Improving Voice Outcomes After Thyroid Surgery - Review of Safety Parameters for Using Energy-Based Devices Near the Recurrent Laryngeal Nerve

Comparative outcomes of video-assisted thyroidectomy and traditional open surgery: a 5-year analysis of a single center experience

OBJECTIVE

This study aimed to evaluate and compare the outcomes of patients undergoing video-assisted thyroidectomy versus those undergoing traditional open surgery.

METHODS

In this retrospective study, we reviewed the clinical records of 449 patients who underwent thyroid surgery at our institution between April 2017 and March 2022. Of these, 209 underwent video-assisted thyroidectomy, while 248 underwent traditional open surgery. After excluding those who received total thyroidectomy, central node dissection, or lateral node dissection, we focused our analysis on 136 patients with video-assisted lobectomy and 92 patients with traditional open surgery. We compared patient outcomes, including surgical results and adverse events, between these groups.

RESULTS

Significant differences were observed in the maximum tumor diameter between the video-assisted lobectomy and traditional open surgery groups. However, no significant differences were noted in surgical time, bleeding, or adverse events.

CONCLUSION

Video-Assisted Neck Surgery (VANS) offers great cosmetic benefits and is comparable to traditional open surgery in terms of adverse events.

LEVEL OF EVIDENCE

IV.

Thyroid Radiofrequency Ablation-Thermal Effects on Recurrent Laryngeal Nerve Using Continuous Intraoperative Neuromonitoring Animal Model

OBJECTIVE

When performing radiofrequency ablation for thyroid nodules, it is essential to avoid thermal injury to the recurrent laryngeal nerve. This porcine animal model study used continuous intraoperative neuromonitoring to investigate the thermal safety parameters of thyroid radiofrequency ablation.

STUDY DESIGN

Porcine animal study.

SETTING

University animal laboratory.

METHODS

Twelve piglets were tested at different radiofrequency power levels, and the real-time electromyography signal changes were recorded under continuous intraoperative neuromonitoring. The spread heat study (8 piglets) included spontaneous recovery tests and cold water irrigation tests to investigate the safety distance from the recurrent laryngeal nerve to the active tip during 5-second activation with standard stimulation patterns. The residual heat study (4 piglets) investigated the safety cooling durations by touching the recurrent laryngeal nerve with the tip after a 5-second activation.

RESULTS

In the spread heat study, substantial signal attenuation events were observed at an spread heat distance of 2, 3, 5, and 5 mm when the power was set as 10, 20, 30, and 50 W, respectively. No signal recovery could be observed in 20 minutes with or without cold water irrigation in the injured recurrent laryngeal nerve area. The residual heat study shows the residual thermal effect of the tip is minimal, and no substantial signal attenuation event was observed at all experiments.

CONCLUSIONS

This innovative study established the thermal safety parameters for radiofrequency ablation in a porcine model at various power levels, which can potentially assist operators in delineating a precise ablation field and providing effective thyroid ablation treatment safely.

A prospective study comparing the gasless endoscopic thyroidectomy trans-axillary approach to conventional open thyroidectomy: health and quality of life outcomes

BACKGROUND

The relationship between different surgical treatments and quality of life remains uncertain for differentiated thyroid carcinoma (DTC). The aim of this study is to compare the gasless endoscopic thyroidectomy trans-axillary approach (ET) and traditional open thyroidectomy (OT) through a prospective cohort study focusing on the rate of the efficacy, and quality of life (QoL).

METHODS

This prospective observational longitudinal cohort study enrolled 134 female patients diagnosed with DTC from December 01/2021 to December 31/2022. Multiple scales were applicated to evaluate the differences in quality of life, effectiveness, safety, etc. between the two groups during preoperative and postoperative follow-up periods, including the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30, version 3.0 (QOL-C30), Symptom Checklist (SCL-90), Scar Cosmesis Assessment and Rating (SCAR-Q), voice impairment score (VIS), swallowing impairment score (SIS), and neck impairment score (NIS).

RESULTS

Among them, 68 accepted ET and 66 patients underwent OT. To enhance comparability between the two groups, the patients enrolled in this study are female. Compared with the OT group, the ET group performed significantly better postoperative physical quality of life, including sound (p = 0.036), swallowing (p < 0.001), and neck function (p = 0.010). The ET group was also associated with significantly better cosmetic satisfaction (p < 0.001), and relatively faster recovery in psychological and emotional situation.

CONCLUSIONS

Gasless endoscopic thyroidectomy through an axillary approach leads to good cosmetic and psychological effects, improves postoperative QoL, and could be recommended for rapid postoperative recovery and involvement in daily and social activities.

Prospective cohort study of parathyroid function and quality of life after total thyroidectomy for thyroid cancer: robotic surgery vs. open surgery

OBJECTIVE

To compare robot-assisted thyroidectomy (RT) and open thyroidectomy (OT) through a prospective cohort study focusing on the rate of postoperative hypoparathyroidism, efficacy, and quality of life (QoL).

