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

Chapter 11: Treatment modalities

Treatment modalities for primary hyperparathyroidism must take account of the expected benefits and risks of each treatment envisaged, before choosing the definitive option to be proposed to the patient. In this section, a Foreword puts in perspective the difficulties involved in choosing the criteria for a particular treatment method. Treatments are then considered one after the other: surgery, local destruction and medical management. This section does not consider therapeutic indications, which are dealt with in a section 9.

Does 18F-Fluorocholine PET/CT add value to positive parathyroid scintigraphy in the presurgical assessment of primary hyperparathyroidism?

Introduction

To investigate the value of presurgical 18F-FCH PET/CT in detecting additional hyperfunctioning parathyroids despite a positive 99mTc-sestamibi parathyroid scintigraphy in patients with primary hyperparathyroidism (pHPT).

Methods

This is a retrospective study involving patients with pHPT, positive parathyroid scintigraphy performed before 18F-FCH PET/CT, and parathyroid surgery achieved after PET/CT. Imaging procedures were performed according to the EANM practice guidelines. Images were qualitatively interpreted as positive or negative. The number of pathological findings, their topography, and ectopic location were recorded. Histopathology, Miami criterion, and biological follow-up were considered to ensure effective parathyroidectomy confirming the complete excision of all hyperfunctioning glands. The impact of 18F-FCH PET/CT on therapeutic strategy was recorded.

Results

64/632 scanned pHPT patients (10%) were included in the analysis. According to a per lesion-based analysis, sensitivity, specificity, positive predictive value, and negative predictive value of 99mTc-sestamibi scintigraphy were 82, 95, 87, and 93%, respectively. The same values for 18F-FCH PET/CT were 93, 99, 99, and 97%, respectively. 18F-FCH PET/CT showed a significantly higher global accuracy than 99mTc-sestamibi scintigraphy: 98% (CI: 95-99) vs. 91% (CI: 87-94%). Youden Index was 0.79 and 0.92 for 99mTc-sestamibi scintigraphy and 18F-FCH PET/CT, respectively. Scintigraphy and PET/CT were discordant in 13/64 (20%) patients (49 glands). 18F-FCH PET/CT identified nine pathologic parathyroids not detected by 99mTc-sestamibi scintigraphy in 8 patients (12.5%). Moreover, 18F-FCH PET/CT allowed the reconsideration of false-positive scintigraphic diagnosis (scinti+/PET-) for 8 parathyroids in 7 patients (11%). The 18F-FCH PET/CT influenced the surgical strategy in 7 cases (11% of the study population).

Conclusion

In a preoperative setting, 18F-FCH PET/CT seems more accurate and useful than 99mTc-sestamibi scan in pHPT patients with positive scintigraphic results. Positive parathyroid scintigraphy could be not satisfactory before neck surgery particularly in patients with multiglandular disease, suggesting a need to evolve the practice and define new preoperative imaging algorithms including 18F-FCH PET/CT at the fore-front in pHPT patients.

Surgical Aspects of Primary Hyperparathyroidism

Parathyroidectomy (PTX) is the treatment of choice for symptomatic primary hyperparathyroidism (PHPT). It is also the treatment of choice in asymptomatic PHPT with evidence for target organ involvement. This review updates surgical aspects of PHPT and proposes the following definitions based on international expert consensus: selective PTX (and reasons for conversion to an extended procedure), bilateral neck exploration for non-localized or multigland disease, subtotal PTX, total PTX with immediate or delayed autotransplantation, and transcervical thymectomy and extended en bloc PTX for parathyroid carcinoma. The systematic literature reviews discussed covered (i) the use of intraoperative PTH (ioPTH) for localized single-gland disease and (ii) the management of low BMD after PTX. Updates based on prospective observational studies are presented concerning PTX for multigland disease and hereditary PHPT syndromes, histopathology, intraoperative adjuncts, localization techniques, perioperative management, "reoperative" surgery and volume/outcome data. Postoperative complications are few and uncommon (<3%) in centers performing over 40 PTXs per year. This review is the first global consensus about surgery in PHPT and reflects the current practice in leading endocrine surgery units worldwide. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Primary Hyperparathyroidism: Defining the Appropriate Preoperative Imaging Algorithm

