Unilateral neck exploration under local anesthesia: the approach of choice for asymptomatic primary hyperparathyroidism

Combined ultrasound and Sestamibi scintigraphy provides accurate preoperative localisation for patients with primary hyperparathyroidism

INTRODUCTION

Minimally invasive parathyroidectomy has advantages over the traditional bilateral neck exploration for the surgical treatment of primary hyperparathyroidism. It requires accurate localisation of the parathyroid pathology prior to surgery. The best method of preoperative localisation in a district general hospital setting is not well understood.

METHODS

All patients who underwent parathyroidectomy for primary hyperparathyroidism from 2008 to 2016 were identified from a prospectively maintained database. Operative findings were correlated with radiological and histological results. Sensitivity and specificity of ultrasound, sestamibi scintigraphy and the two together were calculated for diagnostic precision and compared.

RESULTS

One hundred and eighty-four patients met the inclusion criteria, of whom 81.5% had a histological diagnosis of a parathyroid adenoma. Ultrasound had higher sensitivity than sestamibi scintigraphy. Used together, ultrasound and sestamibi scintigraphy performed better than either ultrasound or sestamibi scintigraphy alone (P< 0.001). Twenty-two of 184 cases had no lesion located by either ultrasound or sestamibi scintigraphy preoperatively. Where neither ultrasound nor sestamibi scintigraphy located the lesion, additional computed tomography led to the excision of parathyroid pathology in one in ten patients.

CONCLUSION

The combination of ultrasound and sestamibi scintigraphy provides the highest sensitivity of preoperative localisation. This approach led to a high success rate of minimally invasive parathyroidectomy. Where preoperative localisation is not achieved with ultrasound or sestamibi scintigraphy, computed tomography adds little additional benefit. In this setting other modalities of localisation such a selective venous sampling, intraoperative methylene blue or intraoperative parathyroid hormone levels could be considered.

Focused Parathyroidectomy Under Local Anesthesia - A Feasibility Study

PURPOSE

We conducted this study to evaluate the feasibility, patient satisfaction, and cost of performing focused parathyroidectomy under local anesthesia (LA) and mild sedation, administered and monitored by a surgeon.

MATERIALS AND METHODS

This was a prospective observational study of 30 patients with primary hyperparathyroidism (PHPT) undergoing a focused parathyroidectomy under LA and mild sedation at a single institution. The clinical features, gland weight, operating time, procedure time, postoperative pain scores, overall patient satisfaction, postoperative nausea and vomiting, analgesic requirements, complications, cost, and cure rates were documented. Data were analyzed using SPSS software version 17.0.

RESULTS

In two patients (6.7%), the procedure had to be completed under general anesthesia (GA). Postoperative temporary hypocalcemia was witnessed in 14 of 30 (46.7%), but only 1 required intravenous calcium infusion. About 21 of 30 (75%) were completely satisfied with LA, whereas 25 of 30 (89%) were completely satisfied with surgical procedure. Furthermore, all patients were keen to recommend this procedure under LA to their friends and family. Comparing the cost between performing the procedure under LA with that under GA, a significant difference was witnessed (P = 0.001). Among the 26 patients reviewed at 6 months, all had a normal serum calcium and parathyroid hormone levels indicating 100% cure rate.

CONCLUSION

Performing focused parathyroidectomy under LA is feasible; additionally, this method can significantly reduce the cost of the procedure (P = 0.001).

Intraoperative PTH: Effect of sample timing and vitamin D status

Objective

To assess the effect of timing of intraoperative parathormone (iPTH) samples and 25-hydroxyvitamin D (25-OHD) status on decision-making during parathyroidectomy.

Methods

A total of 77 patients with primary hyperparathyroidism and iPTH levels (preincision, preremoval, 5 (T5) and 10 (T10) minutes postremoval) performed during parathyroidectomy were reviewed.

Results

Forty-one percent of patients were 25-OHD insufficient. We noted a significant correlation between preoperative 25-OHD and preincision iPTH ( P = 0.002) but not iPTH at postremoval levels (T5, P = 0.89; T10, P = 0.42). When compared with preincision iPTH, the use of either the higher preincision or preremoval iPTH baseline significantly improves the assay sensitivity from 83% to 93% at T5 ( P = 0.01) and 87% to 97% at T10 ( P = 0.02). Surgical cure was obtained in 98% of patients.

Conclusion

Obtaining preremoval iPTH allowed earlier decision with respect to operative completion in 38% of cases. 25-OHD status does not appear to significantly affect interpretation of iPTH levels.

Significance

Obtaining both baseline levels significantly improves sensitivity in iPTH monitoring. © 2007 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Parathyroid surgery: correlation between pre-operative localization studies and surgical outcomes

OBJECTIVE

Pre-operative imaging techniques have enabled minimally invasive parathyroid surgery to supersede the traditional approach to hyperparathyroidism (HPT) surgery, which included cervical exploration. Cervical ultrasound (US) and sestamibi scan (MIBI) are commonly performed, but the results of these localization tests do not always match. This study correlated surgical outcomes with pre-operative localization findings, including matched positive US and MIBI studies, one positive study (US or MIBI), conflicting studies or negative results.

DESIGN

Retrospective medical record review.

PATIENTS

A hundred and sixty nine consecutive patients who underwent parathyroidectomy from January 2005 to December 2012.

MEASUREMENTS

Correlation between surgical outcomes and pre-operative localization tests.

RESULTS

All patients (134F/35M, 59·6 ± 13·5 years of age) had primary HPT. US and MIBI localization studies matched in 76%, whereas 10·7% had positive MIBI only and 8·3% US only. Studies were negative in 3·6% and contradictory in 1·8%. Minimally invasive parathyroidectomy was performed in 87% of the matched group and 89% of the MIBI-only group. Surgical success rate, defined as postoperative normalization of calcium and PTH levels, was similar in patients with a single positive study (MIBI or US) vs double-matched studies (MIBI and US). Patients were followed up for 6 weeks. Overall, pathology was consistent with adenoma in 95%.

DISCUSSION

Parathyroidectomy success rate was similar in patients with primary HPT and MIBI-only or US-only positive localization studies compared to those with matched US/MIBI studies. The results support a clinical algorithm in which positive results from one imaging technique, either MIBI or US, are sufficient to refer a patient for parathyroid surgery.

