Preoperative identification of small parathyroid adenomas-better done by fluorocholine positron emission tomography/computed tomography

Background

Preoperative localization imaging studies are crucial for safe and successful parathyroidectomy in patients with primary hyperparathyroidism (pHPT), especially in focused approaches. A common imaging sequence is ultrasound followed by scintigraphy. These techniques, but not 18F-fluorocholine positron emission tomography/computed tomography (PET/CT), show lower detection rates in multiglandular disease (MGD), which is associated with smaller adenomas. In this study, we evaluate the accuracy of these modalities in small parathyroid adenomas (PAs) and discuss the potential sequence of preoperative localization diagnostics.

Methods

Patients undergoing parathyroidectomy for pHPT were retrospectively categorized into small adenoma (specimen diameter <10 mm) and large adenoma. The groups were compared for accuracy of preoperative imaging studies, short-term and long-term outcomes.

Results

Among 147 patients retrospectively analyzed in this study, 38 small PAs were found. Preoperative correct quadrant prediction for small adenomas was significantly lower for ultrasound (P=0.03) and single-photon emission computed tomography/CT (SPECT/CT) (P<0.01) but not for choline PET/CT. While PET/CT was performed significantly more often in small PAs (P<0.01), it showed highly significant superiority over the other imaging modalities in accurate preoperative localization in both small (P<0.0001) and large PAs (P<0.01). There was no difference in calcium and parathyroid hormone (PTH) levels at latest follow-up with slightly more recurrences in small adenomas (P=0.08).

Conclusions

Choline PET/CT showed a better diagnostic yield especially for small and multiple adenomas and was better in prediction of the correct localization. It could therefore serve as a second-line imaging modality.

The role of 18F-fluoromethylcholine-positron emission tomography-computed tomography for preoperative localization of hyperfunctioning parathyroid glands with special emphasis on multiglandular disease: a retrospective cohort study

Background

Primary hyperparathyroidism (PHPT) is a common endocrine disorder. Definitive treatment is surgical. Preoperative localization of diseased glands increases the chance of successful treatment. The aim of this study is to investigate the diagnostic performance of 18F-fluoromethylcholine-positron emission tomography-computed tomography (18F-FCh-PET-CT) in preoperative localization of diseased parathyroid glands, when first-line examinations were inconclusive.

Methods

This is a retrospective study. All patients with PHPT who underwent 18F-FCh-PET-CT, after inconclusive ultrasound examination and 99mTc-methoxyisobutylisonitrile/single-photon emission CT-CT, were included in cohort I. Patients who were subsequently operated for their parathyroid disease, were included in cohort II. The performance of 18F-FCh-PET-CT was analyzed in two sets: per-lesion, and per-gland analysis.

Results

Out of 52 patients in cohort I, 18F-FCh-PET-CT identified single or multiple parathyroid lesions in 43 patients (83%). Nine patients had multiglandular disease. Thirty-four (65%) patients were subsequently operated and included in cohort II. Forty-four lesions were removed from these patients and 33 patients (97%) were cured. 18F-FCh-PET-CT localized 40 out of 44 lesions, with per-lesion and per-gland sensitivities of 97% and 95%, and positive predictive values (PPVs) of 93% and 87%, respectively, in addition to a specificity of 97% and a negative predictive value (NPV) of 94% in the per-gland analysis. Comparable excellent results were detected in multiglandular disease with sensitivity of 94.1%, specificity of 89%, PPV of 84%, and NPV of 94%.

Conclusions

Our study demonstrates the high diagnostic performance of 18F-FCh-PET-CT in the preoperative localization of diseased parathyroid gland in patients with PHPT, especially in multiglandular PHPT.

The Presence of an Arteria Lusoria Should Be Checked When Reporting 18 F-FCH PET/CT Performed to Localize Hyperfunctioning Parathyroid Glands

ABSTRACT

Nonrecurrent inferior laryngeal nerve (NRILN) is a rare anatomical variant, which significantly increases the risk of nerve injury during neck surgery, for example, thyroidectomy or parathyroidectomy (PTX). The absence of the brachiocephalic trunk and presence of arteria lusoria (AL) are strong predictors of NRILN in the right neck. FCH PET/CT is now a recognized imaging modality in hyperparathyroidism (HPT). We report 2 patients with primary or renal HPT in whom FCH PET detected right HFPTs and low-dose noncontrast CT evidenced AL. The NRILN was thus preserved during PTX. We recommend searching for AL on FCH PET/CT (even low-dose) in HPT before PTX.

Surgical site infections in thyroid and parathyroid surgery in Japan: An analysis of the Japan Nosocomial Infections Surveillance database from 2013 to 2020

Surgical site infections (SSIs) after thyroid surgery are rare complications, with incidence rates of 0.3%-1.6%. Using a Japanese database, we conducted exploratory analyses on the incidence of SSIs, investigated the incidence of SSIs by the National Nosocomial Infections Surveillance risk index, and identified the causative bacteria of SSIs. SSIs occurred in 50 (0.7%) of 7388 thyroid surgery cases. Risk index-0 patients had the lowest incidence rate of SSIs (0.41%). The incidence of SSIs in risk index-1 patients was 3.05 times the incidence of SSIs in risk index-0 patients. The rate of SSI occurrence for risk index-2 patients was 4.22 times the rate of SSI occurrence for risk index-0 patients. Thirty-one bacterial species were identified as the cause of SSIs in thyroid surgery cases, of which 12 (38.7%) SSIs were caused by Staphylococcus aureus and Staphylococcus epidermidis. Of the nine SSIs caused by Staphylococcus aureus, 55.6% (five cases) were attributed to methicillin-resistant Staphylococcus aureus. Therefore, routine prophylactic antibiotic administration should be avoided, while the target for administration should be narrowed, according to the SSI risk. Administration of prophylactic antibiotics, such as 2 g piperacillin or 1 g cefazolin, is considered appropriate.

