Recurrent Laryngeal Nerve Preservation Strategies in Pediatric Thyroid Oncology: Continuous vs. Intermittent Nerve Monitoring

[30 years of prophylactic thyroidectomy for hereditary medullary thyroid cancer : A milestone in translational medicine]

Medullary thyroid cancer (MTC) is the most frequent manifestation of multiple endocrine neoplasia type 2 (MEN2) that determines the oncological outcome. Germline mutations in the rearranged during transfection (RET) protooncogene, a tumor suppressor gene on chromosome 10q11.2, were identified 30 years ago as the genetic basis of MEN2 and published in 1993 and 1994. These seminal findings gave rise to the concept of prophylactic thyroidectomy for asymptomatic gene mutation carriers based on a positive RET gene test, which has become the standard of care ever since. Clinical genetic investigations showed genotype-phenotype correlations with respect to the individual gene mutation regarding the penetrance and onset of MTC and to a lesser extent also with respect to the other components of MEN2, pheochromocytoma and primary hyperparathyroidism. From this a clinically relevant risk stratification could be derived. Initially, the optimal timing of prophylactic thyroidectomy was primarily based on the RET genotype alone, which was not sufficient for a precise age recommendation and subsequently required additional consideration of calcitonin serum levels for fine tuning. Calcitonin levels first show the risk of lymph node metastasis when they exceed the upper normal limit of the assay independent of carrier age and RET mutation. Routine calcitonin screening of patients with nodular thyroid disease, screening of families on identification of MEN2 index patients, and pre-emptive thyroidectomy in carriers of gene mutations with normal calcitonin levels have led to the fact that nowadays, 30 years after the first description of the gene mutations causing the disease, the life-threatening hereditary MTC has become curable: a shining example for the success of translational transnational medical research for the benefit of patients.

Thyroid surgery in children and adolescents: results from a multi-institutional German and Austrian database

BACKGROUND

Outcomes of paediatric thyroid surgery have only been reported in smaller series or over long intervals. The aim of this multicentre study was to describe the recent outcomes of paediatric thyroid surgery in Germany and Austria.

METHODS

Patients aged less than or equal to 18 years who underwent thyroid surgery and were prospectively documented in the StuDoQ|Thyroid registry between March 2017 and August 2022 were studied.

RESULTS

In total, 604 patients from 90 institutions were included. The mean age was 15.4 years and 75 per cent of patients were female. The most frequent benign pathologies were nodular goitre (35.6 per cent), follicular adenoma (30.1 per cent), and Graves' disease (28.5 per cent). Among 126 thyroid malignancies, papillary thyroid carcinoma was diagnosed in 77.8 per cent of patients, follicular thyroid carcinoma was diagnosed in 10.3 per cent of patients, and medullary thyroid carcinoma was diagnosed in 8.7 per cent of patients. Lymph node metastases were found in 45.9 per cent of patients with papillary thyroid carcinoma and in 36.4 per cent of patients with medullary thyroid carcinoma. Vascular invasion was found in 62.9 per cent of patients with follicular thyroid carcinoma. The mean tumour diameters were 18, 42, and 13 mm in patients with papillary thyroid carcinoma, follicular thyroid carcinoma, and medullary thyroid carcinoma respectively. Early postoperative recurrent laryngeal nerve injury was seen in 27 of 556 patients (4.9 per cent) (22 of 617 (3.6 per cent) nerves at risk with intermittent intraoperative nerve monitoring and 5 of 237 (2.1 per cent) nerves at risk with continuous intraoperative nerve monitoring). Persistent recurrent laryngeal nerve injury was documented in 4 of 556 patients (0.7 per cent). Early postoperative hypoparathyroidism correlated with Graves' disease, thyroid carcinoma, and lymph node dissection.

CONCLUSION

Papillary thyroid carcinoma and follicular thyroid carcinoma in children were often advanced at presentation. Persistent or recurrent lymph node metastases were mainly seen in papillary thyroid carcinoma. Overall survival was excellent, but longer follow-up is needed.

The Utility of Intraoperative Neuromonitoring in Pediatric Surgical Oncology

BACKGROUND

Intraoperative nerve monitoring (IONM) is a technique used to decrease the possibility of nerve-associated morbidity and damage to nearby neural structures during complex surgical procedures. The use and potential benefits of IONM in pediatric surgical oncology are not well-described.

METHODS

An overview of the current literature was performed to elucidate the various techniques that may be useful to pediatric surgeons for resection of solid tumors in children.

RESULTS

The physiology and common types of IONM relevant to the pediatric surgeon are described. Important anesthetic considerations are reviewed. Specific applications for IONM that may be useful in pediatric surgical oncology are then summarized, including its use for monitoring the recurrent laryngeal nerve, the facial nerve, the brachial plexus, spinal nerves, and lower extremity nerves. Troubleshooting techniques regarding common pitfalls are then proposed.

CONCLUSION

IONM is a technique that may be beneficial in pediatric surgical oncology to minimize nerve injury during extensive tumor resections. This review aimed to elucidate the various techniques available. IONM should be considered as an adjunct for the safe resection of solid tumors in children in the proper setting with the appropriate level of expertise. A multidisciplinary approach is advised. Additional studies are necessary to further clarify the optimal use and outcomes in this patient population.

LEVELS OF EVIDENCE

Level III.

Paediatric differentiated thyroid carcinoma: a UK National Clinical Practice Consensus Guideline

This guideline is written as a reference document for clinicians presented with the challenge of managing paediatric patients with differentiated thyroid carcinoma up to the age of 19 years. Care of paediatric patients with differentiated thyroid carcinoma differs in key aspects from that of adults, and there have been several recent developments in the care pathways for this condition; this guideline has sought to identify and attend to these areas. It addresses the presentation, clinical assessment, diagnosis, management (both surgical and medical), genetic counselling, follow-up and prognosis of affected patients. The guideline development group formed of a multi-disciplinary panel of sub-speciality experts carried out a systematic primary literature review and Delphi Consensus exercise. The guideline was developed in accordance with The Appraisal of Guidelines Research and Evaluation Instrument II criteria, with input from stakeholders including charities and patient groups. Based on scientific evidence and expert opinion, 58 recommendations have been collected to produce a clear, pragmatic set of management guidelines. It is intended as an evidence base for future optimal management and to improve the quality of clinical care of paediatric patients with differentiated thyroid carcinoma.

Optimal Monitoring Technology for Pediatric Thyroidectomy

This retrospective study aimed to describe, firstly, characteristics and outcomes of the intraoperative neural monitoring technology in the pediatric population, and secondarily the recurrent laryngeal nerve complication rate. Thirty-seven patients (age <18 years) operated on from 2015 to 2021 by conventional open thyroid surgery were included. Twenty-four (64.9%) total thyroidectomies and 13 (35.1%) lobectomies were performed. Seven central and six lateral lymph node dissections completed 13 bilateral procedures. Histology showed malignancy in 45.9% of the cases. The differences between the electromyographic profiles of endotracheal tubes or electrodes for continuous monitoring were not statistically significant. In our series of young patients, both adhesive (even in 4- or 5-year-olds) and embedded endotracheal tubes were used, while in patients 3 years old or younger, the use of a more invasive detection method with transcartilage placement recording electrodes was required. Overall, out of 61 total at-risk nerves, 5 (8.2%) recurrent laryngeal nerves were injured with consequent intraoperative loss of the signal; however, all these lesions were transient, restoring their normal functionality within 4 months from surgical procedure. To our knowledge, this is the first study of intraoperative neural monitoring management in a cohort of Italian pediatric patients.