SUMMARY BACKGROUND DATA

Hypoparathyroidism is a frequent complication after thyroidectomy. Reducing the risk of hypoparathyroidism after total thyroidectomy is a crucial and difficult task for thyroid surgeons.

METHODS

We prospectively enroled 306 patients with papillary thyroid carcinoma into an RT group and OT group. The former used "super-meticulous" capsular dissection) and the latter used traditional meticulous capsular dissection. Patients were evaluated by scales [Short Form (SF)-36, Visual Impairment Scale (VIS), Swallowing Impairment Scale (SIS), Neck Impairment Scale (NIS), Scar questionnaire (SCAR-Q)].

RESULTS

The rates of transient hypoparathyroidism, permanent hypoparathyroidism, and transient hypocalcemia after surgery in the OT group and RT group were significantly different ( P <0.001). SIS and VIS scores in the two groups were significantly different ( P <0.001). SF-36 showed significant differences ( P <0.001) in the subsections of "physiological function", "body pain", "general health", "vitality", "social function", "role emotional", and "mental health" between the two groups. SCAR-Q showed that the length and appearance of scars showed significant differences between the two groups.

CONCLUSIONS

RT with Super-meticulous capsular dissection can protect parathyroid function and improve postoperative QoL, and could be a new option for robot-assisted surgery against thyroid cancer.

Abu Dhabi Neural Mapping (ADNM) during Minimally Invasive Thyroidectomy Enables the Early Identification of Non-Recurrent Laryngeal Nerve and Prevents Voice Dysfunction

The aim of this study was to evaluate the diagnostic accuracy of a neuromonitoring protocol-the Abu Dhabi Neural Mapping protocol (ADNM)-using a new device, Nim-Vital™, during minimally invasive thyroidectomy in the early identification of non-recurrent laryngeal nerve (n-RLN) problems and the preservation of its function.

METHOD

Patients with thyroid disorders that required thyroid resection, who were admitted to the Department of Surgery at Burjeel Hospital, Abu Dhabi, between January and July 2022, were included in the study. The data were extracted from a prospective database and were analyzed retrospectively. All nerves at risk were identified and exposed at seven precisely defined anatomical points, with strict adherence to the intraoperative technical steps of neuromonitoring. These were sequentially applied to the vagal nerve (VN), the superior laryngeal nerve (SLN), and the recurrent laryngeal nerve (RLN). In the next step after the creation of the skin-platysma flap, the strap muscle's lateral border was moved from the medial limb of the sternocleidomastoid without using any electrical device and without any manipulation of the thyroid gland. The VN was exposed in the carotid sheath and then stimulated using a monopolar probe at a precisely defined point above the clavicle, using anatomical landmarks.

RESULTS

In total, 136 women with a mean age of 40 years (range 18-74) and 36 men with a mean age of 42 (range 21-66), demonstrating 270 nerves at risk, were included in the analysis. Indications for surgery were malignancy in 70 cases, toxic goiter/Graves in 23 cases, retrosternal goiter in 21, and symptomatic multinodular goiter in 64 cases. Of these, 100 patients received a total thyroidectomy, 46 received a right lobectomy, and 24 received a left lobectomy only. For a total thyroidectomy, the median skin-to-skin surgery duration was 52 min (range 24-104 min) and the median hospital stay was 2 days (range 1-4 days). In 4 cases (4/146; 2.74%) the pre-dissection stimulation of the vagal nerve (VN1) at the ADNM's precisely defined point did not create any signal or proper EMG-curve that indicated the existence of the non-RLN. Proximal dissection of the right VN at a precisely defined point by the ADNM's level of incisura of the larynx created a positive signal. The separation point of the right non-RLN from the VN was discovered in all four patients. The postoperative video-laryngoscopy confirmed bilateral mobile vocal cords in all cases.

CONCLUSIONS

Following the ADNM protocol during thyroid surgery minimizes the risk of a non-laryngeal nerve injury and prevents voice dysfunction.

Novel application of microdissection tungsten needle in total thyroidectomy with central neck dissection for papillary thyroid carcinoma

Background

Energy-based devices (EBD) have been popularized in thyroidectomy worldwide. Microdissection tungsten needle (MDTN) is characterized by the ultra-sharp tip providing safe and meticulous dissection with effective hemostasis. However, little study has applied MDTN in thyroidectomy.

Methods

This retrospective study compared clinical data of the patients who underwent total thyroidectomy (TT) with central neck dissection (CND) using MDTN, harmonic scalpel (HS), and conventional electrocautery (CE). We assessed outcomes related to surgical efficacy and safety. The injury degree of tissue was assessed by biochemical indicators and early-stage inflammatory factors in the drainage fluid. Histological sections of the thyroid specimens were evaluated to compare levels of thermal damage by the three EBD.

