Operation for primary hyperparathyroidism: the new versus the old order. A randomised controlled trial of preoperative localisation

A Retrospective Cohort Study of the Utility of Ultrasound, 99mTc-Sestamibi Scintigraphy, and Four-Dimensional Computed Tomography for Pre-Operative Localization of Parathyroid Disease To Facilitate Minimally Invasive Parathyroidectomy

Background

This study investigated the utility of ultrasound (US), 99mTc-Sestamibi scintigraphy (Sestamibi), and four-dimensional computed tomography (4DCT) for pre-operative localization of a single abnormal parathyroid gland prior to minimally invasive parathyroidectomy (MIP) to determine the optimum pre-operative scans to facilitate a MIP.

Methods

Patients with primary hyperparathyroidism who underwent curative parathyroidectomy at Broomfield Hospital, Mid and South Essex NHS Foundation Trust between 2009 and 2018 were included. Diagnostic performance parameters and the agreement between US, Sestamibi, and 4DCT were evaluated. Cohen’s κ was used to assess the strength of agreement between imaging modalities.

Results

At localizing pathology to the correct side of the neck, Sestamibi had the highest sensitivity (87%), followed by US (76%) and 4DCT (64%). 4DCT had a positive predictive value (PPV) of 95%, similar to Sestamibi (96%), but higher than US (92%). Amongst patients who underwent both US and Sestamibi, the abnormal parathyroid gland was localized to the same area by both imaging modalities in 77% of patients (Cohen’s κ: 0.383). Following an inconclusive US or Sestamibi scan, or discordance between the two modalities, 4DCT was correct at localization in 63% of patients.

Conclusion

Sestamibi has the highest sensitivity and PPV for accurately localizing parathyroid pathology. The addition of US to a positive Sestamibi scan adds little additional value. 4DCT is the preferred imaging modality following an inconclusive Sestamibi or US.

Minimally invasive parathyroidectomy guided by intraoperative parathyroid hormone monitoring (IOPTH) and preoperative imaging versus bilateral neck exploration for primary hyperparathyroidism in adults

BACKGROUND

Bilateral neck exploration (BNE) is the traditional approach to sporadic primary hyperparathyroidism. With the availability of the preoperative imaging techniques and intraoperative parathyroid hormone assays, minimally invasive parathyroidectomy (MIP) is fast becoming the favoured surgical approach.

OBJECTIVES

To assess the effects of minimally invasive parathyroidectomy (MIP) guided by preoperative imaging and intraoperative parathyroid hormone monitoring versus bilateral neck exploration (BNE) for the surgical management of primary hyperparathyroidism.

SEARCH METHODS

We searched CENTRAL, MEDLINE, WHO ICTRP and ClinicalTrials.gov. The date of the last search of all databases was 21 October 2019. There were no language restrictions applied.

