INCIDENTAL PARATHYROIDECTOMY DURING THYROID SURGERY - RISK, PREVENTION AND CONTROVERSIES; AN EVIDENCE-BASED REVIEW

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.

Comparison of incidental parathyroid tissue detection rates on pathology after total thyroidectomy performed with or without near-infrared autofluorescence imaging

BACKGROUND

Near-infrared autofluorescence imaging is an adjunct to parathyroid identification. As it does not show perfusion, it is important to study its impact during thyroidectomy by measuring quantifiable data on parathyroid detection rather than function. The aim of this study was to compare incidental parathyroidectomy rates in patients undergoing total thyroidectomy with or without near-infrared autofluorescence.

METHODS

Retrospective study of patients who underwent total thyroidectomy between 2014 and 2022 at one center. Clinical parameters, including rates of incidental parathyroid tissue on pathology reports, were compared between near-infrared autofluorescence and non-near-infrared autofluorescence groups. Near-infrared autofluorescence was used to guide dissection (identification) and/or to confirm tissue as parathyroid (confirmation). Statistical analysis was done with Wilcoxon rank sum test and χ2 analysis.

RESULTS

There were 300 patients in the near-infrared autofluorescence and 750 patients in the non-near-infrared autofluorescence group. The rate of incidental parathyroid tissue detection on final pathology was 13.3% (n = 40) in the near-infrared autofluorescence and 23.2% (n = 174) in the non-near-infrared autofluorescence group (P < .001). The rate of incidental parathyroid tissue detected on pathology with near-infrared autofluorescence decreased when used for identification and confirmation of parathyroid tissue (30.0% to 13.4%, P < .001), but not when used for confirmation only (19.6% to 18.5%, P = .89). Impact of near-infra red autofluorescence in decreasing the rate of incidental parathyroid tissue was more profound for early (38.5% to 17.1%) versus mid-late career surgeons (20% to 13%).

CONCLUSION

Our results suggest that the use of near-infrared autofluorescence may help decrease the rate of incidental parathyroid tissue detected on final pathology if used for both identification and confirmation of parathyroid glands during thyroidectomy.

Comparing Thyroidectomy Techniques, Surgical Loupe and Neuromonitoring Between ENT and Endocrine Surgeons-an Observational Study

Thyroid surgery is performed by ENT head and neck (ENT-HNS), endocrine (ES) and general surgeons (GS). Each modality adopts different surgical techniques causing difference in outcome, operative time and postoperative complication. A retrospective chart review of thyroid surgeries performed by two ENT-HNS, three ES of a single tertiary center was conducted. We compared the use of neuromonitoring and surgical loupe and subsequent patient outcomes between surgeries performed by ENT-HNS versus ES, focusing on parathyroid gland identification, operative duration, vocal cord paralysis and length of hospital stay. A total of 167 patients underwent thyroid surgery. Surgical loupes were used in all the surgeries performed by ENT-HNS vs. 85% by the ES. Parathyroid glands were identified in all the surgeries performed by ENT-HNS versus 95% by ES. Neuromonitoring was used in all the surgeries performed by ENT-HNS, and none by the ES. Vocal cord paralysis developed in two patients of ES versus none in the ENT-HNS. Mean operative duration for total thyroidectomy in ENT-HN surgeries, 183.7 min vs. 151 min in the ES. The mean hospital stay of patients was 3.6 ± 1.6 days for ENT-HNS, and 5.45 ± 3 days for ES. Identification of parathyroid gland and recurrent laryngeal nerve by neuromonitoring and surgical loupes may increase operative time but decrease the rate of vocal cord paralysis and increases the chance of parathyroid gland identification.

Lobo-isthmectomy in the management of differentiated thyroid cancer

We have recently witnessed a rapid increase in the incidence of differentiated thyroid carcinoma (DTC), particularly low and very low-risk papillary thyroid carcinoma. Simultaneously, the number of cancer-related deaths has remained stable for more than 30 years. Such an indolent nature and long-term survival prompted researchers and experts to an ongoing discussion on the adequacy of DTC management to avoid, on the one hand, the overtreatment of low-risk cases and, on the other hand, the undertreatment of highly aggressive ones.The most recent guidelines of the American Thyroid Association (ATA GL) moved primary thyroid surgery in DTC towards a less aggressive approach by making lobectomy an option for patients with intrathyroidal low-risk DTC tumors up to 4 cm in diameter without evidence of extrathyroidal extension or lymph node metastases. It was one of the key changes in DTC management proposed by the ATA in 2015.Following the introduction of the 2015 ATA GL, the role of thyroid lobectomy in DTC management has slowly become increasingly important. The data coming from analyses of the large databases and retrospective studies prove that a less extensive surgical approach, even if in some reports it was related to a slight increase of the risk of recurrence, did not show a negative impact on disease-specific and overall survival in T1T2N0M0 low-risk DTC. There is no doubt that making thyroid lobectomy an option for low-risk papillary and follicular carcinomas was an essential step toward the de-escalation of treatment in thyroid carcinoma.This review summarizes the current recommendations and evidence-based data supporting the necessity of de-escalation of primary thyroid surgery in low-risk DTC. It also discusses the controversies raised by introducing new ATA guidelines and tries to resolve some open questions.

