Search

Hee Kyung Kim,1,* Hyun-Jo Kim,2,* Jae Yun Kim,3 Myung Jin Ban,4 Jiwon Son,5 Yongsung Hwang,5,6 Sung Bin Cho7 1Department of Pathology, Soonchunhyang University Bucheon Hospital, Bucheon, Korea; 2CNP Skin Clinic, Cheonan, Korea; 3Department of Dermatology, Soonchunhyang University Hospital, Cheonan, Korea; 4Department of Otorhinolaryngology-Head and Neck Surgery, Soonchunhyang University Hospital, Cheonan, Korea; 5Soonchunhyang Institute of Medi-Bio Science (SIMS), Soonchunhyang University, Cheonan, Korea; 6Department of Integrated Biomedical Science, Soonchunhyang University, Cheonan, Korea; 7Yonsei Seran Dermatology and Laser Clinic, Seoul, Korea*These authors contributed equally to this workCorrespondence: Sung Bin Cho, Yonsei Seran Dermatology and Laser Clinic, Geumcheon REMAIN CITY 6F, 224 Siheung-daero, Geumcheon-gu, Seoul, 08628, Korea, Tel +82 2-2135-1375, Fax +82 70-8250-1375, Email drsbcho@gmail.comBackground: Single to multiple pulse packs of bipolar, alternating current radiofrequency (RF) oscillations have been used for various medical purposes using invasive microneedle electrodes. This study was designed to evaluate the effects of pulse widths and cycles of RF pulse packs on immediate and delayed thermal tissue reactions in in vivo rat skin.Methods: RF energy at the frequency of 1 MHz and power of 70 W was delivered at each experimental setting into in vivo rat skin at 1.5-mm microneedle penetration, and then, tissue samples were obtained after 1 h and 3, 7, 14, and 21 days and histologically analyzed.Results: A single-pulse-pack RF treatment generated coagulative necrosis zones in the dermal peri-electrode area and zones of non-necrotic thermal reactions in the dermal inter-electrode area. Multiple pulse-pack, RF-treated rat skin specimens revealed that the number and size of peri-electrode coagulative necrosis were markedly decreased by increasing the number of pulse packs and accordingly decreasing the conduction time of each pulse pack. The microscopic changes in RF-induced non-necrotic thermal reaction in the inter-electrode area were more remarkable in specimens treated with RF of 7 or 10 pulse packs than in specimens treated with RF of 1– 4 pulse packs.Conclusion: The gated delivery of multiple RF pulse packs using a bipolar, alternating current, 1-MHz RF system using insulated microneedle electrodes efficiently generates non-necrotic thermal tissue reactions over the upper, mid, and deep dermis and subcutaneous fat in the inter-electrode areas.Keywords: radiofrequency, bipolar, alternating current, gated pulse, tissue reaction, rat

Even at trace concentrations, micropollutants, including pesticides and pharmaceuticals, pose considerable ecological risks, and the increasing presence of synthetic chemical substances in aquatic systems has emerged as a growing concern. Moreover, limited machine-learning (ML) approaches exist for analyzing environmental data, and the increasing complexity of ML models has made it challenging to understand predictor-outcome relationships. In particular, understanding complex interactions among multiple variables remains challenging. This study applies and integrates explainable ML techniques and network analysis to identify the sources of micropollutants in a large watershed and determine the factors affecting micropollutant levels. We assessed the performance of four ML algorithms-support vector machine, random forest, extreme gradient boosting (XGB), and autoencoder-XGB-in predicting micropollutant levels based on the spatial characteristics of the watershed. We applied the synthetic minority oversampling technique to address the data imbalance. The XGB model demonstrated superior predictive performance, particularly for high concentration levels, achieving an accuracy of 87%-99%. Shapley additive explanations (SHAP) analysis identified temperature and rainfall as significant factors. Moreover, agricultural activities contributed to pesticide pollution, whereas urban activities contributed to pharmaceutical contamination. The network analysis corroborated the SHAP findings and revealed event-specific contamination characteristics. This included distinct discharge pathways during a dry summer event and shared pathways during a wet winter event. This approach enhances an understanding of contamination sources and pathways and subsequently aids in developing control measures and making informed policy decisions to preserve water quality in mixed land-use areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Irradiation (IR)-induced xerostomia is the most common side effect of radiation therapy in patients with head and neck cancer (HNC). Xerostomia diagnosis is mainly based on the patient's medical history and symptoms. Currently, no direct biomarkers are available for the early prediction of IR-induced xerostomia. Here, we identified PIEZO1 as a novel predictive tissue biomarker for xerostomia. Our data demonstrate that PIEZO1 is significantly upregulated at the gene and protein levels during IR-induced salivary gland (SG) hypofunction. Notably, PIEZO1 upregulation coincided with that of inflammatory (F4/80) and fibrotic markers (fibronectin and collagen fibers accumulation). These findings suggest that PIEZO1 upregulation in SG tissue may serve as a novel predictive marker for IR-induced xerostomia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The Korean Society of Laryngology, Phoniatrics and Logopedics created a task force to establish clinical practice guidelines for the use of botulinum toxin (BT) in otolaryngology. We selected 10 disease categories: spasmodic dysphonia, essential vocal tremor, vocal fold granuloma, bilateral vocal fold paralysis, Frey's syndrome, sialocele, sialorrhea, cricopharyngeal dysfunction, chronic sialadenitis, and first bite syndrome. To retrieve all relevant papers, we searched the CORE databases with predefined search strategies, including Medline (PubMed), Embase, the Cochrane Library, and KoreaMed. The committee reported 13 final recommendations with detailed evidence profiles. The guidelines are primarily aimed at all clinicians applying BT to the head and neck area. In addition, the guidelines aim to promote an improved understanding of the safe and effective use of BT by policymakers and counselors, as well as in patients scheduled to receive BT injections.