Results

There was a significant decrease in the intraoperative blood loss, operation time and 24-hour drainage volume in the MDTN group compared to the CE group. The total drainage volume, duration of drainage, and average length of stay of the MDTN group were less compared to the CE group though they did not reach statistical significance. No disparity was observed between the MDTN group and HS group in these variables. Total costs were not significantly different among these groups. The incidence of recurrent laryngeal nerve (RLN) injury was the lowest using MDTN compared to the CE (P = 0.034) and HS (not significant). No statistical differences were observed among these groups regarding postoperative wound pain and infection, hypoparathyroidism, and postoperative hemorrhage. Analysis of biochemical indicators showed a lower level of hemoglobin in the MDTN and HS group than the CE group (P = 0.046 and 0.038, respectively) and less triglyceride in the HS group than the MDTN and CE group (P = 0.002 and 0.029, respectively) but no significant difference in cholesterol level in these groups. Early-stage inflammatory factors including TNF-α and IL-6 showed significantly higher concentration in the CE group than the MDTN and HS group. Histological sections of thyroid specimens revealed that MDTN caused the lowest degree of thermal damage followed by HS then CE.

Conclusion

MDTN exhibited comparable surgical efficacy and safety outcomes as HS in thyroidectomy. Therefore, MDTN is a safe and viable alternative for hemostasis in thyroidectomy.

Improving Voice Outcomes after Thyroid Surgery and Ultrasound-Guided Ablation Procedures

The field of endocrine surgery has expanded from the traditional open neck approach to include remote access techniques as well as minimally invasive approaches for benign and malignant thyroid nodules. In experienced hands and with careful patient selection, each approach is considered safe, however complications can and do exist. Post-operative dysphonia can have serious consequences to the patient by affecting quality of life and ability to function at work and in daily life. Given the significance of post-procedural dysphonia, we review the surgical and non-surgical techniques for minimizing and treating recurrent laryngeal nerve injury that can be utilized with the traditional open neck approach, remote access thyroidectomy, or minimally invasive thermal ablation.

Effects of Intraoperative Neural Tunnel in Protecting Recurrent Laryngeal Nerve: Experiences in Open, Trans Breast, and Transoral Endoscopic Thyroidectomy

BACKGROUND

Energy-based devices (EBDs) increase the risks of thermal nerve injuries. This study aimed to introduce a surgical strategy of intraoperative neural tunnel protecting (INTP) for evaluating the effect in reducing the incidence of recurrent laryngeal nerve (RLN) damage in open, trans breast, and transoral endoscopic thyroidectomy.

METHODS

INTP strategy was introduced: a tunnel was established and protected by endoscopic gauze along the direction of the nerve. A total of 165, 94, and 200 patients with papillary thyroid carcinoma (PTC) were to use INTP in respectively open, trans breast, and transoral endoscopic thyroidectomy as the INTP group. Additionally, 150, 95, and 225 patients who received the same methods without INTP were enrolled in the control group. Ipsilateral thyroidectomy or total thyroidectomy, and central compartment dissection were performed on the enrolled patients.

RESULTS

Clinicopathologic characteristics, surgical outcomes, and surgical complications were similar between the INTP group and the control group in open, trans breast, and transoral endoscopic thyroidectomy. The incidences of electromyography (EMG) changes in the INTP group were lower as compared to the control group in trans breast endoscopic thyroidectomy (p < 0.05). The incidence of postoperative hoarse in the INTP group was lower as compared to the control group in open and transoral endoscopic thyroidectomy (p < 0.05). Postoperative calcium levels (p < 0.01) were significantly higher, and the white blood cells (p < 0.05) and C-reactive protein levels (p < 0.01) were significantly decreased in the INTP group compared with the control group in transoral endoscopic thyroidectomy.

CONCLUSIONS

This was the first instance of the INTP strategy being introduced and was found to be an effective method for protecting the RLN in open, trans breast, and transoral endoscopic thyroidectomy. Additionally, INTP helped protect other important tissues such as the parathyroid glands in transoral endoscopic thyroidectomy as well as in reducing postoperative inflammatory responses.

Safety Parameters of Quantum Molecular Resonance Devices During Thyroid Surgery: Porcine Model Using Continuous Neuromonitoring

OBJECTIVES

Quantum molecular resonance (QMR) devices have been applied as energy-based devices in many head and neck surgeries; however, research on their use in thyroid surgery is lacking. This study aimed to investigate the safety parameters of QMR devices during thyroidectomy when dissection was adjacent to the recurrent laryngeal nerve (RLN).

METHODS

This study included eight piglets with 16 RLNs, and real-time electromyography (EMG) signals were obtained from continuous intraoperative neuromonitoring (C-IONM). QMR bipolar scissor (BS) and monopolar unit (MU) were tested for safety parameters. In the activation study, QMR devices were activated at varying distances from the RLN. In the cooling study, QMR devices were cooled for varying time intervals, with or without muscle touch maneuver (MTM) before contacting with the RLN.

RESULTS

In the activation study, no adverse EMG change occurred when QMR BS and MU were activated at distances of 2 mm or longer from the RLNs. In the cooling study, no adverse EMG change occurred when QMR BS and MU were cooled in 2-second intervals or immediately after MTM.

CONCLUSION

QMR devices should be carefully used when performing RLN dissection during thyroid surgery. According to the activation and cooling safety parameters in this study, surgeons can avoid RLN injury by following standard procedures when using QMR devices.