Identification of pathological and normal parathyroid tissue by fluorescent labeling with 5-aminolevulinic acid during endocrine neck surgery

BACKGROUND

When performing parathyroid or thyroid surgery, surgeons must distinguish parathyroid tissue from the surrounding thyroid tissue, to preserve healthy parathyroid tissue while excising diseased thyroid tissue or to completely remove pathological parathyroid lesions. Here, we explored the feasibility of labeling the parathyroid glands for easy identification by administering 5-aminolevulinic acid (5-ALA) orally to patients undergoing endocrine neck surgery, because 5-ALA accumulates in the parathyroid and has a fluorescent metabolite, protoporphyrin IX.

METHODS

Twenty-nine patients about to undergo endocrine (parathyroid or thyroid gland) neck surgery were orally given 5-ALA, a nontoxic substance that occurs naturally in the human body and has no known major side effects. During surgery, we used blue light to excite protoporphyrin IX, the fluorescent metabolite of 5-ALA, and viewed the resulting bright red fluorescence through an optical filter.

RESULTS

In the majority of the patients, the parathyroid glands were defined by a clear fluorescence. In 23 patients with pathological parathyroid tissue, the fluorescence enabled us to identify and completely remove diseased parathyroid tissue. In 3 patients with thyroid disease, we were able to easily remove diseased thyroid tissue, and an accidentally removed parathyroid gland was autotransplanted during surgery.

CONCLUSIONS

In all but a few cases, 5-ALA clearly labeled parathyroid tissue, allowing for its clean removal or preservation according to the purpose of the surgery. This simple, benign technique is extremely useful for identifying parathyroid tissue, whether pathological or normal, during endocrine neck surgery.

Rapid intraoperative determination of intact parathyroid hormone during surgery for primary hyperparathyroidism. Experience at our center

INTRODUCTION

Primary hyperparathyroidism (PHPT) is due to a single adenoma in 85%-95% of cases, and is often cured after adenoma removal. Intraoperative rapid determination of intact parathyroid hormone (PTHio) may be a tool for monitoring the effectiveness of PHPT surgery. The main objective of our study was to evaluate PTHio determination and to establish whether its successful implementation contributed to achieve minimally invasive surgery (MIS) and major ambulatory surgery (MAS) in the treatment of PHPT.

MATERIAL AND METHODS

Retrospective study of a consecutive series of patients diagnosed and operated on for PHPT at the University General Hospital of Ciudad Real between January 2005 and January 2012.

RESULTS

In the study period, 91 patients underwent surgery. 39 (42.9%) under general anesthesia, while 52 (57.1%) were candidates for regional anesthesia by cervical block. Seventy-six of all patients (83.5%) were amenable to MIS using a unilateral approach. Classical cervicotomy was performed in all other patients. PTHio determination was done in 75 patients, showing cure in the same surgery in 68 of them. MAS was performed in 70.3% (64) of patients.

CONCLUSIONS

Determination of PTHio may allow for changing the surgical approach to PHPT at our department, allowing for performance of MIS on an outpatient basis in a significant proportion of patients with some cosmetic improvement, probably less pain, shorter hospital stay, and less potential complications than bilateral cervical exploration.

Safety and efficacy of minimally-invasive parathyroidectomy (MIP) under local anaesthesia without intra-operative PTH measurement

BACKGROUND

Minimally invasive parathyroidectomy (MIP) is the choice of treatment in patients with sporadic adenomas localized on preoperative imaging. Currently there is no centre in the UK which performs this procedure under local anaesthesia. The aim of this study was to assess the efficacy and safety of MIP under local anaesthesia in patients with sporadic primary hyperparathyroidism (pHPT).

METHODS

This is a prospective, nonrandomized study of 86 patients with pHPT localized with Tc99m Sestamibi scan and ultrasound. MIPs were performed under local anaesthesia and sedation at the Oxford University Hospitals. Serum Ca and PTH were measured before discharge, at 6 weeks follow up, and at 6 months. Main outcome measures were cure at 6 months, complications with the procedure and operative time.

RESULTS

86 patients (58 females: 28 males) with a mean age of 65 (range 24-87) underwent MIP under local anaesthesia and sedation. All patients (100%) were normocalcaemic at 6 months following surgery. There was no incidence of temporary or permanent recurrent laryngeal nerve palsy or persistent hypercalcaemia. Two patients had temporary hypocalcaemia that resolved in 6 weeks. In one patient the neck incision needed extension for bleeding, with no incidence of wound haematoma or infection.

CONCLUSION

This study demonstrates that MIP (without ioPTH) can be safely performed under local anaesthesia for patients with sporadic primary hyperparathyroidism.

Minimally invasive parathyroidectomy in patients with previous endocrine surgery

Minimally invasive parathyroidectomy with a lateral approach was found to be an acceptable option in select patients with sporadic primary hyperparathyroidism and previous endocrine neck surgery.

Objective:

Previous endocrine neck surgery (PENS) in patients with sporadic primary hyperparathyroidism (PHP) is considered a contraindication for minimally invasive parathyroidectomy (MIP). The purpose of our study was to determine the effectiveness of MIP in such patients.

Methods:

From January 2004 to December 2009, 270 patients with PHP were treated in our department; 30 had had PENS in the past. Eighteen were selected to have MIP, while the other 12 had traditional neck explorations. Selection criteria for MIP were unilateral single- or double-gland disease localized preoperatively with at least 2 concordant imaging techniques and patient informed consent. Imaging studies included high-resolution neck ultrasound and sestamibi scan in most patients, and CT scan, selective venous sampling, and MRI in 7 patients. Unilateral explorations via a lateral approach with the patients under local (UALA in 13 patients), general (MIP in 4 patients), or local followed by general anesthesia (1 patient) were performed.

Results:

Sixteen of the 17 patients became normocalcemic after the operation. There was no conversion to traditional exploration. A single adenoma was found in 16 patients and hyperplasia in one. One patient underwent a successful parathyroidectomy 8 months later via mesothoracoscopy, because the parathyroid gland was localized correctly but was beyond access via neck. There were no postoperative complications. Mean duration of the procedure and length of stay were similar to MIP in patients without PENS. Mean follow-up of 33 months (range, 4 to 70) did not reveal any recurrence.