SELECTION CRITERIA

We included randomised controlled trials comparing MIP to BNE for the treatment of sporadic primary hyperparathyroidism in persons undergoing surgery for the first time.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Two review authors independently screened for inclusion, extracted data and carried out risk of bias assessment. The content expert senior author resolved conflicts. We assessed studies for overall certainty of the evidence using the GRADE instrument. We conducted meta-analyses using a random-effects model and performed statistical analyses according to the guidelines in the latest version of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We identified five eligible studies, all conducted in European university hospitals. They included 266 adults, 136 participants were randomised to MIP and 130 participants to BNE. Data were available for all participants post-surgery up to one year, with the exception of missing data for two participants in the MIP group and for one participant in the BNE group at one year. Nine participants in the MIP group and 11 participants in the BNE group had missing data at five years. No study had a low risk of bias in all risk of bias domains. The risk ratio (RR) for success rate (eucalcaemia) at six months in the MIP group compared to the BNE group was 0.98 (95% confidence interval (CI) 0.94 to 1.03; P = 0.43; 5 studies, 266 participants; very low-certainty evidence). A total of 132/136 (97.1%) participants in the MIP group compared with 129/130 (99.2%) participants in the BNE group were judged as operative success. At five years, the RR was 0.94 (95% CI 0.83 to 1.08; P = 0.38; 1 study, 77 participants; very low-certainty evidence). A total of 34/38 (89.5%) participants in the MIP group compared with 37/39 (94.9%) participants in the BNE group were judged as operative success. The RR for the total incidence of perioperative adverse events was 0.50, in favour of MIP (95% CI 0.33 to 0.76; P = 0.001; 5 studies, 236 participants; low-certainty evidence). Perioperative adverse events occurred in 23/136 (16.9%) participants in the MIP group compared with 44/130 (33.9%) participants in the BNE group. The 95% prediction interval ranged between 0.25 and 0.99. These adverse events included symptomatic hypocalcaemia, vocal cord palsy, bleeding, fever and infection. Fifteen of 104 (14.4%) participants experienced symptomatic hypocalcaemia in the MIP group compared with 26/98 (26.5%) participants in the BNE group. The RR for this event comparing MIP with BNE at two days was 0.54 (95% CI 0.32 to 0.92; P = 0.02; 4 studies, 202 participants). Statistical significance was lost in sensitivity analyses, with a 95% prediction interval ranging between 0.17 and 1.74. Five out of 133 (3.8%) participants in the MIP group experienced vocal cord paralysis compared with 2/128 (1.6%) participants in the BNE group. The RR for this event was 1.87 (95% CI 0.47 to 7.51; P = 0.38; 5 studies, 261 participants). The 95% prediction interval ranged between 0.20 and 17.87. The effect on all-cause mortality was not explicitly reported and could not be adequately assessed (very low-certainty evidence). There was no clear difference for health-related quality of life between the treatment groups in two studies, but studies did not report numerical data (very low-certainty evidence). There was a possible treatment benefit for MIP compared to BNE in terms of cosmetic satisfaction (very low-certainty evidence). The mean difference (MD) for duration of surgery comparing BNE with MIP was in favour of the MIP group (-18 minutes, 95% CI -31 to -6; P = 0.004; 3 studies, 171 participants; very low-certainty evidence). The 95% prediction interval ranged between -162 minutes and 126 minutes. The studies did not report length of hospital stay. Four studies reported intraoperative conversion rate from MIP to open procedure information. Out of 115 included participants, there were 24 incidences of conversion, amounting to a conversion rate of 20.8%.

AUTHORS' CONCLUSIONS

The success rates of MIP and BNE at six months were comparable. There were similar results at five years, but these were only based on one study. The incidence of perioperative symptomatic hypocalcaemia was lower in the MIP compared to the BNE group, whereas the incidence of vocal cord paralysis tended to be higher. Our systematic review did not provide clear evidence for the superiority of MIP over BNE. However, it was limited by low-certainty to very low-certainty evidence.

Surgical Treatment of Primary Hyperparathyroidism: Which Therapy to Whom?

Primary hyperparathyroidism (pHPT) is characterized by an increase in the levels of PTH and Ca, or one of these (Ca, PTH) as a result of a dysregulation of calcium (Ca) metabolism due to inappropriate excess parathyroid hormone (PTH) autonomously produced from one or more than one parathyroid glands. Ninety to 95% of pHPT is a sporadic type, which is not associated with the familial history and other endocrine organ tumors, and 5-10% of it is hereditary. While 80-85% of pHPT arises from a single parathyroid adenoma, 4-5% is caused by a double adenoma, 10-15% by multigland hyperplasia and less than 1% by parathyroid cancer. The diagnosis of pHPT is reached biochemically. The only curative treatment of pHPT is surgery. The choice of surgery in pHPT may vary depending on whether the patient has hereditary HPT or thyroid disease requiring surgical treatment, preoperative localization studies and the findings in these studies, the possibilities of using intraoperative PTH and the preference of the surgeon. The preoperatively determined surgical strategy can be revised according to intraoperative findings in case of need to achieve excellent results. The two main approaches in the surgical treatment of pHPT are BNE (bilateral neck exploration) and MIP (minimal invasive parathyroidectomy). Although BNE is a consistently valid option that has excellent results in the surgical treatment of pHPT and is considered the gold standard, MIP is the ideal approach in selected patients with clinically and radiologically considered a single-gland disease. Negative imaging is not a contraindication for parathyroid surgery and is not a criterion for the presence or absence of surgical indication. Although both methods are safe and effective in the surgical treatment of sporadic pHPT, there is still controversy regarding the effectiveness of both methods. Surgical intervention should establish the risk-benefit balance well, minimize the risk of persistent and recurrent disease and provide the highest cure rate without increasing the risk of complications. Complication rates are higher in the secondary surgery, thus in secondary procedures, selective surgery should be performed under guidance of an imaging modality. The surgical strategy should be determined to achieve maximum cure with minimum dissection and minimal morbidity. In this study, we aimed to determine the type of surgical treatment and pHPT patients suitable for the surgical treatment.

