Causes of failed primary exploration and technical aspects of re-operation in primary hyperparathyroidism

Factors affecting the rates of incidental parathyroidectomy during thyroidectomy

BACKGROUND

The most important factors affecting the development of postoperative hypocalcaemia (PH) include intraoperative trauma to the parathyroid glands, incidental parathyroidectomy (IP), and the surgeon's experience. In this study, we aimed to determine the incidence of IP, evaluate its effect on postoperative calcium levels and investigate the effect of surgeon experience and volume on IP incidence and postoperative calcium levels.

METHODS

This retrospective study included 645 patients who underwent thyroid surgery at the Department of General Surgery, Kütahya Health Sciences University between September 2016 and March 2020. All patients underwent surgery at a single clinic by general surgeons experienced in thyroid surgery and their residents (3-5 years).

RESULTS

Normal parathyroid glands were reported in 58 (8.9%) of 645 patients. In 5 (8.6%) of 58 patients the parathyroid gland was detected in the intrathyroidal region. PH developed in ten patients (17.2%) with incidental removal of the parathyroid glands. A statistically significant difference was found between the number of incidentally removed parathyroid glands and the development of hypocalcaemia (p<0.05). Normal parathyroid glands were reported in the pathology of 37 (7.9%) patients operated on by general surgeons and 22 (12.6%) patients operated on by their residents. PH developed in 39 (8.2%) patients operated on by general surgeons and in 8 (4.5%) patients operated on by their residents.

CONCLUSIONS

We found that the complication rate during the resident training process was the same as that of experienced general surgeons. A thyroidectomy can be safely performed by senior residents during residential training.

[Robot-assisted Mediastinal Surgery]

Because of the many important anatomical structures located closely together at very small distances, mediastinal surgery has been traditionally demanding and challenging within thoracic surgery. With their great variability, mediastinal masses in the anterior, middle or posterior mediastinal compartment result in surgical indications with different principle focuses. The technical opportunities of robotic assistance can thereby most effectively support the requirement of precision for all oncological aspects. Anterior mediastinal operations are most often performed, thymectomy being the most common operation. The radicality of thymectomy is of special importance. The worldwide tremendous development of robot-assisted mediastinal surgery confirms its initial and continuous role as a pacemaker for minimally invasive thoracic surgery.

[Current approach in cases of persistence and recurrence of primary hyperparathyroidism]

Primary hyperparathyroidism (pHPT) is now diagnosed much earlier and is often asymptomatic. Biochemically mild pHPT is characterized by small parathyroid adenomas (NSDA) and the results of localization diagnostics as well as surgical treatment are poorer. The frequency of redo surgery is 3-14% in large registries. The planning of a reoperation is no different from the basic principles for the first intervention. Diagnosis and differential diagnoses must be checked. This is followed by a review of the first operation and the associated histology as well as imaging and the course of parathyroid hormone (PTH) values. The next step is to check whether the reoperation is necessary. Most patients still have comprehensible indications that correspond to the guidelines and also ex-post. In contrast to the first intervention, there is always a need to attempt to localize the NSDA. The first procedure is a surgically performed ultrasound. Other localization options are MIBI-SPECT scintigraphy, 4D-CT and FEC-PET-CT, with the latter having the highest sensitivity. There is a clear relationship between higher case numbers and better surgical outcomes. Personal experience is decisive and in terms of predicting success this is even more important than the results of localization procedures. The goal of maximizing the outcome and minimizing morbidity justifies what is from the perspective of those affected probably the most important requirement for the future: no redo surgery for HPT outside of a high-volume center.

[Mediastinal Tumors]

If mediastinal tumours cause symptoms these are related to their anatomical localization or a paraneoplastic syndrome. The differential diagnosis is based on the clinical situation with finding the lesion, and, furthermore, taking into account the age and sex of the patient, and the mediastinal compartment where the lesion is located. Cross-sectional radiographic diagnostic is essential for defining the therapeutic strategy. The anterior mediastinum is dominated by thymic tumours, mediastinal lymphomas, germ cell tumours and ectopic mediastinal poiters. The middle mediastinal compartment is the most frequent place of mediastinal cystic tumours, whereas the posterior mediastinum is the domain of neurogenic tumours. For selected cases a tissue biopsy is required. Surgery is the mainstay for most mediastinal tumours. Median sternotomy is the most frequent conventional surgical technique while minimally invasive surgery with thoracoscopic and above all robot assisted operation techniques are increasingly frequent. Combined chemotherapy and modern radiotherapy are essential components of the comprehensive treatment for mediastinal tumours.

Ultrasound dye-assisted parathyroidectomy (USDAP): Experience of a tertiary center

BACKGROUND

Primary hyperparathyroidism is primarily caused by parathyroid adenoma, followed by hyperplasia and parathyroid carcinoma. In the era of minimally invasive, targeted parathyroidectomy, the main challenge remains that of distinguishing intraoperatively pathological parathyroid from normal glands and peri-thyroid fat tissue. The aim of this study is to evaluate the surgical outcomes of a novel minimally invasive technique called ultrasound-guided dye-assisted parathyroidectomy (USDAP).

