Remedial parathyroid surgery: changing trends in 130 consecutive cases

The Parathyroid Gland: An Overall Review of the Hidden Organ for Radiologists

Parathyroid glands are small endocrine glands that regulate calcium metabolism by producing parathyroid hormone (PTH). These are located at the back of the thyroid gland. Typically, four glands comprise the parathyroid glands, although their numbers may vary among individuals. Parathyroid diseases are related to parathyroid gland dysfunction and can be caused by problems with the parathyroid gland itself or abnormal serum calcium levels arising from renal disease. In recent years, as comprehensive health checkups have become more common, abnormal serum calcium levels are often found incidentally in blood tests, after which several additional tests, including a PTH test, ultrasonography (US), technetium-99m sestamibi parathyroid scan, single-photon-emission CT (SPECT)/CT, four-dimensional CT (4D-CT), and PET/CT, are performed for further evaluation. However, the parathyroid gland remains an organ less familiar to radiologists. Therefore, the normal anatomy, pathophysiology, imaging, and clinical findings of the parathyroid gland and its associated diseases are discussed here.

Role of hospital and patient factors in the outcome of reoperations for primary hyperparathyroidism: a retrospective multicenter cohort study

BACKGROUND

There are few data on outcomes after reintervention for persistent or recurrent primary hyperparathyroidism (PHPT). The authors hypothesized that the variation in outcomes at the hospital level after reoperation would be significant. After accounting for this variability, some patient-level clinical criteria could be identified to help inform treatment decisions in this patient population. The aim of this study was to determine whether there is significant variation in outcomes after reoperation for PHPT between hospitals (hospital-level analysis) and identify clinical factors (patient-level analysis) that influence postoperative outcomes.

MATERIALS AND METHODS

This retrospective multicenter cohort study was performed using the Eurocrine registry. Data from 11 countries and 76 hospitals from January 2015 to October 2020 were extracted. A generalized linear mixed model was used to assess the variation in outcomes at the hospital level and to identify risk factors of postoperative outcomes at the patient level. The primary endpoint (textbook outcome) was achieved when all six of the following postoperative conditions were met: no hypocalcemia or persistent hypercalcemia, no laryngeal nerve injury, no negative exploration, no normal parathyroid gland only on histopathology, and no postoperative death.

RESULTS

Among 13 593 patients who underwent parathyroidectomy for PHPT, 617 (4.5%) underwent reoperative parathyroidectomy. At follow-up, 231 patients (37.4%) were hypocalcemic, 346 (56.1%) were normocalcemic without treatment, and 40 (6.5%) had persistent hypercalcemia. Textbook outcomes were achieved in 321 (52.0%) patients. The hospital-level variation in textbook outcome rates was significant ( P <0.001), and this variation could explain 29.1% of the observed outcomes. The criterion that remained significant after controlling for inter-hospital variation was 'a single lesion on sestamibi scan or positron emission tomography (PET) imaging' (odds ratio 2.08, 95% confidence interval 1.24-3.48; P =0.005).

CONCLUSION

Outcomes after reoperation are significantly associated with hospital-related factors. A 'single lesion observed on preoperative sestamibi scan or PET' appears relevant to select patients before reoperation.

Persistent and Recurrent Primary Hyperparathyroidism: Etiological Factors and Pre-Operative Evaluation

Primary hyperparathyroidism (pHPT) is the most common cause of hypercalcemia and currently the only definitive treatment is surgery. Although the success rate of parathyroidectomy is over 95% in experienced centers, surgical failure is the most common complication today. Persistent HPT (perHPT) is defined as persistence of hypercalcemia after parathyroidectomy or recurrence of hypercalcemia within the first 6 months, and recurrence of hypercalcemia after a normocalcemic period of more than 6 months is defined as recurrent HPT (recHPT). In the literature, perHPT is reported to be 2-22%, and the rate of recHPT is 1-15%. perHPT is often associated with misdiagnosed pathology or inadequate resection of hyperfunctioning parathyroid tissue, recHPT is associated with newly developing pathology from potentially pathologically natural tissue left in situ at the initial surgery. In the pre-operative evaluation, the initial diagnosis of pHPT and the diagnosis of perHPT or rec HPT should be confirmed in patients who are evaluated with a pre-diagnosis (suspect) of perHPT and recHPT. Surgery is recommended if it meets any of the recommendations in surgical guidelines, as in patients with pHPT, and there are no surgical contraindications. The first preoperative localization studies, surgical notes, operation drawings, if any, intraoperative PTH results, pathological results, and post-operative biochemical results of these patients should be examined. Localization studies with preoperative imaging methods should be performed in all patients with perHPT and recHPT with a confirmed diagnosis and surgical indication. The first-stage imaging methods are ultrasonography and Tc99m sestamibi single photon tomography Tc99mMIBI SPECT or hybrid imaging method, which is combined with both single-photon emission computed tomography and computed tomography (SPECT/CT). The combination of USG and sestamibi scintigraphy increases the localization of the pathological gland. In the secondary stage, Four-Dimensional computer tomography (4D-CT) or dynamic 4-dimensional Magnetic Resonance Imaging (4D-MRI) can be applied. It is focused on as a secondary stage imaging method, especially when the lesion cannot be detected by conventional methods. Positron Emission Tomography (PET) and PET/CT examinations with 11C-choline or 18F-fluorocholine are promising imaging modalities. Invasive examinations can rarely be performed in patients in whom suspicious, incompatible or pathological lesion cannot be detected in noninvasive imaging methods. Bilateral jugular vein sampling, selective venous sampling, parathyroid arteriography, imaging-guided fine-needle aspiration biopsy, and parathormone washout are invasive methods.

Determinants and clinical significance of negative scintigraphic findings in primary hyperparathyroidism: a retrospective observational study

AIM

In patients with recurrent primary hyperparathyroidism (pHPT) or preceding thyroid operation, scintigraphic localization of the pathological parathyroid gland is sometimes unsuccessful. Reason for diagnostic failure, and its clinical relevance is poorly understood.