Preliminary experience with the EleVision IR system in detection of parathyroid glands autofluorescence and perfusion assessment with ICG

BACKGROUND

Postoperative hypoparathyroidism remains the most frequent complication of neck endocrine surgery. In order to reduce the incidence of this feared complication, several systems for imaging of near infrared autofluorescence (NIRAF) have been invented to help surgeons identify parathyroid glands (PTGs) and evaluate their vascularization. We evaluated the efficacy of the EleVision IR system in thyroid and parathyroid surgery.

METHODS

We used the EleVision IR system in 25 patients who underwent thyroid/parathyroid surgery or both at our institution between December 2020 and July 2021. At various stages of the surgery, the surgeon first looked for PTGs with the naked eye and then completed the visual inspection with NIRAF imaging. We then compared both the naked eye and NIRAF-supported PTGs detection rates. At the end of surgery, we performed indocyanine green angiography of PTGs in 17 patients.

RESULTS

In total, we identified 80% of PTGs: 65% with the naked eye only and additional 15% with the assistance of the EleVision IR system. 14 of 17 patients evaluated by ICG angiography had at least one well-vascularized PTG. Only one of these patients (a case of subtotal parathyroidectomy for tertiary hyperparathyroidism) developed symptomatic postoperative hypocalcemia despite a normal parathormone level. The three other patients had at least one remaining moderately-vascularized PTG and only one patient developed transient postoperative hypoparathyroidism.

CONCLUSION

We concluded that EleVision IR provides an efficient support for identification and evaluation of PTGs, and may be of great assistance in endocrine surgery. The images are easy to interpret even for less experienced surgeons thanks to the different types of color visualization and the possibility to measure the relative fluorescence intensity of PTGs and surrounding tissues.

Rate of Incidental Parathyroidectomy in a Pediatric Population

Objective

Incidental parathyroidectomy is a relatively common occurrence in thyroid surgery, which may lead to hypoparathyroidism and postoperative hypocalcemia, but it is not well studied in children. The objectives of this study were to determine the rate of incidental parathyroidectomy, identify potential risk factors, and investigate postoperative complications in children undergoing thyroidectomy.

Study Design

Retrospective cohort study.

Setting

Patients who underwent thyroidectomy over a 10-year period at a tertiary children’s hospital.

Methods

Pathology reports were reviewed to determine incidental parathyroid gland tissue. Additional data collected included patient demographics, type of procedure, underlying thyroid pathology, as well as immediate and long-term postoperative clinical outcomes.

Results

Of 209 patients, 65 (31%) had incidental parathyroidectomy. Several variables were associated with incidental parathyroidectomy on univariable analysis. However, in the final multivariable model, only thyroidectomy with lymph node dissection was associated with increased odds of having incidental parathyroidectomy (odds ratio, 3.3; P = .04; 95% CI, 1.1-9.8). After a median follow up of 1 year, a significantly higher percentage of patients with incidental parathyroidectomy had evidence of long-term hypoparathyroidism (9/62 [15%] vs 3/144 [2%], P = .001).

Conclusion

Incidental parathyroidectomy was relatively common in our pediatric thyroidectomy population, which may be a result of several anatomic, clinical, and surgeon-related factors. Close attention to parathyroid preservation with meticulous surgical technique is the most practical method of preventing long-term hypoparathyroidism and hypocalcemia.

Near-infrared autofluorescence-based parathyroid glands identification in the thyroidectomy or parathyroidectomy: a systematic review and meta-analysis

PURPOSE

To evaluate the diagnostic accuracy of near-infrared autofluorescence-based identification in the identification of parathyroid glands during thyroidectomy or parathyroidectomy.

