Use of minimally invasive parathyroidectomy techniques in sporadic primary hyperparathyroidism: systematic review

Open Minimally Invasive Parathyroidectomy Versus Minimally Invasive Video-Assisted Parathyroidectomy: A Systematic Review and Meta-Analysis

Various minimally invasive techniques exist for surgical parathyroidectomy. The aim of this study was to conduct a meta-analysis comparing two popular minimally invasive techniques: minimally invasive video-assisted parathyroidectomy (MIVAP) and open minimally invasive parathyroidectomy (OMIP). An extensive search was conducted of online databases to identify all previous studies that had compared MIVAP and OMIP. The primary outcome measures considered were visual analog scale (VAS) score 24 hours postoperatively, conversion of operation (to open), failure rate and analgesic consumption. The data from these studies was extracted and compiled into a meta-analysis. The literature search yielded 104 studies of which four were included, enrolling 903 patients in this analysis. A significant difference was found regarding rates of conversion to open parathyroidectomy between the two groups, with the OMIP group demonstrating fewer conversions (MD = 3.52, CI = (2.04-6.08), P< 0.00001). No statistically significant differences were found between the two groups when comparing postoperative VAS scores at 24 hours (MD = -1.75, CI = (-9.8-6.3), P = 0.67), consumption of analgesia (OR = 0.49, CI = 0.07-3.54, P = 0.48) or failure rates (OR = 1.81, CI = 0.58-5.72, P = 0.31). OMIP was seen to require less need to convert to open parathyroidectomy with shorter operative times, while similar complication rates and scar lengths to MIVAP. More studies are required to evaluate the superior technique for parathyroidectomy.

ACR Appropriateness Criteria® Parathyroid Adenoma

Hyperparathyroidism is defined as excessive parathyroid hormone production. The diagnosis is made through biochemical testing, in which imaging has no role. However, imaging is appropriate for preoperative parathyroid gland localization with the intent of surgical cure. Imaging is particularly useful in the setting of primary hyperparathyroidism whereby accurate localization of a single parathyroid adenoma can facilitate minimally invasive parathyroidectomy. Imaging can also be useful to localize ectopic or supernumerary parathyroid glands and detail anatomy, which may impact surgery. This document summarizes the literature and provides imaging recommendations for hyperparathyroidism including primary hyperparathyroidism, recurrent or persistent primary hyperparathyroidism after parathyroid surgery, secondary hyperparathyroidism, and tertiary hyperparathyroidism. Recommendations include ultrasound, CT neck without and with contrast, and nuclear medicine parathyroid scans. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Role of Vitamin D Supplements in Prevention of Hungry Bone Syndrome after Successful Parathyroidectomy for Primary Hyperparathyroidism: A Prospective Study

BACKGROUND

We postulated that the preoperative correction of vitamin D levels can significantly reduce the incidence of hunger bone syndrome among patients undergoing parathyroidectomy for primary hyperparathyroidism.

METHODS

We performed a prospective, randomized, open-label study on 102 patients with primary hyperparathyroidism and coexisting vitamin D deficiency who were scheduled to undergo parathyroidectomy. Patients were divided into the following two groups: group I which included 52 patients who did not receive preoperative vitamin D supplementation; and group II which included 50 patients who received cholecalciferol 1000-2000 IU daily or 50000 IU weekly until they achieve vitamin D levels >20 ng/mL (group IIa = 25 patients) or vitamin D levels >30 ng/mL (group IIb = 25 patients).

RESULTS

The incidence of hunger bone syndrome in group IIb was lower than group I and group IIa (8% versus 16% versus 23%, respectively); however, this difference did not reach the level of statistical significance (p = 0.22). Patients with hunger bone syndrome were significantly younger and had higher serum phosphorus, alkaline phosphatase, magnesium, and bone mineral density at baseline than patients without hunger bone syndrome. On the other hand, patients with hunger bone syndrome had significantly lower 25-hydroxyvitamin D at baseline than patients without hunger bone syndrome (p = 0.001). The ROC curve showed that the baseline level of serum 25-hydroxyvitamin D was not an independent discriminator of hunger bone syndrome (area under curve = 0.21 (95% CI: 0.06-0.34); p = 0.011).