METHODS

This retrospective observational study in patients suffering from a pHPT evaluated independent predictors of a negative preoperative scintigraphy (SC) result, and its relevance for intraoperative outcome using logistic regression analysis.

RESULTS

Among 86 pHPT patients scheduled for parathyroid operation, 63 (73%) had a history of a preceding thyroid or parathyroid operation. Preoperative SC could not identify an adenoma in 30 patients (34.9%), and in 12 patients (14.0%), the surgeon was subsequently unable to localize abnormal parathyroid tissue. Preoperative parathyroid hormone concentration was the only significant independent predictor of a negative SC finding (non-linear and indirect association). Independent from surgical history, an unsuccessful intraoperative focus localization was exclusively predicted by preoperative ultrasonographic (US) and SC findings (OR per diagnostic category 2.98; 95%-CI 1.03-8.58, p=0.043, and OR 2.26; 95%-CI: 1.10-4.63, p=0.027, respectively). Compared to exclusive US, however, the combination of SC and US significantly increased the sensitivity and predictive power to identify patients at a high risk for a complicated surgical procedure.

CONCLUSION

In patients before parathyroidectomy, a low preoperative parathyroid hormone concentration is significantly associated with a high likelihood for a negative SC finding. Combining US with SC before operation significantly increases the chance to identify patients prone to negative intraoperative findings.

Evaluation of diagnostic efficacy for localization of parathyroid adenoma in patients with primary hyperparathyroidism undergoing repeat surgery

Purpose

Repeat surgery in patients with primary hyperparathyroidism (pHPT) is associated with an increased risk of complications and failure. This stresses the need for optimized strategies to accurately localize a parathyroid adenoma before repeat surgery is performed. However, evidence on the extent of required diagnostics for a structured approach is sparse.

Methods

A retrospective single-center evaluation of 28 patients with an indication for surgery due to pHPT and previous thyroid or parathyroid surgery was performed. Diagnostic workup, surgical approach, and outcome in terms of complications and successful removement of parathyroid adenoma with biochemical cure were evaluated.

Results

Neck ultrasound, sestamibi scintigraphy, C11-methionine PET-CT, and selective parathyroid hormone venous sampling, but not MRI imaging, effectively detected the presence of a parathyroid adenoma with high positive predictive values. Biochemical cure was revealed by normalization of calcium and parathormone levels 24–48h after surgery and was achieved in 26/28 patients (92.9%) with an overall low rate of complications. Concordant localization by at least two diagnostic modalities enabled focused surgery with success rates of 100%, whereas inconclusive localization significantly increased the rate of bilateral explorations and significantly reduced the rate of biochemical cure to 80%.

Conclusion

These findings suggest that two concordant diagnostic modalities are sufficient to accurately localize parathyroid adenoma before repeat surgery for pHPT. In cases of poor localization, extended diagnostic procedures are warranted to enhance surgical success rates. We suggest an algorithm for better orientation when repeat surgery is intended in patients with pHPT.

[Asymptomatic primary hyperparathyroidism : Operation or observation?]

BACKGROUND

In many cases primary hyperparathyroidism (PHPT) remains asymptomatic for years and is only detected by abnormalities in routine diagnostics. While symptomatic disease almost always requires surgical treatment, in symptom-free patients the question of whether and in what form treatment should be carried out is particularly important.

OBJECTIVE

The aim of this review is to summarize the current recommendations regarding the diagnostics and treatment of asymptomatic PHPT, taking the existing evidence into account.

RESULTS AND CONCLUSION

The diagnostics of asymptomatic PHPT is the same as for symptomatic disease. The diagnosis is made in the presence of elevated parathyroid hormone and balanced vitamin D levels when a combination of hypercalcemia, hypophosphatemia and hypercalciuria is present. Borderline laboratory findings occur especially in asymptomatic PHPT and the differential diagnosis of familial hypocalciuric hypercalcemia must be considered. Once the diagnosis is made sonography, radiography or computed tomography (CT) is used to search for nephrolithiasis or nephrocalcinosis. Regarding bone mineral density (BMD) measurements, in addition to routine measurements at the lumbar spine and femur, measurement at the distal radius is important as it is the most sensitive site for detecting osteoporosis in PHPT. An indication for parathyroidectomy is confirmed in the case of hypercalcemia > 1.0 mg/dl (>0.25 mmol/l) above the upper limit of normal, hypercalciuria > 400 mg/day (>10 mmol/day), renal insufficiency, proven osteoporosis or age < 50 years. If none of these criteria are fulfilled and surgery is not desired by the patient, annual laboratory check-ups and assessment of BMD every 1-2 years are recommended.

Volume-outcome relationship in parathyroid surgery

BACKGROUND

Since its first description, several studies have highlighted the role of the surgeon's experience in the outcome of parathyroid surgery, however, no uniform consensus exists regarding the minimum operative experience required for good surgical outcomes. This work aims to summarize the current data regarding the surgeon volume-outcome relationship for parathyroidectomy.

METHODS

An electronic literature review identified 85 publications, and after study selection 11 were included. An additional nine publications were added based on reference review and inclusion of publications not initially captured.

CONCLUSIONS

There are insufficient data to dogmatically conclude a minimum number of cases required to achieve optimal surgical results. However, extrapolation from the inclusive studies support the conclusions that higher operative volumes improve cure rates and decrease the rates of complications, recurrent disease, and perioperative costs. Endocrine Surgery fellowships or mentorships may help prepare the less experienced surgeon for successful outcomes. Although reticent to offer firm minimal volume requirements, we have made suggestions in this manuscript.

