Background/Aims: Appropriate tissue tension and clear visibility of the dissection area using traction are essential for effective and safe endoscopic submucosal dissection (ESD). In this study, we developed a retractable robot-assisted traction device and evaluated its performance in colorectal ESD. Methods: An experienced endoscopist performed ESD 18 times on an ex vivo porcine colon using the robot and 18 times using the conventional method. The outcome measures were procedure time, dissection speed, procedure-related adverse events, and blind dissection rate. Results: Thirty-six colonic lesions were resected from ex vivo porcine colon samples. The total procedure time was significantly shorter in robot-assisted ESD (RESD) than in conventional ESD (CESD) (20.1±4.1 minutes vs 34.3±8.3 minutes, p<0.05). The submucosal dissection speed was significantly faster in the RESD group than in the CESD group (36.8±9.2 mm 2 /min vs 18.1±4.7 mm 2 /min, p<0.05). The blind dissection rate was also significantly lower in the RESD group (12.8%±3.4% vs 35.1%±3.9%, p<0.05). In an in vivo porcine feasibility study, the robotic device was attached to a colonoscope and successfully inserted into the proximal colon without damaging the colonic wall, and ESD was successfully performed. Conclusions The dissection speed and safety profile improved significantly with the retractable RESD. Thus, our robotic device has the potential to provide simple, effective, and safe multidirectional traction during colonic ESD.

Background: The US Food and Drug Administration (FDA) and European Medicines Agency (EMA) approved empagliflozin for reducing cardiovascular mortality and heart failure (HF) hospitalization in patients with both HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). However, limited data are available on the generalizability of empagliflozin to clinical practice. Therefore, we evaluated real-world eligibility and potential cost-effectiveness based on a nationwide prospective HF registry. Methods: A total of 3,108 HFrEF and 2,070 HFpEF patients from the Korean Acute Heart Failure (KorAHF) registry were analyzed. Eligibility was estimated by inclusion and exclusion criteria of EMPagliflozin outcomE tRial in Patients With chrOnic heaRt Failure With Reduced Ejection Fraction (EMPEROR-Reduced) and EMPagliflozin outcomE tRial in Patients With chrOnic heaRt Failure With Preserved Ejection Fraction (EMPEROR-Preserved) trials and by FDA & EMA label criteria. The cost-utility analysis was done using a Markov model to project the lifetime medical cost and quality-adjusted life year (QALY). Results: Among the KorAHF patients, 91.4% met FDA & EMA label criteria, while 44.7% met the clinical trial criteria. The incremental cost-effectiveness ratio of empagliflozin was calculated at US$6,764 per QALY in the overall population, which is far below a threshold of US$18,182 per QALY. The cost-effectiveness benefit was more evident in patients with HFrEF (US$5,012 per QALY) than HFpEF (US$8,971 per QALY). Conclusion There is a large discrepancy in real-world eligibility for empagliflozin between FDA & EMA labels and clinical trial criteria. Empagliflozin is cost-effective in HF patients regardless of ejection fraction in South Korea health care setting. The efficacy and safety of empagliflozin in real-world HF patients should be further investigated for a broader range of clinical applications.

Background/Aims: A full colonoscopy is currently required in children and adolescents with colorectal polyps, because of their potential of neoplastic transformation and complications such as intussusception. We aimed to analyze the associations of polyp characteristics in children and adolescents with colorectal polyps. Based on these findings, we also aimed to reevaluate the necessity of conducting a full colonoscopy. Methods: Pediatric patients <18 years of age who had undergone a colonoscopic polypectomy and those with <5 colorectal polyps were included in this multicenter, retrospective study. Baseline clinicodemographics, colonoscopic and histologic findings were investigated. Results: A total of 91 patients were included. Multivariate logistic regression analysis showed that polyp size was the only factor associated with the presence of any polyps located proximal to the splenic flexure (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.28 to 4.28; p=0.007). Furthermore, polyp location proximal to the splenic flexure and sessile morphology were associated with the presence of any adenomatous polyp (OR, 8.51; 95% CI, 1.43 to 68.65; p=0.023; OR, 18.41; 95% CI, 3.45 to 173.81; p=0.002, respectively). Conclusions In children and adolescents presenting with <5 colorectal polyps, polyp size and the presence of any adenomatous polyp were positively associated with polyp location proximal to the splenic flexure. This finding supports the necessity of a full colonoscopic exam in pediatric patients with colorectal polyps for the detection of polyps before the occurrence of complications such as intussusception or neoplastic transformation.