Conclusion:

These results illustrate that MIP is a valuable option in select patients with sporadic PHP and PENS. Localization with 2 or more concordant imaging techniques could avoid intraoperative sestamibi or qPTH testing with low morbidity (0%), high biochemical cure rate (100% in this series), rapid recovery, and finally substantially lower the cost of the procedure.

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.

Successful removal of intrathyroidal parathyroid adenoma diagnosed and accurately located preoperatively by parathyroid scintigraphy (SPECT-CT)

We describe the case of a large intrathyroidal parathyroid adenoma in a 46-year-old woman who had a history of recently diagnosed hypercalcaemia and a 2-year history of an asymptomatic enlargement of the right lobe of the thyroid. This rare case highlights the potential difficulties that can arise in the evaluation of hyperparathyroidism, especially in cases of multinodular goiter. In some cases, including this one, even a thorough preoperative evaluation that includes radiological studies (ultrasonography and computed tomography [CT]) may not allow for a definitive preoperative diagnosis due to limited sensitivity, especially in multinodular goiter. The overlapping histological features between thyroid and parathyroid lesions can also be problematic at the time of the intraoperative frozen-section evaluation. We present a case in which, with parathyroid scintigraphy and combination of structural and functional imaging (SPECT-CT), we could accurately locate the intrathyroidal parathyroid adenoma in a patient with multinodular goiter.

[Biology of primary hyperparathyroidism: selective venous sampling]

The diagnosis of primary hyperparathyroidism (PHP) is chemical: high level of Parathormone (PTH) in conjunction with hypercalcaemia. In borderline cases with sub-normal plasma PTH and calcium, an oral calcium load test could allow a differential diagnosis from other causes of high PTH. Imaging is required only for PHP. Selective venous sampling can help in localizing a parathyroid adenoma in difficult cases by PTH cartography in the following situations: imaging in favour of an ectopic mediastinal gland or a deep cervical adenoma, persistent or recurrent PHP after first failed surgery with negative neck exploration or unsatisfactory in case of another hypersecreting gland, PHP well diagnosed with indeterminate imaging, symptomatic PHP with normal PTH and negative imaging. Venous blood sampling performed in a vascular radiological department with a quick PTH assay can reveal an area of maximum secretion potentially linked to a nodule localized by previous ultrasound coupled to scintigraphy, giving thus a "biological imaging" study. The association of imaging and biology is an efficient procedure enabling localization of an area of abnormal PTH secretion and characterization of the level of PTH secretion. The area with the highest gradient of PTH concentration can help to protocol CT and MR examination.

Role of cervical ultrasonography in primary hyperparathyroidism

AIM

To evaluate the role of USG in the preoperative localization of parathyroid adenomas in patients with symptomatic hyperparathyroidism and to compare its usefulness with that of scintigraphy scan and postoperative findings.

MATERIAL AND METHODS

Twenty-five patients with symptomatic primary hyperparathyroidism were subjected to USG of the neck and nuclear scintigraphy, followed by surgery. The results were independently analyzed and compared with per-operative findings.

RESULTS

The 25 patients had a total of 28 abnormal glands: 22 solitary adenomas, and 6 multiple adenomas (two each in three patients). USG detected 20 out of 22 solitary adenomas and three out of six multiple adenomas. USG missed five abnormal glands, two of which were in the neck and three in the mediastinum. Scintigraphy was positive in 26 abnormal glands, out of which 22 were single and four were multiple. Two abnormal glands were missed: one in the neck and one in the mediastinum.

CONCLUSION

As limited neck dissection for primary hyperparathyroidism becomes increasingly popular, USG has been found to be a sensitive, specific, and easily available noninvasive investigation for parathyroid localization. It can be easily offered to patients as a method for preoperative localization prior to limited parathyroid surgery outside tertiary care settings.

[Treatment of primary hyperparathyroidism at Cochin hospital (Paris). Changes in procedures during the last thirty years]

The association of high performance techniques and low morbidity has enabled the development of preventive surgery for hyperparathyroidism. Over the last 30 years, 2500 patients have undergone this type of procedure at the Visceral Surgery Unit of the Cochin Hospital in Paris. This experience has enabled us to achieve the current concept of surgical treatment for primary hyperparathyroidism, particularly with the development of minimally invasive techniques performed under local anesthesia. The promotional role played by our institution over the last 30 years in this area has enabled sturdy evidence-based reflection. The report of the work accomplished would not be complete without the story of the rich adventure which began in the 19th century. We propose here a review of the major advance achieved in order to better apprehend the principles currently regulation our approach to surgery of the parathyroid glands.

A "defined baseline" in PTH monitoring increases surgical success in patients with multiple gland disease

BACKGROUND

Parathyroid hormone (PTH) monitoring with a quick intact PTH (QIPTH) assay is used in minimally invasive exploration for primary hyperparathyroidism (PHPT) in order not to miss multiple gland disease (MGD). Controversy exists on which criterion is most reliable to predict cure.

METHODS

QIPTH values of 310 consecutive patients (single gland disease [SGD]: n = 289; MGD: n = 21) with sporadic PHPT were analyzed using 3 different criteria: "Vienna Criterion": >/=50% decay from a defined "baseline" level (right after induction of anesthesia before skin incision) 10 min after excision. "Miami Criterion": >/=50% decay from highest (preincision or preexcision) value 10 min after excision; "Halle Criterion": decay of the PTH- level to less than or equal to 35 pg/mL within 15 min after excision.

RESULTS

The "Vienna" and "Halle Criteria" correctly detected MGD in 19 (91%) and the "Miami Criterion" in 12 (57%) of 21 patients. Incorrect prediction of incomplete excision occurred in 22 patients (8%) with SGD, using the "Vienna Criterion" ("Miami Criterion": 2%, "Halle Criterion": 29%). All of these were recognized intraoperatively from unintended intraoperative manipulation (n = 18), technical failure (n = 2), or borderline increased PTH values (n = 2), and they did not lead to bilateral exploration. Analyzing patients with SGD and MGD, accuracy and specificity were 92% and 89% for the "Vienna Criterion," 93% and 54% applying the "Miami Criterion," and 72% and 89% using the "Halle Criterion."

CONCLUSION

Strict definition of a PTH "baseline level" ("Vienna Criterion") improves intraoperative diagnosis of MGD, thus reducing reoperations and increasing long-term cure.