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Ecological risk assessment of contaminated sediment has become a fundamental component of water quality management programs, supporting decision-making for management actions or prompting additional investigations. In this study, we proposed a machine learning (ML)-based approach to assess the ecological risk of contaminated sediment as an alternative to existing index-based methods and costly toxicity testing. The performance of three widely used index-based methods (the pollution load index, potential ecological risk index, and mean probable effect concentration) and three ML algorithms (random forest, support vector machine, and extreme gradient boosting [XGB]) were compared in their prediction of sediment toxicity using 327 nationwide data sets from Korea consisting of 14 sediment quality parameters and sediment toxicity testing data. We also compared the performances of classifiers and regressors in predicting the toxicity for each of RF, SVM, and XGB algorithms. For all algorithms, the classifiers poorly classified toxic and non-toxic samples due to limited information on the sediment composition and the small training dataset. The regressors with a given classification threshold provided better classification, with the XGB regressor outperforming the other models in the classification. A permutation feature importance analysis revealed that Cr, Cu, Pb, and Zn were major contributors to toxicity prediction. The ML-based approach has the potential to be even more useful in the future with the expected increase in available sediment data., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Wastewater-based epidemiology (WBE) is drawing increasing attention as a promising tool for an early warning of emerging infectious diseases such as COVID-19. This study demonstrated the utility of a spatial bisection method (SBM) and a global optimization algorithm (i.e., genetic algorithm, GA), to support better designing and operating a WBE program for disease surveillance and source identification. The performances of SBM and GA were compared in determining the optimal locations of sewer monitoring manholes to minimize the difference among the effective spatial monitoring scales of the selected manholes. While GA was more flexible in determining the spatial resolution of the monitoring areas, SBM allows stepwise selection of optimal sampling manholes with equiareal subcatchments and lowers computational cost. Upon detecting disease outbreaks at a regular sewer monitoring site, additional manholes within the catchment can be selected and monitored to identify source areas with a required spatial resolution. SBM offered an efficient method for rapidly searching for the optimal locations of additional sampling manholes to identify the source areas. This study provides strategic and technical elements of WBE including sampling site selection with required spatial resolution and a source identification method., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objectives: To compare the surgical outcomes of externally monitored and conventional buried flaps with the goal of determining the usefulness of external monitoring of buried flaps., Methods: In this case-control study with propensity score matching, 30 patients were evenly divided into externally monitored buried flap and conventional buried flap groups. The total operative time for free flap reconstruction, the flap survival rate, the length of hospital stay, the initial time of a reliable visual assessment, complications, the final diet achieved, and the duration until diet initiation were compared between the groups., Results: The mean operative time for reconstruction was 115 minutes (interquartile range, 85-150 minutes) and 142 minutes (interquartile range, 95-180 minutes) in the externally monitored and conventional groups, respectively (P= 0.245). The median length of hospital stay was 24 days (interquartile range, 18-30 days) and 27 days (interquartile range, 20-41 days) in the externally monitored and conventional groups, respectively (P=0.298). The median duration until diet initiation was 15 days (interquartile range, 15-21 days) and 18 days (interquartile range, 15-34 days) in the externally monitored and conventional groups, respectively (P=0.466). The final diet, initial time of a reliable visual assessment, and complications were comparable between the groups, but the external skin paddle provided an excellent visual assessment immediately postoperatively in all cases., Conclusion: The outcomes were comparable between the groups, indicating that externalization of the cutaneous component of a buried flap may be a straightforward and useful technique for monitoring a buried anterolateral thigh free flap in laryngopharyngeal reconstructions. The salvage and false-positive rates of compromised flaps should be compared in large subject groups in future studies to prove that the use of an external skin paddle improves flap monitoring.

Objectives/hypothesis: Microsurgical removal with a microflap technique via direct laryngoscopy is considered the primary treatment option for vocal cysts. However, the microflap technique is technically difficult and challenging. Therefore, we developed the "cotton ball self-retraction" technique to aid in vocal cyst surgery and reduce the cyst rupture incidence. This study aimed to evaluate the efficacy of this technique in microflap dissection for vocal cysts by comparing its treatment outcomes with those of the conventional technique as well as investigate the rate of recurrence using a retrospective chart review., Study Design: A retrospective review., Methods: We reviewed the medical records of 169 patients who underwent surgery with the microflap technique for vocal cysts from December 2006 to December 2017. The patients were divided into two groups: 78 patients underwent laryngomicrosurgery using the conventional microflap technique (group A), whereas the remaining 91 patients underwent surgery with the microflap technique with cotton ball self-retraction (group B). The voice outcomes and operative data of the two groups were retrospectively reviewed and compared., Results: The cyst ruptured intraoperatively in 42 of 78 (53.8%) patients in group A and 17 of 91 (18.6%) patients in group B. Recurrence during the follow-up period was detected in 9 of 78 (11.5%) patients in group A and 2 of 91 (2.19%) patients in group B. The degrees of improvement in assessed voice parameters were not significantly different between the groups., Conclusion: The cotton ball technique allows accurate and effective dissection during microflap surgery for intracordal cysts., Level of Evidence: 3 Laryngoscope, 131:E2553-E2557, 2021., (© 2021 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Parotidectomy is the primary treatment for parotid gland tumors. However, complications may include a prominent facial scar or infra-auricular depressed deformity, Frey's syndrome, first bite syndrome, or other facial pain, numbness, and paralysis. Acellular dermal matrix (ADM) has been widely used to prevent these complications in parotid surgery, but there have been no prospective, multi-center trials documenting its efficacy. This study evaluates the effectiveness of ADM implantation in preventing infra-auricular depressed deformity, Frey's syndrome and first bite syndrome after parotidectomy., Methods: We analyzed 51 cases of standard parotidectomy and 58 cases of parotidectomy with implantation of Megaderm™ ADM through prospective multicenter trial. Acute complications including infection, seroma, hematoma, skin necrosis, and acute parotid area pain were evaluated 1 week postoperatively. Clinician grading of Frey's syndrome and blinded clinician evaluation of infra-auricular depressed deformities were conducted at 3, 6, and 12 months. Patients evaluated subjective satisfaction with neck appearance, Frey's syndrome quality, and acute parotid area pain at 3, 6, and 12 months., Results: There was a higher incidence of seroma in the Megaderm™ group than in the control group at week 1. The incidence and total clinician-evaluated Frey's syndrome scores were significantly lower in the Megaderm™ group than in the control group at 3, 6, and 12 months. Both the objective and subjective evaluations of the facial contour showed a better outcome in the Megaderm™ group compared to the control group at 3, 6, and 12 months. There were no significant differences between the groups in the patient-reported Frey's syndrome quality scores at 3, 6, and 12 months, but the Megaderm™ group reported significantly less acute pain than the control group., Conclusions: ADM implantation can effectively reduce the occurrence of Frey's syndrome, infra-auricular depressed deformity, and first bite syndrome after parotidectomy. ADM may be especially advantageous in complex parotidectomy cases when significant complications are expected., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/gs-20-703). The authors have no conflicts of interest to declare., (2021 Gland Surgery. All rights reserved.)

