Endoscopic thyroidectomy versus traditional open thyroidectomy for identification of the external branch of the superior laryngeal nerve

Key points for protecting the external branch of the superior laryngeal nerve in open thyroidectomy: A possible exploration technique

OBJECTIVE

Injury of the external branch of the superior laryngeal nerve (EBSLN) is easily overlooked in thyroidectomy, and voice changes caused by the injury have a negative effect on an increasing number of patients. This study aimed to reduce the injury rate of EBSLN by expanding the sternothyroid-laryngeal triangle and standardizing the exploration procedure.

METHODS

A total of 520 patients who had undergone thyroidectomy at the First Affiliated Hospital of Nanchang University between September 2021 and April 2022 were analyzed. During the operation, the exposure rate of the EBSLN before and after sternothyroid-laryngeal triangle expansion was compared, and all EBSLNs were anatomically classified.

RESULTS

The exposure rate of EBSLN after sternothyroid-laryngeal triangle expansion reached 82.7%, which is much higher than that before sternothyroid-laryngeal triangle expansion (33.7%), and voice change caused by injury of the EBSLN was reported in one case (the injury rate was 0.2%). The classification and proportion of the EBSLN were as follows: Type 1 (55.3%), the nerve ran within 1 cm above the STP, but no coincidence or crossover with blood vessels was observed in this region; Type 2 (14.7%), the nerve travelled within 1 cm above the STP and overlapped or intersected with blood vessels in this region; Type 3 (12.7%), the EBSLN ran below the level of the STP; and Type 4 (17.3%), no EBSLN was observed within 1 cm above the STP.

CONCLUSION

In thyroidectomy, injury to the EBSLN can be effectively reduced by expanding the sternothyroid-laryngeal triangle and exploring the upper pole area of the thyroid as far as possible, which has great clinical significance in reducing postoperative voice box injury.

Endoscopic hemithyroidectomy plus prophylactic central neck dissection via breast approach versus gasless transaxillary approach in treating low-risk papillary thyroid cancer: a retrospective series

Hemithyroidectomy plus prophylactic central neck dissection (pCND) has been adopted as a de-escalating surgical strategy for low-risk papillary thyroid cancer (PTC). This study aimed to evaluate and compare the outcomes of these two different endoscopic approaches in the treatment of PTC with hemithyroidectomy plus pCND. This retrospective study reviewed medical records of 545 patients receiving breast approach (ETBA) (n = 263) or gasless transaxillary approach (ETGTA) (n = 282) in treating PTC. Demographics and outcomes were compared between the two groups. Preoperatively, the two groups were similar in demographics. Regarding surgical outcomes, no differences were found in terms of intraoperative bleeding, total amount of drainage, duration of drainage, postoperative pain, hospital stay, vocal cord palsy, hypoparathyroidism, hemorrhage, wound infection, chyle leakage, or subcutaneous ecchymosis. Conversely, ETBA recorded fewer skin paresthesia (1.5% vs. 5.0%, respectively) but longer operative times (138.1 ± 27.0 vs. 130.9 ± 30.8 min,) and more swallowing disturbances (3.4% vs. 0.7%) compared to ETGTA (p < 0.05). No difference in scar cosmetic results, but ETBA had lower neck assessment score than ETGTA (2.6 ± 1.2 vs. 3.2 ± 2.0, p < 0.05). For low-risk PTC, endoscopic hemithyroidectomy plus pCND using either ETBA or ETGTA is both feasible and safe. Although the two approaches are comparable in terms of most surgical and oncological outcomes, ETBA is superior to ETGTA in terms of neck cosmetic results and skin paresthesia but is associated with more swallowing disturbances and requires a longer operative time.

Learning curve and volume outcome relationship of endoscopic trans-oral versus trans-axillary thyroidectomy; A systematic review and meta-analysis

BACKGROUND

In the modern era, minimally invasive surgery is rapidly evolving and even replacing conventional open techniques in many surgical fields. Thyroidectomy was not an exception, with the introduction of multiple endoscopic thyroidectomy techniques. Trans-oral endoscopic trans-vestibular thyroidectomy (TOT) is a novel technique with promising outcomes. We conducted this meta-analysis to compare surgical outcomes and learning curves for TOT and other endoscopic thyroidectomy techniques.