Primary hyperparathyroidism

In this Review, we describe the pathogenesis, diagnosis and management of primary hyperparathyroidism (PHPT), with a focus on recent advances in the field. PHPT is a common endocrine disorder that is characterized by hypercalcaemia and elevated or inappropriately normal serum levels of parathyroid hormone. Most often, the presentation of PHPT is asymptomatic in regions of the world where serum levels of calcium are routinely measured. In addition to mild hypercalcaemia, PHPT can manifest with osteoporosis and hypercalciuria as well as with vertebral fractures and nephrolithiasis, both of which can be asymptomatic. Other clinical forms of PHPT, such as classical disease and normocalcaemic PHPT, are less common. Parathyroidectomy, the only curative treatment for PHPT, is recommended in patients with symptoms and those with asymptomatic disease who are at risk of progression or have subclinical evidence of end-organ sequelae. Parathyroidectomy results in an increase in BMD and a reduction in nephrolithiasis. Various medical therapies can increase BMD or reduce serum levels of calcium, but no single drug can do both. More data are needed regarding the neuropsychological manifestations of PHPT and the pathogenetic mechanisms leading to sporadic PHPT, as well as on risk factors for complications of the disorder. Future work that advances our knowledge in these areas will improve the management of the disorder.

Update in Parathyroid Imaging

Primary hyperparathyroidism (PHPT) is characterized by excessive, dysregulated production of parathyroid hormone (PTH) by 1 or more abnormal parathyroid glands. Minimally invasive surgical techniques have created a need for more precise localization of the parathyroid lesion by imaging. A variety of imaging protocols and techniques have been used for this purpose, but no one modality is clearly superior. Nuclear medicine scintigraphy and ultrasound imaging are established modalities, although multiphase or 4-dimensional computed tomography is an emerging modality with several advantages. This review provides a background regarding PHPT and key anatomy, and discusses these alternative parathyroid imaging modalities with updates.

[The minimally invasive video-assisted parathyroidectomy for primary hyperparathyroidism]

AIM

To study feasibility, effectiveness and safety of minimally invasive video-assisted parathyroidectomy in patients with primary hyperparathyroidism; to define the advantages and disadvantages of this technique compared with conventional open surgery.

MATERIAL AND METHODS

The study includes the results of 33 minimally invasive video-assisted parathyroidectomies performed in patients with primary hyperparathyroidism. The control group included 36 patients who underwent conventional open surgery.

RESULTS

There were significantly increased time of surgery in the main group (41.2±12.7 min vs. 28.4±10.9 min, p<0.05), decreased need for postoperative analgesia (1,2±0.3 vs. 1.9±0.5 days, p<0.05) and significantly longer postoperative scar (1.8±0.2 vs. 6.2±0.5 cm, p<0.01). Incidence of complications was similar in both groups (6.1% vs. 8.3%, p>0.05).

CONCLUSION

Minimally invasive video-assisted parathyroidectomy for primary hyperparathyroidism is feasible, safe and effective intervention that improves early postoperative course and cosmetic outcomes.

Hepatic metastasis of a parathyroid carcinoma treated with intra-arterial embolization

Se reporta el caso de una paciente con carcinoma de paratiroides metastásico al hígado con hipercalcemia de muy difícil control pese a manejo con ácido Zoledrónico y Cinacalcet. La paciente fue llevada a embolización intraarterial con microesferas de alcohol polivinílico de la arteria hepática derecha, con lo que se obtuvo un excelente control bioquímico después de la intervención.

The Incidental Thyroid Lesion in Parathyroid Disease Management

Objective

The incidental thyroid lesion is a common finding during general imaging studies. Their management has been the subject of numerous studies and recommendations. Parathyroid disease workup necessitates imaging investigation of the adjacent thyroid gland and therefore provides a unique window to the perioperative management of thyroid incidentaloma. The specific prevalence of incidental thyroid lesions in the context of parathyroid disease is unknown. We seek to investigate its prevalence during parathyroid workup and surgery and to ascertain if there was a change in management of these patients.

Study Design

Five-year retrospective database review.

Setting

Tertiary care medical center.

Subjects and Methods

The source and indication for referral, preoperative investigation findings, and management of the incidental thyroid lesions were examined. The actual procedure performed and final pathology results were assessed.

Results

A total of 98 patients and 106 operations, including revision surgeries, were identified. There were 21 incidental thyroid lesions (21.4%) detected, whereby 15 patients underwent fine-needle aspirations and 12 subsequently had diagnostic hemithyroidectomies. This decision was made preoperatively in 5 patients and intraoperatively in 7 patients at the time of parathyroid surgery. Along with other pathologies, there were 7 patients with micropapillary thyroid carcinoma identified.

Conclusions

In our series, the prevalence of incidental thyroid lesion and thyroid malignancy is comparable to the general population. The management of the initial parathyroid disease in our patients was altered by the imaging and cytological findings of these thyroid lesions. This has implications on perioperative counseling of the thyroid and parathyroid disease.

18F Fluorocholine PET/MR Imaging in Patients with Primary Hyperparathyroidism and Inconclusive Conventional Imaging: A Prospective Pilot Study

Purpose To investigate the performance of flourine 18 (¹⁸F) fluorocholine (FCH) positron emission tomography (PET)/magnetic resonance (MR) imaging in patients with hyperparathyroidism and nonlocalized disease who have negative or inconclusive results at ultrasonography (US) and technetium 99m (^99mTc) sestamibi scintigraphy. Materials and Methods This study was approved by the institutional review board. Between May and December 2015, 10 patients (mean age, 70.4 years; range, 58-82 years) with biochemical primary hyperparathyroidism and inconclusive results at US and ^99mTc sestamibi scintigraphy were prospectively enrolled. All patients gave informed consent. Directly after administration of 3 MBq/kg of FCH, PET imaging was performed, followed by T1- and T2-weighted MR imaging before and after gadolinium enhancement. Intraoperative localization and histologic results were the reference standard for calculating sensitivity and positive predictive value. The Wilcoxon rank test was used to calculate the mean difference in maximum standardized uptake value (SUV_max) between abnormal parathyroid uptake and physiologic thyroid uptake. The Wilcoxon rank-sum test was performed. Results MR imaging alone showed true-positive lesions in five patients and a false-positive lesion in one patient. FCH PET/MR imaging allowed correct localization of nine of 10 adenomas (90% sensitivity), without any false-positive results (100% positive predictive value). One patient had four-gland hyperplasia, of which three hyperplastic glands were not localized. The median SUV_max of the nine preoperatively identified adenomas was 4.9 (interquartile range, 2.45-7.35), which was significantly higher than the SUV, 2.7 (interquartile range, 1.6-3.8), of the thyroid (P = .008). Conclusion FCH PET/MR imaging allowed localization of adenomas with high accuracy when conventional imaging results were inconclusive and provided detailed anatomic information. More patients must be examined to confirm our initial results, and the accuracy of FCH PET/MR imaging for localization of glands in patients with four-gland hyperplasia remains to be investigated. ^© RSNA, 2017.

