Ki Nam Park

Nationwide Multicenter Survey for Current Status of Endoscopic Thyroidectomy in Korea

Objectives We evaluated the current status of endoscopic thyroidectomy procedures in Korea in terms of indications, contraindications, advantages, disadvantages, complications, and limitations of each approach. Methods An email survey, consisting of 15 questions, was sent to 29 experienced endoscopic thyroidectomy surgeons. Results The most commonly used approach was the gasless transaxillary approach (66.7%), followed by the bilateral axillo-breast approach with gas insufflation (23.8%). The most common indication was less than 1 cm, single papillary thyroid cancer. The role of endoscopic thyroidectomy is not still established; some consider it a novel procedure (34.8%), others a transition to robotic thyroidectomy (34.8%). Conclusion Our results shed light on the general consensus of opinions about endoscopic thyroidectomy, such as the advantages, disadvantages, complications, limitations, and even its future role.

Clinical Features and Surgical Outcomes Following Closed Reduction of Arytenoid Dislocation

IMPORTANCE Arytenoid dislocation is a rare condition characterized by vocal fold immobility and is easily mistaken as recurrent laryngeal nerve paralysis. OBJECTIVE To describe the presenting features, multimodal diagnostic evaluation, and surgical outcomes following closed reduction (CR) of arytenoid dislocation. DESIGN, SETTING, AND PARTICIPANTS Prospective case series at a single academic medical center. Evaluation and treatment data were obtained from 22 consecutive patients with arytenoid dislocation over a 7-year period. INTERVENTIONS Patients underwent direct laryngoscopy and CR of the dislocated arytenoid, with adjunct injection laryngoplasty or botulinum toxin administration in select cases. MAIN OUTCOMES AND MEASURES Initial diagnosis was confirmed using flexible laryngeal endoscopy with stroboscopy, computed tomography, electromyography, and interoperative palpation. Arytenoid motion (primary outcome measure) and vocal function data (secondary outcome measures) were collected before treatment and up to 6 months after treatment. RESULTS Key history features included emergent intubation, elective intubation, and external laryngeal trauma. Sixteen patients (73%) had anterior and 6 patients (27%) posterior dislocation. One patient experienced spontaneous recovery. Following CR, with or without adjunct therapy, 18 of the remaining patients (86%) exhibited arytenoid motion recovery with concomitant voice improvement. Recovery was sustained at 6 months after CR. Closed reduction performed within 21 days of the presumed dislocation event was associated with a superior arytenoid motion recovery rate. CONCLUSIONS AND RELEVANCE These data represent the largest clinical series on arytenoid dislocation with complete vocal function data and follow-up at 6 months after CR. These findings also corroborate existing evidence for early surgical intervention.

Long-Term Results of Endoscopic Dilatation for Tracheal and Subglottic Stenosis

Objectives The purpose of this study was to assess the long-term results of endoscopic dilatation of airway stenosis and to evaluate predictive factors for favorable results. Methods Fifty-four patients with tracheal and subglottic stenosis who underwent endoscopic dilatation with at least 12 months follow-up were enrolled in this study. We evaluated predictive factors for final treatment outcome such as stenosis length, location, characteristics, procedure type, and the severity of stenosis. Results The final outcome of endoscopic dilatation showed a cure rate of 40.7%, improvement rate of 46.3%, and failure rate of 13.0%. Patients with mild stenosis or a shorter stenotic segment and those who underwent a touch-up procedure following tracheal resection with end-to-end anastomosis showed better outcomes. The cure rate of endoscopic dilatation for patients with shorter mild stenosis was 72.2%. Conclusion Endoscopic dilatation may be a primary treatment modality for patients with airway stenosis characterized by mild severity and a short stenotic segment.

Treatment efficacy of electromyography versus fiberscopy-guided botulinum toxin injection in adductor spasmodic dysphonia patients: a prospective comparative study.

Introduction. This study prospectively evaluates and compares the treatment efficacy of botulinum toxin injection under electromyography guidance (EMG group) and percutaneous botulinum toxin injection under flexible fiberscopic guidance (fiberscopy group). Methods. Thirty patients with adductor spasmodic dysphonia (ADSD), who had never received treatment, were randomly allocated into EMG- or fiberscopy-guided botulinum toxin injections between March 2008 and February 2010. We assessed acoustic and aerodynamic voice parameters, and the voice handicap index (VHI) before injection and at 1, 3, and 6 months after injection. Results. The mean total dosage of botulinum toxin was similar for both groups: 1.7 ± 0.5 U for the EMG group and 1.8 ± 0.4 U for the fiberscopy group (P > 0.05). There were no significant differences in outcomes between the two groups in either the duration of effectiveness or complications such as breathy voice and aspiration. Conclusion. Botulinum toxin injection under fiberscopic guidance is a viable alternative to EMG-guided botulinum toxin injection for the treatment of adductor spasmodic dysphonia when EMG equipment is unavailable.