METHODS

The clinical studies were retrieved from PubMed, the Cochrane Central Register of Controlled Trials, Embase, Web of Science, SCOPUS, and Google Scholar. The study protocol was registered on Open Science Framework ( https://osf.io/um8rj/ ). The search period ranged from the date of each database's inception to May 2021. Cohort studies dealing with patients of whom parathyroid glands were detected by near-infrared autofluorescence and confirmed clinically or pathologically during thyroidectomy or parathyroidectomy were included. Editorials, letters, "how-I-do-it" descriptions, other site head and neck tumors, and articles with lack of diagnostic identification data were excluded. True positive, true negative, false positive, and false negative were extracted. The QUDAS ver. 2 was used to evaluate the methodological quality.

RESULTS

Seventeen studies with 1198 participants were evaluated in this analysis. Near-infrared autofluorescence-based identification of parathyroid glands showed a diagnostic odds ratio of 228.8759 (95% confidence interval, 134.1099; 390.6063). The area under the summary receiver operating characteristic curve was 0.967. The sensitivity, specificity, negative predictive value, and positive predictive value were 0.9693 (0.9491; 0.9816), 0.9248 (0.8885; 0.9499), 0.9517 (0.8981; 0.9778), and 0.9488 (0.9167; 0.9689), respectively. Subgroup analyses were performed to compare two autofluorescence detection methods, because there was high heterogeneity in the outcomes. The diagnostic accuracy was higher in probe-based detection than in image-based detection.

CONCLUSIONS

Near-infrared autofluorescence-based identification is valuable for identifying the parathyroid glands of patients during thyroidectomy or parathyroidectomy.

INCIDENTAL PARATHYROIDECTOMY DURING TOTAL THYROIDECTOMY AS A POSSIBLE RISK FACTOR OF HYPOCALCEMIA. EXPERIENCE OF A SINGLE CENTER AND REVIEW OF LITERATURE

CONTEXT

Post-operative clinical and biochemical hypocalcemia is a common complication of thyroid surgery and the correlation with incidental parathyroidectomy (IP) remains controversial.

OBJECTIVE

To evaluate the incidence of IP during TT, its correlation to early post-surgery hypocalcemia, and its potential risk factors.

PATIENTS AND METHODS

77 consecutive patients submitted to thyroid surgery between January 2018 and December 2019. Demographic, clinical, biochemical, surgical and histopathological factors were assessed. Statistical multivariate analysis was performed to identify the risk of IP.

RESULTS

IP was evident in 22 (28.5%) patients who underwent TT, TT with lymph node dissection of the central compartment (CLND) and reoperation for previous hemithyroidectomy with CLND. Early symptomatic hypocalcemia 24 hours after TT was demonstrated in 12/22 (54.5%) patients, with PTH value of <14pg/mL in 7/12 (58.3%) patients, and in 6 of these 7 patients (85.7%) the PTH value was <6.3pg/mL. In 5/22 (22.7%) patients the IP was associated with biochemical hypocalcemia <8.4mg/dL, and in 5/22 (22.7%) patients anatomical damage was not associated with a reduction in plasma calcium levels. The severity of early post-op hypocalcemia was not correlated with the number of parathyroid glands left in situ. The multivariate analysis did not show statistically significant values between the clinical-pathological variables and increased risk of IP.

CONCLUSIONS

No IP clinical-pathological risk factors have been identified during thyroid surgery. In all cases of TT, with or without CLND, the meticulous identification of the parathyroid glands, whose incidental removal is frequently associated with clinical and biochemical hypocalcemia, is recommended.

THYROID SURGERY, IONM AND SUGAMMADEX SODIUM RELATIONSHIPS: BENEFITS IN SUGAMMADEX SODIUM USE FOR IONM

Background

It is important to protect recurrent laryngeal nerve (RLN) during thyroid surgery. Thus, intra- operative neuromonitoring (IONM) has got popularity. But, the half life of neuromuscular blocking agents used has a reverse correlation with reliability and effectiveness of IONM. This study aimed to research the effect of Sugammadex Sodium, a specific nemuromuscular blocking agent antagonist, on nerve conduction and IONM.

Materials and methods

Twenty patients who underwent thyroidectomy under IONM followed an enhanced NMB recovery protocol-rocuronium 0.6 mg/kg at anesthesia induction and sugammadex 2 mg/kg at the beginning of operation. To prevent laryngeal nerve injury during the surgical procedures, all patients underwent intraoperative monitoring. At the same time, the measurement of TOF-Watch acceleromyograph of the adductor pollicis muscle response to ulnar nerve stimulation was performed; recovery was defined as a train-of-four (TOF) ratio ≥ 0.9. Age, sex, recurrent laryngeal nerve transmission speeds prior to and after operation, BMI, duration of surgery, the change in nerve transmission after drug administration and complications were analyzed.