Performance of magnetic resonance imaging in the evaluation of first-time and reoperative primary hyperparathyroidism

BACKGROUND

Preoperative imaging in patients with primary hyperparathyroidism and a previous parathyroid operation is essential; however, performance of conventional imaging is poor in this subgroup. Magnetic resonance imaging appears to be a good alternative, though overall evidence remains scarce. We retrospectively investigated the performance of magnetic resonance imaging in patients with and without a previous parathyroid operation, with a separate comparison for dynamic gadolinium-enhanced magnetic resonance imaging.

METHODS

All patients undergoing magnetic resonance imaging prior to parathyroidectomy for primary hyperparathyroidism (first time or recurrent) between January 2000 and August 2015 at a high-volume, tertiary care, referral center for endocrine operations were included. We compared the sensitivity and positive predictive value of magnetic resonance imaging with conventional ultrasound and sestamibi on a per-lesion level.

RESULTS

A total of 3,450 patients underwent parathyroidectomy, of which 84 patients with recurrent (n = 10) or persistent (n = 74) disease and 41 patients with a primary operation were included. Magnetic resonance imaging had a sensitivity and positive predictive value of 79.9% and 84.7%, respectively, and performance was good in both patients with and without a previous parathyroid operation. Adding magnetic resonance imaging to the combination of ultrasound and sestamibi resulted in a significant increase in sensitivity from 75.2% to 91.5%. Dynamic magnetic resonance imaging produced excellent results in the reoperative group, with sensitivity and a positive predictive value of 90.1%.

CONCLUSION

Technologic advances have enabled faster and more accurate magnetic resonance imaging protocols, making magnetic resonance imaging an excellent alternative modality without associated ionizing radiation. Our study shows that the sensitivity of multimodality imaging for parathyroid adenomas improved significantly with the use of conventional and dynamic magnetic resonance imaging, even in the case of recurrent or persistent disease.

Imaging of the parathyroid glands in primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is one of the most frequent endocrine diseases worldwide. Surgery is the only potentially curable option for patients with this disorder, even though in asymptomatic patients 50 years of age or older without end organ complications, a conservative treatment may be a possible alternative. Bilateral neck exploration under general anaesthesia has been the standard for the definitive treatment. However, significant improvements in preoperative imaging, together with the implementation of rapid parathyroid hormone determination, have determined an increased implementation of focused, minimally invasive surgical approach. Surgeons prefer to have a localization study before an operation (both in the classical scenario and in the minimally invasive procedure). They are not satisfied by having been referred a patient with just a biochemical diagnosis of PHPT. Imaging studies must not be utilized to make the diagnosis of PHPT. They should be obtained to both assist in determining disease etiology and to guide operative procedures together with the nuclear medicine doctor and, most importantly, with the surgeon. On the contrary, apart from minimally invasive procedures in which localization procedures are an obligate choice, some surgeons believe that literature on parathyroidectomy over the past two decades reveals a bias towards localization. Therefore, surgical expertise is more important than the search for abnormal parathyroid glands.

Persistent Primary Hyperparathyroidism, Severe Vitamin D Deficiency, and Multiple Pathological Fractures

Persistent primary hyperparathyroidism (PHPT) refers to the sustained hypercalcemia state detected within the first six months following parathyroidectomy. When it coexists with severe vitamin D deficiency, the effects on bone can be devastating. We report the case of a 56-year-old woman who was sent to this center because of persistent hyperparathyroidism. Her disease had over 3 years of evolution with nephrolithiasis and hip fracture. Parathyroidectomy was performed in her local unit; however, she continued with hypercalcemia, bone pain, and pathological fractures. On admission, the patient was bedridden with multiple deformations by fractures in thoracic and pelvic members. Blood pressure was 100/80, heart rate was 86 per minute, and body mass index was 19 kg/m². Calcium was 14 mg/dL, parathormone 1648 pg/mL, phosphorus 2.3 mg/dL, creatinine 2.4 mg/dL, urea 59 mg/dL, alkaline phosphatase 1580 U/L, and vitamin D 4 ng/mL. She received parenteral treatment of hypercalcemia and replenishment of vitamin D. The second surgical exploration was radioguided by gamma probe. A retroesophageal adenoma of 4 cm was resected. Conclusion. Persistent hyperparathyroidism with severe vitamin D deficiency can cause catastrophic skeletal bone softening and fractures.

Patterns of disease in patients at a tertiary referral centre requiring reoperative parathyroidectomy

INTRODUCTION

Reoperative parathyroidectomy is required when there is persistent or recurrent hyperparathyroidism following the initial surgery (at least 5% of parathyroidectomies nationally). By convention, 'persistent disease' is defined as the situation where the patient has not been cured by the first operation. The term 'recurrent hyperparathyroidism' is used when the patient was confirmed to be biochemically cured for six months from the first operation but has hyperparathyroidism after this date. Reoperative surgery is associated with higher rates of postoperative complications as well as a greater rate of failure to cure. The aim of our study was to review our departmental experience of reoperative parathyroidectomy, with a view to identify patterns of disease persistence and recurrence.