METHODS

We perform a retrospective analysis of patients affected by parathyroid adenoma, treated with USDAP at our institution between 2014 and 2019. Data were collected on patient age and sex, tumor location and size, preoperative investigations, histopathology, perioperative complications and surgical outcomes.

RESULTS

Between January 2014 and June 2019, 43 patients underwent parathyroidectomy in our Institute. Each case was discussed by the Institutional Multidisciplinary Board. All patients undergoing thyroidectomy together with USDAP or patients undergoing USDAP under endoscopic control were excluded from the present study. The final cohort, the largest to our knowledge, consisted of 29 patients. All patients were successfully treated with USDAP and remained disease-free during follow up. In all cases, pathological parathyroid was correctly identified and removed. There was no postoperative allergic reaction, nor were there neurotoxicity complications. USDAP permitted a shortening of operative and hospitalization time.

CONCLUSIONS

USDAP is an effective and safe procedure both as first line treatment and as a re-operative procedure after previous surgical failures in selected cases.

Factors contributing to unintentional parathyroidectomy during thyroid surgery

Unintentional parathyroidectomy during thyroid surgery has an incidence ranging between 1% and 31% across institutions. Many studies have identified malignancy and central neck dissection as risk factors for losing parathyroid glands, but few studies have evaluated the impact of other factors such as lymphocytic thyroiditis, hyperthyroidism, or concomitant primary hyperparathyroidism. The purpose of this study was to investigate which factors contribute to parathyroid loss during thyroid surgery. Charts of 269 patients undergoing thyroid surgery at a tertiary care medical center from 2010 to 2013 were retrospectively reviewed. Sixty-six patients (24.5%) experienced unintentional parathyroidectomy. Bivariate analysis showed no significant differences in patient characteristics. Patients with unintentional parathyroid removal had a significantly smaller largest thyroid nodule size (P = 0.002), higher rate of central neck dissection (30.3% vs 7.9%, P < 0.0001), and higher rate of malignancy (50% vs 36.0%, P = 0.04). Multivariable analysis showed that the strongest risk factor for unintentional parathyroidectomy was central neck dissection (P = 0.0008; odds ratio 4.72, confidence interval 1.91-11.71). In conclusion, central neck dissection for thyroid malignancy is the strongest risk factor for unintentional thyroidectomy. The presence of concomitant primary hyperparathyroidism, lymphocytic thyroiditis, or hyperthyroidism did not appear to increase the risk of unintentional parathyroidectomy.

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.

AHNS Series: Do you know your guidelines? Optimizing outcomes in reoperative parathyroid surgery: Definitive multidisciplinary joint consensus guidelines of the American Head and Neck Society and the British Association of Endocrine and Thyroid Surgeons

BACKGROUND

Revision parathyroid is challenging due to possible diagnostic uncertainty as well as the technical challenges it can present.

METHODS

A multidisciplinary panel of distinguished experts from the American Head and Neck Society (AHNS) Endocrine Section, the British Association of Endocrine and Thyroid Surgeons (BAETS), and other invited experts have reviewed this topic with the purpose of making recommendations based on current best evidence. The literature was also reviewed on May 12, 2017. PubMed (1946-2017), Cochrane SR (2005-2017), CT databases (1997-2017), and Web of Science (1945-2017) were searched with the following strategy: revision and reoperative parathyroidectomy to ensure completeness.

RESULTS

Guideline recommendations were made in 3 domains: preoperative evaluation, surgical management, and alternatives to surgery. Eleven guideline recommendations are proposed.

CONCLUSION

Reoperative parathyroid surgery is best avoided if possible. Our literature search and subsequent recommendations found that these cases are best managed by experienced surgeons using precision preoperative localization, intraoperative parathyroid hormone (PTH), and the team approach.

Inadvertent parathyroidectomy: incidence, risk factors, and outcomes

BACKGROUND

Parathyroid glands are ≤5 mm, often subcapsular or intrathyroidal, and obscured by lymph nodes, making preservation a challenge. The purpose of this study was to determine the incidence of inadvertent parathyroidectomy (IP) and whether it contributes to hypoparathyroidism after thyroidectomy.

MATERIALS AND METHODS

A retrospective review of all thyroidectomies by a single surgeon from January 2010 to August 2014 was completed to determine the rate of IP and permanent hypoparathyroidism. Medical records were assessed for demographics, extent of thyroidectomy, central compartment neck dissection, thyroid gland weight, parathyroid autotransplantation, reoperation, pathology, postoperative calcium levels, and number of parathyroid glands removed.

RESULTS

A total of 386 patients underwent thyroidectomy. Mean age was 52 y, and 327 (85%) patients were women. There were 25 (7%) patients who underwent reoperation, 40 (10%) who underwent central compartment neck dissection, and 128 (33%) who underwent parathyroid autotransplantation. IP occurred in 78 (20%) patients. Permanent hypoparathyroidism occurred in 7 (2.7%) of 258 patients after total or completion thyroidectomy, four (6.7%) with IP compared with three (1.5%) without IP (P = 0.033). Logistic regression analysis revealed that female gender (odds ratio = 2.768, P = 0.040), central compartment neck dissection (odds ratio = 9.584, P = 0.001), and thyroid gland weight (odds ratio = 0.994, P = 0.022) were independent factors associated with IP.