Background: Several cases of pediatric acute hepatitis of unknown etiology related to adenoviral infections have been reported in Europe since January 2022. The aim of this study was to compare the incidence, severity, possible etiology, and prognosis of the disease with those in the past in Korea. Methods: The surveillance group collected data between May and November 2022 using a surveillance system. Acute hepatitis of unknown etiology was defined in patients aged < 16 years with a serum transaminase level > 500 IU/L, not due to hepatitis A-E or other underlying causes. For comparison, data from 18 university hospitals were retrospectively collected as a control group between January 2021 and April 2022. Results: We enrolled 270 patients (mean age, 5 years). The most common symptom was fever. However, the incidence was similar between 2021 and 2022. Liver function test results, number of patients with acute liver failure (ALF), liver transplantation (LT), death, and adenovirus detection rates did not differ between the two groups. None of the adenoviruspositive patients in either group experienced ALF, LT, or death. In the surveillance group, adenovirus-associated virus-2 was detected in four patients, one of whom underwent LT. Patients with an unknown etiology showed significantly higher bilirubin levels, a lower platelet count, and a higher LT rate than patients with a possible etiology. Conclusion The incidence of pediatric acute hepatitis of unknown etiology and adenovirus detection rate have not increased in Korea.

Evidence of the ethical appropriateness and clinical benefits of shared decision-making (SDM) are accumulating. This study aimed to not only identify physicians’ perspectives on SDM, and practices related to end-of-life care in particular, but also to gauge the effect of SDM education on physicians in Korea. Methods: A 14-item questionnaire survey using a modified Delphi process was delivered to nephrologists and internal medicine trainees at 17 university hospitals. Results: A total of 309 physicians completed the survey. Although respondents reported that 69.9% of their practical decisions were made using SDM, 59.9% reported that it is not being applied appropriately. Only 12.3% of respondents had received education on SDM as part of their training. The main obstacles to appropriate SDM were identified as lack of time (46.0%), educational materials and tools (29.4%), and education on SDM (24.3%). Although only a few respondents had received training on SDM, the proportion of those who thought they were using SDM appropriately in actual practice was high; the proportion of those who chose lack of time and education as factors that hindered the proper application of SDM was low. Conclusion: The majority of respondents believed that SDM was not being implemented properly in Korea, despite its use in actual practice. To improve the effectiveness of SDM in the Korean medical system, appropriate training programs and supplemental policies that guarantee sufficient application time are required.

Background: Although respiratory tract infection is one of the most important factors triggering acute exacerbation of chronic obstructive pulmonary disease (AE-COPD), limited data are available to suggest an epidemiologic pattern of microbiology in South Korea. Methods: A multicenter observational study was conducted between January 2015 and December 2018 across 28 hospitals in South Korea. Adult patients with moderate-to-severe acute exacerbations of COPD were eligible to participate in the present study. The participants underwent all conventional tests to identify etiology of microbial pathogenesis. The primary outcome was the percentage of different microbiological pathogens causing AE-COPD. A comparative microbiological analysis of the patients with overlapping asthma–COPD (ACO) and pure COPD was performed. Results: We included 1,186 patients with AE-COPD. Patients with pure COPD constituted 87.9% and those with ACO accounted for 12.1%. Nearly half of the patients used an inhaled corticosteroid-containing regimen and one-fifth used systemic corticosteroids. Respiratory pathogens were found in 55.3% of all such patients. Bacteria and viruses were detected in 33% and 33.2%, respectively. Bacterial and viral coinfections were found in 10.9%. The most frequently detected bacteria were Pseudomonas aeruginosa (9.8%), and the most frequently detected virus was influenza A (10.4%). Multiple bacterial infections were more likely to appear in ACO than in pure COPD (8.3% vs. 3.6%, p=0.016). Conclusion Distinct microbiological patterns were identified in patients with moderate-to-severe AE-COPD in South Korea. These findings may improve evidence-based management of patients with AE-COPD and represent the basis for further studies investigating infectious pathogens in patients with COPD.

