Wonjae Cha

Chemocauterization of the internal opening with trichloroacetic acid as first-line treatment for pyriform sinus fistula.

Pyriform sinus fistula is a rare brachial pouch anomaly. However, it is difficult and risky to remove the fistula tract completely. Circumferential chemocauterization of the internal opening with trichloroacetic acid (TCA) for pyriform sinus fistula is simple, reproducible, reliable, and causes less morbidity. The aim of this study was to determine the feasibility of TCA chemocauterization for pyriform sinus fistula.

Anticancer effects of anandamide on head and neck squamous cell carcinoma cells via the production of receptor‐independent reactive oxygen species

The endocannabinoids, anandamide (AEA) and 2‐arachidonoyl glycerol (2‐AG), are considered promising potential anticancer agents. In this study, we examined the anticancer effects of AEA and 2‐AG in head and neck squamous cell carcinoma (HNSCC) cell lines.

Imaging and Analysis of Human Vocal Fold Vibration Using Two-Dimensional (2D) Scanning Videokymography

OBJECTIVE Laryngeal videokymography and high-speed digital kymography are the currently available techniques for studying aperiodic vibration of the vocal folds. However, videokymography has a fundamental limitation that only linear portions of the vocal fold mucosa can be visualized, whereas high-speed digital kymography has the disadvantages of lack of immediate feedback during examination and considerable waiting time before kymographic visualization. We developed a new system, two-dimensional (2D) scanning videokymography, that provides a possible alternative for evaluation of the vibratory pattern of the vocal folds. Herein, we report the application of 2D scanning videokymography for visualization of vocal fold vibration in humans and an analysis of its parameters. MATERIALS AND METHODS Two young healthy volunteers (one man and one woman) took part in this study. The vibratory patterns of their vocal folds were evaluated using 2D scanning videokymography and laryngeal stroboscopy. RESULTS Two-dimensional scanning videokymography provided a high-definition image of the vibratory movements of the vocal folds. In analysis of the images acquired by the device, various parameters including fundamental frequency; ratio of the vibratory phases; phase, amplitude, and glottal area symmetry; and cycle-to-cycle variability were extracted. CONCLUSIONS Our results indicate that 2D scanning videokymography is a useful and promising tool for visualization of the vibratory movement of the vocal folds. This new technique might improve our understanding of the mechanism of vocal fold vibration and contribute to voice research as well as clinical practice.

The First Application of the Two-Dimensional Scanning Videokymography in Excised Canine Larynx Model

OBJECTIVE Evaluation of the vibratory pattern of vocal folds is of paramount importance to diagnose vocal fold disorders. Currently, laryngeal videokymography (VKG) and digital kymography from high-speed videolaryngoscopy are the available techniques for studying aperiodic vibrations of vocal folds. But VKG has the fundamental limitation that only linear portion of the vocal fold mucosa can be visualized. Digital kymography has the disadvantages of no immediate feedback during examination, considerable waiting time before kymographic visualization, recoding duration limited to seconds, and extreme demands on storage space. We developed a new system--two-dimensional (2D) scanning VKG--for evaluation of the vibratory pattern of vocal folds, and the method provided a possible alternative with its advantages and disadvantages. Thus, we aimed to evaluate the feasibility of the new device for the vocal fold vibration in excised canine larynx model. METHODS The vibrating pattern for vocal folds was evaluated using high-speed videolaryngoscopic and 2D scanning videokymographic system in the excised canine larynx model. RESULTS The images of canine vocal folds were captured with high-speed videolaryngoscopic system and converted to the kymographic images using the software. The kymographic image acquired by 2D scanning VKG was comparable with multi-line digital kymography at multiple locations. CONCLUSIONS The vocal fold vibration could be evaluated in the excised canine larynx model using 2D scanning VKG. And this new device is expected to be a promising tool to evaluate the vocal fold vibration for clinical practice and voice research.

Negative pressure wound therapy for cervical esophageal perforation with abscess.