Postoperative cerebral hemorrhage death in a patient with secondary hyperparathyroidism: a report of one case and literature review

Secondary Hyperparathyroidism (SHPT) is a common complication of end-stage renal disease (ESRD), and parathyroid surgery (PTX) is an effective way to treat patients with severe SHPT. ESRD has multiple associations with cerebrovascular diseases. For example, the incidence of stroke in patients with ESRD is 10 times higher than that in the general population, the risk of death after acute stroke is three times higher, and the risk of hemorrhagic stroke is significantly higher. High/low serum calcium, high PTH, low serum sodium, high white blood cell count, previous occurrences of cerebrovascular events, polycystic kidney disease (as a primary disease), and the use of anticoagulants are independent risk factors for hemorrhagic stroke in hemodialysis patients with uremia. The risk of stroke in patients who undergo PTX decreases significantly in the second year of follow-up and persist thereafter. However, studies on the risk of perioperative stroke in SHPT patients are limited. After undergoing PTX, the PTH levels in SHPT patients drop suddenly, they undergo physiological changes, bone mineralization increases, and calcium in the blood gets redistributed, often accompanied by severe hypocalcemia. Serum calcium might influence the occurrence and development of hemorrhagic stroke at various stages. To prevent bleeding from the operated area, the use of anticoagulants after surgery is reduced in some cases, which often decreases the frequency of dialysis and increases the quantity of fluid in the body. An increase in the variation in blood pressure, instability of cerebral perfusion, and extensive intracranial calcification during dialysis promote hemorrhagic stroke, but these clinical problems have not received enough attention. In this study, we reported the death of an SHPT patient who suffered a perioperative intracerebral hemorrhage. Based on this case, we discussed the high-risk factors for perioperative hemorrhagic stroke in patients who undergo PTX. Our findings might help in the identification and early prevention of the risk of profuse bleeding in patients and provide reference for the safe performance of such operations.

Evolution of the Diagnosis and Treatment of Primary Hyperparathyroidism

This study aims to present the evolution of our center's approach to treating primary hyperparathyroidism (PHPT) from diagnosis to intraoperative interventions. We have also evaluated the intraoperative localization benefits of indocyanine green fluorescence angiography. This retrospective single-center study involved 296 patients who underwent parathyroidectomy for PHPT between January 2010 and December 2022. The preoperative diagnostic procedure included neck ultrasonography in all patients, [99mTc]Tc-MIBI scintigraphy in 278 patients, and, in 20 doubtful cases, [18F] fluorocholine positron emission tomography (PET) computed tomography (CT) was performed. Intraoperative PTH was measured in all cases. Indocyanine green has been administered intravenously since 2020 to guide surgical navigation using a fluorescence imaging system. The development of high precision diagnostic tools that can localize an abnormal parathyroid gland in combination with intra-operative PTH assay (ioPTH) enables the surgical treatment of PHPT patients with focused approaches and excellent results that are stackable with bilateral neck exploration (98% of surgical success). Indocyanine green angiography has the potential to assist surgeons in identifying parathyroid glands rapidly and with minimal risk, especially when pre-operative localization has failed. When everything else fails, it is only an experienced surgeon who can resolve the situation.

The Role of Primary Repair of the Recurrent Laryngeal Nerve during Thyroid/Parathyroid Surgery in Vocal Outcomes-A Systematic Review

Recurrent laryngeal nerve (RLN) injury is a well and long-known complication of thyroid and parathyroid surgery that significantly affects the quality of life of patients. Despite the advances in surgical techniques and technology, it still occurs in clinical practice either as temporary paresis or as permanent paralysis of the corresponding vocal cord. The purpose of the current systematic review is to examine the value of intraoperative repair of the RLN in voice restoration. A systematic review of the existing literature was conducted using PubMed, Scopus, Cochrane Library, and Google Scholar databases according to the PRISMA guidelines. The systematic review resulted in 18 studies, which met the inclusion criteria. An improvement in phonatory function and voice quality was observed in all these studies after immediate RLN reconstruction (not always statistically significant). This improvement appears to be comparable to or even higher than that achieved with other methods of repair, and in some cases, the improvement approaches levels found in normal subjects. Intraoperative RLN reconstruction is not widely used in clinical practice, but the evidence so far makes it a viable and safe alternative to traditional techniques with better long-term results, as it prevents the occurrence of atrophy of the vocal cord and should be considered in the operating room if possible.

Parathyroid Autofluorescence in Pediatric Thyroid Surgery: Experience With False Positive and False Negative Results

Devices for near-infrared light stimulation of autofluorescence (NIRAF) allow for intraoperative identification of parathyroid glands with high sensitivity in adults. However, their performance in the pediatric population is unknown. In this case series with chart review at a tertiary academic children's hospital, we investigated pediatric patients undergoing thyroid surgery and concurrent use of a probe-based NIRAF device. Thirteen patients (ages 6-18 years) underwent thyroid and/or neck dissection procedures, and 2 patients had revision procedures for a total of 15 cases with the NIRAF device. Eight cases had NIRAF values that matched surgeon opinion of parathyroid tissue or histology when available. Six cases had false positive NIRAF readings (40.0%) and 1 case had false negative readings (6.7%). Compared with surgeon opinion or histology, the NIRAF device confirmed 26 of 34 parathyroid gland candidates (76.5%). These devices need further investigation in pediatric patients, whose tissues may have different autofluorescence characteristics.

Parathyroid adenoma in pregnancy: A case report and systematic review of the literature

OBJECTIVE

Primary hyperparathyroidism is a common disorder of the parathyroid glands. Parathyroid adenoma (PA) in pregnancy is a relatively rare disease, whose diagnosis and treatment is a challenging task. The aim of the present study is to present a new case of parathyroid adenoma during pregnancy and to give a detailed account of all reported cases of parathyroid adenoma during pregnancy in the literature.