Primary hyperparathyroidism is a common and potentially debilitating endocrine disorder for which surgery is the only curative treatment. Preoperative imaging is always recommended, even in cases of conventional bilateral neck exploration, with a recognized role for 99mTc-sestamibi scintigraphy in depicting ectopic parathyroid lesions. Scintigraphy can also play a major role in guiding a targeted, minimally invasive parathyroidectomy. However, the ability to recognize multiple-gland disease (MGD) varies greatly depending on the imaging protocol used. Preoperative diagnosis of MGD is important to reduce the risks of conversion to bilateral surgery or failure. In this article we discuss imaging strategies before first surgery as well as in the case of repeat surgery for persistent or recurrent primary hyperparathyroidism. We describe a preferred algorithm and alternative options. Dual-tracer 99mTc-sestamibi/123I subtraction scanning plus neck ultrasound is the preferred first-line option. This approach should improve MGD detection and patient selection for minimally invasive parathyroidectomy. Second-line imaging procedures in case of negative or discordant first-line imaging results are presented. High detection rates can be obtained with 18F-fluorocholine PET/CT or with 4-dimensional CT. The risk of false-positive results should be kept in mind, however. Adding a contrast-enhanced arterial-phase CT acquisition to conventional 18F-fluorocholine PET/CT can be a way to improve accuracy. We also briefly discuss other localization procedures, including 11C-methionine PET/CT, MRI, ultrasound-guided fine-needle aspiration, and selective venous sampling for parathyroid hormone measurement.

Routine bilateral neck exploration and four-gland dissection remains unnecessary in modern parathyroid surgery

Objective

Recent advances in preoperative imaging techniques and intraoperative parathyroid hormone (ioPTH) assays have made single-gland, minimally invasive parathyroidectomy (MIP) the preferred treatment option for most patients with primary hyperparathyroidism (pHPT). Despite this evolution, a recommendation for bilateral neck exploration (BNE) with four-gland dissection in all patients has recently been advocated by a parathyroid surgical group. The current study compares the long-term outcomes of MIP with those of conventional BNE with four-gland dissection in patients with pHPT.

Methods

In order to objectively assess a recommendation in the literature that universal BNE with four-gland dissection is advisable, all patients undergoing an initial MIP with ioPTH assessment for pHPT in a tertiary endocrine practice during a 10-year period were reviewed. The cure rates from this procedure were compared with published results of conventional BNE with four-gland dissection.

Results

Of the 561 patients undergoing parathyroidectomy during the study period, 337 had initial surgery for pHPT; 282 of these patients met inclusion criteria and 212 had sufficient follow-up data available. A single adenoma was identified in 87.3% of cases. Preoperative imaging studies were co-localizing in 148 (69.8%), and 127 (85.8%) of these patients with co-localizing imaging required only single-gland surgery. Imaging studies did not co-localize in 49 patients, yet 32 (65.3%) of these patients were still cured with unilateral surgery. The cure rate for patients undergoing MIP was 98.6%, with a long-term recurrence rate of <2%.

Conclusion

When coupled with the ioPTH assay, patients with at least one preoperative localizing study can undergo MIP and anticipate a cure rate of 99%, which is as good as or better than the published rates for conventional BNE with four-gland dissection. With unilateral surgery, the risks of permanent hypoparathyroidism and airway obstruction from bilateral vocal fold paralysis are completely eliminated. Therefore, despite recommendations to the contrary, most patients with pHPT should not have a planned four-gland exploration.

Level of Evidence

III or IV.

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

BACKGROUND

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

PURPOSE

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION

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

DATA SYNTHESIS

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

LIMITATIONS

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

CONCLUSION

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

Persistent and recurrent hyperparathyroidism

Despite remarkable progress in imaging modalities and surgical management, persistence or recurrence of primary hyperparathyroidism (PHPT) still occurs in 2.5-5% of cases of PHPT. The aim of this review is to expose the management of persistent and recurrent hyperparathyroidism. A literature search was performed on MEDLINE using the search terms "recurrent" or "persistent" and "hyperparathyroidism" within the past 10 years. We also searched the reference lists of articles identified by this search strategy and selected those we judged relevant. Before considering reoperation, the surgeon must confirm the diagnosis of PHPT. Then, the patient must be evaluated with new imaging modalities. A single adenoma is found in 68% of cases, multiglandular disease in 28%, and parathyroid carcinoma in 3%. Others causes (<1%) include parathyromatosis and graft recurrence. The surgeon must balance the benefits against the risks of a reoperation (permanent hypocalcemia and recurrent laryngeal nerve palsy). If surgery is necessary, a focused approach can be considered in cases of significant imaging foci, but in the case of multiglandular disease, a bilateral neck exploration could be necessary. Patients with multiple endocrine neoplasia syndromes are at high risk of recurrence and should be managed regarding their hereditary pathology. The cure rate of persistent-PHPT or recurrent-PHPT in expert centers is estimated from 93 to 97%. After confirming the diagnosis of PHPT, patients with persistent-PHPT and recurrent-PHPT should be managed in an expert center with all dedicated competencies.