Perforation of the cervical esophagus is a rare but life-threatening condition. Cervical esophageal perforation with abscess formation can be usually treated with conservative treatments of simple drainage and antibiotics. Aggressive surgical treatments are considered if conservative treatments fail. But the aggressive treatments have low success rate and high morbidity in cervical esophageal perforation. Negative pressure wound therapy (NPWT) was widely used in various complicated wounds, such as diabetic foot ulcers, open abdomen, pressure ulcers, open fractures, sterna wounds, grafts, and flaps since it had been introduced in 1997. NPWT is known to be a valuable tool in the management of various complicated wounds. In this report, we described a case of intractable cervical esophageal perforation with abscess, which was successfully treated with NPWT after the failure of conservative management.

Office‐based biopsies for laryngeal lesions: Analysis of consecutive 581 cases

Office‐based biopsy (OBB) is widely used to diagnose suspicious laryngeal lesions. However, its routine use is still controversial and the algorithm for clinical strategy is not concrete. We tried to evaluate the accuracy of OBB as a diagnostic tool for laryngeal malignancy.

Gene network inherent in genomic big data improves the accuracy of prognostic prediction for cancer patients

Accurate prediction of prognosis is critical for therapeutic decisions regarding cancer patients. Many previously developed prognostic scoring systems have limitations in reflecting recent progress in the field of cancer biology such as microarray, next-generation sequencing, and signaling pathways. To develop a new prognostic scoring system for cancer patients, we used mRNA expression and clinical data in various independent breast cancer cohorts (n=1214) from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) and Gene Expression Omnibus (GEO). A new prognostic score that reflects gene network inherent in genomic big data was calculated using Network-Regularized high-dimensional Cox-regression (Net-score). We compared its discriminatory power with those of two previously used statistical methods: stepwise variable selection via univariate Cox regression (Uni-score) and Cox regression via Elastic net (Enet-score). The Net scoring system showed better discriminatory power in prediction of disease-specific survival (DSS) than other statistical methods (p=0 in METABRIC training cohort, p=0.000331, 4.58e-06 in two METABRIC validation cohorts) when accuracy was examined by log-rank test. Notably, comparison of C-index and AUC values in receiver operating characteristic analysis at 5 years showed fewer differences between training and validation cohorts with the Net scoring system than other statistical methods, suggesting minimal overfitting. The Net-based scoring system also successfully predicted prognosis in various independent GEO cohorts with high discriminatory power. In conclusion, the Net-based scoring system showed better discriminative power than previous statistical methods in prognostic prediction for breast cancer patients. This new system will mark a new era in prognosis prediction for cancer patients.

Development of a device for real‐time light‐guided vocal fold injection: A preliminary report

Vocal fold injection is a minimally invasive technique for various vocal fold pathologies. The shortcomings of the cricothyroid (CT) membrane approach are mainly related to invisibility of the injection needle. If localization of the needle tip can be improved during vocal fold injection with the CT approach, the current problems of the technique can be overcome. We have conceptualized real‐time light‐guided vocal fold injection that enables simultaneous injection under precise localization. In this study, we developed a device for real‐time light‐guided vocal fold injection and applied it in excised canine larynx.

Supramaximal neurostimulation with laryngeal palpation to predict postoperative vocal fold mobility

Recurrent laryngeal nerve (RLN) injury during thyroidectomy or parathyroidectomy is a challenging issue and causes significant morbidity. We adopted the supramaximal stimulation protocol for neurostimulation with laryngeal palpation (NSLP) and tried to evaluate the predictive values of supramaximal NSLP for immediate postoperative vocal fold (VF) mobility.

False‐positive cytopathology results for papillary thyroid carcinoma: A trap for thyroid surgeons

Current preoperative diagnosis of thyroid nodules remains imperfect despite recent advances in cytopathology and molecular diagnostics. False positivity in preoperative fine‐needle aspiration cytology (FNAC) may lead to overtreatment of patients, including total thyroidectomy, and sometimes to lawsuits for misdiagnosis and malpractice. In this study, we analysed clinical characteristics and pathologic findings in patients with false positivity for papillary thyroid carcinoma (PTC) in FNAC.