this fall correctly predicted operative success.

National trends in parathyroid surgery from 1998 to 2008: a decade of change

BACKGROUND

The introduction of limited explorations (LE) for parathyroidectomy broadened the management possibilities for hyperparathyroidism. We sought to document this evolution of change in parathyroid surgery.

STUDY DESIGN

Members of the American Association of Endocrine Surgeons and the American College of Surgeons were sent a 49-question survey, and 256 surgeons, accounting for 46% of parathyroid operations nationwide, responded. Associations derived from questionnaire data were tested for significance using chi-square and Kruskal-Wallis methods.

RESULTS

Currently, 10% of surgeons practice bilateral neck exploration, 68% practice LE, and 22% have a mixed practice. Five years ago, these percentages were, respectively, 26%, 43%, and 31%; and 10 years ago they were 74%, 11%, and 15%. Shift to LE was greatest among endocrine surgeons, high-volume surgeons, and surgeons trained by mentors who practiced LE. A focal, single-gland examination under general anesthesia and 23-hour observation are preferred by most surgeons. Half of all general surgeons, in contrast to fewer than 10% of endocrine surgeons, never monitor parathyroid hormone intraoperatively, even with LE. Dramatic differences were apparent among subsets of surgeons in operative volumes, indications for bilateral neck exploration, followup care, expertise with ultrasound and sestamibi, and perceptions of cure and complication rates. Evidence-based literature and guidance from surgical societies had the greatest influence on the decision to practice LE.

CONCLUSIONS

This survey formally documents the evolution of practice patterns in parathyroid surgery over the last decade. Although LE has achieved wide acceptance, surgical management of hyperparathyroidism has become increasingly disparate. This trend may highlight a need to define best-practice guidelines.

Utility of intraoperative PTH for primary hyperparathyroidism due to multigland disease

BACKGROUND

Surgical resection is the only curative therapy for patients with primary hyperparathyroidism (1HPT). Although cure rates of parathyroidectomy are generally high, failure is most often due to unrecognized multigland disease (MGD), which compromises 15-20% of patients with 1HPT. The use of intraoperative PTH (ioPTH) monitoring is well established for single-gland disease. Controversy remains over the utility of ioPTH in MGD, with concern for false-positive results leading to prematurely concluding the operation and leaving behind abnormal parathyroid tissue, risking future recurrence. The aim of this study was to determine the utility of ioPTH monitoring for MGD.

METHODS

Between November 2000 and March 2008, data were prospectively collected on 755 patients with 1HPT who underwent parathyroidectomy. PTH samples were collected pre-incision, and then at 5, 10, and 15 min after excision of suspected abnormal parathyroid gland(s). Surgical cure was defined as a drop of greater than 50% in PTH level. Patients were clinically cured if they became normocalcemic postoperatively and remained so for 6 months. The data were analyzed to determine how accurately ioPTH predicted success or failure of parathyroidectomy.

RESULTS

Of the 755 patients, 163 (21.5%) were found to have MGD on pathology. Intraoperative PTH monitoring was used in 161 of these cases. In 146/161 cases (90.7%), the ioPTH level fell by at least 50% after removal of all suspected abnormal glands. All of these patients (100%) remained normocalcemic postoperatively. In 15/161 cases (9.3%), the PTH level did not fall by >50%. For 11/15 cases (73%), patients remained hypercalcemic postoperatively or had recurrence. However, in the remaining four cases, the patients became normocalcemic postoperatively despite failure of the PTH to fall by >50%. In each of these patients, PTH levels fell by 40-50%.

CONCLUSIONS

ioPTH monitoring accurately predicted success or failure of parathyroidectomy in 97.5% (157/161) of patients with MGD. A fall of ioPTH by >50% can be used as a highly accurate predictor of cure in patients with MGD. Therefore, ioPTH monitoring is a very useful tool in patients with 1HPT and MGD.

Outpatient minimally invasive parathyroidectomy is safe for elderly patients

BACKGROUND

Elderly patients with primary hyperparathyroidism (PHPT) are often not referred for surgical intervention because of concern of comorbid conditions that may increase perioperative complications. Because PHPT is more common in the elderly, we sought to compare indications and complications of minimally invasive parathyroidectomy in patients 70 years of age and older (elderly) with their younger counterparts.

STUDY DESIGN

A review was conducted of a prospectively collected database of all patients undergoing parathyroidectomy on our endocrine surgery service. Data collected included patient demographic, biochemical pathologic, and operative findings. Wilcoxon rank sum and chi-square tests were used for comparisons.

RESULTS

Three hundred eighty-eight patients with PHPT recently underwent parathyroidectomy over a 3-year period (elderly, n=101; younger, n=287). The elderly cohort had significantly higher median preoperative creatinine (elderly, 2.0 mg/dL; younger,1.0 mg/dL; p=0.002) and parathyroid hormone (elderly, 145 pg/mL; younger, 123 pg/mL; p=0.026) levels. The elderly cohort also had more severe osteoporosis, with a significantly worse median bone mineral density T-score (elderly, -2.5; younger, -1.8; p<0.001). The rate of postoperative complications was similarly low in both groups (elderly, 5.9%; younger, 3.5%; p=0.38).