METHODS

Using a departmental database, patients were identified who had undergone reoperative parathyroidectomy between 2006 and 2014. All the pre, intra and postoperative information was documented including the operative note so as to record the location of the abnormal parathyroid gland found at reoperation.

RESULTS

Almost two-thirds (63%) of patients had negative, equivocal or discordant conventional imaging so secondary investigative tools were required frequently. The majority of abnormal glands were found in eutopic locations. The most common locations for ectopic glands were intrathyroidal, mediastinal and intrathymic. A third (33%) of the patients had multigland disease and over a quarter (28%) had coexisting thyroid disease.

CONCLUSIONS

Persistent hyperparathyroidism represents a challenging patient subgroup for which access to all radiological modalities and intraoperative parathyroid hormone monitoring are required. Patient selection for reintervention is a key determinant in the reoperation cure rate.

Dynamic Parathyroid Computed Tomography (4DCT) Facilitates Reoperative Parathyroidectomy and Enables Cure of Missed Hyperplasia

BACKGROUND

Four-dimensional computed tomography (4DCT) is an emerging imaging modality in the evaluation of primary hyperparathyroidism (PHPT). We assessed the role of 4DCT in patients presenting for reoperative parathyroidectomy.

METHODS

A prospective database of patients with persistent or recurrent PHPT undergoing reoperative parathyroidectomy during the years 2006-2014 was analyzed. Patients treated before versus after the advent of 4DCT were compared for operative eligibility, operative success, operative time, and concordance of imaging results with surgical findings.

RESULTS

Ninety patients were included in the study (61 before 4DCT, 29 after 4DCT). The post-4DCT group had a higher rate of surgical concordance with imaging results (63 vs. 90 %, p < 0.01) and shorter operative time (114 vs. 76 min, p < 0.05). The operative success rate was not different (87 vs. 86 %). A similar pattern was observed in the subset of sestamibi-negative patients, with post-4DCT patients having a higher rate of surgical concordance (12 vs. 83 %, p < 0.0001) and shorter operative time (181 vs. 89 min, p < 0.05). Among patients ultimately found to have parathyroid hyperplasia, 4DCT correctly identified multiple enlarged glands in 80 % (4 of 5) and correctly lateralized one or more glands in 100 % (5 of 5) of cases, facilitating successful subtotal parathyroidectomy in the reoperative setting.

CONCLUSIONS

4DCT enables successful and efficient reoperative parathyroidectomy. These benefits extend to difficult cases, including sestamibi-negative patients and those with missed hyperplasia.

Long-term effectiveness of localization studies and intraoperative parathormone monitoring in patients undergoing reoperative parathyroidectomy for persistent or recurrent hyperparathyroidism

BACKGROUND

Reoperative parathyroidectomy (RPTX) for persistent or recurrent hyperparathyroidism is associated with a high rate of operative failure. The long-term effectiveness of RPTX using localization studies and intraoperative parathormone monitoring (IPM) was examined.

METHODS

Retrospective analysis of prospectively collected data from patients undergoing targeted RPTX with IPM for persistent or recurrent hyperparathyroidism was performed. Persistent hyperparathyroidism was defined as elevated calcium and parathormone (PTH) levels above normal range less than 6 months after parathyroidectomy. Recurrent hyperparathyroidism was defined as elevated calcium and PTH levels greater than 6 months after successful parathyroidectomy. Sensitivity and positive predictive value (PPV) for sestamibi, surgeon-performed ultrasound, intraoperative PTH dynamics, and surgical outcomes were evaluated.

RESULTS

Of the 1,064 patients, 69 patients underwent 72 RPTXs with localizing studies and IPM. Sestamibi (n = 69) had a sensitivity of 74% and a PPV of 83%, whereas surgeon-performed ultrasound (n = 38) had a sensitivity of 55% and a PPV of 76%. IPM had a sensitivity of 100% and a PPV of 98%. An intraoperative PTH drop greater than or equal to 50% was predictive of operative success (P < .01). Overall, operative success and recurrence were 94% and 1.4%, with a mean patient follow-up of 59 ± 12.8 months.

CONCLUSION

RPTX can be performed in a targeted approach using preoperative localization studies and IPM, leading to a low rate of complications and a high rate of long-term operative success.

Predictors of Multigland Disease in Primary Hyperparathyroidism: A Scoring System with 4D-CT Imaging and Biochemical Markers

BACKGROUND AND PURPOSE

Multigland disease represents a challenging group of patients with primary hyperparathyroidism. Additional lesions may be missed on imaging because they are not considered or are too small to be seen. The aim of this is study was to identify 4D-CT imaging and biochemical predictors of multigland disease.

MATERIALS AND METHODS

This was a retrospective study of 155 patients who underwent 4D-CT and successful surgery with a biochemical cure that compared patients with multigland and single-gland disease. Variables studied included the size of the largest lesion on 4D-CT, the number of lesions prospectively identified on 4D-CT, serum calcium levels, serum parathyroid hormone levels, and the Wisconsin Index (the product of serum calcium and parathyroid hormone levels). Imaging findings and the Wisconsin Index were used to calculate a composite multigland disease scoring system. We evaluated the predictive value of individual variables and the scoring system for multigland disease.

RESULTS

Thirty-six patients with multigland disease were compared with 119 patients with single-gland disease. Patients with multigland disease had significantly lower Wisconsin Index scores, smaller lesion size, and a higher likelihood of having either multiple or zero lesions identified on 4D-CT (P ≤ .01). Size cutoff of <7 mm had 85% specificity for multigland disease, but including other variables in the composite multigland disease score improved the specificity. Scores of ≥4, ≥5, and 6 had specificities of 81%, 93%, and 98%, respectively.

CONCLUSIONS

The composite multigland disease scoring system based on 4D-CT imaging findings and biochemical data can identify patients with a high likelihood of multigland disease. Communicating the suspicion for multigland disease in the radiology report could influence surgical decision-making, particularly when considering re-exploration in a previously operated neck or initial limited neck exploration.