CONCLUSIONS

IP, which occurred in 20% of patients undergoing thyroidectomy, is a potentially remediable factor associated with a higher rate of hypoparathyroidism. Central compartment neck dissection is an independent risk factor for IP.

ROLE OF IMAGING TESTS FOR PREOPERATIVE LOCATION OF PATHOLOGIC PARATHYROID TISSUE IN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM

OBJECTIVE

Primary hyperparathyroidism (PHPT) can be cured by parathyroidectomy, and the preoperative location of enlarged pathologic parathyroid glands is determined by imaging studies, especially cervical ultrasonography and scintigraphy scanning. The aim of this retrospective study was to evaluate the use of preoperative cervical ultrasonography and/or parathyroid scintigraphy in locating pathologic parathyroid tissue in a group of patients with PHPT followed in the same endocrine center.

METHODS

We examined the records of 61 patients who had undergone parathyroidectomy for PHPT following (99m)Tc-sestamibi scintigraphy scan and/or cervical ultrasonography. Scintigraphic and ultrasonographic findings were compared to histopathologic results of the surgical specimens.

RESULTS

Ultrasonography detected enlarged parathyroid glands in 87% (48/55) of patients with PHPT and (99m)Tc-sestamibi scintigraphy in 79% (37/47) of the cases. Ultrasonography was able to correctly predict the surgical findings in 75% (41/55) of patients and scintigraphy in 72% (34/47). Of 7 patients who had negative ultrasonography, scintigraphy correctly predicted the surgical results in 2 (29%). Of 10 patients who had negative scintigraphy, ultrasonography correctly predicted the surgical results in 4 (40%). When we analyzed only patients with solitary eutopic parathyroid adenomas, the predictive positive values of ultrasonography and scintigraphy were 90% and 86%, respectively.

CONCLUSION

Cervical ultrasonography had a higher likelihood of a correct positive test and a greater predictive positive value for solitary adenoma compared to (99m)Tc-sestamibi and should be used as the first diagnostic tool for preoperative localization of affected parathyroid glands in PHPT.

ABBREVIATIONS

Ca = calcium IEDE = Instituto Estadual de Diabetes e Endocrinologia Luiz Capriglione PHPT = primary hyperparathyroidism PTH = parathyroid hormone.

Successful Localization of Abnormal Parathyroid Gland Using Ultrasound-Guided Methylene Blue Dye Injection in the Reoperative Neck

Persistent or recurrent hyperparathyroidism is a challenging problem for endocrine surgeons. The aim of this study was to review our experience using ultrasound-guided (US-G) methylene blue dye injection for the localization and removal of abnormal parathyroid glands in patients having primary hyperparathyroidism and previous neck surgery. Between January 2012 and May 2013, six consecutive patients with primary hyperparathyroidism (PHPT) and previous neck surgery underwent focused parathyroidectomy with the use of US-G methylene blue dye injections to localize the presumed parathyroid adenoma were included in the study. We analyzed the data of six patients who underwent reoperative parathyroid surgery using US-G methylene blue dye injection retrospectively. The dye injection was performed just prior to surgery. All patients were successfully treated for their hyperparathyroidism which was confirmed by at least 50 % drop in intraoperative parathormone level 10 min after resection. There were no complications related with US-G dye injection or with surgery. US-G methylene blue dye injection is a cheap, safe, and effective method for localization of diseased parathyroid glands and guiding surgery in the reoperative neck.

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.

Undescended parathyroid adenomas as cause of persistent hyperparathyroidism

BACKGROUND

Undescended glands are a rare cause of primary and secondary hyperparathyroidism (HPT), but they are more common, however, among patients with recurrent HPT or those who have undergone a failed initial cervical exploration. The currently development of more precise noninvasive imaging techniques has improved the results of preoperative diagnosis of these ectopic lesions.

METHODS

The operative reports of patients undergoing parathyroidectomy at our institution were reviewed to identify patients with an undescended parathyroid gland adenomas. Demographic, clinical, imaging and surgical variables were recorded.

RESULTS

Three patients were included: 2/598 parathyroidectomies performed for primary HPT and 1/93 performed for secondary HPT. One case is presented as jaw tumor syndrome (JTS). All the patients had undergone at least one operation before the definitive focused surgery and represented 6% of our parathyroid reoperations. No significant complications and no recurrences were observed in the long-term follow up.

CONCLUSIONS

Accurate preoperative localization of these lesions was possible with noninvasive studies. High cure rate is possible through selective approach when accurate preoperative localization. Thorough knowledge of parathyroid embryology and meticulous surgical technique are essential, particularly in patients with previous unsuccessful explorations.

Ultrasound-guided methylene blue dye injection for parathyroid localization in the reoperative neck

BACKGROUND

The goal of this study was to review a single institution's experience using intraoperative ultrasound-guided (ioUSG) methylene blue dye injection for the localization and removal of enlarged parathyroid glands in patients with primary hyperparathyroidism and a history of previous neck surgery.