STUDY DESIGN

A bibliographic research was performed, and characteristics of parathyroid adenomas in pregnancy such as age, gestational week at diagnosis, ionized calcium levels, genetic testing result, symptomatology, radiological method of localization, treatment method, gestational week at operation, and maternal/fetal complications were recorded.

RESULTS

A 34-year-old woman at her 25 weeks' gestation was diagnosed with parathyroid adenoma and was referred to our Surgical Department due to contraindication for conservative treatment. A parathyroidectomy was performed, and the maternal and fetal postoperative period was uneventful. Two hundred eleven cases of parathyroid adenoma in pregnancy were recorded in the literature, and statistical analysis was performed. The median gestational week at diagnosis was 21 ± 9.61 weeks. The mean level of ionized calcium was 2.69 mmol/l [SD = 0.75 (2.55-2.84 95% CI)]. Most cases were familiar (72.4%), while surgery was the preferred treatment option (67.3%). The majority of cases were asymptomatic (21.7%), and the main radiological method applied for localization was ultrasound (63.4%).

CONCLUSION

Parathyroid adenoma in pregnancy is a rare condition. The early diagnosis is of great importance as surgical treatment at the second trimester of pregnancy outweighs the maternal and fetal risks.

Morbidity following thyroid and parathyroid surgery: Results from key performance indicator assessment at a high-volume centre in New Zealand

BACKGROUND

Complications following thyroid/parathyroid surgery include recurrent laryngeal nerve (RLN) injury, hypocalcaemia and return to theatre for haematoma evacuation. Rates of these form the basis of key performance indicators (KPI). An endocrine database, containing results from 1997, was established at the North Shore Hospital in Auckland, New Zealand. We aimed to measure complication rates by procedure (thyroid and parathyroid), explore a temporal change in our unit and compare our results against international literature.

METHODS

A retrospective review of the database between July 1997 and February 2020 was performed. The results for each KPI were analysed in total and over consecutive time periods. A review of the literature was carried out to find international complication rates for comparison. A cumulative sum (CUSUM) analysis was performed to give visual feedback on performance.

RESULTS

There were 1062 thyroidectomies and 336 parathyroidectomies from July 1997 to February 2020. Thyroid surgery results found rates of temporary/permanent RLN injury of 1.9%/0.3%, temporary/permanent hypocalcaemia of 22.3/2.5%, and return to theatre for haematoma evacuation of 1.1%. Parathyroid surgery results were, temporary RLN injury of 0.8% (no permanent injury), temporary/permanent hypocalcaemia of 1.7%/0.4%, and return to theatre for haematoma evacuation of 0.3%. CUSUM analysis found KPI results to be comparable with international literature.

CONCLUSION

Our unit's KPI results are comparable to published results in the literature. The use of this clinical database will help in future monitoring of performance and help drive improvement in the service. Embedding prospective data collection as routine practice allows for continuous improvement for the unit.

Hyperparathyroidism subsequent to radioactive iodine therapy for Graves' disease

BACKGROUND

The development of primary hyperparathyroidism (PHPT) after radioactive iodine (RAI) treatment for thyroid disease is poorly characterized. The current study is the largest reported cohort and assesses the disease characteristics of patients treated for PHPT with a history of RAI exposure.

METHODS

A retrospective analysis comparing patients, with and without a history of RAI treatment, who underwent surgery for PHPT.

RESULTS

Twenty-eight of the 469 patients had a history of RAI treatment, all for Graves' disease. Patients with a history of RAI exposure had similar disease characteristics compared to control; however, patients with a history of RAI treatment had a higher rate of recurrence (7.4% vs 1.2%, p = 0.012).

CONCLUSION

PHPT in patients with a history of RAI treatment can be approached in the same manner as RAI naive PHPT patients; however, the risk of recurrence of PHPT in RAI exposed patients may be higher.

Role of intraoperative neuromonitoring of recurrent laryngeal nerve in thyroid and parathyroid surgery

Objective

To investigate whether intraoperative neuromonitoring (IONM) has a significant advantage in reducing the incidence of recurrent laryngeal nerve (RLN) injury.

Methods

Patients who underwent thyroid and parathyroid surgery from October 2012 to December 2017 at the Center for Thyroid and Breast Surgery of Xuanwu Hospital were retrospectively analyzed. They were divided into the IONM group and visualization alone group (VA group) according to whether IONM was used.

Results

In total, 1696 nerves at risk of injury (IONM group, n = 1104; VA group, n = 592) were included in the analysis. Among the high-risk nerves, permanent damage occurred in no cases in the IONM group but in one case in the VA group. Because the higher proportion of central lymph node metastasis caused difficulties in central cervical lymph node dissection and identification of the RLN, the patients undergoing lateral cervical lymph node dissection in the VA group had a significantly higher risk of postoperative RLN injury (11.76% vs. 0.00%).

Conclusion

IONM technology has advantages in protection of the RLN, especially in high-risk nerves and patients with a high proportion of central lymph node metastasis who require central and lateral cervical lymph node dissection.

Patient Self-Assessment and Acoustic Voice Analysis in Screening of Postoperative Vocal Fold Paresis and Paralysis

Background and objective:

The aim of this study was to evaluate the utility of two items in vocal fold paresis and paralysis screening after thyroid and parathyroid surgery: patient self-assessment of voice using the Voice Handicap Index and computer-based acoustic voice analysis using the Multi-Dimensional Voice Program.