Results

The mean age and the mean BMI were 47.6±11.82 years and 28.74±3.20, respectively. The mean operation duration was 52.65±5.51 minutes. There was no difference in either right or left RLN monitoring values before and after surgery. Following the drug injection, the TOF guard measurements on the 1^st, 2^nd, 3^rd and 4^th minutes were 23.5±4.90; 69.5±6.86; 88±4.1 and 135.9±10.62, respectively.

Conclusion

Neuromuscular blocking antagonist use and monitoring nerve transmission speed with TOF-guard can provide a safer resection.

Effect of incidental parathyroidectomy on postoperative calcium levels after to-tal thyroidectomy

BACKGROUND

Incidental parathyroidectomy during total thyroidectomy may occur even in the most experienced hands. This study aims to assess the incidence, risk factors, and impact of incidental parathyroidectomy on this very targeted group of patients.

METHODS

Three hundred and four consecutive cases undergoing total thyroidectomy in a tertiary referral center were prospectively studied. Based on the histopathology report, incidental parathyroidectomy was assessed in relation to postoperative transient/permanent hypocalcemia. Demographic, clinical, and histological data were analyzed.

RESULTS

The overall incidence of unintentional removal of parathyroid glands during total thyroidectomy was 35.5 %. Indicators were the postoperative hypocalcemia, the percent change of parathormone serum levels, and the presence of lymph nodes in the histopathology report. Patients with incidental parathyroidectomy exhibited a higher incidence of transient hypocalcemia and hypoparathyroidism postoperatively.

CONCLUSIONS

Incidental parathyroidectomy is associated with transient hypocalcemia after total thyroidectomy. Even single parathyroid in the histopathology specimen may be sufficient for influencing postoperative PTH levels and calcium. Every effort should be made by surgeons to identify and protect all parathyroid glands successfully. HIPPOKRATIA 2020, 24(2): 72-76.

Risk Factors of Incidental Parathyroidecomy in Thyroid Surgery

Background: Incidental parathyroidectomy with subsequent hypoparathyroidism and postoperative hypocalcemia is thought to be one of the common complications of thyroidectomy. Current literature reports wide discrepancy in incidence and risk factors.

Objectives: The aim of our study was to evaluate the incidence and risk factors of incidental parathyroidectomy in thyroid surgery.

Methods: A retrospective study included 270 patients who had thyroid surgery that was performed over two years from January 2017 to December 2018 in two tertiary care hospitals. Preoperative and postoperative records were assessed. Factors such as gender, diagnosis, type of surgery, and usage of surgical loupes during the procedure were evaluated and were compared to find the association with incidental parathyroidectomy in thyroid surgery.

Results: Incidental parathyroidectomy was noticed in 62 (23%) surgical specimens during histopathologic examination. There was no significant association between incidental parathyroidectomy and sex of patient, use of surgical loupes, pathology of thyroid disease, or neck dissection.

Conclusion: Although the risk of incidental parathyroidectomy is inevitable, careful dissection and meticulous intraoperative identification of parathyroid gland during thyroidectomy can reduce the incidence of incidental parathyroidectomy, thereby minimizing the risk of postoperative hypoparathyroidism and hypocalcemia.

Fatal Hypocalcaemia Due to Hungry Bone Syndrome with Secondary Refractory HyperParathyroidism after Parathyroidectomy: A Case Report

Introduction

Hungry bone syndrome (HBS) refers to the rapid, profound, and prolonged hypocalcaemia associated with hypophosphatemia and hypomagnesaemia, and is exacerbated by suppressed parathyroid hormone (PTH) levels, which follows parathyroidectomy in patients with severe primary hyperparathyroidism (PHPT) and preoperative high bone turnover. [1]

Case report

This report concerns a dialysed patient who underwent surgical treatment for secondary refractory hyperparathyroidism. Haemodialysis was carried out pre-operatively, and subsequently, a total parathyroidectomy with auto-transplantation of parathyroid tissue in the sternocleidomastoid muscle (SCM) was performed. Rapid and progressive hypocalcaemia symptoms developed during the second day postoperatively. Acute cardiac symptoms with tachyarrhythmia, haemodynamic instability and finally asystole occurred, which required cardiopulmonary resuscitation (CPR). The ionic calcium level was 2.2 mg/dL being consistent with a diagnosis of HBS. A second cardiac arrest unresponsive to CPR followed an initial period of normal sinus rhythm. Death ensued shortly after. Before death, the ionic calcium was 3.1 mg/dL.

Conclusion

HBS, after parathyroidectomy in patients with secondary hyperparathyroidism (SHPT), may be severe, prolonged and sometimes fatal. Generally, HBS symptomatology is that of a mild hypocalcaemia. It can, however, include heart rhythm disturbances with haemodynamic alterations requiring intensive care measurements and even cardiopulmonary resuscitation. A close clinical and laboratory post-parathyroidectomy monitoring of dialysed patients is of the utmost importance.