METHODS

We performed a retrospective review of nine consecutive patients who underwent reoperative parathyroidectomy using ioUSG methylene blue dye injection.

RESULTS

All patients had successful resolution of their hyperparathyroidism, with at least a 50 % decrease in intraoperative parathyroid hormone level after resection. One patient had transient recurrent laryngeal nerve paresis. There were no permanent recurrent laryngeal nerve injuries or cases of permanent hypoparathyroidism.

CONCLUSIONS

Blue dye injection is a safe and effective method of localizing diseased parathyroid glands in the reoperative neck.

Operative treatment of primary hyperparathyroidism: balancing cost-effectiveness with successful outcomes

Parathyroidectomy is the most cost-effective treatment for hyperparathyroidism. Randomized prospective trials have shown no difference in cure rate between focused parathyroidectomy and bilateral exploration. Costs of the two techniques differ depending on the preoperative and intraoperative localization used, speed of the operation, ability to discharge the patient on the same day as the operation, cure rate, and complications. It may be less costly and more effective to use a policy of routine 4-gland exploration without the use of preoperative or intraoperative localization studies. The potential economic impact and the expected outcome of the various strategies should be formally evaluated.

Adenomas of cervical maldescended parathyroid glands: pearls and pitfalls

BACKGROUND

Missed parathyroid adenoma (PTA) is the commonest cause of persistent hyperparathyroidism. Although many are subsequently found in well-described locations, some are found in unusual regions of the neck. This paper presents the combined experience of three large tertiary endocrine surgery centres with maldescended PTA (MD-PTA).

METHODS

Patients were recruited from the endocrine surgical databases of three tertiary endocrine surgery units. Patients with PTA found >1 cm above the superior thyroid pole or other cervical locations as a result of abnormal or incomplete descent were included for analysis.

RESULTS

MD-PTA was identified in 16 patients out of a total of 5241 patients who had undergone parathyroidectomies in the 7-year study period (incidence 0.3%). Seven (44%) patients had minimally invasive parathyroidectomy, while nine (56%) had bilateral neck exploration. The mean excised gland weight was 750 + 170 mg. Cure was achieved in all patients with a minimum follow-up of 6 months. The locations of MD-PTA in this study included submandibular triangle, retropharyngeal space, carotid sheath (at carotid bifurcation and intravagal), parapharyngeal space (superior to thyroid cartilage or superior thyroid pole) and cricothyroid space.

CONCLUSIONS

Despite their rare occurrence, incompletely or abnormally descended PTAs can be encountered by any surgeon who performs parathyroidectomies. It is important to develop a strategy to systematically locate these glands. High cure rates can still be achieved with minimally invasive parathyroidectomy if confident preoperative localization is available. A sound knowledge of embryology and a thorough exploration also facilitate an overall high success rate with open exploration.

Reoperations for primary hyperparathyroidism--improvement of outcome over two decades

PURPOSE

Reoperations (R-PTX) for primary hyperparathyroidism (pHPT) are challenging, since they are associated with increased failure and morbidity rates. The aim was to evaluate the results of reoperations over two decades, the latter considering the implementation of Tc(99m)sestamibi-SPECT (Mibi/SPECT), intraoperative parathormone (IOPTH) measurement, and intraoperative neuromonitoring (IONM).

PATIENTS AND METHODS

Data of 1,363 patients who underwent surgery for pHPT were retrospectively analyzed regarding reoperations. Causes of persistent (p) pHPT or recurrent (r) pHPT, preoperative imaging studies, surgical findings, and outcome were analyzed. Data of patients who underwent surgery between 1987 and 1997 (group 1; G1) and between 1998 and 2008 (group 2; G2) with the use of Mibi/SPECT, IOPTH, and IONM were evaluated.

RESULTS

One hundred twenty-five patients with benign ppHPT (n = 108) or rpHPT (n = 17) underwent reoperations (R-PTX). Group 1 included 54, group 2 71 patients. Main cause of ppHPT (G1 = 65 % vs. G2 = 53 %) and rpHPT (G1 = 80 % vs. G2 = 60 %) was the failed detection of a solitary adenoma (p = 0.2). Group 1 patients had significantly less unilateral/focused neck re-explorations (G1 = 23 % vs. G2 = 57 %, p = 0.0001), and more sternotomies (G1 = 35 vs. G2 = 14 %, p = 0.01). After a median follow-up of 4 (range 0.9-23.4) years, reversal of hypercalcemia was achieved in 91 % (G1) and in 98.6 % in group 2 (p = 0.08, OR 7.14 [0.809-63.1]). The rates of permanent recurrent laryngeal nerve palsy (G1 = G2 = 9 %, p = 1) and of postoperative permanent hypoparathyroidism (G1 = 9 % vs. G2 = 6 %, p = 0.5) were not significantly different. Other complications such as wound infection, postoperative bleeding, and pneumonia were significantly lower in group 2 (p < 0.001).

CONCLUSION

Nowadays, cure rates of R-PTX are nearly the same as in primary operations for pHPT. These results can be achieved in high-volume centers by routine use of well-established preoperative Mibi/SPECT and US in combination with IOPTH. However, morbidity is still considerably high.