Outcomes of Parathyroidectomy in Patients with Primary Hyperparathyroidism: A Systematic Review and Meta-analysis

BACKGROUND

Parathyroidectomy is a definitive treatment for primary hyperparathyroidism. Patients contemplating this intervention will benefit from knowledge regarding the expected outcomes and potential risks of the currently available surgical options.

PURPOSE

To appraise and summarize the available evidence regarding benefits and harms of minimally invasive parathyroidectomy (MIP) and bilateral neck exploration (BNE).

DATA SOURCES

A comprehensive search of multiple databases (MEDLINE, EMBASE, and Scopus) from each database's inception to September 2014 was performed.

STUDY SELECTION

Eligible studies evaluated patients with primary hyperparathyroidism undergoing MIP or BNE.

DATA EXTRACTION

Reviewers working independently and in duplicate extracted data and assessed the risk of bias.

DATA SYNTHESIS

We identified 82 observational studies and 6 randomized trials at moderate risk of bias. Most of them reported outcomes after MIP (n = 71). Using random-effects models to pool results across studies, the cure rate was 98 % (95 % CI 97-98 %, I (2) = 10 %) with BNE and 97 % (95 % CI 96-98 %, I (2) = 86 %) with MIP. Hypocalcemia occurred in 14 % (95 % CI 10-17 % I (2) = 93 %) of the BNE cases and in 2.3 % (95 % CI 1.6-3.1 %, I (2) = 87 %) with MIP (P < 0.001). There was a statistically significant lower risk of laryngeal nerve injury with MIP (0.3 %) than with BNE (0.9 %), but similar risk of infection (0.5 vs. 0.5 %) and mortality (0.1 vs. 0.5 %).

LIMITATIONS

The available evidence, mostly observational, is at moderate risk of bias, and limited by indirect comparisons and inconsistency for some outcomes (cure rate, hypocalcemia).

CONCLUSION

MIP and BNE are both effective surgical techniques for the treatment of primary hyperparathyroidism. The safety profile of MIP appears superior to BNE (lower rate of hypocalcemia and recurrent laryngeal nerve injury).

A 20-year study on 190 patients with primary hyperparathyroidism in a developing country: Turkey experience

The aim of this study was to present our 20-year experience regarding primary hyperparathyroidism (PHPT). PHPT patients who underwent parathyroidectomy in our clinic were reviewed retrospectively. There were 190 PHPT patients, of whom 137 were asymptomatic (72%). The mean serum calcium at the time of diagnosis was 11.9 ± 2.2 mg/dL. The mean parathyroid hormone (PTH) level was 467 ± 78 pg/mL. Ultrasonography (USG) identified all abnormal glands accurately (82.6%) and Technetium-99m sestamibi scintigraphy (MIBI) was used in 89.4% of the patients and magnetic resonance imaging (MRI) in 61%. The common use of USG and MIBI detected 92% of the lesions. Bilateral neck exploration (BNE) was performed in 12.2% of the patients and focused unilateral neck exploration (FUNE) in the remaining 87.8%. Surgical intervention was unsuccessful in 1 patient (0.5%). The conversion ratio from FUNE to BNE was 5.2%. The mean operation time and mean hospital stay decreased significantly in patients with FUNE. Pathologic examination revealed single adenoma in 93% of the patients. New imaging techniques result in the conversion of surgical treatments of PHPT. FUNE in parathyroidectomy performed by an experienced surgeon may provide successful treatment rates.