Methods:

This was a prospective study of 181 patients who underwent thyroid or parathyroid surgery over a 1-year study period (2017). Preoperatively, all patients underwent laryngoscopic vocal fold inspection and acoustic voice analysis, and they completed the Voice Handicap Index questionnaire. Postoperatively, all patients underwent laryngoscopy prior to hospital discharge; 2 weeks after the surgery, they completed the Voice Handicap Index questionnaire a second time. Two weeks postoperatively, patients with vocal fold paresis or paralysis and 20 randomly selected controls without vocal fold paresis or paralysis underwent a follow-up acoustic voice analysis.

Results:

Fourteen patients had a new postoperative vocal fold paresis or paralysis. Postoperatively, the total Voice Handicap Index score was significantly higher (p = 0.040) and the change between preoperative and postoperative scores was greater (p = 0.028) in vocal fold paresis or paralysis patients. A total postoperative Voice Handicap Index score > 30 had 55% sensitivity, and 90% specificity, for vocal fold paresis or paralysis. In the postoperative Multi-Dimensional Voice Program analysis, vocal fold paresis or paralysis patients had significantly more jitter (p = 0.044). Postoperative jitter > 1.33 corresponded to 55% sensitivity, and 95% specificity, for vocal fold paresis or paralysis.

Conclusions:

In identifying postoperative vocal fold paresis or paralysis, patient self-assessment and jitter in acoustic voice analysis have high specificity but poor sensitivity. Without routine laryngoscopy, approximately half of the patients with postoperative vocal fold paresis or paralysis could be overlooked. However, if the patient has no complaints of voice disturbance 2 weeks after thyroid or parathyroid surgery, the likelihood of vocal fold paresis or paralysis is low.

Current Trainee and Workforce Patterns for Thyroid and Parathyroid Surgery in the United States

OBJECTIVE

Thyroid and parathyroid surgery is performed by both general surgeons and otolaryngologists. We describe the proportion of surgeries performed by specialty, providing data to support decisions about when and to whom to direct research, education, and quality improvement interventions.

METHODS

We tabulated case numbers for privately insured patients undergoing thyroid and parathyroid surgery in Marketscan: 2010-2016 and trainee case logs for residents and fellows in general surgery and otolaryngology. Summary statistics and tests for trends and differences were calculated.

RESULTS

Marketscan data captured 114 500 thyroid surgeries. The proportion performed by each specialty was not significantly different. Otolaryngologists performed 58 098 and general surgeons performed 56 402. Otolaryngologists more commonly performed hemithyroidectomy (n = 25 148, 43.29% of all thyroid surgeries performed by otolaryngologists) compared to general surgeons (n = 20 353, 36.09% of all thyroid surgeries performed by general surgeons). Marketscan data captured 21 062 parathyroid surgeries: 6582 (31.25%) were performed by otolaryngologists, and 14 480 (68.75%) were performed by general surgeons. The case numbers of otolaryngology and general surgery trainees completing residency and fellowship varied 6- to 9-fold across different sites. The wide variation may reflect both the level of exposure a particular training program offers and trainee level of interest.

CONCLUSION

Thyroid surgical care is equally provided by general surgeons and otolaryngologists. Both specialties contribute significantly to parathyroid surgical care. Both specialties should provide input into and be targets of research, quality, and education interventions.

Training Courses in Laryngeal Nerve Monitoring in Thyroid and Parathyroid Surgery- The INMSG Consensus Statement

Intraoperative neural monitoring (IONM) is now an integral aspect of thyroid surgery in many centers. Interest in IONM and the number of institutions that perform monitored thyroidectomies have increased throughout the world in recent years. For surgeons considering the introduction of IONM in their practice, specific training in IONM devices and procedures can substantially shorten the learning curve. The International Neural Monitoring Study Group (INMSG) has been at the forefront of IONM technology and procedural adoption since the introduction of neural monitoring in thyroid and parathyroid surgery. The purpose of this document is to define the INMSG consensus on essential elements of IONM training courses. Specifically, this document describes the minimum training required for teaching practical application of IONM and consensus views on key issues that must be addressed for the safe and reliable introduction of IONM in surgical practice. The intent of this publication is to provide societies, course directors, teaching institutions, and national organizations with a practical reference for developing IONM training programs. With these guidelines, IONM will be implemented optimally, to the ultimate benefit of the thyroid and parathyroid surgical patients.

Informed Consent for Intraoperative Neural Monitoring in Thyroid and Parathyroid Surgery - Consensus Statement of the International Neural Monitoring Study Group

In the past decade, the use of intraoperative neural monitoring (IONM) in thyroid and parathyroid surgery has been widely accepted by surgeons as a useful technology for improving laryngeal nerve identification and voice outcomes, facilitating neurophysiological research, educating and training surgeons, and reducing surgical complications and malpractice litigation. Informing patients about IONM is not only good practice and helpful in promoting the efficient use of IONM resources but is indispensable for effective shared decision making between the patient and surgeon. The International Neural Monitoring Study Group (INMSG) feels complete discussion of IONM in the preoperative planning and patient consent process is important in all patients undergoing thyroid and parathyroid surgery. The purpose of this publication is to evaluate the impact of IONM on the informed consent process before thyroid and parathyroid surgery and to review the current INMSG consensus on evidence-based consent. The objective of this consensus statement, which outlines general and specific considerations as well as recommended criteria for informed consent for the use of IONM, is to assist surgeons and patients in the processes of informed consent and shared decision making before thyroid and parathyroid surgery.

Randomized Prospective Comparison of Glidescope Video Laryngoscope with Macintosh Laryngoscope in Adult who Underwent Thyroid or Parathyroid Surgery Using Neuromonitorization

Objectives

The present study aims to compare the effects of Glidescope Video Laryngoscope (GVL) and Machintosh Laryngoscope (ML) on the hemodynamic response, intubation time and mucosal damage in adult patients who underwent thyroid or parathyroid surgery using neuromonitorization.

