Is Unilateral Neck Surgery Feasible in Patients with Sporadic Primary Hyperparathyroidism and Double Negative Localisation?

A 15-year experience: intraoperative parathyroid hormone assay for the management of primary hyperparathyroidism in a UK endocrine surgical unit

PURPOSE

This study aims to evaluate the outcomes of first-time parathyroidectomy for primary hyperparathyroidism using intraoperative PTH (IOPTH) assay in the light of the UK National Institute for Health and Care Excellence (NICE) guidelines for the management of primary hyperparathyroidism.

METHOD

This is a retrospective cohort analysis of a prospectively maintained database of endocrine surgery in a tertiary centre. Preoperative radiological localisation (concordance and accuracy), intraoperative PTH parameters and adjusted serum calcium at minimum 6-month follow-up were analysed. The accuracy of IOPTH to predict post-operative normocalcaemia and the number needed to treat (NNT) within the cohort when IOPTH was utilised were determined. Differences between groups were evaluated with Chi-squared and Fisher's exact test.

RESULTS

Between January 2004 and September 2018, 849 patients (75.4% women), median age 64 years (IQR 54-72), were analysed. The median preoperative adjusted serum calcium was 2.80mmol/l (IQR 2.78-2.90), and the median preoperative PTH was 14.20pmol/l (IQR 10.70-20.25). The overall first-time cure (normocalcaemia) rate was 96.4%. The sensitivity, specificity, positive predictive value and negative predictive values of IOPTH were 96.8%, 83.2%, 97.6% and 78.8%, respectively, with an accuracy of 95.1%. For patients with concordant scans (48.3%), a targeted approach without IOPTH would have achieved a cure rate of 94.1% compared with 98.0% using IOPTH (p<0.01) CONCLUSION: The use of IOPTH assay significantly improved the rate of normocalcaemia at 6 months. The low NNT to benefit from IOPTH, particularly those patients with a single positive scan, and the inevitable reduction in the potential costs incurred from failure and reoperation justify its utilisation.

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 the performance of ultrasonography and 99mTc-sestamibi scintigraphy for primary hyperparathyroidism surgery

INTRODUCTION

Minimally invasive surgery has become the standard surgical attitude in primary hyperparathyroidism. It requires precise preoperative lesion localization. The aim of the present study was to evaluate the performance of ultrasonography and 99mTc-sestamibi scintigraphy in minimally invasive surgery for primary hyperparathyroidism.

MATERIALS AND METHODS

A retrospective study included all patients managed surgically for primary hyperparathyroidism between January 2008 and November 2017 in the University Hospital of Brest (France). Two hundred and seventy-three patients underwent ultrasonography and 99mTc-sestamibi scintigraphy. Results determined intrinsic (sensitivity and specificity) and extrinsic (positive and negative predictive values) performance on per-patient and per-gland analysis. Demographic, preoperative, interventional and cure data were compared according to ultrasonography and scintigraphy results, distinguishing 3 patient groups: concordant n=156, discordant n=99, negative n=18.

RESULTS

On per-gland analysis, sensitivity was 70% for ultrasound, 74% for 99mTc-sestamibi scintigraphy and 81% for associated ultrasound-scintigraphy; positive predictive values were 89%, 91% and 96%, respectively. Gland volume and concomitant thyroid pathology rates differed significantly (both p=0.003) between the 3 imaging results groups.

CONCLUSION

The performance of associated ultrasound-99mTc-sestamibi-scintigraphy provided a positive predictive value of 96%. Combining the two techniques reduced surgical morbidity.

Surgical Treatment of Primary Hyperparathyroidism: Which Therapy to Whom?

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

The surgical management of sporadic primary hyperparathyroidism

Sporadic primary hyperparathyroidism (pHPT) is the commonest cause of hypercalcaemia in the ambulatory population. It has a female preponderance and its incidence is increasing. In 85% of cases it is caused by a single parathyroid adenoma, with four gland hyperplasia in up to 20%. Parathyroidectomy is the only cure and bilateral neck exploration remains the gold standard to achieve this. Several adjuncts have been developed to improve success rates or limit the extent of surgery. Pre-operative localisation permits planned targeted surgery. Ultrasound scanning and scintigraphy are the most commonly employed, although 4DCT has become a useful modality in complex cases. However, excellent rates of biochemical cure can be achieved in specialist centres when pre-operative imaging is negative. Pre-operative prediction models and intra-operative parathyroid hormone (ioPTH) assist, with high sensitivity, to predict single gland disease. Reoperations present a major challenge to the endocrine surgeon.

Primary hyperparathyroidism: findings from the retrospective evaluation of cases over a 6-year period from a regional UK centre

BACKGROUND

Although there are international guidelines on diagnosis and management of primary hyperparathyroidism (PHPT), clinical practice varies in different centres. Periodic review of diagnostic work-up, surgical treatment by parathyroidectomy (PTX) and clinical surveillance in nonsurgical treatment group among patients with PHPT is expected to improve the quality of care. We report a retrospective study of cases with PHPT managed at a regional centre in the United Kingdom.

METHODS

Clinical data of cases with calcium ≥2.6 mmol/L and parathyroid hormone (PTH) ≥9.0 pmol/L was procured from biochemistry database from January 2011 to December 2016. Laboratory parameters, imaging studies for renal stones, osteoporosis and localisation of parathyroid adenomas, type of treatment received (PTX or nonsurgical), complications of treatment, other medical co-morbidities and mortality during follow-up was recorded in each case to examine the outcomes of care of patients with PHPT.

RESULTS

The study included 160 patients: 127 (79%) females and 33 (21%) males. Median age was 70 years in females and 74 in males. Thirty cases (19% of 159) had renal stones and 47 (37.3% of 126) had osteoporosis. Eighty-one cases (51%) received PTX. Logistic regression analysis showed that higher calcium levels (odds ratio (OR) = 73.991; p < 0.001), peak PTH (OR = 1.023; p = 0.025), peak alkaline phosphatase (OR = 0.985, p < 0.001), lower age (OR = 0.985, p < 0.001) and male gender (OR = 0.209, p < 0.002) as statistically significant predictors for patients receiving PTX. Higher age at diagnosis of PHPT was associated with increased risk of co-existent hypertension (OR = 10.904, p = 0.001) and fractures (OR = 1.067, p = 0.004). Higher peak calcium concentration was an independent predictor of acute kidney injury (OR = 9.631, p = 0.011). PTX cured 76 cases (94%) with only 7 (9%) postoperative complications. Twenty-four cases (15%) died from the entire cohort (only one from PTX group) during a median follow-up period of 3.6 years (interquartile range = 1.5).

CONCLUSIONS

PTX treatment is associated with cure of disease in patients with PHPT with acceptable risk of complications. Improvements in diagnostic work-up and follow-up care should improve the morbidity from PHPT.