Minimally Invasive Parathyroidectomy Versus Bilateral Neck Exploration for Primary Hyperparathyroidism

Primary hyperparathyroidism is a disease that is caused by excess parathyroid hormone (PTH) secretion from 1 or more of the parathyroid glands. Surgery is the only cure. Traditional surgical management consists of a 4-gland cervical exploration. Development of imaging specific to identification of parathyroid glands and application of the rapid PTH assay to operative management have made more minimal exploration possible. There are distinct advantages and disadvantages of minimally invasive parathyroidectomy (MIP) and bilateral neck exploration (BNE). The advantages of MIP seem to outweigh those of BNE, and MIP has replaced BNE as the operation of choice by many surgeons.

No Need to Abandon Focused Unilateral Exploration for Primary Hyperparathyroidism with Intraoperative Monitoring of Intact Parathyroid Hormone

BACKGROUND

We investigated the rate of persistent and recurrent hyperparathyroidism after focused unilateral exploration (UE) with intraoperative monitoring of intact parathyroid hormone (IOPTH).

STUDY DESIGN

A prospective cohort of 915 patients with primary hyperparathyroidism (PHP) underwent parathyroid surgery by a single surgeon from January 2003 to September 2013. A total of 556 patients with at least a single positive preoperative localization by ultrasound (US) and/or sestamibi scan (STS) underwent UE with IOPTH. The criterion for completion of surgery was an IOPTH fall of 50% from the highest intraoperative level and into the normal range 5 to 10 minutes after resection of the localized gland.

RESULTS

Fifteen patients had either persistent or recurrent PHP, yielding a 2.7% (95% CI 1.6% to 4.4%) overall recurrence rate based on the refined Wilson method with continuity correction. Four patients had persistent PHP. Three of these patients were cured with reoperation, and the fourth patient was followed nonoperatively. Eleven patients had recurrent PHP, with 5 corrected by surgery and 6 patients followed nonoperatively. The mean postoperative serum calcium (Ca) level was 9.4 mg/dL over a mean follow-up interval of 44.0 months. Preoperative localization rates by each localization study were: US 74.3% (n = 413), STS 86.9% (n = 483), and US and STS 71.4% (n = 397). There was no difference in the preoperative study that localized the hyperfunctional parathyroid gland in recurrent vs nonrecurrent patients by the Fisher's exact test (US, p =1.00; STS, p =0.65; US and STS, p =1.00).

CONCLUSIONS

The low rate of recurrent PHP after focused unilateral exploration with IOPTH suggests that this procedure should not be abandoned.

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.

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.

Parathyroidectomy in a district general hospital: outcomes and evolution in the era of minimally invasive surgery

AIM

To determine the outcomes of bilateral neck exploration (BNE) and uptake as well as outcomes of minimally invasive parathyroidectomy (MIP) for primary hyperparathyroidism in a district general hospital (DGH).

METHODS

Patients who underwent first-time parathyroidectomy for primary hyperparathyroidism between August 1999 and December 2010 were identified from a prospectively maintained database of a single surgeon and were analysed for outcomes of MIP and BNE. MIP was adopted in 2006 and prior to that all patients underwent BNE. Results were analysed on an intention-to-treat basis.

RESULTS

A total of 368 patients underwent parathyroid surgery; BNE (n = 314) and MIP (n = 54). Overall cure rate was 97%. Intention-to-treat analysis, based on surgical approach, showed cure rates of 96.5% with BNE and 96.3% with MIP (p = 1.0). Of the 92 patients assessed for MIP, localisation by ultrasound and sestamibi were noted in 60 (65%) and 65 (71%) patients respectively; however, concordance between the scans was noted in only 54 (59%) patients. Of the 54 patients who underwent MIP, 5 (9.2%) were converted to BNE. Intention-to-treat analysis, based on preoperative imaging, showed cure rates of 96% with BNE and 98% with MIP (p = 0.53).