CONCLUSION

Preoperative course of vitamin D supplements has no preventive role on the postoperative incidence of hunger bone syndrome among patients with primary hyperparathyroidism and coexisting vitamin D deficiency undergoing parathyroidectomy.

Accuracy of 4-Dimensional Computed Tomography for Localization in Primary Hyperparathyroidism

BACKGROUND

The etiology of primary hyperparathyroidism (PHP) is single-gland adenoma in most patients. Imaging localization of single-gland disease allows for a focused operation. We sought to determine the accuracy of imaging for localizing a solitary parathyroid adenoma.

METHODS

A single-institution retrospective review was performed of adult patients with PHP undergoing parathyroidectomy from January 2017 through December 2018. Surgeon-performed ultrasound (US), four-dimensional computed tomography (4DCT), and sestamibi were assessed for localization of a parathyroid adenoma yielding a single-gland parathyroidectomy. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for each imaging modality.

RESULTS

One hundred fifty-four patients underwent parathyroidectomy for PHP during the study period, with 100 patients meeting inclusion criteria with a mean age of 61.1 (SD 10) y and 80% women. Mean calcium was 11.1 mg/dL (SD 0.7) and mean PTH was 116 pg/mL (SD 66). All 100 patients had surgeon-performed US with 17 localized, 51 patients had 4DCT with 41 (80%) localized, and 69 patients had sestamibi with 53 (77%) localized. Eighty-two patients underwent successful unilateral parathyroidectomy, 18 required bilateral neck exploration. US was the most specific imaging modality at 94%. Accuracy of imaging localization was 32% for US, 70% for sestamibi, and 86% for 4DCT.

CONCLUSIONS

Surgeon-performed US is a highly specific imaging modality for preoperative localization of solitary parathyroid adenoma in patients with PHP. 4DCT is the most accurate imaging localization study and should be considered for patients with a nonlocalized US.

Day case parathyroidectomy: is this the right way for the patients?

Background

Minimally-invasive video-assisted parathyroidectomy (MIVAP) can be considered as the primary treatment of choice for single parathyroid adenoma. Often, this technique is performed in a day surgery setting and is associated with regional anaesthesia (RA). Many studies have already reported the feasibility and safety of MIVAP in day surgery. Here our focus has been on the patient's personal experience with these procedures through an assessment of their recovery at home.

Methods

We conducted a prospective observational study in the University Hospital of Pisa Day Surgery Unit. Forty-eight patients were enrolled and divided by personal choice of anaesthesia technique: a regional anaesthesia group (RAg) and general anaesthesia group (GAg). Data were extracted from the medical records and three questionnaires: the first was self-compiled at discharge (Q1), while the second (Q2) and the third (Q3) were administered as telephone surveys.

Results

None of the patients in RAg reported pain longer than 1 day after discharge, whereas 15% of patients in GAg reported pain relief the third day after discharge (P=0.0065). Discharge in RAg was within 3 hours in 12.5% of patients, within 4 hours in 78.1%, and within 5 hours in 9.4%. Discharge in GAg was within 5 hours in 53.8% and in more than 5 hours in 46.1% (P=0.0027).

Conclusions

Patients highly appreciated day-case parathyroidectomy. Furthermore, the association of RA with MIVAP leads to better results than those of general anaesthesia (GA) and MIVAP. Finally, we point out that it is fundamental that the physicians pay attention to what the patients consider important for them; that is, the personal meaning of the hospitalization.

Management protocol for primary hyperparathyroidism in a single institution: utility of surgeon performed ultrasound

Background

We aimed to: (I) discover preoperative diagnostic studies, intraoperative techniques, and patient factors most predictive of cure within a single hospital system; (II) establish practice guidelines for surgical treatment of primary hyperparathyroidism to maximize outcomes based on this hospital system's performance.

Methods

A retrospective chart review was undertaken of all parathyroid-related procedures from 01/01/02 to 7/31/15 at the Veteran's Administration Hospital.

Results

Seventy-one patients were eligible and charts available for analysis. Preoperative studies most predictive of cure were a combination of sestamibi parathyroid scan and surgeon performed ultrasound (S-US). When studies did not agree, S-US was most often correct. Intraoperative parathyroid hormone (PTH) rapid assay was helpful in predicting cure, but added an average of 33 minutes to operating room time. Patients who had two corroborating preoperative localizing studies, one of which was S-US, that agreed with intraoperative findings, and who did not undergo intraoperative PTH confirmation enjoyed equal cure rates and shorter operating room times. Successful achievement of normal calcium was high at 95.8%. Vitamin D deficiency was prevalent in this patient population, prompting more aggressive preoperative investigation and replacement.