Objectives: We assessed fibroblast growth factor (FGF) regenerative efficacy in an aged vocal fold rat model and confirmed it in a prospective clinical trial., Design, Setting, and Participants: For animal experiments, 48 Sprague-Dawley rats were divided into two groups: 24 six-month-olds (young group) and 24 twenty-four-month-olds (old group). FGF was injected once a week thrice into the left vocal fold of the old group, dividing them into two sub-groups (injected [left] and uninjected [right]). Additionally, we conducted a prospective clinical trial for 38 patients with aged atrophic vocal fold., Main Outcome Measures: A month post-injection, excised larynx from the three groups was subjected to comparative histopathological (ratio of relative lamina propria to total vocal fold) and mRNA expression analysis (of procollagen I, hyaluronic acid synthase (HAS)-2 and matrix metalloproteinase (MMP)-2) by real-time PCR. We performed perceptual, stroboscopic, acoustic aerodynamic test and Voice Handicap Index survey prior to and 1, 6 and 12 months after FGF injection., Results: In rats, the relative lamina propria ratio increased after FGF injection. Procollagen I mRNA level decreased, whereas that of HAS-2 and MMP-2 increased significantly in the injected compared to the uninjected old group. Enrolled patients showed improved subjective and objective voice parameters after FGF injection, and these were maintained for a year. Potential side effects were not observed., Conclusions: Animal experiments and prospective clinical trial suggest that FGF injection to vocal fold can significantly improve voice quality until one year, without complications, and is effective for aged atrophic vocal fold treatment., (© 2020 John Wiley & Sons Ltd.)

Objective: In this study, we assessed the effectiveness of a tonsil-derived mesenchymal stem cell (TMSC)-transplanted polycaprolactone/beta-tricalcium phosphate prosthesis (specifically designed for easier fixing and grafting with a single scaffold) on rabbit mandible osteogenesis., Methods: The mandibles of 18 rabbits were exposed, and 10 × 8-mm bone defects were made. Two rabbits did not receive implants; four were reconstructed with the scaffold control (SC) (SC group); four were reconstructed with scaffolds soaked in peripheral blood (PB) (PB group); four were reconstructed with TMSC-transplanted scaffolds (TMSC group); and four were reconstructed with differentiated osteocyte-transplanted scaffolds (DOC) (DOC group). Each rabbit was sacrificed 12 weeks after surgery, and the area of new bone formation was investigated by mechanical testing, histology, and micro-computed tomography., Results: More extended and denser new bone masses were observed in the TMSC and DOC groups, although fibrosis and vascular formation levels were similar in all groups, suggesting that the dual-structured scaffold alone provides a good environment for bone attachment and regeneration. The bone volumes of representative scaffolds from the SC, PB, TMSC, and DOC groups were 43.12, 48.35, 53.10, and 57.44% of the total volumes, respectively., Conclusion: The design of the scaffold resulted in effective osteogenesis, and TMSCs showed osteogenic potency, indicating that their combination could enable effective bone regeneration., Level of Evidence: NA Laryngoscope, 130:358-366, 2020., (© 2019 The American Laryngological, Rhinological and Otological Society, Inc.)

Under physiological and pathological conditions, mechanical forces generated from cells themselves or transmitted from extracellular matrix (ECM) through focal adhesions (FAs) and adherens junctions (AJs) are known to play a significant role in regulating various cell behaviors. Substantial progresses have been made in the field of mechanobiology towards novel methods to understand how cells are able to sense and adapt to these mechanical forces over the years. To address these issues, this review will discuss recent advancements of traction force microscopy (TFM), intracellular force microscopy (IFM), and monolayer stress microscopy (MSM) to measure multiple aspects of cellular forces exerted by cells at cell-ECM and cell-cell junctional intracellular interfaces. We will also highlight how these methods can elucidate the roles of mechanical forces at interfaces of cell-cell/cell-ECM in regulating various cellular functions. [BMB Reports 2020; 53(2): 74-81].

Objective: Loss of signal (LOS) during intraoperative neuromonitoring (IONM) of robotic or endoscopic thyroidectomy via a retroauricular approach (RAT) and during conventional open thyroidectomy (COT) was investigated to compare the risk of recurrent laryngeal nerve (RLN) injury between the two groups., Study Design: Original article., Methods: This is a retrospective case series study performed between May 2014 and September 2016. IONM using the NIM 3.0 system (Medtronic Xomed, Inc., Jacksonville, FL) was used for this study. Pre- and postoperative vocal cord functions were assessed using a flexible laryngoscope. LOS types noted intraoperatively and their associations with postoperative vocal cord palsy (VCP) were evaluated. LOS rate and temporary and permanent VCP rates were compared between the two groups. The surgical events associated with LOS were also documented and analyzed in this study., Results: In total, 153 patients were recruited, and 111 patients were enrolled in the RAT group; the remaining 42 patients were enrolled in the COT group. No statistically significant differences in intraoperative LOS (P = 0.812) and postoperative VCP rates (early, permanent; P = 0.259 and P = 0.577, respectively) between the two groups were observed. IONM accuracy of predicting postoperative VCP was 99.1% in our case series., Conclusion: On the basis of IONM findings, the risks of injury to RLN were similar between the two groups. Comparison of LOS was an objective method for verifying the novel RAT approach. We applied our IONM protocol and troubleshooting algorithm during RAT with acceptable accuracy, but the international standardized method of IONM is applicable and recommended for reducing false results using vagal nerve stimulation., Level of Evidence: 3b Laryngoscope, 129:2199-2204, 2019., (© 2018 The American Laryngological, Rhinological and Otological Society, Inc.)