CONCLUSIONS

Satisfactory cure rates for parathyroidectomy are achievable in a 'medium-volume' endocrine unit within a DGH. Preoperative localisation studies with USS and MIBI have a positive concordance rate in only 60% of those considered for MIP, thereby limiting the use of MIP and reinforcing the role of BNE in this era of minimally invasive surgery.

A predictive model of suitability for minimally invasive parathyroid surgery in the treatment of primary hyperparathyroidism [corrected]

BACKGROUND

Improved preoperative localizing studies have facilitated minimally invasive approaches in the treatment of primary hyperparathyroidism (PHPT). Success depends on the ability to reliably select patients who have PHPT due to single-gland disease. We propose a model encompassing preoperative clinical, biochemical, and imaging studies to predict a patient's suitability for minimally invasive surgery.

METHODS

For the purposes of the present study, 180 consecutive patients were included for analysis. A 5-variable model based on preoperative ionized serum calcium (>1.4 mmol/l), intact parathyroid hormone level (≥ 2 times the upper limit of normal), positive sestamibi scan for a single affected gland, positive ultrasound scan for a single gland, and concordance between the two imaging modalities for single-gland disease at a similar location was employed, where a score of 1 was allocated for each variable present.

RESULTS

Of the 180 patients, 62 (34%) underwent bilateral exploration, 63 (36%) underwent unilateral exploration, and 55 (30%) underwent minimally invasive parathyroidectomy. The results showed that 92% had single-gland disease, 3% had double adenomas, and 5% had hyperplasia. Biochemical cure was achieved in 98.9%. Mean follow-up was 153 days (range: 80-342 days). With the predictive scoring model, a score of ≥ 3 had a positive predictive value of 100% for single-gland disease.

CONCLUSIONS

A scoring model encompassing preoperative biochemical and imaging data can be successfully employed to predict suitability for minimally invasive surgery in the majority of patients with single-gland disease.

Intrathyroid adenomas in primary hyperparathyroidism: are they frequent enough to guide surgical strategy?

BACKGROUND

Ectopic parathyroid adenoma, including intrathyroid adenoma, is a common cause of failed parathyroid operations. The aim of this study was to evaluate the operative strategy/outcome in patients with primary hyperparathyroidism (pHPT), with special regard to intrathyroid adenomas.

METHOD

The authors performed an analysis of all patients receiving operative treatment for pHPT from 2003 through 2005. The operative strategy consisted of systematic perithyroid exploration followed by extended cervical exploration in cases where the adenoma was not found initially. In cases of persistent, high intraoperative parathyroid hormone levels, hemithyroidectomy was performed on the side with higher suspicion of intrathyroid adenoma or with more extended thyroid changes.

RESULTS

During the study, 115 patients received surgical treatment for sporadic pHPT. A single parathyroid adenoma (normal parathyroid position) was found in 95 patients (82.6%), ectopic single adenoma was found in 7 patients (6.1%), and double adenomas were found in 10 (8.7%) patients. Operative failure occurred in 3 cases (2.6%). In all, 4 of 7 ectopic single adenomas were intrathyroidal and were removed by hemithyroidectomy according to the authors' standard protocol.

CONCLUSION

The strategy of (a) cervical exploration, (b) extended cervical exploration, and (c) hemithyroidectomy was highly successful for removing undetectable intrathyroid parathyroid adenomas during primary intervention, thereby reducing the risks associated with reintervention.

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.