Fewer adverse events after reoperative parathyroidectomy associated with initial minimally invasive parathyroidectomy

BACKGROUND

This study compared reoperative complication rates after initial minimally invasive parathyroidectomy and standard cervical exploration.

METHODS

Records from patients who underwent 1 reoperative parathyroidectomy at a single institution (1998 to 2012) were retrospectively reviewed.

RESULTS

Seventy-seven patients were included; 74% underwent initial standard cervical exploration. Preoperative and operative characteristics were similar between groups; 74% underwent focused, unilateral reoperation. A significantly higher rate of postoperative complications occurred in the initial standard cervical exploration group (42% vs 15%, P = .03) that could not be explained by differences in the rates of symptomatic hypocalcemia (P = .5). The type of prior parathyroidectomy was significantly associated with postoperative complications (odds ratio 4.1, 95% confidence interval 1.1 to 15.7, P = .04). In a multivariable logistic regression model that included body mass index, type of operation (for initial and reoperation), and initial operation performed prereferral as covariates, type of prior parathyroidectomy remained a significant predictor of postoperative complications.

CONCLUSION

Higher rates of postoperative sequelae after initial standard cervical exploration should be considered before performing routine 4-gland exploration.

Reoperations for persistent or recurrent primary hyperparathyroidism: results of a retrospective cohort study at a tertiary referral center

BACKGROUND

Parathyroid reoperations are challenging and achieving a cure requires multidisciplinary treatment team cooperation. The aims of this study were to summarize our experience in revision surgery for persistent (pHPT) or recurrent primary hyperparathyroidism (rHPT) and to explore factors underlying failure to cure at initial surgery.

MATERIAL AND METHODS

This was a retrospective cohort study of patients who underwent reoperations for pHPT or rHPT at a tertiary referral center. The database of parathyroid surgery was searched for eligible patients (treated in the years 2000-2012). The primary outcome was the cure rate. All the patients were followed-up for at least 12 months postoperatively. Factors underlying failure to cure at initial surgery were reviewed based on hospital records.

RESULTS

The study group comprised 88 patients (69 women, 19 men) operated on for persistent (n=57) or recurrent disease (n=31), who underwent 98 reoperations, including 26 (2.4%) patients first operated on at our institution, and 72 (81.8%) patients operated on elsewhere, but referred for revision surgery. A long-term cure was achieved in 83/88 patients (94.3%). The mean post-reoperation follow-up was 91.7 (12-176) months. Missed hyperfunctioning parathyroid gland was found on reoperation in eutopic position in 49 (55.5%) patients, and in ectopic position in 39 (44.3%) patients, including 20 (22.7%) cases of cervical ectopy and 19 (21.6%) cases of mediastinal ectopy.

CONCLUSIONS

Multidisciplinary treatment team cooperation at a tertiary referral center, consisting of an accurate preoperative localization, expertise in parathyroid re-explorations, and correct use of intraoperative adjuncts, contribute to the high success rate of parathyroid reoperations.

Clinical review: Parathyroid localization and implications for clinical management

CLINICAL CONTEXT

The prevalence of hyperparathyroidism, especially primary hyperparathyroidism, has increased in recent decades due to improvements in diagnostic techniques with a corresponding surge in parathyroid surgery, leading to the development of focused, minimally invasive surgical approaches. Focused parathyroidectomy is predicated on preoperative localization of suspected parathyroid pathology. As a result, there has been a proliferation of parathyroid imaging modalities and protocols, resulting in confusion about their indications and applications.

EVIDENCE ACQUISITION

Bibliographies from clinical trials and review articles published since 2000 were reviewed and supplemented with targeted searches using biomedical databases. We also employed our extensive clinical experience.

EVIDENCE SYNTHESIS

The best-studied modalities for parathyroid localization are nuclear scintigraphy and sonography and are widely applied as initial studies. Multiple variations exist, and several additional noninvasive imaging techniques, such as computed tomography and magnetic resonance, are described. The exquisite anatomical detail of 4-dimensional computed tomography must be balanced with significant radiation exposure to the thyroid gland. Invasive venous PTH sampling and parathyroid arteriography have important roles in remedial cases. Due to considerable heterogeneity in imaging, multidisciplinary collaboration between endocrinologists, surgeons, and radiologists is beneficial.

CONCLUSIONS

Parathyroid localization is indicated in surgical candidates. Crucial considerations when selecting an imaging study include availability, cost, radiation exposure, local expertise, and accuracy. Additional factors include the patient's anticipated pathology and whether it is de novo or refractory disease. An approach to imaging for patients with primary hyperparathyroidism is presented.

Influence of surgical volume on operative failures for hyperparathyroidism

Hyperparathyroidism is a disease that is often seen in the United States. Patients may present with a wide variety of symptoms affecting multiple organs, but frequently, they are found to be hyperparathyroid on a routine blood examination. Although these patients may be asymptomatic, new consensus guidelines exist for when they should undergo surgery, and several studies have shown multiple benefits from operative intervention. Surgical cure rates can be greater than 95%, but if the initial surgery is unsuccessful, the cure rate becomes 80%. In the hands of experienced surgeons, both initial cure rates and those for reoperations are much higher, illustrating that the surgical volume does affect failure in parathyroid surgery.

Dynamic MDCT for localization of occult parathyroid adenomas in 26 patients with primary hyperparathyroidism

OBJECTIVE

The objective of our study was to evaluate the accuracy of dynamic contrast-enhanced 4D MDCT in the preoperative identification of parathyroid adenomas in patients with primary hyperparathyroidism (PHPT) and a history of failed surgery or unsuccessful localization on standard imaging.

MATERIALS AND METHODS

Thirty-four patients with PHPT underwent 4D CT. Retrospective blinded review of the 4D CT examinations was performed by three radiologists for the presence and location of a suspected parathyroid adenoma or adenomas. At the time of the study, 25 patients underwent surgical exploration after 4D CT. Twenty patients had solitary parathyroid adenomas, two patients had two adenomas resected, two patients did not have an adenoma, and one patient had mild four-gland hyperplasia. One patient did not have PHPT on repeat serum biochemistry. Surgical and pathology reports, adenoma enhancement, and biochemical and clinical follow-up were reviewed. Data were compared with 4D CT interpretations and interobserver reliability was calculated.