FIRST DAY SERUM CALCIUM AND PARATHYROID HORMONE LEVELS AS PREDICTIVE FACTORS FOR SAFE DISCHARGE AFTER THYROIDECTOMY

Context

Permanent hypocalcemia is a rare but significant complication of thyroid surgery.

Objective

The aim of this study was to identify predictive factors of hypocalcemia and hypoparathyroidism after thyroidectomy.

Design

Study included 134 total patients submitted to thyroidectomy from two endocrine units (January 2015 - August 2016).

Methods

We measured total serum calcium (sCa) and intact PTH (iPTH) on postoperative day one and 1 month after surgery.

Results

118 patients were women with F/M ratio of 7.3/1 and a mean age of 51.8 years. 64 patients were included in group A (iPTH <12 pg/mL) and 70 patients in group B (iPTH >12 pg/mL). sCa and hypocalcemia symptoms were correlated with iPTH, measured 24 hours after surgery. The cut-off value was for sCa 8.05 mg/dL with a sensitivity of 85.29% and a specificity of 88.0% and for iPTH 11.2 pg/mL, with a sensitivity of 82.3% and a specificity of 71.0%. SCa (< 8.05 mg/dL) was a predictive factor with a 99 (IC95%:12.86-761.58) and iPTH (<11.2 pg/mL) with a 10.77 higher risk (CI95%: 3.83-30.30) to be associated with symptoms.

Conclusion

SCa and iPTH represent good predictive factors of early and safe hospital discharge and can predict the risk of prolonged and permanent hypoparathyroidism.

Sepsis in Acute Mediastinitis - A Severe Complication after Oesophageal Perforations. A Review of the Literature

BACKGROUND

Despite recent advancements in antibiotic therapy and the progress made in critical care and modern diagnostic methods, acute mediastinitis continues to be a severe condition.

DIAGNOSIS AND TREATMENT

Acute mediastinitis can occur in the context of cardio-thoracic surgery, oesophageal perforations and oropharyngeal infections condition. Forty-five percent of oesophageal perforations occurs during simple endoscopy. Spontaneous perforation (Boerhaave syndrome) accounts for 15% of perforations, and twelve percent are due to the ingestion of foreign bodies. Other causes include blind or penetrating trauma, and circa 9% to intraoperative lesions. CT scan is the standard investigation that reveals direct signs of mediastinitis.The oral administration of contrast substances can underscore the level of oesophageal perforation. Conservative treatment is the first-choice treatment and surgical treatment is reserved only for specific situations.The principles of surgical treatment consist of drainage, primary suture, oesophageal exclusion with or without the application of oesophagectomy, endoscopic vacuum wound assisted therapy of the perforation and associated paraoesophageal mediastinal drainage and endoscopic stenting associated with drainage.

CONCLUSIONS

The lowest mortality rate is recorded in patients with perforations diagnosed less than twenty-four hours after the onset of symptoms. Surgical treatment remains the gold standard especially in cases of thoracic and abdominal perforations while further investigations are mandatory before endoscopic stenting is carried out.

Hypercalcaemic Crisis Due to Primary Hyperparathyroidism: Report of Two Cases

INTRODUCTION

A hypercalcaemic crisis, also called para thyrotoxicosis, hyper parathyroid crisis or parathyroid storm, is a complication of primary hyperparathyroidism (PHPT) and an endocrinology emergency that can have dramatic or even fatal consequences if it is not recognised and treated in time.

CASE PRESENTATION

Two cases presented in the emergency department with critical hypercalcaemic symptoms and severe elevation of serum calcium and parathyroid hormone levels, consistent with a hypercalcaemic crisis. The first case, a 16-year-old female patient, had imaging data that highlighted a single right inferior parathyroid adenoma and a targeted surgical approach was used. The second case, a 35-year-old man was admitted for abdominal pain, poor appetite, nausea and vomiting. Laboratory tests revealed severe hypercalcaemia, hypophosphatemia and an increased serum iPth level. There was no correlation between scintigraphy and ultrasonography, and a bilateral exploration of the neck was preferred, resulting in the exposure of two parathyroid adenomas. The patients were referred for surgery and recovery in both cases was uneventful.

CONCLUSION

These cases support the evidence that surgery remains the best approach for patients with a hypercalcaemic crisis of hyperparathyroidism origin, ensuring the rapid improvement of both the symptomatology and biochemical alterations of this critical disease.