Conclusions

A management protocol was developed based on the findings of this study: (I) obtain two preoperative localization studies, one of which is surgeon-performed ultrasound; (II) obtain preoperative vitamin D levels and supplement as indicated; and (III) in select patients who have two strongly corroborating preoperative localization studies, one of which is surgeon performed ultrasound, and intraoperative findings are consistent with the localizing studies, intraoperative PTH (IOPTH) may not be necessary.

Morbidity in parathyroid surgery for renal disease is under reported: a comparison of outcomes with primary hyperparathyroidism

Introduction Parathyroidectomy is considered to be a safe procedure with low morbidity. However, while this is true for primary hyperparathyroidism, whether it applies to tertiary disease is not so well documented. The aim of this study was to assess the morbidity of surgery for tertiary hyperparathyroidism compared with primary disease and to establish whether there are predictive factors for poor outcomes. Methods Data for patients subjected to parathyroidectomy during the period 2007-2015 were retrospectively analysed from a prospectively collected database. Patient age, sex, American Society of Anesthesiologists (ASA) score, renal status, extent of operation and indications for surgery were examined. The complication and mortality rate were compared and independent predictors of outcome were examined. Results A total of 1079 patients were scheduled for a parathyroidectomy during the study period of whom 158 for renal related hyperparathyroidism (renal group) and 921 for primary disease (non-renal group). There was a significantly higher complication rate in the renal parathyroid group, including a higher mortality (1.3% vs 0.1%, P = 0.011), overall complication rate (7.0% vs 2.3%, P = 0.001), surgery related complication rate (4.4% vs 1.7%, P = 0.03) and systemic complication rate (2.5% vs 0.4%, P = 0.005). In patients with ASA score ≤ 2 reoperative surgery (OR 9.25, 95% confidence interval, CI 1.41-60.75), male sex (OR 4.12, 95% CI 1.46-11.63) and renal impairment were (OR 5.86, 95% CI 1.65-20.78) were predictors of worse outcomes. In patients with ASA score ≥3 renal impairment, in addition to other variables, were not predictors of complications. Conclusions Parathyroidectomy in renal-related disease is associated with a significantly higher risk of morbidity and mortality compared with primary hyperparathyroidism.

Systematic review of cure and recurrence rates following minimally invasive parathyroidectomy

Background

The majority of patients with primary hyperparathyroidism (PHPT) have a single overactive adenoma. Advances in preoperative imaging and surgical adjuncts have given rise to minimally invasive parathyroidectomy (MIP), with lower complication rates in comparison with bilateral neck exploration. Misdiagnosis and undertreatment of multiglandular disease, leading to potentially higher recurrence rates, remains a concern. This study evaluated risks of long‐term (1 year or more) recurrence following ‘targeted’ MIP in PHPT.

Methods

Multiple databases were searched for studies published between January 2004 and March 2017, looking at long‐term outcomes (1 year or more) following targeted MIP for PHPT. English‐language studies, with at least 50 patients and a mean follow‐up of 1 year, were included.

Results

A total of 5282 patients from 14 studies were included. Overall mean recurrence and cure rates were 1·6 (range 0–3·5) and 96·9 (95·5–100) per cent respectively. Mean follow‐up was 33·5 (1–145) months. When intraoperative parathyroid hormone (PTH) measurements were not done, cure rates were higher (99·3 per cent versus 98·1 per cent with use of intraoperative PTH measurement; P < 0·001) and recurrence rates lower (0·2 versus 1·5 per cent respectively; P < 0·001).

Conclusion

Targeted MIP for a presumed single overactive adenoma was associated with very low recurrence rates, without the need for intraoperative PTH measurement when preoperative imaging studies were concordant. Targeted MIP should be encouraged.

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).

[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.