Diminished Dose Minimally Invasive Radioguided Parathyroidectomy: A Case for Radioguidance

Minimally invasive radioguided parathyroidectomy (MIRP) has been established as an alternative to bilateral neck exploration (BNE) for primary hyperparathyroidism. We investigate whether a diminished dose of technetium-99m sestamibi gives similar results to the standard dose. One hundred one patients were offered MIRP or diminished-dose MIRP (ddMIRP). Patients received intravenous Tc-99m sestamibi at a dose of either 25 mCi 1.5 hours or 5 mCi 1 hour preoperatively. The procedure was terminated when the 20 per cent rule was satisfied. All tissue was confirmed to be parathyroid tissue by frozen section analysis. In addition, intraoperative parathyroid hormone levels were measured in a majority of patients. Patients who failed IOM underwent BNE. Frozen section analysis and intraoperative parathyroid hormone monitoring were also performed in the BNEs. Postoperatively, serum calcium levels were measured at 1 week and 6 months. Fifteen per cent of patients were male and 85 per cent were female. The median age was 63 years (range, 25–89 years). The first 58 patients had the standard dose of 25 mCi, whereas 43 patients had ddMIRP. Six patients (10%) failed intraoperative mapping in the MIRP group and were found to have single-gland disease. Five patients (12%) failed intraoperative mapping in the ddMIRP group. However, two patients were identified to have multigland disease making the true failure rate of intraoperative mapping 7 per cent (three patients). Median operative times for MIRP, ddMIRP, and BNE were 40 minutes, 46 minutes, and 105 minutes, respectively. The 20 per cent rule was satisfied in 96 per cent of patients undergoing MIRP and 98 per cent of patients undergoing ddMIRP. Frozen section analysis and intraoperative parathyroid hormone monitoring did not result in a change in management. Median follow up was 193 days and serum calcium levels at 6 months were normal. Diminished-dose MIRP is a feasible alternative to standard-dose MIRP without compromising surgical outcomes.

Thyroid and Parathyroid Operations in Veterans Affairs and Selected University Medical Centers: Results of the Patient Safety in Surgery Study

BACKGROUND

There is increasing interest in surgical outcomes. The Patient Safety in Surgery (PSS) Study database was examined about thyroid and parathyroid procedures to determine risk factors for adverse outcomes and outcomes rates. Relative outcomes performance for the Veterans Affairs (VA) and private-sector populations was compared after risk adjustment.

STUDY DESIGN

Preoperative, operative, and postoperative data were analyzed for 7,082 patients: 2,814 VA patients and 4,268 private sector patients. Prevalence of risk or process factors was described. Occurrence rates and unadjusted odds ratios (OR) for adverse outcomes were calculated. Stepwise multiple logistic regressions were performed to model the impact of various factors on outcomes and to calculate the adjusted OR for any adverse event for the VA population compared with the private sector.

RESULTS

Overall mortality rate was 0.35% and 0.60% in the VA and 0.19% in the private sector. Overall rate of any adverse outcomes was 2.90% and 4.48% in the VA and 1.97% in the private sector. Adjusted OR for thyroid versus parathyroid operation was 0.94 (95% CI, 0.67-1.31). Adjusted OR for operation in the VA versus private sector was 1.25 (95% CI, 0.87-1.78).

CONCLUSIONS

Overall rates of mortality and any morbidity were low and consistent with previous reports. Based on adjusted OR, there was no significant difference in outcomes for thyroid versus parathyroid operation. Similarly, there was no apparent significant difference in surgical outcomes between the VA and private-sector groups after risk adjustment.

Parathyroidectomy monitored by intra-operative PTH: The relevance of the 20 min end-point

OBJECTIVES

RI-PTH measurements are a prerequisite for minimally invasive parathyroidectomy, providing guidance regarding the removal of hyper-functioning tissue. Different criteria of PTH decrease, concentration and clearance were analyzed in order to predict surgical treatment.

DESIGN AND METHODS

Blood samples at pre-incision, manipulation, 5, 10 and 20 min after resection, were collected from 145 patients presenting unambiguous, pre-surgical "single adenoma" diagnosis.

RESULTS

The meeting of Irvin criterion would have permitted the identification of 28% uncured cases leading to 4% unnecessary neck exploration. On the contrary, we would have identified all of the uncured patients, to the detriment of 7% unnecessarily prolonged procedure by taking into account PTH drop, concentration and clearance shape at 20 min.

CONCLUSIONS

The 20' end-point plays a key role in the correct determination of surgical outcome, strongly improving the possibility of adequate patient treatment. However, since the high success rate of traditional parathyroidectomy, yet not provided by RI-PTH, the utmost improvement to hyper-parathyroidism surgical treatment by RI-PTH could be achieved in pre-operative equivocal glands localization or multiglandular disease selected population to quickly guide and confirm the complete removal of all hyper-secreting tissue.

Hyperparathyroidism in patients over 80: clinical characteristics and their ability to undergo outpatient parathyroidectomy

OBJECTIVE

Parathyroid surgery in elderly patients is commonly delayed due to perceived high operative risk. We evaluated the presentation of patients over 80 with primary hyperparathyroidism (PHPT) and their ability to tolerate outpatient, minimally invasive parathyroidectomy.

METHODS

We conducted a prospective cohort study of 150 consecutive patients over the age of 80 for the treatment of sporadic, nonfamilial PHPT. Presenting symptoms were compiled by questionnaire and compared between male and female (32 males, 118 females) and to 2600 patients under the age of 80. All patients underwent minimally invasive parathyroidectomy and were discharged from the recovery room. Operative findings and outcomes were assessed.

RESULTS

97% reported at least one symptom--the majority had five or more. The most common symptoms were fatigue, hypertension, and memory problems (occurring in 62%, 62%, and 57% of patients, respectively). Symptoms were similar between men and women, with the exception of bone pain being twice as common in women and kidney stones being twice as common in men (both p < 0.05). Preoperative calcium and parathyroid hormone (PTH) levels as well as the frequency of each symptom closely paralleled those of patients less than 80 years old with no significant differences. Average operative time was 18 +/- 5 minutes with discharge averaging 1.9 +/- 0.2 hours later. The incidence of single adenoma, double adenoma, or hyperplasia was identical to patients less than 80 (p = NS). Two patients required rehospitalization within 30 days of the procedure (congestive heart failure and pulmonary embolism), neither one for hypocalcemia. There were no deaths, and the cure rate was 99.3%.