Comparison of minimally invasive parathyroidectomy under local anaesthesia and minimally invasive video-assisted parathyroidectomy for primary hyperparathyroidism: a cost analysis

BACKGROUND

Primary hyperparathyroidism (PHPT) origins from a solitary adenoma in 70- 95% of cases. Moreover, the advances in methods for localizing an abnormal parathyroid gland made minimally invasive techniques more prominent. This study presents a micro-cost analysis of two parathyroidectomy techniques.

PATIENTS AND METHODS

72 consecutive patients who underwent minimally invasive parathyroidectomy, video-assisted (MIVAP, group A, 52 patients) or "open" under local anaesthesia (OMIP, group B, 20 patients) for PHPT were reviewed. Operating room, consumable, anaesthesia, maintenance costs, equipment depreciation and surgeons/anaesthesiologists fees were evaluated. The patient's satisfaction and the rate of conversion to conventional parathyroidectomy were investigated. T-Student's, Kolmogorov-Smirnov tests and Odds Ratio were used for statistical analysis.

RESULTS

1 patient of the group A and 2 of the group B were excluded from the cost analysis because of the conversion to the conventional technique. Concerning the remnant patients, the overall average costs were: for Operative Room, 1186,69 € for the MIVAP group (51 patients) and 836,11 € for the OMIP group (p<0,001); for the Team, 122,93 € (group A) and 90,02 € (group B) (p<0,001); the other operative costs were 1388,32 € (group A) and 928,23 € (group B) (p<0,001). The patient's satisfaction was very strongly in favour of the group B (Odds Ratio 20,5 with a 95% confidence interval).

CONCLUSIONS

MIVAP is more expensive compared to the "open" parathyroidectomy under local anaesthesia due to the costs of general anaesthesia and the longer operative time. Moreover, the patients generally prefer the local anaesthesia. Nevertheless, the rate of conversion to the conventional parathyroidectomy was relevant in the group of the local anaesthesia compared to the MIVAP, since the latter allows a four-gland exploration.

Primary hyperparathyroidism

Primary hyperparathyroidism is a common endocrine disorder caused by overactivation of parathyroid glands resulting in excessive release of parathyroid hormone. The resultant hypercalcemia leads to a myriad of symptoms. Primary hyperparathyroidism may increase a patient's morbidity and even mortality if left untreated. During the last few decades, disease presentation has shifted from the classic presentation of severe bone and kidney manifestations to most patients now being diagnosed on routine labs. Although surgery is the only curative therapy, many advances have been made over the past decades in the diagnosis and the surgical management of primary hyperparathyroidism. The aim of this review is to summarize the characteristics of the disease, the work up, and the treatment options.

Intraoperative scintigraphy using a large field-of-view portable gamma camera for primary hyperparathyroidism: initial experience

Background. We investigated a novel technique, intraoperative ^99 mTc-Sestamibi (MIBI) imaging (neck and excised specimen (ES)), using a large field-of-view portable gamma camera (LFOVGC), for expediting confirmation of MIBI-avid parathyroid adenoma removal. Methods. Twenty patients with MIBI-avid parathyroid adenomas were preoperatively administered MIBI and intraoperatively imaged prior to incision (neck) and immediately following resection (neck and/or ES). Preoperative and intraoperative serum parathyroid hormone monitoring (IOPTH) and pathology (path) were also performed. Results. MIBI neck activity was absent and specimen activity was present in 13/20 with imaging after initial ES removal. In the remaining 7/20 cases, residual neck activity and/or absent ES activity prompted excision of additional tissue, ultimately leading to complete hyperfunctioning tissue excision. Postexcision LFOVGC ES imaging confirmed parathyroid adenoma resection 100% when postresection imaging qualitatively had activity (ES) and/or no activity (neck). The mean ± SEM time saving using intraoperative LFOVGC data to confirm resection versus first IOPTH or path result would have been 22.0 ± 2 minutes (specimen imaging) and 26.0 ± 3 minutes (neck imaging). Conclusion. Utilization of a novel real-time intraoperative LFOVGC imaging approach can provide confirmation of MIBI-avid parathyroid adenoma removal appreciably faster than IOPTH and/or path and may provide a valuable adjunct to parathyroid surgery.