Serum Calcium and Risk of Nonmedullary Thyroid Cancer in Patients with Primary Hyperparathyroidism

Background

Clinical cases of nonmedullary thyroid carcinoma (NMTC) in combination with primary hyperparathyroidism (PHPT) have been reported occasionally. However, the clinical characteristics and risk factors of concomitant NMTC in PHPT patients remain unclear. This study aimed to assess the association between PHPT and NMTC, and evaluate the clinical characteristics and risk factors of NMTC in Chinese patients with PHPT.

Material/Methods

This was a retrospective cohort analysis. We reviewed the medical records of 155 patients who underwent surgery for PHPT in two large medical centers in China between 2009 and 2014. The clinical manifestations, biochemical abnormalities, and histological characteristics of PHPT patients were analyzed.

Results

Of the 155 patients with PHPT, 58 patients (37.4%) had thyroid nodules and 12 patients (7.7%) were ill with concomitant NMTC. PHPT patients with NMTC demonstrated significantly lower preoperative serum calcium levels compared to PHPT patients with benign thyroid nodules (p<0.05). A significantly negative association between preoperative serum calcium levels and the presence of NMTC was found in PHPT patients (p<0.05). Furthermore, ROC analysis revealed that albumin-corrected serum calcium levels <2.67 mmol/L had good capacity to differentiate the PHPT patients with NMTC from those with benign thyroid nodules.

Conclusions

Compared with the reported much lower prevalence of thyroid carcinoma in the general population, our results suggest that PHPT might be a risk factor for the malignancy of thyroid nodules; a lower level of serum calcium may predict the existence of NMTC in PHPT patients with thyroid nodules.

The Essentials of Parathyroid Hormone Venous Sampling

Hyperparathyroidism is an excess of parathyroid hormone in the blood due to over-activity of one or more parathyroid gland. Localization of abnormal glands with noninvasive imaging modalities, such as technetium sestamibi scan and cross-sectional imaging, has a high success rate. Parathyroid venous sampling is performed for patients with persistent or recurrent disease after previous parathyroid surgery, when repeat noninvasive imaging studies are negative or discordant. The success of invasive localization studies and results interpretation is dependent on the interventional radiologist's understanding of the normal and ectopic anatomic locations of parathyroid glands, as well as their blood supply and venous drainage. Anatomic and technical considerations for selective parathyroid venous sampling are reviewed.

Iodine 125 Seed for Localization in Primary Hyperparathyroidism

Background. Preoperative localization of the parathyroid gland prior to a minimally invasive parathyroidectomy (MIP) is important because of varying locations of the parathyroid gland. Several methods have been described to localize the affected gland. One novel technique is the use of an iodine 125 (I-125) seed as a marker. The aim of this study is to evaluate the feasibility of using an I-125 seed in localizing the diseased parathyroid gland prior to MIP. Materials and methods. This is a pilot study of 10 patients performed in the Amphia Hospital, the Netherlands. Patients in whom primary hyperparathyroidism (PHPT) was diagnosed in combination with 1 enlarged parathyroid gland on ultrasound (US) and scintigraphy and who were eligible for MIP were included in this study. These patients underwent a preoperative US-guided I-125 seed placement in the affected parathyroid gland. The main study parameters were the feasibility of the placement, intraoperative localization of the diseased gland and complications. Results. A total of 10 patients were included. The US-guided I-125 placement in the affected parathyroid gland was technically feasible in the majority of cases. Because of the anatomical location of the gland, the placement was difficult in 2 patients, resulting in suboptimal position and possible misplacement of the marker. MIP was uncomplicated in most cases. Complications during surgery were mainly intraoperative bleeding. Conclusions. The use of an I-125 seed for preoperative localization in PHPT is a relatively safe technique in parathyroid surgery. More research is needed to compare this technique with other preoperative localization techniques.

Contemporary surgical treatment of primary hyperparathyroidism without intraoperative parathyroid hormone measurement

INTRODUCTION

Primary hyperparathyroidism (pHPT) is usually the result of a single adenoma that can often be accurately located preoperatively and excised by a focused operation. Intraoperative parathyroid hormone (IOPTH) measurement is used occasionally to detect additional abnormal glands. However, it remains controversial as to whether IOPTH monitoring is necessary. This study presents the results of a large series of focused parathyroidectomy without IOPTH measurement.