Limitations of Tc99m-MIBI-SPECT imaging scans in persistent primary hyperparathyroidism

Background

In primary hyperparathyroidism (PHPT) the predictive value of technetium 99m sestamibi single emission computed tomography (Tc99m-MIBI-SPECT) for localizing pathological parathyroid glands before a first parathyroidectomy (PTx) is 83–100%. Data are scarce in patients undergoing reoperative parathyroidectomy for persistent hyperparathyroidism. The aim of the present study was to determine the value of Tc99m-MIBI-SPECT in localizing residual hyperactive parathyroid tissue in patients with persistent primary hyperparathyroidism (PHPT) after initial excision of one or more pathological glands.

Method

We retrospectively evaluated the localizing accuracy of Tc99m-MIBI-SPECT scans in 19 consecutive patients with persistent PHPT who had a scan before reoperative parathyroidectomy. We used as controls 23 patients with sporadic PHPT who had a scan before initial surgery.

Results

In patients with persistent PHPT, Tc99m-MIBI-SPECT accurately localized a pathological parathyroid gland in 33% of cases before reoperative parathyroidectomy, compared to 61% before first PTx for sporadic PHPT. The Tc99m-MIBI-SPECT scan accurately localized intra-thyroidal glands in 2 of 7 cases and a mediastinal gland in 1 of 3 cases either before initial or reoperative parathyroidectomy.

Conclusions

Our data suggest that the accuracy of Tc99m-MIBI-SPECT in localizing residual hyperactive glands is significantly lower before reoperative parathyroidectomy for persistent PHPT than before initial surgery for sporadic PHPT. These findings should be taken in consideration in the preoperative workup of patients with persistent primary hyperparathyroidism.

Incidental parathyroidectomy during thyroid resection: incidence, risk factors, and outcome

BACKGROUND AND OBJECTIVES

Thyroidectomy is a commonly performed procedure for thyroid problems. Inadvertent removal of the parathyroid glands is one of its recognized complications, which occurs more frequently in certain high-risk patients. The aim of this study was to identify the incidence, risk factors, and clinical relevance of incidental parathyroidectomy during thyroid surgery.

DESIGN AND SETTING

A retrospective review of thyroid operations performed at a tertiary referral hospital between January 2004 and December 2008.

METHODS

Pathology reports were reviewed to identify the specimens that included parathyroid tissue and underlying thyroid pathology. Postoperative calcium levels were reviewed in these patients.

RESULTS

During the study period, 287 thyroidectomies were performed and 47 (16.4%) patients had incidentally removed parathyroid glands. Risk factors for inadvertent parathyroid resection included total thyroidectomy (P=.0001), Hashimoto thyroiditis (P=.004), and extrathyroidal spread (P=.0003). Postoperative hypocalcemia occurred in 18 (38.3%) of the patients in whom the parathyroid gland was removed inadvertently and in 48 (20%) of the rest of the patients (P=.0123).

CONCLUSION

The incidence of incidental removal of parathyroid tissue during thyroidectomy is 16.4%. Total thyroidectomy, extrathyroidal extension of the tumor, and thyroiditis were found to be the risk factors. Hypocalcemia was significantly higher among patients who had inadvertent parathyroidectomy.

Reoperative surgery for primary hyperparathyroidism

Successful in up to 90 per cent of patients

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.

Remedial surgery for primary hyperparathyroidism

Remedial parathyroid surgery is a complex undertaking for even the most experienced parathyroid surgeon. It involves a careful preoperative evaluation, including the confirmation of the initial diagnosis of primary HPTH, use of the appropriate localization studies, knowledge of the details of the previous exploration, and surgical re-exploration, including the use of intraoperative localization adjuncts, such as the rapid intraoperative PTH assay (Fig. 6). Althoughthe success rate of remedial explorations can be as high as 98%, complication rates are higher than in initial cervical explorations for parathyroid disease.

Incidental Parathyroidectomy during Thyroid Surgery: An Underappreciated Complication of Thyroidectomy