CONCLUSION

PHPT is similar symptomatically, biochemically, and histopathologically between patients > 80 years old and younger patients. Modern techniques allow for small incisions, quick operative times, outpatient discharge, and uneventful recovery. Patients over 80 years old tolerate outpatient parathyroidectomy without event.

[Influence of quick intraoperative measurements of intact parathyroid hormone in the surgical management of primary hyperparathyroidism]

OBJECTIVE

To evaluate whether a quick parathyroid hormone assay that measures intact parathyroid hormone (iPTH) level intraoperatively has modified the surgical strategy for primary hyperparathyroidism in the Meixoeiro Hospital in Vigo (Pontevedra, Spain).

DESIGN

An observational, analytic, historic cohort study was performed. Two study groups were established. In group 1 (n = 28) iPTH levels were not measured intraoperatively. In group 2 (n = 39) iPTH was measured intraoperatively. iPTH was monitored using blood samples from cannulated peripheral veins. A positive test was defined as a decrease in iPTH level of >or= 50% of the baseline preincision level at 10 minutes postexcision, even when the baseline value was outside the normal range. The dependent variables evaluated were operating time, the number of parathyroid glands visualized, the number of parathyroid glands biopsied, length of postoperative hospital stay, unilateral exploration, and the percentages of cure, persistence, and recurrence in each group.

RESULTS

Group 2 showed a statistically significant decrease in operating time (144.7 +/- 62.1 versus 178.8 +/- 57.5 minutes; p = 0.025), the number of parathyroid glands visualized (1.9 +/- 0.9 versus 2.8 +/- 1.3; p = 0.002), the number of parathyroid glands biopsied (1.5 +/- 0.9 versus 2.2 +/- 1.4; p = 0.025), and the need for bilateral exploration (30.77% versus 85.72%) in comparison with group 1. No significant differences were observed in length of postoperative hospital stay or in the percentages of cure (94.8% versus 92.85%), persistence (5.12% versus 7.14%), and recurrence (2.56% versus 3.57%).

CONCLUSIONS

In our hospital, intraoperative measurement of iPTH improved the surgical strategy of primary hyperparathyroidism and has therefore been included in our routine treatment protocol.

[Utility of methoxy isobutyl isonitrile (MIBI) scintigraphy, ultrasound and computerized axial tomography in preoperative topographic diagnosis of hiperparathyroidism]

OBJECTIVES

1. To assess the sensitivity of scintigraphy using methoxy isobutyl isonitrile (MIBI). 2. To compare its resolution with that of ultrasound (US) and computerized axial tomography (CAT). 3. To use its diagnostic reliability to determine whether selective approaches can be used to treat hyperparathyroidism (HPT).

PATIENTS AND METHOD

A study of 76 patients who underwent surgery for HPT between 1996 and 2005 was performed. MIBI scintigraphy and cervical US were used for whole-body scanning in all patients; CAT was used in 47 patients. Intraoperative and postoperative biopsies were used for final evaluation of the tests, after visualization and surgical extirpation.

RESULTS

The results of scintigraphy were positive in 65 patients (85.52%). The diagnosis was correct in all of the single images. Multiple images were due to hyperplasia and parathyroid adenomas with thyroid disease (5.2%). Three images, incorrectly classified as negative (3.94%), were positive. The sensitivity of US was 63% and allowed detection of three MIBI-negative adenomas (4%). CAT was less sensitive (55%), but detected a further three MIBI-negative adenomas (4%).

CONCLUSIONS

1. The sensitivity of MIBI reached 89.46%. In the absence of thyroid nodules, MIBI diagnosed 100% of single lesions. Pathological thyroid processes produced false-positive results (5.2%) and there were diagnostic errors (4%). 2. MIBI scintigraphy was more sensitive than US and CAT. 3. Positive, single image scintigraphy allows a selective cervical approach. US and CAT may help to save a further 8% of patients (with negative scintigraphy).

Local/cervical block anesthesia versus general anesthesia for minimally invasive parathyroidectomy: what are the advantages?

BACKGROUND

Minimally invasive parathyroidectomy (MIP) under local/cervical block anesthesia (LA) is safe and effective for patients with primary hyperparathyroidism (HPT). Advantages of LA versus general anesthesia (GA) for these focused procedures have not been clearly demonstrated.

METHODS

Between 3/01 and 6/04, 177 consecutive patients with primary HPT and positive localization studies underwent MIP. Seventy-three (41%) had surgery under LA while 104 (59%) had GA. Primary endpoints were IV narcotic use, anti-emetic use, nausea, vomiting, and post-operative pain.

RESULTS

Patients who had parathyroidectomy under LA were older (64 +/- 2 vs. 57 +/- 2 years, P = 0.001). Cure and complication rates were identical between the two groups. Patients who had parathyroidectomy under LA required less IV narcotic pain mediation (mean morphine equivalents 11.4 +/- 1.3 mg vs. 22.5 +/- 1.1 mg; P < 0.001) compared to GA patients. The LA patients had better pain control as shown by lower post-operative peak pain scores (2.9 +/- 0.3 vs. 5.0 +/- 0.4; P < 0.001) and lower overall pain scores (mean 1.9 +/- 0.2 vs. 3.1 +/- 0.2; P < 0.001). The LA group required fewer anti-emetic medications compared to the GA patients (mean 0.4 +/- 0.1 vs. 1.7 +/- 0.1 doses; P < 0.001). Fewer LA patients experienced post-operative nausea (16% vs. 49%; P < 0.001), and vomiting (7% vs. 24%; P = 0.002). Length of stay was similar between the groups (0.4 +/- 0 vs. 0.3 +/- 0; P = 0.22).

CONCLUSIONS

In this study the choice of anesthesia did not affect surgical cure rate, morbidity, or length of stay. LA was associated with significantly lower post-operative pain, nausea, and vomiting. LA appears to offer specific advantages more than GA for patients undergoing MIP.

Ultrasonography in detection of single and multiple abnormal parathyroid glands in primary hyperparathyroidism: comparison with radionuclide scintigraphy and surgery

BACKGROUND

Among the parathyroid imaging techniques, ultrasonography (USG) has the advantage of convenience, easy availability and low cost.