METHODS

Data from 2003 to 2014 were collected on 180 consecutive patients who underwent surgical treatment for pHPT by a single surgeon. Preoperative ultrasonography and sestamibi imaging was performed routinely, with computed tomography (CT) and/or selective venous sampling in selected cases. The preferred procedure for single gland disease was a focused lateral approach guided by on-table surgeon performed ultrasonography. Frozen section was used selectively and surgical cure was defined as normocalcaemia at the six-month follow-up appointment.

RESULTS

Focused surgery was undertaken in 146 patients (81%) and 97% of these cases had concordant results with two imaging modalities. In all cases, an abnormal gland was discovered at the predetermined site. Of the 146 patients, 132 underwent a focused lateral approach (11 of which were converted to a collar incision), 10 required a collar incision and 4 underwent a mini-sternotomy. At 6 months following surgery, 142 patients were normocalcaemic (97% primary cure rate). Three of the four treatment failures had subsequent surgery and are now biochemically cured. There were no complications or cases of persistent hypocalcaemia.

CONCLUSIONS

This study provides further evidence that in the presence of concordant preoperative imaging, IOPTH measurement can be safely omitted when performing focused parathyroidectomy for most cases of pHPT.

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.

A retrospective case-controlled study of video-assisted versus open minimally invasive parathyroidectomy

INTRODUCTION

Minimally invasive parathyroidectomy (MIP) with intraoperative parathyroid hormone assay (IOPTH) has successfully replaced conventional neck exploration in most patients with primary hyperparathyroidism (pHPT) and preoperatively localized parathyroid adenoma.

AIM

To compare outcomes of video-assisted MIP (MIVAP) to open MIP (OMIP).

MATERIAL AND METHODS

A retrospective case-controlled study of 455 patients with sporadic pHPT undergoing MIP with IOPTH at our institution in 2003-2012 was undertaken. The primary outcome measure was postoperative pain. Secondary outcome measures were: duration of surgery, recurrent laryngeal nerve (RLN) identification rate, conversion rate, length of hospital stay, cure rate, patients' satisfaction with cosmetic outcome, morbidity, costs, and diagnostic accuracy of IOPTH.

RESULTS

Of 455 patients with pHPT and a solitary parathyroid adenoma on preoperative imaging, 151 underwent MIVAP and 304 had OMIP. The following outcomes were favourable for MIVAP vs. OMIP: lower pain intensity during 24 h postoperatively (p < 0.001), lower analgesia request rate (p < 0.001), lower analgesics consumption (p < 0.001), higher recurrent laryngeal nerve identification rate (p < 0.001), shorter scar length (p < 0.001), and better cosmetic satisfaction at 1 month (p = 0.013) and at 6 months (p = 0.024) after surgery. However, MIVAP vs. OMIP had longer duration of surgery (p < 0.001), and was more expensive (p < 0.001). No differences were noted in the conversion rate, length of hospital stay, and morbidity.

CONCLUSIONS

Both MIVAP and OMIP approaches were equally safe and effective. However, the outcomes of MIVAP operations were superior to OMIP in terms of lesser postoperative pain, lower analgesics consumption, and better cosmetic satisfaction resulting from a smaller scar.

The relationship between secondary hyperparathyroidism and thyroid cancer in end stage renal disease: a population based cohort study

OBJECTIVES

We conducted a retrospective cohort study to investigate the risk of cancer in end stage renal disease (ESRD) patients with secondary hyperparathyroidism (HPT).

PATIENTS AND METHODS

This study investigated the elevated overall cancer risk in ESRD patients with secondary HPT in Taiwan. We used a population-based retrospective cohort consisting of original claims data of 1 million beneficiaries randomly sampled from the Taiwan National Health Insurance Research Database (NHIRD). We calculated the hazard ratios (HRs) and 95% confidence intervals (CIs) of cancer in the ESRD with secondary HPT and comparison cohorts, using the Cox proportional hazards regression model.

RESULTS

We observed that ESRD patients with secondary HPT exhibited a 10.1-fold increased risk of thyroid cancer than did ESRD patients without this parathyroid complication, after adjusting for comorbidities (95% confidence interval=1.12-91.0).

CONCLUSION

These phenomena indicate that ESRD patients with secondary HPT are at greater risk of thyroid cancer. Physicians should be alert for occult thyroid cancer in ESRD patients with secondary HPT.

