Soo Yeon Jung

Triple-layered polyurethane prosthesis with wrinkles for repairing partial tracheal defects

The purpose of this study was to develop a triple‐layered artificial polyurethane (PU) scaffold with a wrinkled layer for reconstruction of partial tracheal defects.

Voice Change in End-Stage Renal Disease Patients After Hemodialysis: Correlation of Subjective Hoarseness and Objective Acoustic Parameters

INTRODUCTION Patients with end-stage renal disease (ESRD) who are treated with hemodialysis (HD) frequently complain about hoarseness after completion of each HD session. The HD treatment affects laryngeal volume and muscle function. This study attempted to evaluate the vocal effect of HD by acoustic and aerodynamic analysis and to determine the difference between voice change group (VCG) and nonvoice change group (NVCG). MATERIALS AND METHODS A total of 55 patients (34 females and 21 males) diagnosed with ESRD and undergoing outpatient HD were enrolled. The subjects were divided into the VCG (n=13) and NVCG (n=42) by the change of the Korean Voice Handicap Index score. Patients underwent weighing and acoustic, aerodynamic analysis before and after the HD. Fundamental frequency (F0), jitter, shimmer, noise-to-harmonics ratio (NHR), pitch range, habitual pitch, voice energy, and maximal phonation time (MPT) were obtained. The pre- and post-HD data were compared using paired t test. The results were compared after dividing the total group into the VCG and NVCG categories. Correlation between the change of the weight and change of the voice analysis result was certified by Pearson correlation coefficient. RESULTS The F0 and habitual pitch increased in all subjects. The NHR and MPT parameters significantly decreased (P<0.05). In the NVCG group, all the results were same as the total group. In the VCG group, the NHR result differed from the total group. All acoustic parameters showed no statistically significant differences between the two groups. There was no correlation between the weight change (%) and the change of acoustic parameter results. CONCLUSIONS The NVCG group of patient displayed improvement in NHR, whereas the VCG group showed no change. Weight change did not significantly correlate with the voice analysis results.

Clinical Usefulness of Ultrasonography-Guided Laryngeal Electromyography

OBJECTIVES/HYPOTHESIS To investigate the proper approach and technical method of ultrasonography-guided laryngeal electromyography (US-guided LEMG). STUDY DESIGN This is a prospective study. METHODS Twenty patients who underwent US-guided LEMG were enrolled. US-guided LEMG was cooperatively performed by one otolaryngologist, one neurologist, and one radiologist. The location of the needle electrode was confirmed with US after electrode insertion into the laryngeal intrinsic muscle. The US transducer was applied on the neck by a transverse/midline and transverse/oblique approach to identify the cricothyroid (CT), thyroarytenoid (TA) muscles, and the location of the needle electrode. RESULTS CT muscles were easily identified on US in all 20 patients. TA muscles were identified in 17 patients (85%). The transverse/oblique approach was helpful to detect TA muscle in case of calcified thyroid cartilage or anatomic variation. CONCLUSIONS US-guided LEMG, which enables the exact insertion of the needle electrode, improves the reliability of examination and is helpful in early detection and to prevent complications.

Preventive effects of tonsil-derived mesenchymal stem cells on osteoradionecrosis in a rat model

The purpose of this study was to investigate the effects of tonsil‐derived mesenchymal stem cells (MSCs) on osteoradionecrosis (ORN).

Standardization of A Physiologic Hypoparathyroidism Animal Model

Ideal hypoparathyroidism animal models are a prerequisite to developing new treatment modalities for this disorder. The purpose of this study was to evaluate the feasibility of a model whereby rats were parathyroidectomized (PTX) using a fluorescent-identification method and the ideal calcium content of the diet was determined. Thirty male rats were divided into surgical sham (SHAM, n = 5) and PTX plus 0, 0.5, and 2% calcium diet groups (PTX-FC (n = 5), PTX-NC (n = 10), and PTX-HC (n = 10), respectively). Serum parathyroid hormone levels decreased to non-detectable levels in all PTX groups. All animals in the PTX—FC group died within 4 days after the operation. All animals survived when supplied calcium in the diet. However, serum calcium levels were higher in the PTX-HC than the SHAM group. The PTX-NC group demonstrated the most representative modeling of primary hypothyroidism. Serum calcium levels decreased and phosphorus levels increased, and bone volume was increased. All animals survived without further treatment and did not show nephrotoxicity including calcium deposits. These findings demonstrate that PTX animal models produced by using the fluorescent-identification method, and fed a 0.5% calcium diet, are appropriate for hypoparathyroidism treatment studies.