RESULTS

The mean sensitivity and specificity of the three readers for the precise CT localization of adenomas was 82% (range, 79-88%) and 92% (range, 75-100%), respectively. Overall interobserver reliability was excellent (κ = 0.70; range, κ = 0.60-0.79). All adenomas resected at surgery showed a biochemical response and clinical response. The mean densities of the confirmed adenomas were 41, 128, 138, and 109 HU at 0, 30, 60, and 90 seconds, respectively. Level II lymph nodes identified in 10 patients showed significantly less enhancement at 30 (p = 0.0001) and 60 (p = 0.006) seconds compared with surgically proven adenomas.

CONCLUSION

Occult parathyroid adenoma shows characteristic early enhancement. In this subset of patients, 4D CT may improve surgical outcomes and decrease morbidity.

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.

Remedial operation for primary hyperparathyroidism

BACKGROUND

Remedial surgery for patients with persistent or recurrent primary hyperparathyroidism (1 degrees HPT) remains a significant challenge. Cervical reexploration is technically difficult; reoperative neck anatomy is distorted by fibrosis and, as a result, remedial 1 degrees HPT patients carry an increased risk of injury to the recurrent (RLN) and superior laryngeal nerve(s) as well as to normal residual parathyroid tissue. Causative hyperfunctioning parathyroid tissue is also more frequently ectopic in the remedial setting and can thus be difficult to localize.

METHODS

This report assimilates the current data underlying preoperative, intraoperative and postoperative remedial 1 degrees HPT management and presents an evidence-based algorithm for the management of remedial parathyroid disease. Recommendations are graded according to the quality of supporting data using the system initially developed by Sackett (Chest 95:2S-4S, 1989) and subsequently modified by Heinrich et al. (Ann Surg 243:154-168, 2006).

RESULTS

Recent advances in preoperative localization and intraoperative adjuncts have lead to substantial improvements in outcomes after remedial surgery. Preoperative localization techniques, including sestamibi scintigraphy (MIBI), high resolution ultrasound (US), US-guided fine needle aspiration (FNA) and selective venous sampling (SVS), coupled with intraoperative adjuncts such as the rapid parathyroid hormone (PTH) assay have lead to reoperative cure rates as high as 96 percent. Nonetheless, management of remedial 1 degrees HPT varies significantly between surgeons and no formal recommendations standardizing the care of these patients have been published.

CONCLUSIONS

Despite the significant challenges associated with remedial surgery for 1 degrees HPT, excellent outcomes can be reproducibly achieved when proper pre-, intra-, and postoperative management is employed.

Operative failures after parathyroidectomy for hyperparathyroidism: the influence of surgical volume

OBJECTIVE

To determine whether surgical volume influences the cause of operative failures after parathyroidectomy for hyperparathyroidism.

SUMMARY AND BACKGROUND DATA

The surgical success rate for hyperparathyroidism from high-volume centers exceeds 95%, but some patients have unsuccessful parathyroidectomies. Although operative failure can be due to hyperfunctioning parathyroid glands in ectopic locations, less experienced surgeons may be more likely to miss an abnormal parathyroid in normal anatomic locations, which we describe as "preventable operative failure."

METHODS

We used 2 prospective databases containing over 2000 consecutive patients who underwent parathyroidectomy. We identified 159 patients with persistent/recurrent hyperparathyroidism subsequently cured with additional surgery. The initially failed operations were classified as being performed at high- (>50 cases/yr) or low-volume (<50 cases/yr) hospitals. Hospital volume was obtained from a Wisconsin state database of 89 hospitals, which reported 6336 parathyroid operations during the same decade.

RESULTS

Patients who initially failed their operation performed at the high- or low-volume centers were similar with regard to age, laboratory values, gender, and parathyroid weights. Despite a higher incidence of multigland disease (which increases the likelihood of operative failure) in the high-volume group, patients in the low-volume group were more likely to have a missed parathyroid gland in a normal anatomic location (89% vs. 13%, P < 0.0001), and thus a higher proportion of preventable operative failures.

CONCLUSIONS

Surgical volume influences the failure pattern after parathyroidectomy for hyperparathyroidism. Preventable operative failures are more common in low-volume centers.

Surgical management of MEN-1 and -2: state of the art

Multiple endocrine neoplasia syndrome type 1 (MEN-1) consists of endocrine tumors of the parathyroid, the endocrine pancreas-duodenum, and the pituitary. Surveillance and screening for the endocrinopathies is recommended in gene carriers. Surgery for MEN-1-related hyperparathyroidism is generally performed as radical subtotal parathyroidectomy, because less surgery is likely to result in persistent or recurrent disease. Multiple endocrine neoplasia syndrome type 2 (MEN-2) consists of medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism. Prophylactic thyroidectomy based on DNA testing in the MEN-2 syndrome is considered one of the greater achievements in cancer treatment, because it may be performed before thyroid carcinoma development and provides cure for the patient.

What steps should be considered in the patient who has had a negative cervical exploration for primary hyperparathyroidism?

The key to cure of the patient with persistent primary hyperparathyroidism is a clear understanding of the investigations, operative procedure and pathology related to the initial procedure. Reinvestigation and subsequent surgery should be performed in a specialist unit. A logical pathway of increasingly sophisticated localization studies (MIBI, ultrasound, CT/MRI, selective venous catheterization for PTH) will usually guide the surgeon to the missing parathyroid gland/s. Improved preoperative localization can facilitate the use of a minimally invasive small incision approach. The surgeon must have a detailed knowledge of the nuances of parathyroid embryology and a meticulous surgical technique, not only to identify and safely remove the retained gland/s but also do so without causing unnecessary morbidity. Results of re-operation (84-98% cure) from centres of excellence are highly commendable, yet the use of 'new' technology (that includes intra-operative PTH) has not translated into improved outcomes in all cases. Some parathyroid glands are extremely difficult to find! Re-operative parathyroid surgery is a challenge, sometimes easy, and on other occasions extremely difficult.