Long-term efficacy of percutaneous steroid injection for treating benign vocal fold lesions: A prospective study

This study assessed the long‐term efficacy and recurrence rates of percutaneous steroid injections (PSIs) for benign vocal fold lesions.

Does Postthyroidectomy Syndrome Really Exist Following Thyroidectomy? Prospective Comparative Analysis of Open vs. Endoscopic Thyroidectomy

Objectives This study prospectively evaluated postthyroidectomy syndrome (PTS) through objective and subjective voice changes following thyroidectomy of open vs. endoscopic thyroidectomy. Methods A prospective clinical trial (SCHBC IRB 09 26) was performed from Jan 2008 to Aug 2010 to compare the open thyroidectomy (OPEN group) and endoscopic thyroidectomy (ENDO group). Of the 110 patients, 75 completed the evaluation before and 1 and 6 months after surgery. Subjective parameters included perceptual analysis (GRBAS [grade, roughness, breathiness, asthenia, and strain] scale), stroboscopic or flexible fiberscopic analysis, voice handicap index, and 5-point visual analog scales for vocal fatigue, singing difficulty, difficulty with high-pitch phonation, and neck discomfort. Objective parameters included acoustic, aerodynamic analysis and the electroglottograph. Results For the ENDO group (n=36), the operation time was longer than in the OPEN group (n=39; P<0.01). For the OPEN group, two objective and five subjective parameters were worse 1 month postoperatively; of these, two subjective parameters persisted for 6 months (P<0.05). For the ENDO group, three objective and six subjective parameters were worse 1 month postoperatively, and three of the subjective parameters persisted 6 months postoperatively (P<0.05). Conclusion PTS really exists following simple thyroidectomy and are very common for both OPEN and ENDO groups. Most of the parameters improved gradually over time, but some subjective changes persisted 6 months postoperatively.

Long-term efficacy of primary intraoperative recurrent laryngeal nerve reinnervation in the management of thyroidectomy-related unilateral vocal fold paralysis

Abstract Conclusion: Primary intraoperative recurrent laryngeal nerve (RLN) reinnervation techniques demonstrated significant voice improvement at 24 months postoperatively and could be an effective alternative treatment for thyroidectomy-related permanent unilateral vocal fold paralysis (VFP). Objectives: To assess the long-term efficacy of intraoperative RLN reinnervation techniques in the management of thyroidectomy-related unilateral VFP. Methods: A prospective study was conducted from January 2008 to June 2012 at Soonchunhyang University Bucheon Hospital. Nineteen patients who underwent RLN reinnervation with either direct reinnervation (neurorrhaphy) or ansa cervicalis to RLN (ansa-RLN) anastomosis and completed subjective and objective voice measurement over a 1-year follow-up period were included in this study. Results: The causes of VFP were cancer involving the RLN (68.4%, 13/19) and iatrogenic nerve transection (31.5%, 6/19). Reinnervation techniques were direct neurorrhaphy (63.2%, 12/19) and ansa-RLN anastomosis (36.8%, 7/19). Subjective parameters such as the Voice Handicap Index (VHI), posterior glottic closure, and mucosal wave demonstrated significant improvement 6 months postoperatively, and the majority of parameters remained stable up to 24 months (p < 0.05). Objective parameters, such as maximum phonation time (MPT), jitter, shimmer, and the harmonics-to-noise ration (HNR), demonstrated significant improvement at 12 months and most remained stable at 24 months (p < 0.05).