OBJECTIVE

To study the role of USG in localization (side and/or site) of abnormal parathyroid glands in primary hyperparathyroidism (PHPT) and to compare with radionuclide scintigraphy and the 'gold standard', surgery.

METHODS

Forty-six consecutive patients undergoing USG of the anterior neck for a diagnosis of PHPT in whom a nuclear scan (technetium-99m sestamibi and/or thallium-201/technetium-99m pertechnetate scintigraphy) was also performed, were studied. The results of imaging were independently interpreted and correlated with reference to surgical findings.

RESULTS

Forty-six patients had 52 abnormal parathyroid glands on surgical exploration and surgery was successful in all but one. Forty-one patients had a single adenoma, four had multigland disease and one had a paraganglioma. USG correctly localized the abnormal gland in 30 (73%) and scintigraphy was positive in 40 (98%) out of 41 patients with a single adenoma as confirmed on surgical exploration. Scintigraphy showed a positive concordant test in all 30 patients with a single abnormal gland detected on USG and picked up 10 out of 11 abnormal glands where USG was negative. The sensitivity and positive predictive value of USG for detecting a single abnormal gland was 73% and 100%, respectively, whereas the sensitivity and positive predictive value for scintigraphy was 98%. In patients with multigland disease, USG missed 3 (30%) out of 10 and scintigraphy missed 6 (60%) out of 10 abnormal parathyroid glands as confirmed on surgical exploration (P < 0.05). However, in two patients who had ectopic parathyroid gland, both the modalities localized the lesion in one (paraganglioma), whereas in the other neither test was helpful (left retro-esophageal).

CONCLUSION

USG is a convenient, affordable and useful modality to localize abnormal enlarged parathyroid glands in the majority of patients with PHPT. However, when USG is negative, scintigraphy is complementary to it.

Appearance of intrathymic parathyroid adenomas on pinhole sestamibi parathyroid imaging

OBJECTIVES

Ectopic inferior parathyroid adenomas (PAs) are frequently located in the anterior mediastinum, quite often in the thymus gland. Correct preoperative localization is particularly helpful for surgical planning. Clinical follow up has shown that most intrathymic adenomas were visualized on pinhole views and located closer to the thyroid than expected. We reviewed the typical appearance of intrathymic PA on pinhole views.

METHODS

We retrospectively reviewed sestamibi pinhole parathyroid imaging performed on 163 patients with primary hyperparathyroidism and final diagnoses established by surgery, histology, intraoperative PTH monitoring, and clinical follow up. Studies showing focal increased activity in the lower pole region of the thyroid were selected and divided into 2 groups, group A (foci that are visually not separable from the thyroid) and group B (foci that are completely separated from the thyroid), and correlated with the final diagnoses.

RESULTS

Of the 163 patients, 102 had 103 clearly abnormal foci in the lower pole region (bilateral lower pole foci in one study). There were 93 foci in group A and 10 foci in group B. Of the 93 foci in group A, there were 80 normally situated inferior PA, 6 descended superior PA, 3 intrathyroidal PA, one hyperplastic parathyroid gland, one thyroid adenoma, one unidentified, and one intrathymic PA. Of the 10 foci in group B, 3 were eutopic inferior PA and 7 were intrathymic PA.

CONCLUSION

Focal increased activity completely separated from the lower pole of thyroid (regardless of the distance of separation) on sestamibi pinhole images indicates a high probability of intrathymic parathyroid adenoma.

Randomized clinical trial comparing regional and general anaesthesia in minimally invasive video-assisted parathyroidectomy

BACKGROUND

This randomized clinical trial was performed in a single institution to compare the results of minimally invasive video-assisted parathyroidectomy (MIVAP) conducted under regional anaesthesia (RA) or general anaesthesia (GA).

METHODS

Fifty-one patients undergoing MIVAP for primary hyperparathyroidism were assigned randomly to either RA (26 patients) or GA (25). RA involved a bilateral deep cervical block, and local infiltration of the incision site with a mixture of 0.25 per cent lignocaine and 0.15 per cent bupivacaine. GA was induced by intravenous administration of propofol, remifentanil and rocuronium bromide.

RESULTS

The two groups were matched for age, sex, adenoma size, and preoperative serum calcium and parathyroid hormone levels. The interval from skin incision to closure was similar in the two groups (27.6 and 25.8 min for RA and GA respectively), whereas the total operating time (from induction of anaesthesia to return to the ward) was significantly lower with RA (72.1 versus 90.2 min; P = 0.001). The postoperative requirement for pain medication, measured in terms of amount of ketorolac administered at the request of the patient, was significantly lower in the RA group (28.5 versus 80 mg/day; P < 0.001).

CONCLUSION

MIVAP performed under RA was associated with a shorter overall operating time and a reduced need for postoperative pain relief.

Parathyroid scintigraphy during hypocalcaemia in primary hyperparathyroidism

BACKGROUND

Minimally invasive parathyroid surgery in patients with primary hyperparathyroidism (PHPT) demands high imaging accuracy. By increasing blood flow to the parathyroid adenoma before injection of a perfusion marker, we intended to improve the parathyroid scintigraphy. We have named the technique stimulated parathyroid scintigraphy (SPS).

METHODS

Twenty minutes after injection of 100 MBq (99m)Tc-pertechnetate a thyroid scintigram was performed in 25 patients with PHPT. During the thyroid scintigraphy sodium citrate was infused which lowered plasma calcium by a mean of 14 +/- 1.3%. Then 700 MBq (99m)Tc-sestamibi was injected and another scintigram of the neck was obtained. Perchlorate was given at the end of the sestamibi scintigram to increase the wash-out of (99m)Tc-pertechnetate from the thyroid gland, and after 2 h a delayed scintigram was obtained. A subtraction of the thyroid scintigram from the initial sestamibi scintigram was performed. The results of SPS and a conventional (99m)Tc-sestamibi dual-phase parathyroid scintigraphy were compared with the operative findings. In nine patients the parathyroid adenoma was also localized with ultrasound and the flow pattern before and after citrate infusion was visualized with Doppler technique.

RESULTS

Eighty-eight per cent of the adenomas were localized correctly with the SPS technique compared with 62% at the conventional parathyroid scintigraphy. Tissue perfusion of the nine adenomas increased after citrate infusion.