The purpose of this study was to assess the relationship between F-18 fluorodeoxyglucose (FDG) uptake in bone marrow (BM) on positron emission tomography/computed tomography (PET/CT) and survival in patients with head and neck squamous cell carcinoma (HNSCC). We retrospectively enrolled 157 HNSCC patients who underwent staging FDG PET/CT and subsequent treatment. On PET/CT, primary tumor metabolic characteristics, mean FDG uptake of BM (BM SUV), and BM-to-liver uptake ratio (BLR) were measured. The prognostic significance of FDG uptake of BM for predicting disease progression-free survival and distant failure-free survival was assessed using a Cox proportional hazards regression model. In univariate analysis for disease progression-free survival, increased BM SUV and BLR were associated with poor survival. In multivariate analysis, BLR ( p = 0.044; hazard ratio, 1.96), TNM stage ( p = 0.014; hazard ratio, 2.87) and maximum FDG uptake of the primary tumor ( p = 0.046; hazard ratio, 2.38) were independently associated with disease progression-free survival. For distant failure-free survival, BLR, TNM stage, tumor size, and metabolic parameters of the primary tumor showed prognostic significance in univariate analysis. However, none of the variables showed significance in multivariate analysis. FDG uptake of BM in HNSCC patients might be a significant predictor for disease progression-free survival. Further studies with large patient population are needed to validate the results.

Background: The aim of this study was to evaluate the relationship of the characteristics of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) to the disease progression-free survival and distant failure-free survival of head and neck squamous cell carcinoma (HNSCC)., Methods: We enrolled 152 HNSCC patients who underwent staging 18 F-fluorodeoxyglucose (FDG) positron emission tomography/CT (PET/CT). Maximum FDG uptake (standardized uptake value [SUV]) and total lesion glycolysis (TLG) of the primary tumor and volume, CT-attenuation (Hounsfield units [HU]), and FDG uptake of SAT and VAT were measured. Survival analysis using Cox proportional hazard modeling was performed to assess the relationship between the adipose tissue parameters of PET/CT and survival., Results: Patients with low VAT volume and high VAT HU had significantly worse progression-free survival and distant failure-free survival than those with high VAT volume and low VAT HU. On multivariate analysis, the volume and HU of VAT were significantly correlated with disease progression-free survival and distant failure-free survival after adjusting for age, sex, body mass index, TNM stage, serum C-reactive protein, maximum SUV, and TLG., Conclusion: The volume and CT-attenuation of VAT were significantly correlated with disease progression-free survival and distant failure-free survival in patients with HNSCC., (© 2019 Wiley Periodicals, Inc.)

Recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) has been a longstanding challenge for head and neck oncologists, and current treatments still have limited efficacy. ERK is aberrantly overexpressed and activated in HNSCC. Herein, we aimed to investigate the cause of the limited therapeutic effect of selumetinib, a selective inhibitor of MEK in HNSCC, as MEK/ERK reactivation inevitably occurs. We assessed the effects of combining selumetinib with fibroblast growth factor receptor 3 (FGFR3) inhibitor (PD173074) on tumor growth. Selumetinib transiently inhibited MAPK signaling and reactivated ERK signaling in HNSCC cells. Rebound in the ERK and Akt pathways in HNSCC cells was accompanied by increased FGFR3 signaling after selumetinib treatment. Feedback activation of FGFR3 was a result of autocrine secretion of the FGF2 ligand. The FGFR3 inhibitor PD173074 prevented MAPK rebound and sensitized the response of HNSCC cells to selumetinib. These results provided rational therapeutic strategies for clinical studies of this subtype of patients that show a poor prognosis with selumetinib. Our data provide a rationale for combining a MEK inhibitor with inhibitors of feedback activation of FGFR3 signaling in HNSCC cells. ERK rebound as a result of the upregulation of FGFR3 and the ligand FGF2 diminished the antitumor effects of selumetinib, which was overcome by combination treatment with the FGFR3 inhibitor., (© 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background: The objective of this retrospective study was to identify predictors of an abscess guaranteed to be surgically drained successfully in patients with deep neck infection (DNI)., Materials and Methods: We divided 97 consecutive patients with DNI into a drained group and a non-drained group. We then developed a clinical prediction score and validated it in 32 further patients., Results: Significant predictors of successful surgical drainage (i.e., positive for pus) were rim enhancement on computed tomography, C-reactive protein, erythrocyte sedimentation rate, and the neutrophil to lymphocyte ratio. The estimated cut-off values (excluding rim enhancement, which is a yes/no parameter) were 41.25, 56.5, and 8.02, respectively, and the clinical prediction score for each of the four other factors was determined to be 2, 2, 3, and 3 points, respectively. The cut-off score for the sum of these points was 6.5 and the scoring system had an accuracy of 87.5% in the validation group., Conclusion: Our clinical prediction scoring system can predict whether drainage is successful in patients with DNI., (Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

The association between chronic laryngitis and tinnitus is not a well-studied topic, unlike the association of these two conditions with many other disorders. Cross-sectional data of 11,347 adults (males: 4,934; females: 6,413), who completed the Korea National Health and Nutrition Examination Survey (KNHANES) from 2010 to 2012 were used to investigate this association. Lifestyle patterns, including smoking and alcohol habits, regular exercise, physical and mental health status, socioeconomic status, nutritional status, and other chronic diseases, were analyzed. Chronic laryngitis and tinnitus were diagnosed by field survey teams, which included otolaryngologists, who conducted chronic disease surveillance using a health status interview, a nutritional status questionnaire, and a physical examination. Chronic laryngitis was significantly associated with age, education beyond high school, depressed mood, voice change, metabolic syndrome, and tinnitus in men. In women, chronic laryngitis was associated with body mass index and diabetes mellitus. Chronic laryngitis in men was significantly associated with tinnitus (odds ratio 1.671, [95% confidence interval: 1.167-2.393]) after adjusting for age, body mass index, smoking status, alcohol intake, regular exercise, metabolic syndrome, education beyond high school, and depressed mood. Additionally, the prevalence of chronic laryngitis increased with increasing severity of tinnitus in men alone (P = 0.002). The study revealed a significant association between chronic laryngitis and tinnitus.

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.

The aim of the study is to investigate the association between olfactory dysfunction (OD), hearing loss, and dysphonia.The cross-sectional data for 17,984 adults who completed the Korea National Health and Nutrition Examination Surveys (2010-12) were analyzed. OD, hearing loss, and dysphonia were assessed using self-reporting questionnaires. The association of OD with hearing loss and dysphonia was evaluated.Hearing loss and dysphonia were significantly more prevalent in patients with OD than in those without OD (hearing loss, 28.1% vs 11.3%; dysphonia, 11.1% vs 5.9%; both P < .0001). After adjusting for confounders, including mental stress and metabolic syndrome, the risk of OD was significantly associated with hearing loss and dysphonia, and was greater in those with combined hearing loss and dysphonia than in both patients without these dysfunctions and in those with a single dysfunction (odds ratio 3.115, 95% confidence interval 1.973-4.917).OD was significantly associated with hearing loss and dysphonia., (Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.)

