Sung-Won Choi

Frozen biopsy of central compartment in papillary thyroid cancer: Quantitative nodal analysis

Nodal metastasis in papillary thyroid cancer (PTC) usually occurs in the central compartment of the ipsilateral neck and spreads laterally. The purpose of this study was to evaluate the diagnostic accuracy of frozen biopsy for quantitative nodal evaluation of central neck metastasis in PTC.

Proton magnetic resonance spectroscopic findings of cerebral fat embolism induced by triolein emulsion in cats.

Background: In experimental studies, embolization of the cerebral hemisphere with triolein emulsion has revealed reversible magnetic resonance imaging (MRI) findings in the subacute stage. Purpose: To investigate the changes in the major metabolites, by proton magnetic resonance spectroscopy (MRS), in a cerebral fat embolism induced by a triolein emulsion. Material and Methods: The internal carotid arteries of 19 cats were injected with a triolein emulsion, and multivoxel MRS was performed 30 min, 1 day, and 7 days later. In the control group, six cats were injected with normal saline. The MR spectra were evaluated for N-acetyl aspartate (NAA), creatine (Cr), and choline (Cho), along with the presence of lipid and lactate. Semiquantitative analyses of NAA/Cr, Cho/Cr, NAA/Cho, and lipid/Cr ratios compared the median values of the ipsilateral metabolite ratios with those of the contralateral side and in the control group for each point in time. Results: The NAA/Cr, Cho/Cr, and NAA/Cho ratios in the ipsilateral cerebral hemisphere of the embolized group after 30 min, 1 day, and 7days were not significantly different from the contralateral hemisphere of the embolized and control groups (P>0.05). The lipid/Cr ratio in the ipsilateral cerebral hemisphere of the embolized group was significantly higher when compared with the control group (P=0.012 at 30 min, P=0.001 on day 1, and P=0.018 on day 7). Conclusion: Cerebral fat embolism induced by a triolein emulsion resulted in no significant change in the major metabolites of the brain in the acute stage, except for an elevated lipid/Cr ratio, which suggests the absence of any significant hypoxic-ischemic changes in the lesions embolized using a fat emulsion.

Some posterior branches of extralaryngeal recurrent laryngeal nerves have motor fibers: Extralaryngeal RLNs in Thyroid Surgery

Anatomical variations of the recurrent laryngeal nerve (RLN), such as extralaryngeal branching, are a well‐known risk factor for RLN injury during thyroid surgery. This study aimed to analyze the surgical anatomy and to investigate the existence of posterior branch motor fibers of extralaryngeal RLNs.

Auricular Cartilage Regeneration with Adipose-Derived Stem Cells in Rabbits

Tissue engineering cell-based therapy using induced pluripotent stem cells and adipose-derived stem cells (ASCs) may be promising tools for therapeutic applications in tissue engineering because of their abundance, relatively easy harvesting, and high proliferation potential. The purpose of this study was to investigate whether ASCs can promote the auricular cartilage regeneration in the rabbit. In order to assess their differentiation ability, ASCs were injected into the midportion of a surgically created auricular cartilage defect in the rabbit. Control group was injected with normal saline. After 1 month, the resected auricles were examined histopathologically and immunohistochemically. The expression of collagen type II and transforming growth factor-β1 (TGF-β1) were analyzed by quantitative polymerase chain reaction. Histopathology showed islands of new cartilage formation at the site of the surgically induced defect in the ASC group. Furthermore, Massons trichrome staining and immunohistochemistry for S-100 showed numerous positive chondroblasts. The expression of collagen type II and TGF-β1 were significantly higher in the ASCs than in the control group. In conclusion, ASCs have regenerative effects on the auricular cartilage defect of the rabbit. These effects would be expected to contribute significantly to the regeneration of damaged cartilage tissue in vivo.

Benign Acute Childhood Myositis: Perplexing Complication after Acute Viral Pharyngitis

Benign acute childhood myositis (BACM) is a rare transient condition that occurs in children during the early convalescent phase of a viral upper respiratory infection. BACM is self-limiting and characterized by sudden-onset bilateral calf pain that leads to difficulty in walking. We report a case of a 5-year-old boy with BACM who presented with acute-onset bilateral calf pain after a resolved episode of viral pharyngitis and subsequently refused to walk. With conservative treatment, the patient recovered completely after approximately 1 week. Although perplexing and challenging for clinicians unfamiliar with BACM, awareness of this rare clinical condition is essential to preventing unnecessary investigations and reassuring the patient and parents of its excellent prognosis.

Comparison of extrusion and patency of silicon versus thermoplastic elastomer tympanostomy tubes

OBJECTIVES This study aimed to assess the differences in the extrusion rate, patency and incidence of otorrhea according to the material properties of tubes in tympanostomy tube (TT) procedures. SUBJECTS AND METHODS A total of 75 children with bilateral chronic otitis media with effusion were randomized in this prospective trial to receive 1.02-mm-sized TTs (thermoplastic elastomer) in one ear and 1.14-mm-sized TTs (silicone) in the other ear. Data were obtained on ventilation tube type, time to extrusion, comorbidities, tube plugging, incidence of TT otorrhea during following up, and age of the patient. Postoperatively, follow-up by an otologist continued every two months to assess the incidence of otorrhea, plugging, and TT extrusion until all tubes were extruded. RESULTS Out of the 75 children, 7 patients were excluded during surgery and 4 were lost during follow-up. The mean extrusion time of 1.02-mm-sized TTs (thermoplastic elastomer) was 10.28 months, whereas that of 1.14-mm-sized TTs (silicone) was 7.36 months, which showed a significant difference. However, thermoplastic elastomer TTs had more plugging events than silicone TTs. CONCLUSIONS There was a significant increase in the time to extrusion in ears with the 1.02-mm-sized thermoplastic elastomer TT, although, generally, the larger inner diameter of the tube last longer in the eardrum. This contrasting result is thought to be due to the different material properties of both TTs. This information may be helpful for TT selection in clinical practice depending on the patients condition.

Prevalence and incidence of clinically significant patulous Eustachian tube: A population-based study using the Korean National Health Insurance Claims Database

OBJECTIVES The aim of this study is to estimate the entire population-based prevalence and incidence of Patulous Eustachian tube (PET) using the Korean National Health Insurance (NHI) claims database. The annual trends of prevalence and incidence of PET were also investigated. METHODS Retrospective analysis of PET patients was performed between 2010 and 2016, from the NHI claims database. PET patients were defined as those who had at least one service claim with a primary diagnosis under an ICD-10-based PET code (H69.0). RESULTS During the study period, there were 20,533 new PET patients in Korea. In 2016 there were 4482 incident cases, and the standardized annual incidence rate was 8.8 per 100,000 persons. The standardized annual prevalence rate increased significantly from 7.2 per 100,000 persons in 2010 to 10.3 per 100,000 persons in 2016. The prevalence increased significantly on annual basis, whereas the incidence rate fluctuated over time. Interestingly, the incidence and prevalence of PET in women was almost twice as high as that in men, and peaked in their 20s. CONCLUSIONS This study demonstrated the substantial annual increase of the NHI claims with PET code (H69.0) in Korea from 2010 to 2016. Statistical results based on the NHI claims, we confirmed the high prevalence and incidence rates of clinically significant PET in women than in men. This study only covered patient using the medical service for PET and missed PET sufferers not seeking medical service. However, this study can provide basic epidemiological information on clinically significant PET.