Background: The incidence of epistaxis during nasotracheal intubation via the left nostril is more frequent than that during intubation via the right nostril. This study evaluated the effect of the reverse bevel and tip direction of the nasotracheal tube on the incidence of epistaxis during nasotracheal intubation via the left nostril. Methods: Patients undergoing right-sided maxillofacial surgery requiring left nasotracheal intubation were randomly allocated to the control (tracheal tube in the conventional direction) or reverse (a 180˚ reverse direction, with the tube bevel facing the nasal septum and the leading edge (i.e., the tip) of the bevel pointing away from the nasal septum) groups (n = 37 for both). The primary outcome was the incidence of epistaxis evaluated using videolaryngoscopy. Results: The incidence of epistaxis in the reverse group was significantly lower than that in the control group (9 [24.3%] vs. 20 [54.1%], P = 0.009; relative risk: 0.45, 95% CI [0.24, 0.85], absolute risk reduction: 29.8%, number needed to treat: 3). The severity of epistaxis was significantly lower in the reverse group (P = 0.002). The first attempt nasal passage (P = 0.027) was significantly higher in the reverse group. Postoperative nasal pain was lower (P < 0.001), and patient satisfaction was higher (P < 0.001) in the reverse group. Nasotracheal tube-related complications did not occur in either group. Conclusions The reverse bevel and tip direction of the nasotracheal tube reduced the incidence and severity of epistaxis and increased patient satisfaction among patients undergoing left nasotracheal intubation.

Background: The incidence of epistaxis during nasotracheal intubation via the left nostril is more frequent than that during intubation via the right nostril. This study evaluated the effect of the reverse bevel and tip direction of the nasotracheal tube on the incidence of epistaxis during nasotracheal intubation via the left nostril. Methods: Patients undergoing right-sided maxillofacial surgery requiring left nasotracheal intubation were randomly allocated to the control (tracheal tube in the conventional direction) or reverse (a 180˚ reverse direction, with the tube bevel facing the nasal septum and the leading edge (i.e., the tip) of the bevel pointing away from the nasal septum) groups (n = 37 for both). The primary outcome was the incidence of epistaxis evaluated using videolaryngoscopy. Results: The incidence of epistaxis in the reverse group was significantly lower than that in the control group (9 [24.3%] vs. 20 [54.1%], P = 0.009; relative risk: 0.45, 95% CI [0.24, 0.85], absolute risk reduction: 29.8%, number needed to treat: 3). The severity of epistaxis was significantly lower in the reverse group (P = 0.002). The first attempt nasal passage (P = 0.027) was significantly higher in the reverse group. Postoperative nasal pain was lower (P < 0.001), and patient satisfaction was higher (P < 0.001) in the reverse group. Nasotracheal tube-related complications did not occur in either group. Conclusions The reverse bevel and tip direction of the nasotracheal tube reduced the incidence and severity of epistaxis and increased patient satisfaction among patients undergoing left nasotracheal intubation.

Background: The incidence of epistaxis during nasotracheal intubation via the left nostril is more frequent than that during intubation via the right nostril. This study evaluated the effect of the reverse bevel and tip direction of the nasotracheal tube on the incidence of epistaxis during nasotracheal intubation via the left nostril. Methods: Patients undergoing right-sided maxillofacial surgery requiring left nasotracheal intubation were randomly allocated to the control (tracheal tube in the conventional direction) or reverse (a 180˚ reverse direction, with the tube bevel facing the nasal septum and the leading edge (i.e., the tip) of the bevel pointing away from the nasal septum) groups (n = 37 for both). The primary outcome was the incidence of epistaxis evaluated using videolaryngoscopy. Results: The incidence of epistaxis in the reverse group was significantly lower than that in the control group (9 [24.3%] vs. 20 [54.1%], P = 0.009; relative risk: 0.45, 95% CI [0.24, 0.85], absolute risk reduction: 29.8%, number needed to treat: 3). The severity of epistaxis was significantly lower in the reverse group (P = 0.002). The first attempt nasal passage (P = 0.027) was significantly higher in the reverse group. Postoperative nasal pain was lower (P < 0.001), and patient satisfaction was higher (P < 0.001) in the reverse group. Nasotracheal tube-related complications did not occur in either group. Conclusions The reverse bevel and tip direction of the nasotracheal tube reduced the incidence and severity of epistaxis and increased patient satisfaction among patients undergoing left nasotracheal intubation.