The aim of this study was to investigate the incidence, risk factors, and clinical relevance of incidental parathyroidectomy during thyroid surgery. Prospective analysis of data in patients following thyroidectomy, specifically regarding the presence of parathyroid parenchyma in the thyroidectomy specimens, the underlying thyroid pathology, and the presence of postoperative hypocalcemia (biochemical/clinical). The clinical records of 158 patients who underwent thyroid surgery during a 2-year period were reviewed. Pathology reports were carefully reviewed for the nature of the underlying thyroid disease, the presence, number, and size of incidentally resected parathyroid gland(s), their location, and possible parathyroid pathology. Serum calcium levels were measured preoperatively, on the day of surgery, and on postoperative days 1, 2, and 7 or even later as needed. Two groups of patients were studied: a group with incidental parathyroidectomy following thyroidectomy (group A) and a group without incidental parathyroidectomy after thyroidectomy (group B). Total/near-total thyroidectomy was the procedure of choice and was performed in 154 patients; total lobectomy and contralateral subtotal lobectomy was performed in the other 4 patients. Elective central neck lymph node dissection was performed in four patients with neck lymphadenopathy. Inadvertently removed parathyroid tissue was found in 28 cases (17.7 %); in 6 of these patients (21%) the parathyroid tissue was intrathyroidal. The percentage of women in group A was significantly higher than in group B (93% vs. 58.5%, P = 0.0002). There was no statistically significant difference between the two groups (A and B) regarding the preoperative (presumed) diagnosis, the histologic diagnosis of thyroid disease (benign versus malignant), the type/extent of surgery, or the presence of thyroiditis. Biochemical and clinical hypocalcemia was observed in 6 (21%) and 2 (7%) patients in group A, respectively, and in 30 (23%) and 8 (6%) patients of group B, respectively. There was no statistically significant difference regarding the occurrence of postoperative hypocalcemia (clinical/biochemical) between the two groups (P = 0.33). Incidental parathyroidectomy is not uncommon following thyroidectomy and in a significant percentage of cases it may be due to the intrathyroidal location of the parathyroid glands. Incidental parathyroidectomy was not found to be associated with postoperative hypocalcemia (biochemical/clinical). Incidental parathyroidectomy may be considered as a potentially preventable but clinically minor complication of thyroid surgery.

[Reoperation for persistent or recurrent primary hyperparathyroidism. Seventy-seven cases among 1888 operated patients]

AIMS

To analyse the results of re-operations for persistent (p) or recurrent (r) primary hyperparathyroidism (PHPT).

PATIENTS AND METHODS

From 1965 throughout 2001, 1888 patients were operated on for PHPT. The cure rate after initial surgery was 97.6%. Seventy-seven (4.1%) were reoperated for p PHPT (n = 54) or r PHPT (n = 23). Thirty-two out of 77 (41%) had been primarily operated elsewhere. In 15 cases (20%) PHPT was genetically determined. The re-operation was undertaken on average 40.7 months after initial surgery (1 day-190 months).

RESULTS

Two out of 77 were cases of familial hypocalciuric hypercalcaemia. Among the 75 patients reoperated for true PHPT, 23 (31%) had uniglandular disease (UGD) and 52 (69%) had multiglandular disease (MGD). There were two cases of recurrent parathyroid carcinoma. Overall 97 pathological glands were resected, 37% being orthotopic and 63% heterotopic. The re-operation was performed by a cervical approach in 80%, by a mediastinal approach in 15%, whereas 5% involved excision of antebrachial implants. In 96% of cases the parathyroid glands were in the cervical position. Among the preoperative localisations studies the sensitivity of scintigraphy utilising 2-methoxyisobutyl-isonitril (MIBI) was 61%. Utilising both MIBI and cervical ultrasound the sensitivity was 64%. Sixty-eight out of 75 (91%) were cured of their hypercalcaemia, but at the cost of permanent hypoparathyroidism in 9% of cases. No sporadic adenoma appears to have been missed. The seven failures after re-operation (9%) involved five cases of MGD, of which four were sporadic, two cases of carcinoma and one case of parathyreomatosis. 39 patients (51%) had more than four parathyroid glands and in 22/39 cases at least one supernumerary gland was pathological.

CONCLUSION

The re-operations for PHPT were essentially due to MGD that was either sporadic or genetically determined. Often the offending supernumerary gland was not detected by imaging studies. Avoiding failures entails an initial bilateral cervicotomy with thymic exploration after MIBI scintigraphy to exclude a mediastinal focus.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Parathyroid re-exploration

Re-operative parathyroid surgery is always a challenge for the endocrine surgeon. This article discusses the issues the parathyroid surgeon must consider before and during re-operative surgery,with special attention to recently introduced adjunctive techniques.

Ultrasonography for preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism: comparison with (99m)technetium sestamibi scintigraphy

OBJECTIVE

To determine the utility of ultrasonography for the preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism, and to compare this method with (99m)technetium sestamibi scintigraphy.

DESIGN

The results of ultrasonography for localization of enlarged parathyroid glands were determined in 120 consecutive patients with primary hyperparathyroidism and compared with findings at surgery (n = 86) and with the results of (99m)technetium sestamibi scintigraphy (n = 99).

PATIENTS

All patients had biochemically documented primary hyperparathyroidism based on elevated serum calcium and 'intact' parathyroid hormone measured by immunoassay. Patients with prior parathyroid surgery or secondary hyperparathyroidism were excluded.

MEASUREMENTS

High-resolution ultrasonography was performed by a single observer. (99m)Technetium sestamibi scintigraphy was performed using early and delayed (2-h) views, and correlated with simultaneous thyroidal 123I uptake in most patients.