Although there are various methods for tracheal reconstruction, such as a simple approximation with suturing and coverage with adjacent soft tissue or muscle, large defects >50% of the tracheal length still present a clinical challenge. Tissue engineering, a recent promising way to possibly resolve this problem, requires a long preparatory period for stem cell seeding on a scaffold and relatively invasive procedures for stem cell harvesting. As an alternative, we used a vascularized myofascial flap for tracheal reconstruction. In four porcine models, the deep inferior epigastric perforator (DIEP) was used in two and the superior epigastric artery perforator (SEAP) in two. Transformation of the surface of the transplanted myofascial flap was analyzed in the airway environment. The flaps failed in the DIEP group due to venous congestion. At 12 weeks postoperatively, none of SEAP group showed any signs of respiratory distress; the inner surface of the implant exhibited stratified squamous epithelium with sparse cilia. In the clinical setting, a patient who underwent a tracheal reconstruction with a vascularized myofascial flap and 2-year follow-up was in good health with no respiratory distress symptoms.

Purpose: Solute carrier organic anion transporter family member 4A1 (SLCO4A1) is involved in the transport of various compounds, including sugars, bile salts, organic acids, metal ions, amine compounds, and estrogen. SLCO4A1 is highly expressed in several cancers and a gender bias has been observed in colorectal cancer (CRC). We investigated SLCO4A1 expression, its prognostic value in patients with CRC, and its role in CRC cell proliferation and metastasis., Methods: SLCO4A1 expression was assessed by immunohistochemistry (IHC) on specimens from 84 patients with CRC. The association of SLCO4A1 expression with clinicopathological features was examined. To confirm the biological role of SLCO4A1 in CRC, four CRC cell lines expressing SLCO4A1 were used and SLCO4A1 expression was knocked down by siRNA. Cell proliferation, MTT, migration, invasion, and semisolid agar colony formation assays were performed., Results: SLCO4A1 was overexpressed in 32% of the CRC samples. SLCO4A1 overexpression and pathologic T stage were independent prognostic factors of decreased survival (P = 0.021). Kaplan-Meier analysis indicated a decreased cumulative survival for patients highly expressing SLCO4A1 compared to patients showing low SLCO4A1 expression (Log-rank test, P = 0.025). In cell lines, SLCO4A1 knockdown resulted in a significant decrease of viability, invasion, and migration when compared to control cells. Semisolid colony formation assay indicated that SLCO4A1-knocked down cells presented poor carcinogenic abilities compared to control cells., Conclusions: SLCO4A1 may be a valuable marker of poor prognostic for CRC. Furthermore, SLCO4A1 plays an important role in CRC cell proliferation, migration, invasion, and carcinogenesis.

Objective: Smartphone-based thermal imaging was evaluated for its utility in the detection of peritonsillar abscesses., Methods: We describe six cases of peritonsillar abscess in which computed tomography and thermography scans of the neck were performed prior to surgery., Results: Open-mouth thermal photographic images were obtained preoperatively from patients, and asymmetric hot spots with significantly higher temperatures in the peritonsillar area were identified as abscesses., Conclusions: This new portable smartphone-based thermal imaging technique may be useful in the detection of peritonsillar abscesses., Competing Interests: Declaration of interest: The authors declare that they have no conflict of interest with any third party.

Previously, the authors have identified that c-Met mediates reactivation of the PI3K/AKT pathway following BRAF inhibitor treatment in BRAF (V600E) mutant anaplastic thyroid cancer, thereby contributing to the acquired drug resistance. Therefore dual inhibition of BRAF and c-Met led to sustained treatment response, thereby maximizing the specific anti-tumor effect of targeted therapy. The present study goes one step further and aims to investigate the effect of acquired resistance of BRAF inhibitor on epithelial-to-mesenchymal transition (EMT) in BRAF mutant thyroid cancer cells and the effect of dual inhibition from combinatorial therapy. Two thyroid cancer cell lines, 8505C and BCPAP were selected and treated with BRAF inhibitor, PLX4032 and its effect on EMT were examined and compared. Further investigation was carried out in orthotopic xenograft mouse models. Unlike BCPAP cells, the BRAF inhibitor resistant 8505C cells showed increased expressions of EMT related markers such as vimentin, β-catenin, and CD44. The combinatorial treatment of PLX4032 and PHA665752, a c-Met inhibitor reversed EMT. Similar results were confirmed in vivo. c-Met-mediated reactivation of the PI3K/AKT pathway contributes to the drug resistance to PLX4032 in BRAF (V600E) mutant anaplastic thyroid cancer cells and further promotes tumor cell migration and invasion by upregulated EMT mechanism. Dual inhibition of BRAF and c-Met leads to reversal of EMT, suggesting a maximal therapeutic response.

This study aimed to evaluate the feasibility and efficacy of minimal endoscope-assisted thyroidectomy (MEAT) through a retroauricular (RA) approach. Most of the thyroidectomy operative time was accounted for by direct visualization through the RA window, minimizing interference between surgical instruments. Endoscope use was minimized and limited to critical surgical aspects, including preservation of the recurrent laryngeal nerve and parathyroid glands. The recurrent laryngeal nerve was neuromonitored throughout the procedure. MEAT through an RA approach was performed in 8 patients with papillary thyroid carcinoma (mean tumor size, 1.2±0.5 cm). The mean patient age was 41.1±7.5 years. The endoscopic operating time was 19±3.4 minutes, and no postoperative hematoma, seroma, or vocal cord paralysis was observed. MEAT through an RA approach was feasible and safe. Solo thyroidectomy through the RA approach is possible without depending on an endoscopic view, overcoming limited working space and minimizing instrument interference during endoscopic RA thyroidectomy., Competing Interests: The authors declare no conflicts of interest.