CONCLUSIONS

Minimally invasive parathyroidectomy for PHPT can be performed as safely in elderly patients as in their younger counterparts. Elderly patients with PHPT are more likely to have osteoporosis and higher creatinine levels at the time of surgical referral. Additional study of the role of earlier intervention is warranted.

Impact of concomitant thyroid pathology on preoperative workup for primary hyperparathyroidism

Background

The former standard surgical treatment in patients with primary hyperparathyroidism (pHPT) has been bilateral cervical exploration. New localization techniques and the possibility of intraoperative measurement of intact parathormone (iPTH) permit a focused, minimally invasive parathyroidectomy (MIP). The introduction of MIP without complete neck exploration leads to the potential risk of missing thyroid pathology. The aim of the present study is to evaluate the value of MIP in respect to coexisting thyroid findings and their impact on preoperative workup for primary hyperparathyroidism.

Methods

This is a prospective study including 30 consecutive patients with pHPT (median age 65 years; 17 females, 13 males). In all patients preoperative localization was performed by ultrasonography and ^99mTc-MIBI scintigraphy-Intraoperative iPTH monitoring was routinely done.

Results

Ten patients (33%) had a concurrent thyroid finding requiring additional thyroid surgery, and two patients (7%) with negative localization results underwent bilateral neck exploration. Therefore, MIP was attempted in 18 (60%) patients. The conversion rate to a four gland exploration was 6% (1/18). The sensitivities of ^99mTc-MIBI scanning and ultrasonography were 83.3% and 76.6%, respectively. The respective accuracy rates were 83.3% and 76.6%. Of note, the combination of the two modalities did not improve the sensitivity and accuracy in our patient population. During a median follow-up of 40 months, none of the patients developed persistent or recurrent hypocalcaemia, resulting in a 100% cure rate.

Conclusion

Coexisting thyroid pathology is relatively frequent in patients with pHPT in our region. Among patients having pHPT without any thyroid pathology, the adenoma localization is correct with either ultrasonography or ^99mTc-MIBI scintigraphy in the majority of cases. MIP with iPTH monitoring are highly successful in this group of patients and this operative technique should be the method of choice.

Recent findings in the use of intraoperative parathyroid hormone monitoring in parathyroid disease

PURPOSE OF REVIEW

To discuss recent findings and controversies regarding intraoperative parathyroid hormone monitoring (IPM) in guiding parathyroidectomy.

RECENT FINDINGS

IPM is being frequently used in guiding surgeons to complete excision of abnormal glands during parathyroidectomy for sporadic primary hyperparathyroidism (SPHPT). This adjunct is now being used in many centers around the world and has become a standard of care in the treatment of SPHPT. As the use of this technique developed, the understanding of what was necessary to return patients with hyperparathyroidism to a eucalcemic state, namely, excision of all parathyroid tissue secreting high amount of parathyroid hormone, was recognized. Two major controversies have developed during the evolution of IPM guided parathyroidectomy. One is that gland excision based on this modality may not recognize all abnormal glands, which, if not excised, will result in operative failure or recurrent hyperparathyroidism. The second disagreement is a technical one and concerns the best intraoperative protocol to be used.

SUMMARY

Parathyroidectomy for SPHPT is highly successful regardless of the operative approach used. Despite the controversies summarized in the present review, IPM has been shown to be accurate as an adjunct to guide parathyroidectomy and has changed the operative management of SPHPT.

Predictors of intra-operative parathyroid hormone decline in subjects operated for primary hyperparathyroidism by minimally invasive parathyroidectomy

BACKGROUND

The predictors of intra-operative PTH (IOPTH) decline during minimally invasive parathyroidectomy (MIP) for primary hyperparathyroidism have been but poorly studied.

MATERIALS AND METHODS

This retrospective study included 108 patients who underwent MIP for a single adenoma. Serum calcium and phosphorus were measured before surgery and 1 day post-operatively. IOPTH was measured before (intra-operative preincision or PTHt0) and 10 min after removal of the adenoma (PTHt10). The Modification of Diet in Renal Disease (MDRD) equation was used to estimate the glomerular filtration rate. The weight of the adenoma was assessed in all the subjects.

RESULTS

The sex ratio female/male was 5.37 with a mean age of 57.3 yr. The mean pre- and postoperative values were for calcium 2.80 and 2.19 mmol/l, respectively (p<0.0001) and for phosphorus 0.90 and 1.16 mmol/l, respectively (p<0.0001). The PTH dropped from a mean value of 184.8 to 50.8 pg/ml 10 min after adenoma resection with a mean drop of 69.7%. Thirteen patients (12%) did not achieve a PTH fall of more than 50%. In a bivariate analysis, age, an MDRD<60 ml/min and weight of adenoma were inversely associated with IOPTH fall (p=0.009, p=0.004, and p<0.001, respectively) while gender, body mass index, hypertension, diabetes, pre-operative phosphorus and calcium had no significant effects. In the multivariate analysis, age, weight of adenoma, and MDRD were still independent negative predictors of the IOPTH fall (p=0.01, p=0.018, and p<0.001, respectively).

CONCLUSION

Our results suggest that during MIP the presence of a parathyroid adenoma with a high weight, in an elderly subject or in a subject with altered renal function, will result in a lesser degree of IOPTH fall.