Methods

In this study, 180 patients, aged between 22 and 65 classified as Class I-II in ASA (American Society of Anesthesiologists) and operated under elective conditions were included. Patients were assigned into two groups: Patients intubated with GVL Group G (n=90) and patients intubated with ML Group M (n=90). In both groups, intubation time and the number of trials were recorded. HR (Heart Rate), SpO2 (Peripheral Capillary Oxygen Saturation), SBP (Systolic Blood Pressure), DBP (Diastolic Blood Pressure) and MBP (Mean Blood Pressure) scores were recorded at preinduction, post-induction, post-intubation and three minutes after intubation. Post-operative intubation-associated complications were recorded.

Results

Post intubation HR, DBP and MBP scores were found to be significantly higher in Group M than Group G (p=0,006, p=0.013, p=0.011). Intubation time was found to be significantly higher in Group G than in group M (35.3±10.3, 22.1±7.7 sec). There was no significant difference between the groups' number of trials and intubation-associated complications.

Conclusion

Despite its long intubation time, we believe that GVL may be the first choice laryngoscopy method in the thyroid or parathyroid cases that intubated with a low dose muscle relaxant for neuromonitoring since it has a slight effect than ML on hemodynamism it does not increase mucosal damage and has improved visibility.

Use of Indocyanine Green and Fluorescence Angiography in Parathyroid Surgery: A Feasibility Study

Background. Indocyanine green (ICG) with near-infrared (NIR) fluorescence is an established method for assessing vascularity in various clinical settings. We hypothesized that parathyroid adenomas, with increased capillary networks, may demonstrate a fluorescence which could aid intraoperative identification and confirmation of the abnormal parathyroid tissue. Methods. This prospective case-control study compared patients with primary hyperparathyroidism undergoing parathyroidectomy (cases) to normal parathyroid in thyroidectomy patients (controls). After exposing the parathyroid gland, ICG was injected and the fluorescence of parathyroid and thyroid was recorded and graded in comparison to the surrounding tissue and vasculature (0 = nonfluorescent and 5 = vasculature). Results. The intensity of parathyroid fluorescence was more in cases (4 ± 2) than controls (2 ± 1) when graded intraoperatively (P = .001). Thyroid fluorescence did not differ (3 vs 3, P = .072); however, parathyroid fluorescence was more intense than thyroid in cases (parathyroid = 4 ± 2 and thyroid = 3 ± 1, P = .018). Conclusions. ICG fluorescence in diseased parathyroid was more intense than normal parathyroid and thyroid, suggesting the ICG/NIR technology may be a useful intraoperative tool for identification of abnormal parathyroid.

Edward D. Churchill (1895-1972): An Innovative Surgeon, His Work, and His Contribution to Parathyroid Surgery

Edward Delos Churchill, one of the most notorious American surgeons of the 20th century, influenced countless surgeons and set medical practices that were used for decades. His scope of interests included surgery of the lungs, heart, thyroid, parathyroid glands, and military surgery among others. Churchill was one of the first to expand the field of the newly found parathyroid bodies by performing several experimental excisions of the glands and publishing numerous guidelines based on his innovative work. Additionally, he aspired to address many of the literature gaps that led him to conclusions that would benefit both the surgeons and patients throughout the country. Most importantly, his deep interest in endocrinology and his aggregate approach of medicine led him to discoveries that paved the way to the modern endocrine surgery practices.

Indocyanine Green Fluorescence Angiography Can Guide Intraoperative Localization During Parathyroid Surgery

BACKGROUND AND AIMS

Intraoperative localization of pathologic parathyroid glands is of major importance for the hyperparathyroidism treatment. Based on the small size and the anatomic variability, the localization can be very challenging. The current practice is to compare preoperative ultrasonography with Technetium-99m sestamibi scintigraphy (MIBI) and plan the resection accordingly. In this study, we implemented indocyanine green angiography for the intraoperative localization of parathyroid glands.

MATERIALS AND METHODS

This is a retrospective analysis of 37 patients with primary, secondary, or tertiary hyperparathyroidism who were operated using indocyanine green angiography for the intraoperative localization of pathological parathyroid glands. An indocyanine green solution of 2.5 mg was were intravenously administered for parathyroid gland visualization. Different fluorescence scores were correlated with changes in postoperative parathyroid hormone levels.

RESULTS

Patients were divided into two groups depending on the presence of uniglandular or multiglandular disease. Sixty-four lesions were resected, and the final histopathologic analysis confirmed the parathyroid origin in 62 of them (96.8%). None of the patients with uniglandular disease developed postoperative hypoparathyroidism, whereas three patients in the multiglandular group developed temporary hypoparathyroidism symptoms. Indocyanine green imaging had higher sensitivity for the intraoperative detection of parathyroid glands compared with ultrasonography and MIBI (p < 0.001).

CONCLUSION

Indocyanine green angiography indicated high sensitivity for the intraoperative identification of pathologic parathyroid glands leading to a resection rate of 95.16%. The modality was useful, especially in cases of revisional surgery or ectopic parathyroid glands. Randomized trials have already proven the value of indocyanine green imaging in predicting postoperative hypocalcemia. Our results support the regular use of this method during parathyroid surgery.

Risk factors and prognosis of voice disorders after surgical treatment of thyroid and parathyroid diseases

AIM

To analyze risk factors and prognosis of voice disorders after surgical treatment of thyroid and parathyroid diseases.

MATERIAL AND METHODS

There were 1272 patients who were operated in the endocrine surgery department for the period from January 1, 2016 to April 30, 2017. We studied the incidence of VF paresis, VF paralysis, and persistent dysphonia as clinical outcomes. Potential risk factors have to be analyzed were sex and age of patients, BMI, diagnosis, surgical technique, thyroid volume, experience of the surgeon and assistant, use of intraoperative neuromonitoring, etc. RESULTS: Significant relationships of risk factors with various complications of thyroid surgery were found. In logistic regression analysis, the independent predictors of complications were the following: 1) for VF paresis - extent of surgery and thyroid volume; 2) for VF paralysis - sex, extent of surgery and thyroid volume; 3) for persistent postoperative dysphonia - age and thyroid volume.