BRAF (V600E) mutation is the most commonly detected genetic alteration in thyroid cancer. Unlike its high treatment response to selective BRAF inhibitor (PLX4032) in metastatic melanoma, the treatment response in thyroid cancer is reported to be low. The purpose of this study is to investigate the resistance mechanism responsible for this low treatment response to BRAF inhibitor in order to maximize the effect of targeted therapy. We examined the expression of feedback regulation mechanisms and alterations in the upper signal transduction pathway in thyroid cancer cell lines harboring BRAF mutation. Also, we investigated the effect of dual inhibition from combinatorial therapy. Two thyroid cancer cell lines, 8505C (anaplastic thyroid cancer) and BCPAP (papillary thyroid cancer) were selected and treated with PLX4032 and its drug sensitivity were examined and compared. Further investigation on the changes in signals responsible for the different treatment response to PLX4032 was carried out and the same experiment was performed on orthotopic xenograft mouse models. Unlike BCPAP cells, 8505C cells presented drug resistance to PLX4032 treatment and this was mainly due to increased expression of c-Met. Effective inhibitions of c-Met, p-AKT, and p-ERK were achieved after dual treatment with BRAF inhibitor (PLX4032) and c-Met inhibitor (PHA665752). Similar results were confirmed by in vivo study with orthotopic xenograft mouse model. c-Met-mediated reactivation of the PI3K/AKT pathway and MAPK pathway contributes to the relative insensitivity of BRAF (V600E) mutant anaplastic thyroid cancer cells to PLX4032. Dual inhibition of BRAF and c-Met leads to sustained treatment response. © 2015 Wiley Periodicals, Inc., (© 2015 Wiley Periodicals, Inc.)

Objectives/hypothesis: As an evolvement of the robotic application to the thyroidectomy, we sought to seek the potential role of robotic thyroidectomy with the retroauricular (RA) approach prior to future comparative study between RA and transaxillary thyroidectomy. This study aims to verify the surgical feasibility of robotic RA thyroidectomy., Study Design: Case series with planned data collection., Methods: A total of 87 patients who underwent robotic RA thyroidectomy for clinically suspicious papillary thyroid carcinoma or benign lesions from January 2013 to May 2014 were retrospectively reviewed and analyzed., Results: All robotic surgeries via RA approach were successfully performed, without any significant intraoperative complications or conversion to open surgery. Based on patient-reported outcome questionnaires, all patients were satisfied with their postoperative surgical scars., Conclusion: Robotic RA thyroidectomy is technically feasible and safe, with satisfactory cosmetic results for patients where indicated., Level of Evidence: 4. Laryngoscope, 126:1952-1957, 2016., (© 2015 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Free-flap reconstruction via a retroauricular approach (RRA) after robot-assisted neck dissection (RAND) could have cosmetic benefits. This study aimed to compare the surgical outcomes of free-flap reconstruction via a RRA and via a transcervical approach in head and neck cancer., Methods: For this matched case-control study, 50 patients with head and neck cancer requiring free-flap reconstruction were divided into two groups: those reconstructed via a RRA group and those reconstructed via a transcervical approach (RTA group). The total operation time for free-flap reconstruction, the flap survival rate, the length of the hospital stay, the complications, and the scar satisfaction scores were compared between the two groups., Results: The RRA group comprised 25 patients, and the RTA group had 25 patients. The mean operation time for reconstruction was 288 ± 77 min in the RRA group and 250 ± 98 min in the RTA group (p = 0.132). Flap failure occurred for two patients in the RRA group (8 %) and for one patient in the RTA group (4 %) (p = 1.000). The mean hospital stay was 21 ± 18 days in the RRA group and 23 ± 14 days in the RTA group (p = 0.669). The complications were comparable between the two groups. However, the overall scar satisfaction was significantly higher in the RRA group (p = 0.000)., Conclusions: For patients with head and neck cancer, RRA has better cosmetic outcomes than RTA. The RRA approach could be used for select patients who undergo RAND and prefer to avoid a visible anterior neck scar.

Objective: To investigate the treatment outcomes of parotid gland cancer at a single center over a 10-year period and to evaluate the prognostic significance of maximum standardized uptake value., Study Design: Retrospective case series with chart review., Setting: Academic care center., Subjects and Methods: Ninety-eight patients with primary parotid gland cancer who were surgically treated at Yonsei University Head & Neck Cancer Clinic between January 1999 and December 2008 were analyzed. Patient data were collected retrospectively from medical charts. The investigators analyzed the association of clinicopathological factors and maximum standardized uptake value on (18)F-fluorodeoxyglucose positron emission tomography-computed tomography scan with disease-specific survival., Results: Mean patient age was 49.7 years. Mean follow-up was 48.8 months. Thirty-three, 40, 30, and 23 patients had stage I, II, III, and IVA disease, respectively. Mucoepidermoid carcinoma was the most common histologic type (34.7%), followed by acinic cell carcinoma (27.6%). Eighteen patients (18.4%) experienced recurrences (mean recurrence gap, 20.6 months; range, 2-87 months). Five- and 10-year disease-specific survival rates were 93.6% and 81.8%, respectively. In the univariate analysis, pathologic T stage, pathologic lymph node status, resection margin, external parenchymal extension, and maximum standardized uptake value were significantly associated with disease-specific survival. Pathologic lymph node status and maximum standardized uptake value were independent prognostic factors in the multivariate analysis., Conclusion: Our single-center experience with parotid gland cancer treatment is consistent with the literature. Cervical lymph node metastasis and high maximum standardized uptake value are associated with poor survival in parotid gland cancer., (© American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.)

Purpose: Although follicular thyroid cancer (FTC) has a relatively fair prognosis, distant metastasis sometimes results in poor prognosis and survival. There is little understanding of the mechanisms contributing to the aggressiveness potential of thyroid cancer. We showed that hypoxia inducible factor-1α (HIF-1α) induced aggressiveness in FTC cells and identified the underlying mechanism of the HIF-1α-induced invasive characteristics., Materials and Methods: Cells were cultured under controlled hypoxic environments (1% O₂) or normoxic conditions. The effect of hypoxia on HIF-1α, and epithelial-to-mesenchymal transition (EMT) related markers were evaluated by quantitative real-time PCR, Western blot analysis and immunocytochemistry. Invasion and wound healing assay were conducted to identify functional character of EMT. The involvement of HIF-1α and Twist in EMT were studied using gene overexpression or silencing. After orthotopic nude mouse model was established using the cells transfected with lentiviral shHIF-1α, tissue analysis was done., Results: Hypoxia induces HIF-1α expression and EMT, including typical morphologic changes, cadherin shift, and increased vimentin expression. We showed that overexpression of HIF-1α via transfection resulted in the aforementioned changes without hypoxia, and repression of HIF-1α with RNA interference suppressed hypoxia-induced HIF-1α and EMT. Furthermore, we also observed that Twist expression was regulated by HIF-1α. These were confirmed in the orthotopic FTC model., Conclusion: Hypoxia induced HIF-1α, which in turn induced EMT, resulting in the increased capacity for invasion and migration of cells via regulation of the Twist signal pathway in FTC cells. These findings provide insight into a possible therapeutic strategy to prevent invasive and metastatic FTC.

