Prophylactic Central Neck Dissection in Papillary Thyroid Carcinoma: All Risks, No Reward.

BACKGROUND: Central neck dissection (CND) remains a controversial intervention for papillary thyroid carcinoma (PTC) patients with clinically negative nodes (cN0) in the central compartment. Proponents state that CND in cN0 patients prevents locoregional recurrence, while opponents deem that the risks of complications outweigh any potential benefit. Thus, there remains conflicting results amongst studies assessing oncologic and surgical outcomes in cN0 PTC patients who undergo CND. To provide clarity to this controversy, we sought to evaluate the efficacy, safety, and oncologic impact of CND in cN0 PTC patients at our institution. MATERIALS AND METHODS: Six hundred and ninety-five patients with PTC who underwent thyroidectomy at our institution between 1998 and 2018 were identified using an institutional cancer registry and supplemental electronic medical record queries. Patients were stratified by whether or not they underwent CND; identified as CND(+) or CND(-), respectively. Patients were also stratified by whether or not they received adjuvant radioactive iodine (RAI) therapy. Patient demographics, pathologic results, as well as surgical and oncologic outcomes were reviewed. Standard statistical analyses were performed using ANOVA and/or t-test and chi-squared tests as appropriate. RESULTS: Among the 695 patients with PTC, 492 (70.8%) had clinically and radiographically node negative disease (cN0). The mean age was 50 ± 1 years old and 368 (74.8%) were female. Of those with cN0 PTC, 61 patients (12.4%) underwent CND. CND(+) patients were found to have higher preoperative thyroid stimulating hormone (TSH) values, 2.8 ± 0.8 versus 1.5 ± 0.2 mU/L (P = 0.028) compared to CND(-) patients. CND did not significantly decrease disease recurrence, development of distant metastatic disease (P = 0.105) or persistence of disease (P = 0.069) at time of mean follow-up of 38 ± 3 months compared to CND(-) patients. However, surgical morbidity rates were significantly higher in CND(+) patients; including transient hypocalcemia (36.1% versus 14.4%; P < 0.001), transient recurrent laryngeal nerve (RLN) injury (19.7% vers us 7.0%; P < 0.001), and permanent RLN injury (3.3% versus 0.7%; P < 0.001). CONCLUSIONS: The majority of patients at our institution with cN0 PTC did not undergo CND. This data suggests that CND was not associated with improvements in oncologic outcomes during the short-term follow-up period and led to increased postoperative morbidity. Therefore, we conclude that CND should not be routinely performed for patients with cN0 PTC.

Feasibility and safety of nerve stimulator attachment to energy-based devices: A porcine model study.

BACKGROUND: Recently, several energy-based devices (EBDs) have been developed and applied in the context of thyroid surgery. EBDs can reduce operation time, blood loss, and postoperative pain. Compared to conventional electrocautery, EBDs operate at a relatively lower temperature and produce minimal lateral tissue damage. Yet, during device operation, the tip of the EBD is hot enough to cause thermal nerve damage, increasing the need for surgeons to be cautious about EBD application. To increase the safety of EBDs, we attached nerve stimulators to the tips of two EBDs and compared them to conventional monopolar nerve stimulation using a porcine model. METHODS: Three piglets (30-40 kg) underwent total thyroidectomy after orotracheal intubation with a nerve integrity monitor (NIM) electromyography (EMG) endotracheal tube. Nerve stimulators were attached to two EBDs (Harmonic Focus®+ and LigaSure™). After dissection and identification of six recurrent laryngeal nerves in the three piglets, both of the EBDs with attached nerve stimulators and a conventional monopolar nerve stimulator were applied near the nerve and EMG parameters were recorded using the NIM 3.0 system. The stimulus intensity was varied from 5 mA to 1 mA and the maximum distance and amplitude at which nerve detection was achieved were measured. RESULTS: There were no statistically significant differences between the maximum distance or mean amplitude obtained from nerve stimulators attached to EBDs and those obtained from the conventional nerve stimulator. Additionally, there were no adverse EMG events related to the use of nerve stimulators attached to EBDs. CONCLUSIONS: Attachment of a nerve stimulator to an EBD for nerve detection during thyroidectomy was as safe and effective as attachment of a conventional nerve stimulator. Use of a nerve stimulator attachment may reduce the likelihood of EBD-associated nerve damage during thyroid surgery.

Morbidity following thyroid surgery: does surgeon volume matter?

PURPOSE: The aim of our study was to analyze the relationship between surgeon volume and morbidity in patients operated on by surgeons with endocrine specialization (EndS group) and those operated on by general surgeons (GenS group) in a single tertiary institution. METHODS: We present the results of a prospective cohort study of all patients undergoing thyroid surgery in our institution between January 2008 and January 2010, all of whom attended for follow-up for at least 12 months. We assessed pre- and postoperative recurrent laryngeal nerve (RLN) function by laryngoscopy. We monitored serum calcium concentrations in all patients until these values were normal without vitamin D and oral calcium supplementation. RESULTS: We studied 225 patients: 30 in the GenS group (six surgeons performing <5 procedures per surgeon per year) and 195 in the EndS group (two surgeons performing >40 procedures per surgeon per year). The total number of exposed RLN was 46 and 325, respectively. The incidence of RLN palsy persisting beyond 12 months was higher in the GenS group (2/46 vs. 1/325 exposed RLNs, p = 0.04). The incidence of hypocalcaemia persisting beyond 12 months (bilateral procedures) was also higher in the GenS group (3/16 vs. 3/130 patients, p = 0.028). CONCLUSIONS: Morbidity in terms of permanent RLN palsy and hypocalcaemia was less frequent among patients operated on by endocrine-dedicated surgeons. Differences in surgical volume and specialized training in neck endocrine surgery may explain these variations in morbidity.