CONCLUSION

The correlation of various risk factors with development of VF paresis, VF paralysis and persistent dysphonia were identified in patients undergoing thyroid and parathyroid surgery.

Utilization of cross-matched blood in elective thyroid and parathyroid surgeries: a single-center retrospective study

Background

Hospital blood banks face the common challenge of maintaining an adequate supply of blood products to serve all potential patients while minimizing the need to discard expired blood products. This study aimed to determine the risk of blood transfusion during elective thyroid and parathyroid surgery and potential factors related to blood loss and risk of transfusion in these cases.

Methods

The study included all thyroid and parathyroid surgeries performed at King Abdulaziz University Hospital between January 2015 and December 2017. After exclusion of patients with incomplete data, 179 patients with complete data who had undergone thyroid and parathyroid surgery were analyzed.

Results

Of the179 patients included in this study, 33 (18.4%) were male. Overall, patients had a mean age and body-mass index of 44.55±13.67 years and 27.66±5.38 kg/m², respectively. The mean duration of surgery was 168.48±90.69 minutes. None of the patients had a history of previous radiotherapy, bleeding disorder, or blood transfusion. Benign goiter was the most common finding (n=78, 43.6%), followed by papillary carcinoma (n=49, 27.4%). During surgery, most patients (n=136, 76.0%) experienced minimal blood loss. None of the patients in our cohort (n= 179) required any blood transfusion or products.

Conclusion

In this study, we aimed to audit the surgical blood-ordering and -transfusion practices associated with elective thyroid and parathyroid surgeries at our institution. These practices are intended to balance the availability of blood products with the avoidance of unnecessary wastage. In our study of patients who underwent elective thyroid and parathyroid surgeries, parathyroid surgeries, none required blood transfusion.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Level of Evidence

III or IV.

Anterior laryngeal electrodes for recurrent laryngeal nerve monitoring during thyroid and parathyroid surgery: New expanded options for neural monitoring

OBJECTIVES/HYPOTHESIS

Intraoperative neural monitoring is a useful adjunct for the laryngeal nerve function assessment during thyroid and parathyroid surgery. Typically, monitoring is performed by measurement of electromyographic responses recorded by endotracheal tube (ETT) surface electrodes. Tube position alterations during surgery can cause displacement of the electrodes relative to the vocal cords, leading to false positive loss of signal. Numerous reports have denoted monitoring equipment-related issues, especially endotracheal tube displacement, as the dominant source of false positive error. The false positive error may result in inappropriate decisions by the surgeon. This study tests the hypothesis that anterior laryngeal electrodes (ALEs) can help reduce this error. Placement of ALEs directly onto the thyroid cartilage represent an adjunctive and possible alternative method to standard ETT surface electrodes.

STUDY DESIGN

Retrospective review.

METHODS

Fifteen consecutive patients undergoing thyroid and parathyroid surgery with intraoperative neuromonitoring using both ETT electrodes and ALEs were studied. Data collected included site of neural stimulation, laterality, and electromyographic parameters.

RESULTS

With vagal and recurrent laryngeal nerve stimulation, the ALEs recorded mean vocalis muscle waveform amplitude within 83% of that recorded with standard ETT electrodes. The latency measurements with the anterior laryngeal and endotracheal electrodes were similar, with both electrodes recording significantly longer latency for the left vagus nerve as compared to the right vagus nerve. With superior laryngeal nerve stimulation, the ALEs recorded a 800% greater mean amplitude than the ETT electrodes. The ALEs demonstrated similar sensitivity to stimulation at low current as ETT electrodes and provided stable intraoperative monitoring information.

CONCLUSIONS

Compared to ETT surface electrodes, the ALEs provide similar and stable electromyographic responses with equal sensitivity for recording evoked responses during neural monitoring in thyroid and parathyroid surgery. The ALEs offer significantly more robust monitoring of the external branch of the superior laryngeal nerve. Furthermore, ALEs are contained within the operative field, are totally surgeon controlled, and are unaffected by the potential vicissitudes of ETT position during surgery.

LEVEL OF EVIDENCE

4 Laryngoscope, 128:2910-2915, 2018.

Near total parathyroidectomy for the treatment of renal hyperparathyroidism

Background

Different surgical strategies are used to treat medical refractory renal hyperparathyroidism. Our preferred choice in patients with moderate secondary hyperparathyroidism (SHPT) and in patients with low compliance with medical treatment is to leave a very small parathyroid remnant in situ: we name this operation "near total parathyroidectomy" (ntPTX). We report here our results with this technique.

Methods

Retrospective study [2001-2015] of all patients submitted to ntPTX in a single centre.

Results

Forty-seven patients were submitted to ntPTX (32 males) aged 47.3 years. Follow-up time is 8.5 years. Thirty-five patients (74%) are alive, 12 are dead. One patient in this series had a functioning renal transplant at time of ntPTX (tertiary hyperparathyroidism), and other 27 subsequently received a renal transplantation (RTx) after ntPTX (still functioning at last follow-up or at death in 19). Amongst the 35 current survivors, the renal graft is functioning in 16 (45.7%). Parathyroid hormone (PTH) at follow-up was 116.1±135.5 pg/mL and calcium 8.6±0.9 mg/dL. Among patients with a functioning RTx PTH was 83 pg/mL and calcium 8.7 mg/dL. There was no persistent disease, and 3 patients (6.4%) had a relapse of hyperparathyroidism at follow-up.