Importance: Robot-assisted neck dissection (RAND) for the management of regional metastases is a recently developed technique in the field of head and neck cancer that uses a robotic surgical system. This is the first report that estimates the learning curve for RAND., Objectives: To evaluate a learning curve for RAND according to the types of neck dissection and report clinical outcomes., Design, Setting, and Participants: Prospective case study of 90 patients undergoing neck dissection between May 2010 and April 2013 at a university tertiary referral center., Interventions: Fifty modified radical neck dissections (MRNDs) and 40 supraomohyoid neck dissections (SONDs) were performed by a single surgeon using a robotic surgical system to treat head and neck cancer. The MRND and the SOND groups were subdivided into 5 and 4 consecutive subgroups of 10 patients each, respectively., Main Outcomes and Measures: Perioperative parameters were compared, including mean operation time, duration and amount of drainage, length of hospital stay, and postoperative complications., Results: Significant decreases in mean operation time were observed as experience performing RAND increased in both the MRND and the SOND groups. The mean operation time for the MRND group decreased by 29% over the course of our study (initial subgroup, 298.1 minutes; last subgroup, 212.4 minutes). The mean operation time for the SOND group decreased by 53% over the course of our study (initial subgroup, 226.5 minutes; last subgroup, 106.1 minutes). There were no significant differences between subgroups for the other perioperative parameters., Conclusions and Relevance: We explored the RAND learning curve in a single institution over a 3-year period. This study can be used as a timeline reference for institutions where the RAND procedure will be adopted as an alternative procedure.

Background: Based on our previous experiences with endoscopic or robotic neck surgery utilizing the retroauricular (RA) or modified facelift (MFL) approach, we realized the value of verifying the feasibility of endoscopic supraomohyoid neck dissection (SOND). Therefore, the purpose of this study was to evaluate the potential role of endoscopic SOND., Methods: Six patients who underwent elective endoscopic SOND of the ipsilateral neck for biopsy proven head and neck cancer from January 2011 to February 2012 were analyzed., Results: All endoscopic operations via RA or MFL were successfully performed without any significant intraoperative complications or conversion to open surgery. Based on patient-reported outcome questionnaires, all patients were satisfied with the cosmetic surgical outcomes., Conclusion: Endoscopic selective neck dissection via an RA or an MFL approach is technically feasible and safe with satisfactory cosmetic results for patients with clinically node-negative early-stage head and neck cancer., (Copyright © 2013 Wiley Periodicals, Inc., A Wiley Company.)