RESULTS

Ultrasonography detected putative enlarged parathyroid glands in 92 of 120 unselected patients (77%). It correctly predicted surgical findings in 64 of 86 patients undergoing surgery (74%), including 61 of 72 patients with solitary eutopic parathyroid adenomas (84%), but only two of eight patients with solitary ectopic adenomas, and only one of six patients with multigland parathyroid disease. Sestamibi scintigraphy was positive in 87 of 99 unselected patients (88%), a higher proportion than ultrasonography (P < 0.05), reflecting superior sensitivity for the detection of ectopic parathyroid adenomas. For 74 patients undergoing parathyroid surgery who underwent both imaging tests there was no statistically significant difference between ultrasonography and sestamibi scintigraphy in ability to correctly predict surgical findings (74%vs. 82%, respectively) or in positive predictive value (93%vs. 90%, respectively). However, sestamibi scintigraphy was clearly more sensitive for ectopic parathyroid adenomas, providing correct localization in 8/8 cases. When one test was negative, testing with the second method was usually positive, improving the likelihood of a positive result to 98% when both tests were employed.

CONCLUSIONS

Ultrasonography can be a sensitive and accurate method for preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism, comparable in overall utility to sestamibi scintigraphy. These results suggest that a strategy of initial testing with one or the other method, followed by the alternate imaging test if the first test is negative, would provide correct parathyroid imaging in most patients without prior parathyroid surgery.

Incidence of inadvertent parathyroid removal during thyroidectomy

OBJECTIVES

To assess the incidence of unintentional parathyroid removal during routine thyroidectomy and to identify factors that might predict patients at high risk.

STUDY DESIGN

Retrospective review of case records. Data analyzed for incidental finding of parathyroid gland(s) in the thyroidectomy specimen and postoperative temporary or permanent hypocalcemia.

METHODS

The clinical records of 220 patients undergoing thyroidectomies between January 1997 and October 1999 were reviewed. Pathology reports were screened for information on the presence of parathyroid tissue along with the thyroid specimen. Operative reports were reviewed to exclude the possibility of intentional parathyroid gland removal. Case records were scrutinized to determine whether the patient developed symptomatic hypocalcemia postoperatively.

RESULTS

Nine percent of the 220 patients were found to have had inadvertent removal of parathyroid tissue. The majority of patients (95%) had two or less parathyroid glands in their specimens. The size and histological nature of the thyroid lesion were not predictive of inadvertent parathyroid removal. Of the 25 repeat operations for recurrent or persistent malignancy, 5 (20%) were found to have unintentional parathyroid removal compared with 15 (7.71%) of 195 primary thyroidectomy cases (P <.05). Nineteen percent of patients who had tracheoesophageal groove node dissection had an incidental parathyroid in their specimen compared with 7% who did not undergo tracheoesophageal groove node dissection (P = .04). None of the patients with unintentional parathyroid gland removal developed either temporary or permanent postoperative hypocalcemia.

CONCLUSIONS

Inadvertent excision of a parathyroid gland(s) occurred in 9% of patients undergoing thyroidectomy in our experience. Reoperative thyroid surgery and tracheoesophageal node dissection were associated with a significantly higher risk of inadvertent parathyroid gland excision. Inadvertent parathyroidectomy did not result in symptomatic temporary or permanent hypocalcemia postoperatively.

An ectopic mediastinal parathyroid adenoma accurately located by a single-day imaging protocol of Tc-99m pertechnetate-MIBI subtraction scintigraphy and MIBI-SPECT-computed tomographic image fusion

PURPOSE

Because ectopic parathyroid adenoma (PA) is a frequent cause of failed initial surgery, an imaging approach with accurate preoperative localization is recommended by some authors in patients with primary hyperparathyroidism (HPT).

METHODS

The authors describe a 52-year-old woman in whom primary HPT was diagnosed incidentally during a screening program for osteoporosis. The peculiarity of this case is that the patient was examined before operation in a single-day multimodal imaging protocol based on the combination of high-resolution cervical ultrasound, planar Tc-99m pertechnetate-MIBI scans, and an MIBI-SPECT-computed tomographic (CT) image fusion study. An ectopic PA was accurately located in the upper middle mediastinum, close to the lower margin of the sternal notch.

RESULTS

Guided by the MIBI-SPECT-CT fusion images, the surgeon performed a limited median sternotomy and easily removed the PA that was revealed before operation. To confirm the completeness of resection, a bilateral neck exploration was performed through the same incision, with identification of three normally sized parathyroid glands.

CONCLUSIONS

Our experience suggests the utility of multimodality imaging procedures for the accurate preoperative localization of PAs, particularly when they are present in ectopic mediastinal locations. Such procedures, including the MIBI-SPECT-CT image fusion study, can be performed in a single day.

Parathyroid gland radionuclide scanning--methods and indications

The usefulness of preoperative radionuclide scanning of the parathyroid glands in patients with primary or secondary hyperparathyroidism was long controversial because available techniques were of limited diagnostic efficacy. Technetium-99m-labeled sestamibi (99Tc-sestamibi) is a new radiopharmaceutical agent easily detected by gamma cameras. The first parathyroid imaging studies done with 99Tc-sestamibi about 10 years ago used a double-phase technique to separate thyroid and parathyroid tissue. Although promising, this method was less than ideal, particularly in multiple gland primary hyperparathyroidism and in secondary hyperparathyroidism. For several years, we have been using subtraction between two images acquired simultaneously, one with 99Tc-sestamibi, which binds to thyroid and parathyroid tissue, and the other with 123-iodine, which binds only to thyroid tissue. The remarkable efficacy of this technique in both primary and secondary hyperparathyroidism invites a reappraisal of the place of radionuclide imaging as a preoperative localization procedure done to reduce the need for repeat surgery. The usefulness of this technique in selecting candidates for unilateral surgery among patients with primary hyperparathyroidism is discussed.