Conclusions

ntPTX is associated to very satisfying rates of normal parathyroid function and of relapse of hyperparathyroidism (6.4%) at long term, either in case of RTx or of maintenance hemodialysis: the concept of "small amount" remnant represents a valuable choice for patients undergoing PTX with a realistic chance of receiving a RTx.

Recurrent laryngeal nerve injury after thyroid and parathyroid surgery: Incidence and postoperative evolution assessment

Recurrent laryngeal nerve (RLN) injury is a feared complication after thyroid and parathyroid surgery. It induces important postoperative morbidity. The present study aimed to assess the incidence of transient/permanent postoperative RLN injuries after thyroid and parathyroid surgery in the present cohort, to observe the timing of recovery, and to identify risk factors for permanent RLN injury after thyroidectomy.All consecutive patients operated on at our institution for thyroid and parathyroid pathologies from 2005 to 2013 were reviewed for vocal cord paresis. Vocal cord paresis was defined based on postoperative fiberoptic laryngoscopy. Demographics, intraoperative details, and postoperative outcomes were collected. Treatment types were assessed, and recovery times collected. Patients with vocal cord paresis on preoperative fiberoptic laryngoscopy were excluded from the analysis.The cohort included 451 thyroidectomies (756 nerves at risk) and 197 parathyroidectomies (276 nerves at risk). There were 63 postoperative vocal cord pareses after thyroidectomy and 13 after parathyroidectomy. Sixty-nine were transient (10.6%) and 7 permanent (1.1%). The main performed treatment was speech therapy in 51% (39/76) of the patients. Median recovery time after transient injuries was 8 weeks. In the group with vocal cord paresis, risk factors for permanent injuries after thyroidectomy were previous thyroidectomy and intraoperative RLN injury on univariate analysis. On multivariate analysis, only intraoperative RLN injury remained significant.Most of the patients with transient postoperative RLN injury recovered normal vocal cord mobility within 6 months. The most common performed treatment was in this cohort speech therapy. Permanent RLN injuries remained rare (1.1%).

Electrophysiological identification of nonrecurrent laryngeal nerves

OBJECTIVES/HYPOTHESIS

The nonrecurrent laryngeal nerve (NRLN) is a common anatomic variation of the right recurrent laryngeal nerve (RLN), which has been associated with an increased risk of injury during thyroid and parathyroid surgery. We suggest that early successful identification using intraoperative nerve monitoring (IONM) and preservation of this variant will help the surgeon to avoid injury to this nerve. Our objective was to examine the electrophysiological parameters of the NRLN and the efficacy of IONM for successful identification of the NRLN.

STUDY DESIGN

Retrospective database analysis.

METHODS

This is a retrospective study of a prospectively collected database of all patients who underwent thyroid and parathyroid surgeries by a single surgeon at a tertiary care center over 3 years (n = 481). Patients' demographic data and operative reports, including the IONM reports, were reviewed. Average stimulation thresholds with resulting amplitudes and latencies were compared. Preoperative and postoperative laryngoscopy were performed in all cases.

RESULTS

We identified 15 NRLNs (2.2%) in a total 682 laryngeal nerves. No left-sided NRLNs were observed. The average right vagus latency in the NRLN group was shorter than that of the RLN group (2.40 ms ± 0.49 ms vs. 3.43 ms ± 1.03 ms; P < .001). No statistically significant difference was observed between the initial amplitudes of the right vagus nerves in the two groups (713.67 μV ± 208.71 μV vs. 816.22 μV ± 470.45 μV; P = .14). All NRLN cases exhibited normal functioning of vocal cords on postoperative laryngoscopy.

CONCLUSIONS

IONM is highly effective in the identification of the NRLN. Right vagus nerve latency in the NRLN group was found to be significantly shorter than in the RLN group. Early identification of the NRLN allowed cautious preservation of the NRLN, resulting in excellent postoperative outcomes. The rate of NRLN identification may be improved by routine use of IONM.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:2189-2193, 2017.

Role of Intraoperative Nerve Monitoring During Parathyroidectomy to Prevent Recurrent Laryngeal Nerve Injury

Injury to the recurrent laryngeal nerve (RLN) is a well known, though less frequent, complication of parathyroid surgery. In recent years, the use of intraoperative nerve monitoring (IONM) has gained popularity amongst surgeons when operating on thyroid gland; however, its utilization in parathyroid surgery is not established. This trend continues to rise, despite multiple studies documenting no statistically significant difference that IONM decreases the incidence of RLN injury. Most surgeons use this technology as an adjunct to visualization alone for identification of RLN. The purpose of this review is to discuss the possible role of IONM in parathyroid surgery with regards to the accuracy, efficacy, and recent trends in the utilization of this technology. There is insufficient evidence that IONM reduces the risk of RLN injury in parathyroidectomy. Although IONM may decrease the likelihood of nerve injury by helping to identify and map the RLN during thyroidectomy, we did not find studies exclusive to parathyroid surgery to see if its use can be supported for parathyroidectomy. Despite this lack of evidence, we believe that IONM is a promising adjunct to visualization alone in detecting nerve structures during neck dissection, but more clinical trials are warranted to establish its role in preventing nerve injury in parathyroid surgery.