The Efficacy of Fibroblast Growth Factor for the Treatment of Chronic Vocal Fold Scarring: From Animal Model to Clinical Application

Objectives This study assessed the regenerative efficacy of basic fibroblast growth factor (FGF) in a rabbit model of chronic vocal fold scarring and then confirmed its utility and safety in a prospective trial of patients with this condition. Methods FGF was injected three times, at 1-week intervals, into a chronic vocal fold scar created in a rabbit model. After 1 month, mRNA level of procollagen I, hyaluronic acid synthetase 2 (HAS 2), and matrix metalloproteinase 2 (MMP 2) were analyzed by real-time polymerase chain reaction. The relative densities of hyaluronic acid (HA) and collagen were examined 3 months post-injection. From April 2012 to September 2014, a prospective clinical trial was conducted at a tertiary hospital in Korea. FGF was injected into the mild vocal fold scar of 17 consecutive patients with a small glottic gap. The patients underwent perceptual, stroboscopic, acoustic aerodynamic test, and Voice Handicap Index (VHI) survey prior to and 3, 6, and 12 months after FGF injection. Results FGF injection of the vocal fold scar decreased the density of collagen and increased mRNA level of HAS 2 and MMP 2 expression significantly compared to the control group injected with phosphate buffered solution in a rabbit model (P<0.05). In the clinical trial, significant improvements in the majority of the subjective and objective voice parameters were registered 3 months after FGF injection and were maintained at 12 months. Complications associated with the FGF injections, such as granuloma, were not observed during the follow-up period. Conclusion Based on the animal model and the prospective clinical trial, vocal fold injections of FGF in patients with mild chronic vocal fold scarring can significantly improve voice quality for as long as 1 year and without side effects. Our results recommend the use of FGF vocal fold injection as an alternative treatment modality for mild chronic vocal fold scarring.

Predictive Value of Estimated Tumor Volume Measured by Ultrasonography for Occult Central Lymph Node Metastasis in Papillary Thyroid Carcinoma.

The clinical and prognostic value of tumor volume in various solid tumors has been investigated. However, there have been few studies on the clinical impact of tumor volume in papillary thyroid carcinoma (PTC). This study was performed to investigate the predictive value of estimated tumor volume measured by ultrasonography for occult central neck metastasis (OCNM) of PTC. A total of 264 patients with clinically node-negative PTC on ultrasonography and computed tomography who underwent total thyroidectomy in conjunction with at least ipsilateral prophylactic central neck dissection were enrolled in this study. Tumor volume was derived with the formula used to calculate ellipsoids from two orthogonal scans during 2-D ultrasonography at initial aspiration biopsy. We retrospectively evaluated demographic characteristics, pre-operative ultrasonographic features (tumor size, volume and multifocality) and pathologic results. The OCNM rate was 35.6%; estimated tumor volume was used to predict OCNM (p = 0.035). At 0.385 mL, sensitivity and specificity were 51.1% and 66.5%, and the area under the curve for OCNM detection was 0.610. In multivariate analysis, tumor volume, but not size, was an independent predictive factor for OCNM (odds ratio = 1.83, p = 0.029). The other factors were extrathyroidal extension (odds ratio = 2.39, p = 0.004) and male gender (odds ratio = 3.90, p < 0.001). The estimated tumor volume of PTC measured by ultrasonography could be a pre-operative predictor of OCNM.

Predictive Factors of Superior Mediastinal Nodal Metastasis from Papillary Thyroid Carcinoma—A Prospective Observational Study

Objectives The purpose of this study was to demonstrate the incidence rates and predictive factors of superior mediastinal lymph node (SMLN) metastasis in PTC (papillary thyroid carcinoma) patients. Methods A prospective observational study was performed between January 2009 and January 2011. PTC patients who had tumors with a maximal diameter greater than 1 cm and clinically negative SMLNs were included in this study. Finally, a total of 217 patients who underwent total thyroidectomy with central compartment neck dissection (CND) and elective superior mediastinal lymph node dissection (SMLND), with or without modified radical neck dissection (MRND) and revisional CND, were included. Results Occult SMLN metastasis was present in 15.7% (34/217). Cytological classifications of tumor, BRAFV600E mutation, Tumor size, T-stage, perithyroidal extension, lymphovascular invasion, multifocality, and paratracheal pN(+) were not predictive of SMLN metastasis (P > .05), while revision surgery, pretracheal pN(+), and multiple lateral pN(+) were associated with SMLN metastasis. There were no major complications related to SMLND. Transient and permanent hypoparathyroidism was observed in 69 cases (31.8%) and 8 cases (3.6%), respectively. Conclusions Despite clinically negative SMLN in preoperative evaluation, SMLN metastasis can be predicted for patients with a PTC tumor size larger than 1 cm, pretracheal LN metastasis, multiple lateral metastasis, and revisional surgery.