Preoperative imaging of parathyroid glands with technetium-99m-labelled sestamibi and iodine-123 subtraction scanning in secondary hyperparathyroidism

BACKGROUND

Parathyroidectomy is unsuccessful in 10-30% of uraemic patients operated on for secondary hyperparathyroidism. We investigated the usefulness of preoperative radionuclide imaging, with simultaneous recording of the distribution images of iodine-123 and technetium-99m-labelled sestamibi.

METHODS

11 patients with secondary hyperparathyroidism underwent prospective imaging and parathyroidectomy. Plasma concentrations of intact parathyroid hormone (PTH) were measured in all patients before and 6 months after subtotal parathyroidectomy.

FINDINGS

Preoperative scanning showed 42 hot-spots suggesting enlarged parathyroid glands. 45 glands were discovered at surgery, and the parathyroidectomy was deemed successful in ten patients. Among the latter, one patient had a supernumerary parathyroid gland detected by scanning and resected from the left thymus. Another patient showed ectopic uptake corresponding to a large parathyroid gland in the upper mediastinum, and another had a parathyroid gland well above the thyroid. No false-positive scan findings were documented. In the patient for whom parathyroidectomy failed, preoperative scanning suggested five enlarged parathyroid glands, though the surgeon found only four glands, in their normal positions. Hyperparathyroidism persisted (intact PTH 527 ng/L, 6 months after surgery). A second scan confirmed the preoperative scan, showing a fifth parathyroid gland in the middle of the right thyroid lobe.

INTERPRETATION

Simultaneous recording of 99mTc-sestamibi and 123I improved the imaging of parathyroid glands in secondary hyperparathyroidism. The technique can identify ectopic and supernumerary parathyroid glands.

Minimally invasive radioguided parathyroidectomy in the reoperative neck

BACKGROUND

Operations for hyperparathyroidism (HPT) in a previously operated neck present a significant challenge and carry much higher morbidity rates than first-time operations. Our extensive experience with minimally invasive radioguided parathyroidectomy (MIRP) for first-time surgery for HPT has shown this method to be a directed approach to the offending adenoma, suggesting that the technique could be used to minimize reoperative neck surgery as well.

METHODS

Over an 11-month period 24 consecutive patients with primary HPT who had undergone at least one previous neck operation were referred for re-exploration. All patients underwent preoperative sestamibi scanning; 21 localized sufficiently to undergo MIRP.

RESULTS

All patients were cured after reoperation. Eighteen patients underwent MIRP under local anesthesia as outpatients; 3 MIRPs were done under general anesthesia. Average total operative time was 44 minutes, average incision length was 3.0 cm +/- 0.2 cm. Nineteen of the procedures were completed without any frozen sections. There were no complications.

CONCLUSION

MIRP is extremely effective in patients with HPT who have undergone previous neck exploration for parathyroid or thyroid disease. The technique allows for such a directed dissection that smaller incisions and local anesthesia in an outpatient setting are routine.

Intrathyroidal parathyroid glands can be a cause of failed cervical exploration for hyperparathyroidism

BACKGROUND

The incidence of intrathyroidal parathyroid glands remains controversial. The purpose of this study was to determine the incidence in a series of patients with hyperparathyroidism.

METHODS

Three hundred nine patients underwent parathyroidectomy. Patients were divided into two groups: uniglandular disease versus hyperplasia.

RESULTS

Eighteen of 309 patients (6%) had abnormal intrathyroidal parathyroid glands. The incidence was 3% (7 of 222) in patients with uniglandular disease versus 15% (11 of 73) in those with hyperplasia. With a mean follow-up of 54 months, 12 patients are eucalcemic, 5 have persistent hypocalcemia, and 1 has recurrent hypercalcemia. There were no recurrent laryngeal nerve injuries.

CONCLUSIONS

These data suggest that an intrathyroidal adenoma is an uncommon cause of failure, whereas abnormal intrathyroidal parathyroid tissue may be a more common cause of failure in patients with hyperplasia.

Localization studies in patients with hyperparathyroidism

Patients with hyperparathyroidism who have not had previous neck surgery do not require preoperative localization because of the high success rate of cervical exploration (95%) and the limited sensitivity and specificity of all imaging modalities currently in use. Successful parathyroid exploration requires knowledge of the normal and frequently encountered variations in parathyroid anatomy (Fig. 4). Experience permits recognition of often subtle multiple gland disease. In skilled surgical hands, results are excellent with minimal morbidity. When recurrent or persistent disease or previously operated patients are encountered, confirmation of the diagnosis and attempts at localization should precede operation. Technetium sestamibi SPECT imaging and ultrasonography with FNA of suspicious glands are complementary tests that are readily available, inexpensive, and well tolerated by patients. If these tests are unsuccessful, MRI, CT, and invasive procedures should be pursued until the gland is localized.