Background: The incidence of epistaxis during nasotracheal intubation via the left nostril is more frequent than that during intubation via the right nostril. This study evaluated the effect of the reverse bevel and tip direction of the nasotracheal tube on the incidence of epistaxis during nasotracheal intubation via the left nostril. Methods: Patients undergoing right-sided maxillofacial surgery requiring left nasotracheal intubation were randomly allocated to the control (tracheal tube in the conventional direction) or reverse (a 180˚ reverse direction, with the tube bevel facing the nasal septum and the leading edge (i.e., the tip) of the bevel pointing away from the nasal septum) groups (n = 37 for both). The primary outcome was the incidence of epistaxis evaluated using videolaryngoscopy. Results: The incidence of epistaxis in the reverse group was significantly lower than that in the control group (9 [24.3%] vs. 20 [54.1%], P = 0.009; relative risk: 0.45, 95% CI [0.24, 0.85], absolute risk reduction: 29.8%, number needed to treat: 3). The severity of epistaxis was significantly lower in the reverse group (P = 0.002). The first attempt nasal passage (P = 0.027) was significantly higher in the reverse group. Postoperative nasal pain was lower (P < 0.001), and patient satisfaction was higher (P < 0.001) in the reverse group. Nasotracheal tube-related complications did not occur in either group. Conclusions The reverse bevel and tip direction of the nasotracheal tube reduced the incidence and severity of epistaxis and increased patient satisfaction among patients undergoing left nasotracheal intubation.

Background: Coronavirus disease 2019 (COVID-19) vaccination is effective in preventing the disease transmission and progression. However, the relatively mild disease course of the omicron variant and the decrease in antibodies over time after vaccination raise questions about the effectiveness of vaccination, especially in young people. We compared the prevalence of pneumonia and chest X-ray severity score according to vaccination status among patients < 50 years old with COVID-19. Methods: From January 17 to March 17, 2022, 579 patients with COVID-19, who were < 50 years old and had a known vaccination history in our institution, were all included in this study. All patients underwent initial chest radiography, and follow-up chest radiographs were obtained every two days until discharge. Pneumonia was scored from the radiographs using the Brixia scoring system. The scores of the six lung zones were added for a total score ranging from 0 to 18. Patients were divided into four groups according to 10-year age intervals. Differences between groups were analyzed using the χ2 or Fisher’s exact tests for categorical variables and the Kruskal–Wallis test or analysis of variance for continuous variables. Results: Among patients aged 12–19 years, the prevalence of pneumonia did not differ depending on vaccination status (non-vaccinated vs. vaccinated, 1/47 [2.1%] vs. 1/18 [5.6%]; P = 0.577).Among patients in their 20s, the prevalence of pneumonia was significantly higher among nonvaccinated patients than among vaccinated patients (8/28, 28.6% vs. 7/138, 5.1%, P < 0.001), similar to patients in their 40s (32/52 [61.5%] vs. 18/138 [13.0%]; P < 0.001). The chest X-ray severity score was also significantly higher in non-vaccinated patients than that in vaccinated patients in their 20s to their 40s (P < 0.001), but not among patients aged 12–19 years (P = 0.678). Conclusion In patients aged 20–49 years, vaccinated patients had a significantly lower prevalence of pneumonia and chest X-ray severity score than non-vaccinated patients.

The COVID-19 Vaccine Safety Research Committee (CoVaSC) was established in November 2021 to address the growing need for independent, in-depth scientific evidence on adverse events (AEs) following coronavirus disease 2019 (COVID-19) vaccination. This initiative was requested by the Korea Disease Control and Prevention Agency and led by the National Academy of Medicine of Korea. In September 2022, the COVID-19 Vaccine Safety Research Center was established, strengthening CoVaSC’s initiatives. The center has conducted various studies on the safety of COVID-19 vaccines. During CoVaSC’s second research year, from September 29, 2022 to July 19, 2023, the center was restructured into 4 departments: Epidemiological Research, Clinical Research, Communication & Education, and International Cooperation & Policy Research. Its main activities include (1) managing CoVaSC and the COVID-19 Vaccine Safety Research Center, (2) surveying domestic and international trends in AE causality investigation, (3) assessing AEs following COVID-19 vaccination, (4) fostering international collaboration and policy research, and (5) organizing regular fora and training sessions for the public and clinicians. Causality assessments have been conducted for 27 diseases, and independent research has been conducted after organizing ad hoc committees comprising both epidemiologists and clinical experts on each AE of interest. The research process included protocol development, data analysis, interpretation of results, and causality assessment. These research outcomes have been shared transparently with the public and healthcare experts through various fora. The COVID-19 Vaccine Safety Research Center plans to continue strengthening and expanding its research activities to provide reliable, high-quality safety information to the public.

BACKGROUND: Tissue engineering, including 3D bioprinting, holds great promise as a therapeutic tool for repairing cartilage defects. Mesenchymal stem cells have the potential to treat various fields due to their ability to differentiate into different cell types. The biomimetic substrate, such as scaffolds and hydrogels, is a crucial factor that affects cell behavior, and the mechanical properties of the substrate have been shown to impact differentiation during incubation. In this study, we examine the effect of the mechanical properties of the 3D printed scaffolds, made using different concentrations of cross-linker, on hMSCs differentiation towards chondrogenesis. METHODS: The 3D scaffold was fabricated using 3D bioprinting technology with gelatin/hyaluronic acid (HyA) biomaterial ink. Crosslinking was achieved by using different concentrations of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methlymorpholinium chloride n-hydrate (DMTMM), allowing for control of the scaffold’s mechanical properties. The printability and stability were also evaluated based on the concentration of DMTMM used. The effects of the gelatin/HyA scaffold on chondrogenic differentiation was analyzed by utilizing various concentrations of DMTMM. RESULTS: The addition of HyA was found to improve the printability and stability of 3D printed gelatin/HyA scaffolds.The mechanical properties of the 3D gelatin/HyA scaffold could be regulated through the use of different concentrations of DMTMM cross-linker. In particular, the use of 0.25 mM DMTMM for crosslinking the 3D gelatin/HyA scaffold resulted in enhanced chondrocyte differentiation. CONCLUSION The mechanical properties of 3D printed gelatin/HyA scaffolds cross-linked using various concentrations of DMTMM can influence the differentiation of hMSCs into chondrocytes.