CONCLUSIONS

SPS has a high accuracy and it is easy to perform. If only subtraction SPS is performed the whole examination can be completed within an hour, which is acceptable for same day surgery.

A systematic review of the diagnosis and treatment of primary hyperparathyroidism from 1995 to 2003

OBJECTIVE

To systematically review the current preoperative diagnostic modalities, surgical treatments, and glandular pathologies associated with primary hyperparathyroidism.

STUDY DESIGN

A systematic literature review.

RESULTS

Of the 20,225 cases of primary hyperparathyroidism reported, solitary adenomas (SA), multiple gland hyperplasia disease (MGHD), double adenomas (DA), and parathyroid carcinomas (CAR) occurred in 88.90%, 5.74%, 4.14%, and 0.74% of cases respectively. Tc 99m -sestamibi and ultrasound were 88.44% and 78.55% sensitive, respectively, for SA, 44.46% and 34.86% for MGHD, and 29.95% and 16.20% for DA, respectively. Postoperative normocalcemia was achieved in 96.66%, 95.25%, and 97.69% of patients offered minimally invasive radio-guided parathyroidectomy (MIRP), unilateral, and bilateral neck exploration (BNE). Intraoperative PTH assays (IOPTH) were helpful in approximately 60% of bilateral neck exploration conversion (BNEC) surgeries.

CONCLUSION

The overall prevalence of multiple gland disease (MGD and DA) was lower than often suggested by conventional wisdom. Furthermore, preoperative imaging was less accurate than it is often perceived for accurately imaging MGD. MIRP and UNE were more successful in achieving normocalcemia than is typically quoted. IOPTH was a helpful but not "fool-proof" adjunct in parathyroid exploration surgery.

SIGNIFICANCE

These results support a greater role for the treatment of primary hyperparathyroidism using less invasive approaches. EMB rating: B-3.

Conventional bilateral cervical exploration versus open minimally invasive parathyroidectomy under local anaesthesia for primary hyperparathyroidism

Background

Minimally invasive parathyroidectomy (MIP) has been introduced for the treatment of patients with primary hyperparathyroidism (pHPT). Thus far, only one randomized trial has compared video-assisted MIP with conventional bilateral cervical exploration (BCE). The value of open MIP is therefore not known.

Methods

Fifty patients with a solitary parathyroid adenoma localized before surgery by sestamibi scintigraphy were randomized to undergo BCE under general anaesthesia (n = 25) or targeted MIP via a 2-cm incision using local anaesthesia (n = 25). Postoperative hypocalcaemia was the primary endpoint. Secondary outcome measures were operating time, complications, postoperative analgesia and recurrent disease. Follow-up was carried out at 1 and 6 months.

Results

All patients who underwent BCE and 24 of those who had MIP were cured by the primary operation. Operating time was 22 min shorter in the MIP group (P = 0·024). Serum levels of calcium were slightly lower during the first 4 days after surgery in the BCE group (P = 0·022). No other no significant differences were found.

Conclusion

Targeted MIP using local anaesthesia reduces operating time and causes less postoperative biochemical hypocalcaemia compared with bilateral neck exploration.

Imaging for primary hyperparathyroidism--what beginners should know

For patients with primary hyperparathyroidism surgical removal of the hyperfunctioning parathyroid gland is curative. With advances in minimally invasive surgery, accurate pre-operative localization of the hyperfunctioning parathyroid tissue is essential to aid successful surgical treatment. The onus of identifying this hyperfunctioning parathyroid tissue therefore falls on imaging techniques such as high-resolution ultrasound, radionuclide imaging, computed tomography and magnetic resonance imaging. This article is not an exhaustive review, and its main aim is to familiarize the general radiologist, trainee radiologists and clinicians with the basics of various imaging techniques and their roles in practical management of patients with primary hyperparathyroidism.

Localization of Parathyroid Adenomas By 99mTc-Sestamibi Scanning: Upper Neck Versus Lower Neck Lesions

OBJECTIVE

To assess the diagnostic properties of (99m)Tc-sestamibi scanning (dual-phase technique) in patients with primary hyperparathyroidism and to establish the overall efficacy of this imaging technique for localization of an adenoma.

METHODS

The medical records of all 131 patients who underwent parathyroid scanning in a tertiary care center between January 1997 and December 2002 were reviewed. The surgical findings were used as the "gold standard" for the diagnosis of parathyroid pathologic conditions.

RESULTS

Primary hyperparathyroidism was diagnosed in 87 of the 131 patients (66.4%); of these, 76 underwent surgical treatment. In 44 patients, sestamibi scanning was also done for conditions other than primary hyperparathyroidism. (99m)Tc-sestamibi scanning had a sensitivity of 79.1%, a specificity of 86.7%, a positive predictive value of 88.3%, a false-positive rate of 11.6%, and a false-negative rate of 23.3% for the diagnosis of parathyroid adenoma. Despite the apparent high sensitivity of this scanning technique, only 58.2% of the adenomas were found intra-operatively at the location predicted by the scan. Lesions in the upper neck area were missed more frequently by sestamibi scanning than were those in the lower neck area (13 of 32 versus 1 of 35, respectively) (P<0.05).

CONCLUSION

Preoperative localization of parathyroid adenomas with use of (99m)Tc-sestamibi scanning showed a limited capacity to reveal their precise location. Thus, such scans must be complemented with other studies, such as intraoperative ultrasonography and rapid parathyroid hormone assay, to ensure a successful excision if a limited surgical procedure is planned.

The cost-effectiveness of sestamibi scanning compared to bilateral neck exploration for the treatment of primary hyperparathyroidism

This article presents a cost-effectiveness analysis to determine whether preoperative imaging with Tc99m-sestamibi for detection and treatment of solitary adenomas associated with primary hyperparathyroidism is cost-effective compared with routine bilateral neck exploration.

Endoscopic parathyroidectomy

This article describes the techniques of endoscopic and endoscopic assisted parathyroidectomy, with a special emphasis on the accumulated experience as well as the advantages and drawbacks of these novel techniques.