Minimally invasive parathyroid surgery

Traditionally, bilateral cervical exploration for localization of all four parathyroid glands and removal of any that are grossly enlarged has been the standard surgical treatment for primary hyperparathyroidism (PHPT). With the advances in preoperative localization studies and greater public demand for less invasive procedures, novel targeted, minimally invasive techniques to the parathyroid glands have been described and practiced over the past 2 decades. Minimally invasive parathyroidectomy (MIP) can be done either through the standard Kocher incision, a smaller midline incision, with video assistance (purely endoscopic and video-assisted techniques), or through an ectopically placed, extracervical, incision. In current practice, once PHPT is diagnosed, preoperative evaluation using high-resolution radiographic imaging to localize the offending parathyroid gland is essential if MIP is to be considered. The imaging study results suggest where the surgeon should begin the focused procedure and serve as a road map to allow tailoring of an efficient, imaging-guided dissection while eliminating the unnecessary dissection of multiple glands or a bilateral exploration. Intraoperative parathyroid hormone (IOPTH) levels may be measured during the procedure, or a gamma probe used during radioguided parathyroidectomy, to ascertain that the correct gland has been excised and that no other hyperfunctional tissue is present. MIP has many advantages over the traditional bilateral, four-gland exploration. MIP can be performed using local anesthesia, requires less operative time, results in fewer complications, and offers an improved cosmetic result and greater patient satisfaction. Additional advantages of MIP are earlier hospital discharge and decreased overall associated costs. This article aims to address the considerations for accomplishing MIP, including the role of preoperative imaging studies, intraoperative adjuncts, and surgical techniques.

Backscattering intensity measurements in optical coherence tomography as a method to identify parathyroid glands

BACKGROUND AND OBJECTIVE

Previous studies have shown that the use of optical coherence tomography (OCT) permits the differentiation between parathyroid tissue, thyroid tissue, lymph nodes and adipose tissue. We investigated the backscattering intensity profiles of OCT images in order to determine whether significant differences between these tissue types exist.

METHODS

Mean backscattering intensity profiles were obtained from OCT images of parathyroid glands, thyroid tissue, lymph nodes and adipose tissue. The profiles were analyzed employing Fisher's Linear Discriminant Analysis (LDA). The results were cross validated employing improved parameter estimation techniques.

RESULTS

Mean backscattering intensity profiles from 300 OCT images of 34 patients undergoing thyroid or parathyroid surgery were analyzed. The overall rate of correct classifications was 96.15%. The cross validation employing improved parameter estimation techniques yielded results identical to those derived from Fisher's LDA.

CONCLUSION

Besides the individual assessment of OCT images by interpreting morphological criteria, backscattering intensity measurements can reliably distinguish between different tissue entities.

Optical coherence tomography as a method to identify parathyroid glands

BACKGROUND AND OBJECTIVE

The identification of parathyroid glands can be a major problem in parathyroid surgery. The purpose of this study was to evaluate the feasibility of optical coherence tomography (OCT) in distinguishing between parathyroid tissue, thyroid tissue, lymph nodes, and adipose tissue.

METHODS

Ex vivo OCT images as well as histological sections were generated from parathyroid glands, thyroid tissue, lymph nodes and fat in order to define significant morphologic differences between these entities. As a second step all OCT images were separately evaluated by two blinded investigators and later compared to the corresponding histology. Sensitivity and specificity of OCT in distinguishing between the different tissues were determined. To assess the interobserver agreement, κ coefficients were calculated from the ratings of each investigator for each OCT image seen.

RESULTS

A total of 320 OCT images from 32 patients undergoing thyroid surgery, parathyroidectomy or lymphadenectomy were compared with the corresponding histology. The sensitivity and specificity in distinguishing parathyroid tissue from the other entities was 84% (second investigator: 82%) and 94% (93%) respectively. Unweighted κ using four diagnostic categories was 0.97 (95% CI, 0.94-0.99) showing substantial agreement between both investigators.

CONCLUSION

OCT is highly sensitive in distinguishing between parathyroid tissue, thyroid tissue, lymph nodes and adipose tissue. These ex vivo results should be confirmed by using OCT imaging intraoperatively.

The role of nerve monitoring to predict postoperative recurrent laryngeal nerve function in thyroid and parathyroid surgery

OBJECTIVES/HYPOTHESIS

To determine the role and efficacy of intraoperative recurrent laryngeal nerve (RLN) stimulation in the prediction of early and permanent postoperative nerve function in thyroid and parathyroid surgery.

STUDY DESIGN

A retrospective review of thyroid and parathyroid surgeries was performed with calculation of sensitivity and specificity of the response of intraoperative stimulation for different pathological groups.

METHODS

Normal electromyography (EMG) response with 0.5 mAmp stimulation was considered a positive stimulation response with postoperative function determined by laryngoscopy. No EMG response at >1-2 mAmps was considered a negative response. The rates of early and permanent paralysis, as well as sensitivity, specificity, and positive and negative predictive values for postoperative nerve function were calculated for separate pathological groups.

RESULTS

The number of nerves at risk analyzed was 909. The overall early and permanent paralysis rates were 3.1% and 1.2%, respectively, with the highest rate being for Grave's disease cases. The overall sensitivity was 98.4%. The specificity was lower at 62.5% but acceptable in thyroid carcinoma and Grave's disease patients. The majority of nerves with a positive stimulation result and postoperative paralysis on laryngoscopy recovered function in 3 to 12 weeks, showing positive stimulation to be a good predictor of eventual recovery.

CONCLUSIONS

Stimulation of the RLN during thyroid and parathyroid surgery is a useful tool in predicting postoperative RLN function. The sensitivity of stimulation is high, showing positive stimulation to be an excellent predictor of normal nerve function. Negative stimulation is more predictive of paralysis in cases of thyroid carcinoma and Grave's disease.

LEVEL OF EVIDENCE

2b.

Primary hyperparathyroidism presenting as recurrent acute pancreatitis: A case report and review of literature

The association between pancreatitis and primary hyperparathyroidism (PHPT) is controversial. We report a 32-year-old man who presented with recurrent episodes of acute pancreatitis. Primary hyperparathyroidism was diagnosed after the fourth episode of pancreatitis. He had no additional risk factors for pancreatitis. Eighteen months after successful parathyroid surgery, there has been no recurrence of abdominal pain and his serum calcium is within the normal range.