Feasibility of autologous plasma gel for tonsil-derived stem cell therapeutics in hypoparathyroidism

Hypoparathyroidism is a deficiency of the parathyroid hormone (PTH) in the body. We previously reported the possibility of treating it using tonsil-derived mesenchymal stem cells (TMSCs) differentiated into PTH-releasing cells. The purpose of this study was to evaluate the feasibility of using autologous plasma gel as scaffold material in treatment of hypoparathyroidism with TMSC. We obtained plasma by venous sampling of autologous blood and centrifuged and fabricated the plasma gel using a sinusoidal pattern heating machine. After we created the hypoparathyroidism animal model, we administered undifferentiated TMSCs and TMSCs differentiated into parathyroid cells at each rat dorsum by intramuscular injection with and without the plasma gel. In the plasma gel groups, intact PTH was detected from on day 21 after TMSC injection; we did not detect intact PTH in the groups that were only transplanted with TMSCs during the entire experimental period. Serum calcium was higher and phosphorous was lower in the TMSC with plasma gel groups than in the groups with TMSCs alone. We detected PTH and chromogranin A in the TMSC-plasma gel-transplanted areas on immunohistochemistry and immunofluorescence stain. Plasma gel can be considered as a cell-delivery scaffold for treating hypoparathyroidism with tonsil-derived mesenchymal stem cells.

Fabrication and characterization of 3D-printed elastic auricular scaffolds: A pilot study: 3D-Printed Elastic Auricular Scaffold

Aesthetic reconstruction of the external ear is challenging due to the complex anatomical shape of the auricle. Recently, artificial scaffolds such as Medpor (Stryker, Kalamasoo, MI, USA) have become widely used in ear reconstruction. However, the Medpor scaffold is stiffer than the natural ear, which may lead to discomfort, and moreover has uniform design for every patient. In this study, we investigated whether three‐dimensional (3D)‐printed artificial polyurethane (PU) scaffolds are suitable for auricular reconstruction.

Trends in the Incidence and Treatment of Benign Vocal Fold Lesions in Korea, 2006–2015: A Nationwide Population-based Study

OBJECTIVE The aim of this study was to determine the prevalence and demographics of benign vocal fold lesions (BVFL) and trends in its treatment in Korea based on data collected from the National Health Insurance Service database. MATERIAL AND METHODS Data for patients diagnosed with BVFL (ICM-10 codes J381, J382, J384) from 2006 to 2015 were selected for analysis. Patient characteristics, including sex, age, income, area of residence, and comorbidity, were analyzed. Treatment was divided into surgical management and conservative management using operation codes. RESULTS The prevalence and incidence of BVFL increased from 7.07% and 5.29%, respectively, in 2006 to 12.47% and 7.98% in 2015. Compared with the non-BVFL population, patients with BVFL were more likely to be female, reside in an urban area, and have gastroesophageal reflux disease. There was no significant change in the incidence of surgical treatment during the study period (around 6000 per year); however, the surgical treatment rate decreased from 19.29% to 8.38%. The probability of undergoing surgical treatment for BVFL was higher in men, those aged 50-59 years, and those in the lowest quartile for income, except for the medical aid group. CONCLUSION In Korea, there was an increase in the number of patients diagnosed with BVFL and a decrease in the operation rate for this condition between 2006 and 2015. Diagnosis of BVFL varied significantly based on income and sex; however, the only variable affecting the operation rate was patient age.

Laryngeal myofascial pain syndrome as a new diagnostic entity of dysphonia

OBJECTIVE To consider the feasibility of diagnosing intrinsic laryngeal muscle myofascial pain syndrome (MPS) in dysphonic patients who demonstrated immediate symptom and stroboscopic finding improvement after laryngeal electromyography (LEMG) without further treatment. METHODS A chart review of patients who showed subtle vocal fold movement abnormalities on a stroboscopic examination and underwent ultrasonography (US)-guided LEMG was performed. Patients with vocal fold paralysis, mucosal lesions, spasmodic dysphonia, and vocal tremor on stroboscopic examination were excluded. Among them, patients with normal EMG findings were included in this study. The patients who reported voice symptom improvement after LEMG without further treatment were placed in laryngeal MPS (LMPS) group and the other patients were placed in non-laryngeal MPS (non-MPS) group. Predisposing factors, voice symptom, symptom-duration, and stroboscopic findings of these patients were reviewed. RESULTS Among the 16 patients, LEMG findings were normal, five (31%) were included in the LMPS group and the other 11 patients (69%) were included in the non-MPS group. All LMPS group patients had a history of voice abuse and reported odynophonia. The Korean Voice Handicap Index-10 score decreased significantly after US-guided LEMG without additional treatment in the LMPS group. The stroboscopic findings revealed that vocal fold hypomobility was the most common finding in the LMPS group, and two patients showed a muscle tension dysphonia pattern. The LMPS groups showed improvement of vocal fold mobility on 1-week stroboscopic evaluation. CONCLUSION LMPS is a potential diagnosis for patients with vocal fold hypomobility finding on stroboscopic findings but with normal EMG results. Diagnosis of LMPS could be considered in patients who showed symptom and vocal fold movement improvement after LEMG.