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.

Surgery for asymptomatic primary hyperparathyroidism: proceedings of the third international workshop

CONTEXT

An international workshop on primary hyperparathyroidism (PHPT) was convened on May 13, 2008, to review and update the previous summary statement on the management of asymptomatic PHPT published in 2002.

EVIDENCE ACQUISITION

Electronic literature sources were systematically reviewed, addressing critical aspects of the surgical issues pertaining to the indications, imaging, surgical treatment, and cost-effective management of patients with PHPT.

EVIDENCE SYNTHESIS

The surgical group concluded that many patients with "asymptomatic" PHPT have neurocognitive symptoms that may be unmasked after successful parathyroidectomy. Furthermore, reduced bone density and increased fracture risk can be improved with parathyroidectomy. When PHPT is symptomatic, it may be associated with nephrolithiasis, increased cardiovascular disease, and decreased survival. Preoperative imaging studies should only be performed to help plan the operation, and negative imaging should never preclude surgical referral. Noninvasive localization studies including ultrasound and sestamibi scans are often employed, especially in anticipation of focused explorations. Invasive localization studies should be reserved for remedial explorations where noninvasive imaging has been unsuccessful.

CONCLUSIONS

When performed by expert parathyroid surgeons, parathyroid surgery is safe, cost-effective, and associated with very low perioperative morbidity. Minimally invasive approaches to parathyroid surgery appear to be as effective as the classic bilateral cervical exploration approach.

Focused approach to parathyroidectomy

Minimally invasive parathyroidectomy is performed after preoperative parathyroid localization-usually with high-quality sestamibi scans and/or ultrasonography-often under cervical block anesthesia during which a limited exploration is performed. The rapid intraoperative parathyroid hormone assay is then employed to confirm an adequate resection and cure of primary hyperparathyroidism. This article discusses imaging, anesthesia, results, and the surgical management of patients undergoing minimally invasive parathyroidectomy.

High success rate of parathyroid reoperation may be achieved with improved localization diagnosis

INTRODUCTION

Because of the difficulty of reoperative parathyroid surgery, preoperative imaging studies have been increasingly adopted. We report the use of consistently applied localization diagnosis to yield high success rates in parathyroid reoperations.

METHODS

Parathyroid reoperation was performed after previous parathyroid surgery in 144 patients with nonmalignant hyperparathyroidism (HPT) between 1962 and 2007. From the year 2000, 46 patients who underwent parathyroid reoperation and 14 patients who were subjected to thyroid surgery before primary parathyroid operation were investigated with sestamibi scintigraphy (MIBI), 11C-methionine PET/CT (met-PET), surgeon-performed ultrasound (US), US-guided fine-needle aspiration biopsy (US-FNA), and selective venous sampling (SVS) with rapid PTH (Q-PTH) analyses. When imaging was considered adequate, additional studies were generally not obtained.

RESULTS

Reversal of hypercalcemia was achieved by reoperation in 134 of 144 (93%) of all patients with previous parathyroid surgery. In patients operated from year 2000, MIBI had 90% sensitivity and 88% predictive value, met-PET 79% sensitivity and 87% predictive value, and US 72% sensitivity and 93% predictive value. SVS with Q-PTH analyses provided accurate localization or regionalization in 11 of 11 recently selected patients. Q-PTH analyses in fine-needle aspirations verified parathyroid origin of excised specimens, and intraoperative Q-PTH helped decide when operations could be terminated. In patients subjected to the algorithm of imaging procedures, reversal of hypercalcemia and apparent cure was obtained after the reoperation in 45 of 46 patients with previous parathyroid surgery, implying a success rate of 98%, and in all patients with previous thyroid surgery.

CONCLUSIONS

Reoperative parathyroid surgery is challenging. Results can be improved by consistently applied sensitive methods of preoperative imaging, and reoperative procedures may then achieve nearly the same success rates as primary operations.

The management of thyroid nodules in patients with primary hyperparathyroidism

BACKGROUND

Thyroid nodules are found in 12-52% of patients with primary hyperparathyroidism (pHPT). With the increasing use of minimally invasive parathyroidectomy (MIP), there is no standard approach for the management of incidental thyroid nodules in pHPT patients.

METHODS

A survey was conducted of the American Association of Endocrine Surgeons. Information was obtained regarding parathyroidectomy practice patterns, including surgical technique, preoperative localization procedures, and algorithms used in the diagnosis/treatment of incidental thyroid nodules.

RESULTS

The survey response rate was 74%. Sixty-seven percent were high-volume parathyroid surgeons (>5/mo); the majority performed MIP. High-volume surgeons were more likely to use Sestamibi/single photon emitted computed tomography for preoperative localization (40% versus 24%; P = 0.011) and to disregard incidentally discovered thyroid nodules <1 cm (41% versus 22%; P = 0.023). They were less likely to evaluate nodules discovered intraoperatively by frozen section (28% versus 41%; P = 0.081), fine-needle aspiration (13% versus 24%; P = 0.078), or thyroidectomy (24% versus 40%; P = 0.03). Surgeons performing open parathyroidectomy were more likely than those who use MIP to biopsy nodules intraoperatively (32% versus 20%; P < 0.05) and perform simultaneous thyroidectomy (30% versus 10%; P < 0.001).

CONCLUSIONS

Experienced endocrine surgeons disagree about the optimal management of incidental thyroid nodules encountered during parathyroidectomy. Our data suggest that high-volume parathyroid surgeons are less aggressive in their evaluation of thyroid pathology in patients with pHPT. Variation in practice among this experienced group implies even greater variation in the broader surgical community, and in the quality and cost of care for patients with pHPT.