METHODS

A systematic review in PubMed, MEDLINE, and EMBASE databases was conducted searching for publications on TOT versus trans-axillary thyroidectomy (TAT). The primary endpoint was operative (OR) time. Secondary endpoints were number of harvested lymph nodes (LNs), estimated blood loss (EBL), recurrent laryngeal nerve (RLN) injury, hoarseness, seroma, infection, chyle leak, hypocalcemia, hospital length of stay (LOS), and Cost. We also investigated the learning curve for each technique. Leave-out-out analysis, meta-regression, and subgroup analysis were used. Random effect inverse variance method was utilized.

RESULTS

Among 3820 retrieved studies, 15 studies (10 unmatched and 5 matched), with 2173 (TOT: 1024(47.12%) and TAT:1149(52.87%)) patients, met the inclusion criteria. The operative time and harvested L. Ns number were higher in TOT versus TAT (standard mean difference (SMD) = 0.72 [95%CI 0.07; 1.37], P = 0.029 and SMD = 0.32 [95%CI 0.02; 0.62], P = 0.036 respectively) while less EBL in TOT versus TAT (SMD = -0.26 [-0.43; -0.09], P = 0.0018). All other outcomes showed no significant difference between both groups. Weighted mean values for TOT and TAT were 158.03 vs 144.97 min for OR time, 6.33 vs 5.16 for harvested LNs, and $5,919.05 vs $6,253.79 for the cost. Statistical significance in learning curve development was noticed ranging between 6 and 15 annual cases.

CONCLUSION

Trans-oral thyroidectomy is a safe and reliable technique with outcomes comparable to other endoscopic techniques. It provides better access to the central compartment with a more feasible LN dissection. Improvement in surgical outcomes is expected with growing learning curve and technique mastery.

Anatomical and functional identification of the external branch of the superior laryngeal nerve: classification based on morphology and electrophysiological monitoring

BACKGROUND

Motor function of the external branch of superior laryngeal nerve (EBSLN) is vital for voice quality. We studied the rate of EBSLN identification and integrity in the era of intraoperative neuromonitoring (IONM).

METHODS

Anatomic and functional identification of 515 EBSLNs-at-risk was performed under the guidance of IONM that motor integrity was electrophysiologically checked. The functional integrity was assessed with crico-thyroid muscle (CTM) twitches and/or recordable waveform amplitude. We tried to establish the systematic classification of EBSLN identification and integrity.

RESULTS

Visual, electrophysiological and total identification rates were 64.3%, 31.6% and 95.9%, respectively. We could identify 4.1% of EBSLNs neither anatomically nor electrophysiologically. We recorded CTM twitches alone or both CTM twitches and wave amplitude in 203(39.4%) and 291(56.5%) branches respectively. Identification features of EBSLNs were systematically classified under three main types: Visualized-monitored (1), non-visualized-monitored (2), unidentified (3), and electrophysiological integrity of EBSLNs under two subtypes: CTM twitches alone (a) and CTM twitches and wave amplitude (b).

CONCLUSION

Dedicated thyroid surgeon could visually identify EBSLNs. IONM contribution significantly increases the identification rate. Systematic classification of identification and electrophysiological integrity of EBSLNs may increase comprehensive knowledge about its motor function that is crucial for complication-free thyroidectomy.

Resecting a solitary cervical vagal nerve neurofibroma via endoscopic surgery: a case report

Neurofibromas predominately consist of Schwann cells and fibroblasts, which mainly originate from neurofibromatosis type 1. However, solitary cervical vagal nerve neurofibroma (VNN) has rarely been reported in previously published literature. Additionally, the onset of VNN is characteristically chronic, asymptomatic, and insidious, and is often discovered unexpectedly through physical examination or imaging. The exact etiology and pathogenesis of VNN are yet to be clarified and need further exploration. Consequently, the definitive diagnosis of VNN mainly depends on pathological and immunohistochemical examinations. Immunohistochemically, tumor cells are positive for transcription factor S-100, SRY-related HMG-box (SOX)-10, and vascular marker CD34 will contribute to the diagnosis of VNN. In this uncommon case of left cervical VNN, the patient received comprehensive radiological evaluation before the operation and then underwent mass resection through endoscopic surgery via an axillary and chest wall approach. The patient was satisfied with the postoperative appearance of the neck. Besides, no postoperative complications or recurrence were observed during the consecutive six-month follow-up. Therefore, the successful application of total endoscopic surgery via the bilateral axilla-breast approach (BABA) on this case of neurogenic tumor presents new insights into expanding the operative indications of this technique, which could be a rational candidate for this kind of neck tumor with the requirements of satisfactory aesthetic appearance.