Comparison of 99mTc-sestamibi and 11C-methionine PET/CT in the localization of parathyroid adenomas in primary hyperparathyroidism

AIM

To evaluate the usefulness of (11)C-methionine PET/CT (MET) in the localization of the parathyroid adenomas and to compare the results with those obtained with the conventional technique in double-phase (99m)Tc-sestamibi scintigraphy (MIBI). We evaluated the optimal timing to acquire MET images.

MATERIAL AND METHODS

A prospective study that included 14 patients (mean age: 65.5 ± 9.7 years) with primary hyperparathyroidism (PH) who underwent surgery was performed. Mean serum iPTH was 215.8 ± 108 pg/mL and serum calcium 10.8 ± 0.9 mg/dL. MIBI (planar and SPECT) was obtained 10 min and 2-3h after injection of 740 MBq (20 mCi) of (99m)Tc-sestamibi. MET was obtained 10 min and 40 min after injection of 740 MBq (20 mCi) of (11)C-methionine. MIBI and MET images were visually evaluated and compared. A score for 10 min and 40 min MET images from 0 (no abnormal uptake) to 3 (intense uptake) was assigned.

RESULTS

MIBI and MET were positive and concordant in 11/14 patients and in 10 of them the parathyroid adenoma was correctly localized. In 3/14 MIBI was positive and MET negative (MIBI correctly localized the parathyroid adenoma in 2 of them). According to the timing of MET imaging acquisition, the 10 min and 40 min acquisition showed the same score in 10 patients, it was higher at 10 min acquisition in 3 and in 1 the parathyroid adenoma was only detected at 40 min acquisition.

CONCLUSION

MIBI remains the technique of choice for the localization of parathyroid adenomas in patients with PH. MET may play a complementary role in selected patients. Delayed acquisition should be included in the MET protocol when the early acquisition is negative.

Minimal benefit to subsequent intraoperative parathyroid hormone testing after all four glands have been identified

BACKGROUND

Modern tools, such as intraoperative parathyroid hormone (IoPTH) assay, reduce operative time and extent of parathyroidectomy. However, the utility of a subsequent final set of IoPTH after all four glands are visualized remains questionable. This study was designed to determine the added value of IoPTH assay following parathyroidectomy with four-gland visualization in patients with primary hyperparathyroidism (PHPT).

METHODS

A retrospective review of patients who underwent parathyroidectomy for PHPT between July 2001 and February 2012 by two experienced endocrine surgeons was performed. Included were patients with operative reports indicating that all four parathyroid glands were identified. Following four-gland visualization a subsequent final set of IoPTH was measured to confirm cure. Cure was defined as at least 50 % fall by 5, 10, or 15 min postexcision compared with preincision levels.

RESULTS

Of 1,838 patients that underwent parathyroidectomy, four glands were visualized in 238 cases (13 %). Of those patients meeting inclusion criteria with four glands visualized, the final set of IoPTH fell to cure criteria in 235 patients (98 %). An inadequate drop was documented in three (2 %) patients all of which were found to have multigland disease. Only in one patient (0.4 %) was a fifth parathyroid gland identified and resected. In all three cases, the subsequent final IoPTH did not affect the ultimate outcome or cure rate.

CONCLUSIONS

When experienced surgeons visualize all four parathyroid glands, drawing a subsequent final set of IoPTH rarely changes the operative course and therefore serves a limited role.

Sex and age modify biochemical and skeletal manifestations of chronic hyperparathyroidism by altering target organ responses to Ca2+ and parathyroid hormone in mice