Background/Aims: This study investigated the prognostic power of corrected QT (QTc) interval in patients with acute heart failure (AHF) according to sex. Methods: We analyzed multicenter Korean Acute Heart Failure registry with patients with AHF admitted from 2011 to 2014. Among them, we analyzed 4,990 patients who were followed up to 5 years. Regarding QTc interval based on 12 lead electrocardiogram, patients were classified into quartiles according to sex. Results: During follow-up with median 43.7 months, 2,243 (44.9%) patients died. The relationship between corrected QT interval and all-cause mortality followed a J-curve relationship. In Kaplan-Meier analysis, both sex had lowest mortality in the second QTc quartile. There were significant prognostic differences between the second and the fourth quartiles in male (log-rank p = 0.002), but not in female (log-rank p = 0.338). After adjusting covariates, the third (hazard ratio [HR], 1.185; 95% confidence interval [CI], 1.001 to 1.404; p = 0.049) and the fourth (HR, 1.404; 95% CI, 1.091 to 1.535; p = 0.003) quartiles demonstrated increased risk of mortality compared to the second quartile in male. In female, however, there was no significant difference across quartiles. QTc interval was associated with 5-year all-cause mortality in J-shape with nadir of 440 to 450 ms in male and 470 to 480 ms in female. Conclusions QTc interval was an independent predictor of overall death in male, but its significance decreased in female. The relationship between QTc interval and all-cause mortality was J-shaped in both sex.

Many previous studies have shown reduced glucose uptake in the ischemic brain. In contrast, in a permanent unilateral common carotid artery occlusion (UCCAO) mouse model, our pilot experiments using 18F-fluorodeoxyglucose positron emission tomography (FDG PET) revealed that a subset of mice exhibited conspicuously high uptake of glucose in the ipsilateral hemisphere at 1 week post-occlusion (asymmetric group), whereas other mice showed symmetric uptake in both hemispheres (symmetric group). Thus, we aimed to understand the discrepancy between the two groups. Cerebral blood flow and histological/metabolic changes were analyzed using laser Doppler flowmetry and immunohistochemistry/Western blotting, respectively. Contrary to the increased glucose uptake observed in the ischemic cerebral hemisphere on FDG PET (p<0.001), cerebral blood flow tended to be lower in the asymmetric group than in the symmetric group (right to left ratio [%], 36.4±21.8 vs. 58.0±24.8, p=0.059). Neuronal death was observed only in the ischemic hemisphere of the asymmetric group. In contrast, astrocytes were more activated in the asymmetric group than in the symmetric group (p<0.05). Glucose transporter-1, and monocarboxylate transporter-1 were also upregulated in the asymmetric group, compared with the symmetric group (p<0.05, respectively). These results suggest that the increased FDG uptake was associated with relatively severe ischemia, and glucose transporter-1 upregulation and astrocyte activation. Glucose metabolism may thus be a compensatory mechanism in the moderately severe ischemic brain.

Background: Although neuromyelitis optica spectrum disorder (NMOSD) is known to be a rare disease, its prevalence and incidence have not yet been studied in Korea. We performed a population-based study to examine the prevalence and incidence of NMOSD in Korea using data from the Korean National Health Insurance (NHI) claims database. Methods: Data from 2013 to 2017 were obtained, with a washout period set as 2013 and 2014. The prevalence and incidence of NMOSD in 2016 and 2017 were calculated using population census data. Subjects were divided into 5 groups at 15-year intervals, depending on the age at which the diagnostic code was entered. The relative risk (RR) for each age group was compared with the oldest (≥ 60 years) age group. Results: The overall prevalence was estimated to be 3.36 and 3.56 per 100,000 individuals, with an incidence of 0.41 and 0.65 per 100,000 individuals-year in 2016 and 2017, respectively. The mean age was 43.08 (standard deviation, 14.56) years, and the ratio of male to females was 1:4.7. The incidence was higher in female individuals aged between 30 and 59 years (RR, 2.8–3.05; P < 0.05). Conclusion Nationwide prevalence of NMOSD in Korea was 3.36 and 3.56/100,000 and its incidence was 0.41 and 0.65/100,000-year in 2016 and 2017 respectively.