Minimally invasive surgery for primary hyperparathyroidism with or without intraoperative parathyroid hormone monitoring

We analyzed the utility of intraoperative parathyroid hormone (IOPTH) monitoring in minimally invasive surgery for primary hyperparathyroidism (pHPT). The subjects were the 167 consecutive patients with pHPT performed initial operation with or without IOPTH between January 2000 and December 2006. Patients were divided into 2 groups. A group who underwent surgery without IOPTH monitoring (Group 1; n=87), and a group who underwent surgery with IOPTH monitoring (Group 2; n=80), in which IOPTH was measured at 5, 10, 15 minutes after excision of the abnormal parathyroid gland. Criterion for evaluation as a cure was a drop in intact PTH level of 50% or more from the preoperative baseline value. The overall cure rate in Group 1 was 93.1%. An enlarged parathyroid gland that was consistent with the results of a preoperative imaging study was found in 84 patients (96.6%). The overall cure rate in Group 2 was 97.5%. In 7 of the patients, there was no drop of 50% or more at any of the 3 points in time measured. Two of these patients were found to have had double adenomas, one on each side, during the initial surgery. Three others were eucalcemic and had normal intact PTH values after surgery, and the remaining 2 patients had persistent disease. Although preoperative localization studies are accurate and essential, IOPTH monitoring improves the cure rate of minimally invasive parathyroidectomy. IOPTH monitoring is a valuable adjunct to achieve adequate intraoperative decision-making, recognizing and resecting additional image-negative hyperfunctioning lesions.

Surgical strategy for sporadic primary hyperparathyroidism an evidence-based approach to surgical strategy, patient selection, surgical access, and reoperations

PURPOSE

Progress in parathyroid imaging has brought substantial changes in the surgical strategy to approach patients with sporadic primary hyperparathyroidism (pHPT). The present review is focused on the safety and efficacy of limited parathyroid exploration.

MATERIALS AND METHODS

Review of the literature focused on studies dealing with unilateral (two-gland exploration) or selective parathyroidectomy (one-gland exploration) in selected patients with pHPT and on the classification of published reports according to the degree of evidence.

RESULTS

Parathyroid exploration limited to a solitary parathyroid adenoma can be considered a minimally invasive procedure that can be performed by the minicervicotomy, video-assisted, or endoscopic approaches. In properly selected patients, it affords results comparable to those of four-gland bilateral exploration in terms of cure and recurrence. It causes less postoperative hypocalcemia.

CONCLUSIONS

Selective parathyroidectomy is an option for patients with positive preoperative localization tests undergoing first-time surgery who have no family history of pHPT, no goiter for which surgical therapy is proposed, and are not on lithium therapy.

Predicting the success of limited exploration for primary hyperparathyroidism using ultrasound, sestamibi, and intraoperative parathyroid hormone: analysis of 1158 cases

OBJECTIVE

The aim of this study was to determine the success of limited neck exploration (LE) for primary hyperparathyroidism (1 degrees HPT).

METHODS

Between 1999 and 2007, 1407 patients with hyperparathyroidism underwent bilateral neck exploration (BE). Of these, 1158 patients with first-time sporadic 1 degrees HPT were analyzed prospectively. Based on surgeon-performed ultrasound (US) and sestamibi scan (MIBI), LE was initially performed. Regardless of results, BE followed to identify the presence of additional parathyroid pathology.

RESULTS

Of 1158 patients, 242 (21%) were found to require concomitant thyroid surgery thus excluding LE. Of the remaining 916 patients, a single abnormal gland was identified on MIBI in 682 (74%), US in 731 (80%), and concordance of both in 588 (64%). Unsuspected multiglandular disease (MGD) was identified at BE in 22%, 22%, and 20% of patients, respectively. Adding intraoperative parathyroid hormone sampling (IOPTH) further reduced the rate of unsuspected MGD to 16%, 17%, and 16%. Overall, IOPTH correctly predicted MGD in only 22%. Neither concomitant nonsurgical thyroid disease nor more stringent selection criteria (preop Ca>11 mg/dL and PTH>120 pg/dL) altered success rates. In patients with MGD, a subsequent gland identified was larger than the index gland in 23%. Ninety-eight percent of BE patients were cured of 1 degrees HPT.

CONCLUSIONS

This is the largest study to evaluate the prevalence of additional parathyroid pathology in patients who are candidates for LE. Limitations in localizing studies and IOPTH fail to identify MGD in at least 16% of patients, risking future recurrence.