We studied mice with or without heterozygous deletion of the Casr in the parathyroid gland (PTG) [(PTG) CaSR(+/-)] to delineate effects of age and sex on manifestations of hyperparathyroidism (HPT). In control mice, aging induced a left-shift in the Ca(2+) /parathyroid hormone (PTH) set point accompanied by increased PTG CaSR expression along with lowered serum Ca(2+) and mildly increased PTH levels, suggesting adaptive responses of PTGs to aging-induced changes in mineral homeostasis. The aging effects on Ca(2+) /PTH set point and CaSR expression were significantly blunted in (PTG) CaSR(+/-) mice, who showed instead progressively elevated PTH levels with age, especially in 12-month-old females. These 12-month-old knockout mice demonstrated resistance to their high PTH levels in that serum 1,25-dihydroxyvitamin D (1,25-D) levels and RNA expression of renal Cyp27b1 and expression of genes involved in Ca(2+) transport in kidney and intestine were unresponsive to the rising PTH levels. Such changes may promote negative Ca(2+) balance, which further exacerbate the HPT. Skeletal responses to HPT were age-, sex-, and site-dependent. In control mice of either sex, trabecular bone in the distal femur decreased whereas cortical bone in the tibiofibular junction increased with age. In male (PTG) CaSR(+/-) mice, anabolic actions of the elevated PTH levels seemed to protect against trabecular bone loss at ≥ 3 months of age at the expense of cortical bone loss. In contrast, HPT produced catabolic effects on trabecular bone and anabolic effects on cortical bone in 3-month-old females; but these effects reversed by 12 months, preserving trabecular bone in aging mice. We demonstrate that the CaSR plays a central role in the adaptive responses of parathyroid function to age-induced changes in mineral metabolism and in target organ responses to calciotropic hormones. Restraining the ability of the PTG to upregulate CaSRs by heterozygous gene deletion contributes to biochemical and skeletal manifestations of HPT, especially in aging females.

Diagnostic performance of positron emission tomography using ¹¹C-methionine in patients with suspected parathyroid adenoma: a meta-analysis

The diagnostic performance of positron emission tomography using ¹¹C-methionine (MET-PET) in detecting parathyroid adenoma has been investigated by several studies with conflicting results. Aim of our study is to meta-analyze published data about this topic. A comprehensive computer literature search of studies published in PubMed/MEDLINE, Scopus and Embase databases through May 2012 and regarding the diagnostic performance of MET-PET in patients with parathyroid adenoma was carried out. No language restriction was used. Only articles in which at least five patients with parathyroid adenoma underwent MET-PET were included in the meta-analysis. Pooled sensitivity and detection rate (DR) on a per patient-based analysis were calculated to assess the diagnostic performance of MET-PET. Nine studies comprising 258 patients with suspected parathyroid adenoma were included in this meta-analysis. Pooled sensitivity and DR values of MET-PET in patients with suspected parathyroid adenoma were 81 % (95 % confidence interval [95 %CI] 74-86 %) and 70 % (95 %CI 62-77 %), respectively, on a per patient-based analysis. The included studies were heterogeneous in their estimate of sensitivity and DR. Our meta-analysis demonstrates that MET-PET is a sensitive and reliable tool in patients with suspected parathyroid adenoma. Thus, this imaging method could be helpful in patients with diagnosis of primary hyperparathyroidism when conventional imaging techniques are negative or inconclusive in localizing parathyroid adenoma.

Interobserver and intraobserver agreement in parathyroid scintigraphy: How can parathyroid scintigraphy be made more reliable?

OBJECTIVE

To determine the intraobserver and interobserver agreement levels in the evaluation of technetium Tc 99m sestamibi parathyroid scintigraphic images.

METHODS

Ninety-eight patients with hyperparathyroidism were included in the study, and their parathyroid images were evaluated by 4 experienced nuclear medicine observers. The 98 cases were evaluated twice by each observer within an interval of 2 weeks. The evaluations were performed directly on workstations with use of digital images. A questionnaire was completed by each observer. The presence of a lesion, the number and the localizations of the lesions, and whether the lesion was clear or doubtful were all evaluated. Cohen kappa statistics and total agreement percentages were calculated by using SPSS version 11.0 software.

RESULTS

The 4 observers performed 8 different evaluations and identified a minimum of 38 and a maximum of 43 cases with a parathyroid lesion (or lesions). Both the intraobserver and the interobserver agreements were "very good" for the presence of a parathyroid lesion. The intra-observer agreement was also "very good" and the interobserver agreement was "good" (for only 1 pair of observers) or "very good" for the evaluation of the number of parathyroid lesions. The intraobserver agreement was "very good" or "good" and the interobserver agreement was "good" for the lesion localization and for the presence of a doubtful lesion.

CONCLUSION

Parathyroid scintigraphy seems to be an observer independent method in the detection of a parathyroid lesion, in the determination of the number of lesions, and in the localizations of the lesions. The measured high agreement between observers increases the reliability of parathyroid scintigraphy.