Background: Carcinomas arising in the thyroglossal duct cysts are rare, accounting only for about 0.7-1.5 % of all thyroglossal duct cysts. Synchronous occurrence of thyroglossal duct carcinoma and thyroid carcinoma is reported to be even rarer. Traditionally, surgical treatments of such coexisting thyroglossal duct cyst carcinoma (TGDCa) and papillary thyroid carcinoma (PTC) were typically performed through a single transverse or double incisions on the overlying skin. A longer, extended cervical incision might be required if neck dissection is necessary. Though this method provides the operator with the optimal surgical view, the detrimental cosmetic effect on the patient of possessing a scar cannot be avoided, despite the effort of the surgeon to camouflage the scar by placing the incision in natural skin creases. Recently, the authors have previously reported the feasibility of robot-assisted neck dissections via a transaxillary and retroauricular ("TARA") approach or modified face-lift approach in early head and neck cancers. On the basis of the forementioned surgical technique, we demonstrate our novel technique for robot-assisted Sistrunk's operation via retroauricular approach as well as robot-assisted neck dissection with total thyroidectomy via transaxillary approach., Methods: This is a case presentation of a 22-year-old woman with synchronous TGDCa and PTC with minimal lymph node metastasis who underwent resection of TGDCa and total thyroidectomy with left neck level III and IV lymph node dissection as well as central compartment lymph node dissection (CCND) via TARA approach with a robotic surgery system after approval from the institutional review board at Severance Hospital, Yonsei University College of Medicine. The incision was just like the TARA approach in head and neck cancer, which has been reported by our institute. The operation was proceeded as follows. First, excision of the TGDCa through the retroauricular incision was done followed by total thyroidectomy with CCND via transaxillary approach. Finally, neck dissection of left level III, IV was conducted via transaxillary approach. The da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA) was introduced via retroauricular or transaxillary port. A 30° dual-channel endoscope was used, and the two instrument arms were equipped with 5 mm Maryland forceps and a 5 mm spatula monopolar cautery for TGDCa excision via retroauricular approach. When conducting total thyroidectomy and neck dissection via transaxillary approach, three instrument arms were utilized, each equipped with 5 mm Maryland forceps, ProGrasp forceps and a 5 mm spatula monopolar cautery or Harmonic curved shears. The rest of the surgery was completed with the robotic system (see Video)., Results: The operative procedure was successfully completed utilizing the robotic surgical system with no conversion to open surgery. The operation time for TGDCa excision was 97 min, including the time for skin flap elevation (15 min), setting up the robotic system (5 min), and console time using the robotic system (77 min). Also, the total operation time for the consecutive total thyroidectomy with CCND and level III, IV dissection was 142 min including the time for skin flap elevation (27 min), setting up the robotic system (3 min), and console time using the robotic system (112 min). There were no intraoperative complications. The retroauricular approach for the removal of the TGDCa allowed for an excellent magnified surgical view revealing important structures of the local anatomy. It also created sufficient space for the cutting of the relevant portion of the hyoid bone. Handling of the robotic instruments through the incision was technically feasible and safe without any mutual collisions throughout the operation. The patient's postoperative parathyroid hormone (PTH) level was within normal range and functions of her both vocal cords were intact. The histopathologic results of the specimens revealed thyroglossal duct cyst with internal papillary carcinoma measuring 1.1 cm with infiltrative tumor margins and papillary microcarcinoma measuring 0.9 cm within the left thyroid lobe with extrathyroidal soft tissue extension. There was no evidence of tumor in the right lobe and the pyramidal lobe of the thyroid gland. As for the lymph nodes resected, 7 out of 9 paratracheal nodes and 2 out of 7 left level III, IV nodes revealed metastatic carcinomas. The patient was discharged on the 8th day after the operation with no complications. The patient was extremely satisfied with the cosmetic results. The patient has received high-dose radioiodine ablation (RAI) therapy and is currently doing well with no evidence of recurrence., Discussion: Although there is still a great deal of controversy regarding the treatment of TGDCa, there is little debate that for the cases of synchronous TGDCa and PTC, total thyroidectomy in addition to the Sistrunk procedure must be performed. As for the patient in our case where left level IV lymph node metastasis was detected under preoperative ultrasonography (USG), if the usual method of surgical procedure was to be selected, double incisions or a single extended transverse incision must be adopted for the Sistrunk's operation and total thyroidectomy with lateral neck dissection. The conventional method to remove neck masses was to do so by placing an incision on the overlying skin. This 'open' approach to viewing the lesion has an advantage of providing the operator with the best surgical view, but the recognizable surgical scar that results from the surgery can be displeasing for patients. Therefore the surgeon can try to make a small incision and camouflage the scar by placing the incision in natural skin creases, yet the cosmetic results can still be displeasing for the patient due to its visibility and permanence. This can be an even greater problem if the patient is young and an active member of his/her society and if the lesion is benign or low-grade malignancy which can be simply dissected and excised. Therefore it is the surgeon's best interest to perform an operation successfully with a 'least obvious' or 'hidden' scar whenever possible. Accordingly, we have adopted a novel approach, the transaxillary and retroauricular approach, in view of our increasing surgical experience with various indications such as submandibular gland (SMG) resections and neck dissections in head and neck cancer or thyroid papillary carcinoma. Some investigators have demonstrated that robot-assisted neck dissections performed on patients with thyroid cancer and lateral neck node metastasis are feasible and safe. We conducted total thyroidectomy with bilateral CCND and level III and IV dissection using the same approach. Although the technical feasibility and safety of neck dissection or SMG resection via retroauricular approach has already been reported previously at our institute, Sistrunk's operation via retroauricular approach will be challenging. In spite of that, we were able to demonstrate successfully Sistrunk's operation including the hyoid bone resection through the retroauricular approach. There are however, certain areas of potential difficulties which must be considered with caution during the operation procedure. First, when removing the TGDCa through the retroauricular port, identification of the ipsilateral hyoid bone is primarily important and it is also crucial that dissection along the capsule must be done carefully so as not to rupture the tumor. It is essential that sufficient working space must be created for the comfortable movement of the robotic arms through the retroauricular port and in order to do so, sufficient skin flap elevation in both superior and inferior directions must be performed. It is necessary to elevate the superior skin flap up to the level of the inferior border of the mandible but during this process, the platysma muscle must be identified and meticulous dissection along the subplatysmal plane must be carried out so as not to damage the marginal mandibular branch of the facial nerve. Another area of potential pitfalls concerns the total thyroidectomy with neck dissection through the transaxillary port. Sufficient amount of working space must be secured in order to perform comfortably the contralateral thyroidectomy and neck dissection and in order to do so, skin flap elevation must be done at least 2 cm further based on the ipsilateral omohyoid muscle and the contralateral thyroid gland must be adequately exposed. Using the robotic surgical system in removing the thyroglossal duct cyst, the free movement of wristed instrumentation through the retroauricular incision allowed for efficient dissection and easy handling of the tissue. In this particular case we could not identify the tract beyond the hyoid and up to the foramen cecum, but we anticipate that there would be no technical problems of dissection and excision had it been so. To our knowledge, Sistrunk's operation and total thyroidectomy with lateral neck dissection via TARA approach utilizing the robotic surgical system has never been attempted before. It has some advantages over the conventional surgery in terms of cosmesis. However, careful consideration in selecting appropriate cases is required and prospective trials should be conducted to recognize long-term outcomes and to overcome potential limitations.

Background: Supraomohyoid neck dissection (SOND) in clinical N0 (cN0) neck of oral cavity squamous cell carcinoma (SCC) is performed by many head and neck surgeons showing improved regional control and disease-specific survival. However, disfiguring neck scars have been accepted to be unavoidable. In this study, we sought to introduce and evaluate the feasibility of our surgical technique to hide the external scar of neck dissection using the robotic system via a modified face-lift or retroauricular approach., Methods: Twenty-six patients with cN0 oral cavity SCC were divided into two groups of robot-assisted neck dissection and conventional neck dissection via external cervical incision. The operation time, amount and duration of drainage, length of hospital stay, complications, number of retrieved lymph nodes, and satisfaction scores were compared., Results: Mean operation time was longer in the robot-assisted group (157 ± 22 min) than the conventional group (78 ± 16 min) (P < 0.001). However, the amount and duration of drainage, hospital stay, retrieved lymph nodes, and complications were comparable. Because the postoperative scar was hidden by the auricle and hair, the satisfaction score was significantly higher in the robot-assisted group (P < 0.001)., Conclusions: Robot-assisted SOND via a modified face-lift or retroauricular approach in cN0 oral cavity SCC was feasible compared to conventional technique and showed a clear cosmetic benefit. Longer operation time remains the drawback of this procedure. However, it could be considered for patients who require SOND and prefer to avoid external neck scar.

Purpose: Vascular disorders and viral infections are considered the main causes of sudden hearing loss (SHL), although its pathogenesis remain unclear. Treatments include carbogen inhalation and lipo-prostaglandin E1 (lipo-PGE1), both of which have circulation-enhancing effects. We investigated the effectiveness of carbogen inhalation and lipo-PGE1 in SHL., Materials and Methods: This retrospective review included 202 patients with idiopathic SHL who visited our clinic within 14 days of symptom onset between January 2006 and June 2010. All patients received oral prednisolone for 10 days. Of the 202 patients, 44 received no additional treatment, 106 received additional carbogen inhalation, and 52 received additional lipo-PGE1. Hearing improvement was measured using Siegel's criteria., Results: Overall recovery rates were 67.9% in the carbogen group, 53.8% in the lipo-PGE1 group, and 52.3% in the steroid-only control group (p=0.097). Limited to type 1 and type 2 categories of Sigels's criteria, the carbogen group had a significantly higher recovery rate (53.8%) than the lipo-PGE1 group (26.9%) and the steroid-only control group (38.6%) (p=0.005)., Conclusion: Carbogen inhalation added to steroid was a more effective treatment than lipo-PGE1 added to steroid or steroid alone in patients with SHL.