With the introduction of coronavirus disease 2019 (COVID-19) vaccines, the Korea Disease Control and Prevention Agency (KDCA) commissioned the National Academy of Medicine of Korea to gather experts to independently assess post-vaccination adverse events. Accordingly, the COVID-19 Vaccine Safety Research Committee (CoVaSC) was launched in November 2021 to perform safety studies and establish evidence for policy guidance. The CoVaSC established 3 committees for epidemiology, clinical research, and communication. The CoVaSC mainly utilizes pseudonymized data linking KDCA’s COVID-19 vaccination data and the National Health Insurance Service’s claims data. The CoVaSC’s 5-step research process involves defining the target diseases and organizing ad-hoc committees, developing research protocols, performing analyses, assessing causal relationships, and announcing research findings and utilizing them to guide compensation policies. As of 2022, the CoVaSC completed this research process for 15 adverse events. The CoVaSC launched the COVID-19 Vaccine Safety Research Center in September 2022 and has been reorganized into 4 divisions to promote research including international collaborative studies, long-/short-term follow-up studies, and education programs. Through these enhancements, the CoVaSC will continue to swiftly provide scientific evidence for COVID-19 vaccine research and compensation and may serve as a model for preparing for future epidemics of new diseases.

Background/Aims: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the stomach. We evaluated the clinical outcomes of endoscopic treatment for gastric GISTs. Methods: This is a single center, retrospective study that enrolled 135 cases of gastric subepithelial tumors (SETs) resected by endoscopic procedures and confirmed as GISTs by histopathology from March 2005 to July 2019. The immediate and long-term clinical outcomes were analyzed retrospectively. Results: The mean patient age was 57.9 years, and the mean tumor size was 2.1 cm. Of the tumors, 43.0% were located in the body, followed by the fundus (26.7%) and cardia (17.0%). Most tumors (85.2%) were resected by endoscopic submucosal dissection, followed by endoscopic mucosal resection (6.7%), submucosal tunneling endoscopic resection (5.9%), and endoscopic full-thickness resection (2.2%). Macroperforation occurred in 4.4% and microperforation in 6.7% of the cases. The R0 resection rate was 15.6%. However, the rate of complete resection by the endoscopic view was 90.4%, of which 54.8% of cases were in the very-low-risk group, followed by the low-risk group (28.1%), intermediate-risk group (11.9%), and high-risk group (5.2%). During 36.5 months of follow-up, recurrence was found in four (3.4%) of the 118 patients who were monitored for more than 6 months (low-risk group, 1/37 [2.7%]; intermediate-risk group, 2/11 [18.2%]; high-risk group, 1/6 [16.7%]). Conclusions Endoscopic treatment of a GIST appears to be a feasible procedure in selected cases. However, additional surgery should be considered if the pathologic results correspond to intermediate- or high-risk groups.

Objective: Extramammary Paget’s disease (EMPD) of the vulva is a rare disease which predominantly presents in postmenopausal Caucasian women. As yet, no studies on Asian female patients with EMPD have been performed. This study aimed to identify the clinical features of patients with vulvar EMPD in Korea, and to evaluate the risk factors of recurrence and postoperative complications in surgically treated EMPD. Methods: We retrospectively reviewed 47 patients with vulvar EMPD who underwent wide local excision or radical vulvectomy. The clinical data and surgical and oncological outcomes following surgery were extracted from medical records and analyzed. Univariate and multivariate analyses for predicting recurrence and postoperative complications were performed. Results: 21.3% of patients had complications after surgery, and wound dehiscence was the most common. 14.9% of patients experienced recurrence, and the median interval to recurrence from initial treatment was 69 (range 33–169) months. Vulvar lesions larger than 40 mm was the independent risk factor of postoperative complications (odds ratio [OR]=7.259; 95% confidence interval [CI]=1.545–34.100; p=0.012). Surgical margin status was not associated with recurrence in surgically treated vulvar EMPD patients (OR=0.83; 95% CI=0.16–4.19; p=1.000). Conclusion Positive surgical margin is a frequent finding in the patients with vulvar EMPD, but disease recurrence is not related with surgical margin status. Since EMPD is a slow growing tumor, a surveillance period longer than 5 years is required.