Is intraoperative parathyroid hormone monitoring necessary with ipsilateral parathyroid gland visualization during anticipated unilateral exploration for primary hyperparathyroidism: a two-institution analysis of more than 2,000 patients

INTRODUCTION

Intraoperative parathyroid hormone (ioPTH) monitoring during focused parathyroidectomy for primary hyperparathyroidism (PHPT) is used commonly, but some argue that ioPTH adds little if a normal ipsilateral parathyroid gland (IPG) is visualized. This hypothesis was tested for validity.

METHODS

The prospective databases of consecutive patients with PHPT undergoing initial parathyroidectomy with ioPTH at two academic institutions were queried. Patients with ectopic adenoma, familial PHPT, previous parathyroidectomy, planned bilateral exploration, or <6 months follow-up were excluded. Persistence was defined as hypercalcemia at <6 months.

RESULTS

From 1998 to 2013, 2,162 patients met inclusion criteria, and the rate of persistent disease was 1.5%. Most (n = 1,353; 63.5%) underwent single-gland resection with ioPTH and no IPG visualization, with 1% persistence. Among patients with a single adenoma resected and a normal IPG visualized, 15.2% had contralateral disease. Resection based on IPG appearance alone would have resulted in 13% persistent disease.

CONCLUSION

In PHPT, the cure rate for initial unilateral exploration guided by ioPTH is 98.5% versus a predicted rate of 87% when decision making is based on IPG appearance alone. Routine visualization of IPG is not necessary during exploration for suspected single adenoma guided by ioPTH. ioPTH remains useful in optimizing outcomes.

Outcomes for minimally invasive parathyroidectomy: widening inclusion criteria based on preoperative imaging results

BACKGROUND

Primary hyperparathyroidism is caused by a single adenoma in at least 80% of cases. Minimally invasive parathyroidectomy (MIP) has overtaken bilateral neck exploration as the gold standard for treatment in cases with adequate preoperative localization. There is evidence that, following careful review of preoperative imaging by the surgeon, increasing numbers of patients can successfully undergo MIP.

METHODS

We conducted a retrospective review of 225 consecutive cases performed by a single surgeon. Outcomes for patients with disease reported as localized by radiologists and nuclear medicine physicians using sestamibi and ultrasound were compared with patients with negative or indeterminate localization studies, in which the surgeon reviewed the sestamibi, performed an ultrasound study and identified likely single adenomas and planned MIP.

RESULTS

One hundred and sixty patients with radiologist-localized disease and an additional 29 patients with surgeon-localized disease underwent MIP. The surgeon-localized group had higher rates of conversion to bilateral neck exploration (21% compared with 4%, P = 0.004), but rates of failure to cure were comparable between the two groups (4.3% compared with 2.8%).

CONCLUSION

Careful review of preoperative sestamibi and ultrasound studies by an experienced surgeon can increase the number of patients that can successfully undergo MIP for the treatment of primary hyperparathyroidism. Offering MIP to these patients does not result in increased rates of failure or recurrence.

Preoperative multiple endocrine neoplasia type 1 diagnosis improves the surgical outcomes of pediatric patients with primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (PHPT) is uncommon in children. The surgical management of PHPT in children has evolved over the past two decades.

METHODS

A retrospective study of patients who underwent parathyroidectomy for PHPT diagnosed at age < 18 years and managed at a tertiary referral center for endocrine and familial disorders.

RESULTS

Thirty-eight patients met eligibility criteria (1981-2012). Median age at PHPT diagnosis was 15 years. Two-thirds of patients were symptomatic (68%, n=26), most commonly from nephrolithiasis. Twenty-six (68%) patients underwent a standard cervical exploration while 32% underwent a focused unilateral parathyroidectomy. Multiple endocrine neoplasia type 1 (MEN1) was diagnosed preoperatively in 22/26 patients. Patients with a preoperative diagnosis of MEN1 were more likely to undergo a complete initial operation (≥ 3 gland parathyroidectomy with transcervical thymectomy, 13/22, 59% vs. 0/4, 0%; P=0.03) and less likely to have recurrent disease (10/22, 45% vs. 3/4, 75%; P<0.001) during follow up than patients diagnosed postoperatively.

CONCLUSIONS

Children with PHPT should raise suspicion for MEN1. Preoperative MEN1 evaluation helped guide the extent of initial parathyroidectomy and was associated with lower rates of recurrence in sporadic and familial PHPT in pediatric patients. Management should occur at a high volume center with experienced clinicians and genetic counseling services.