Unilateral and bilateral surgery for parathyroid disease

The principles of successful parathyroid surgery, regardless of the approach, demand a clear understanding of the philosophy behind the surgical exploration. A systematic approach, founded in science and refined by experience, is necessary to achieve long-term, reproducible surgical success. This article discusses the underlying logic and the advantages and disadvantages of the two basic approaches to parathyroid pathology: unilateral and bilateral cervical exploration. The authors do not to advocate a particular technique;instead, they provide a conceptual framework to surgical parathyroid disease upon which more advanced discussion can be built.

Minimal-access/minimally invasive parathyroidectomy for primary hyperparathyroidism

Minimal-access or minimally invasive parathyroidectomy is replacing a bilateral neck exploration as the surgical approach of choice in primary hyperparathyroidism (pHPT). When a parathyroid adenoma is localized preoperatively, ideally with sestamibi combined with ultrasonography, results equivalent to a bilateral neck exploration can be achieved through an incision less than 2.5 cm. Minimal-access techniques offer the advantage of cure under local anesthesia with a smaller incision and no overnight stay. Intraoperative measurement of parathyroid hormone (PTH) may be a valuable adjunct to confirmation of parathyroid adenoma removal, but currently appears to add little when preoperative localization is optimized. Controlled studies and long-term follow-up will be required to establish the true value of parathyroid minimal-access surgery.

Management of primary hyperthyroidism: toward minimal access surgery

Fifteen years ago, bilateral exploration of the neck was dogma in parathyroid surgery. Now, less invasive procedures can be used to target lesions identified by new tests such as dual-phase Sestamibi scanning or intraoperative documentation of parathyroid hormone (PTH) level changes after removal of a parathyroid gland. A hand-held gamma probe can be used for intraoperative detection of high-uptake lesions, and video-assisted endoscopic surgery has been used successfully. With these new techniques, surgical exploration can be confined to one side of the neck through smaller incisions associated with better cosmetic results. The operating time is reduced, and in some cases the procedure can be done under local anesthesia. The objective of this article is to describe recent changes in the management of parathyroid adenoma requiring surgery.

Unilateral neck exploration for primary hyperparathyroidism

Focused unilateral cervical exploration is a controversial alternative to conventional bilateral neck exploration for primary hyperparathyroidism (HPT) due to solitary adenoma. Development of preoperative localization techniques, notably isotope scintigraphy and small-part, real-time ultrasonography, has increased preoperative parathyroid tumor identification. Critics of scan directed unilateral neck exploration argue it may overlook enlarged parathyroid glands on the unexplored side, increasing the incidence of persistent and recurrent hypercalcemia. Our experience of this operation and prolonged follow-up of patients, however, confirm that it does not increase risk of persistent or recurrent HPT if a strict selection protocol is observed. This ensures the confident further development of minimally invasive surgical procedures for HPT based on the principle of a focused exploration following preoperative localization of the parathyroid adenoma.

Technetium-99m sestamibi scintigraphy and helical CT together in patients with primary hyperparathyroidism: a prospective clinical study

44 consecutive patients with confirmed primary hyperparathyroidism (HPT) undergoing surgery were prospectively enrolled in the study. There were 13 (29.5%) men and 31 (70.5%) women with an overall median age of 59 years (range 23-78 years). Prior to successful parathyroidectomy both (99)Tc(m)-sestamibi/(99)Tc(m)-pertechnetate subtraction scintigraphy (SS) and helical CT were performed, and the results of imaging studies were compared against intraoperative findings. Final histopathology showed 40 (90.9%) solitary parathyroid (PT) adenomata (median size 18 mm, range 8-40 mm), that were in an ectopic location in 13 (32.5%) patients. Moreover, 3 (6.8%) patients had multiglandular disease (one patient with two PT adenomata, two patients with PT hyperplasia), while one (2.3%) patient had a PT carcinoma. The sensitivity and positive predictive value were 86.0% and 97.4% for SS, 88.1% and 94.9% for CT, and 100% and 97.4% for the combination of SS and CT, respectively. Calcium and parathyroid hormone (PTH) serum levels, and the mean size of the removed PT glands of patients with false negative results were lower than that of those with true positive results, but the difference was not significant. Among patients with solitary PT tumours (N=41) the sensitivity was 88.1% and 90.3% for SS and CT-scan, respectively. In conclusion, our study confirms the usefulness of SS, which should be the initial test for patients undergoing parathyroidectomy. However, the strategy of performing two tests in each patient with primary HPT could be of limited utility when the initial SS is positive.

Comparison of intraoperative iPTH assay (QPTH) criteria in guiding parathyroidectomy: which criterion is the most accurate?

BACKGROUND

The quick parathyroid hormone assay (QPTH) reliably measures intact parathyroid hormone (iPTH) levels intraoperatively. The accuracy in predicting postoperative calcemia is related to blood sample timing and the criteria applied. To improve specificity or to decrease the cost of QPTH, several criteria have been used to predict complete excision. This study compares the Miami criterion with other published QPTH criteria in predicting operative outcome.

METHODS

QPTH and the Miami criterion (iPTH drop > or =50% from the highest of either preincision or pre-excision level at 10 minutes after gland excision), were used to predict postoperative calcium levels of 341 consecutive patients with sporadic primary hyperparathyroidism who were followed > or =6 months after the operation or recognized as operative failures. Intraoperative iPTH values of these patients were reanalyzed with the use of 5 published criteria to predict complete resection. Postoperative calcium levels were correlated with criteria predictions.

RESULTS

Miami criterion correctly predicted postoperative calcium levels in 329 of 341 patients and was incorrect in 12 (3 false positives, 9 false negatives). With the use of other criteria, 2 of the 3 false-positive results would be prevented, but the 3% rate of false-negative predictions would increase to between 6% and 24%, causing unnecessary neck explorations to search for multiglandular disease.

CONCLUSIONS

Surgeons trying to increase QPTH specificity significantly decrease the accuracy and intraoperative usefulness of the assay. The Miami criterion has the highest accuracy when compared with other criteria.

Ectopic parathyroid adenoma localised with sestamibi SPECT and image-fused computed tomography

Confident localisation of ectopic parathyroid adenomas, particularly those outside the neck, can be difficult. Even preoperative radiological imaging may not be helpful, as there are few characteristic findings. We report a case in which hyperfunctioning ectopic parathyroid tissue in the mediastinum was detected with technetium-99m-sestamibi single-photon emission computed tomography and accurately localised non-invasively with image-fused computed tomography. This technique directly modified management.