Background: High-resolution chest computed tomography (CT) is a crucial assessment tool for diagnosing Birt-Hogg-Dubé (BHD) syndrome. This study aimed to analyze differences of lung cysts between BHD and other cystic lung diseases. Methods: From January 2020 to December 2022, patients with multiple lung cysts who underwent chest CT at Gangnam Severance Hospital were included. Results: Over a 3-year period (from January 2020 to December 2022), out of 52,823 patients who underwent a chest CT scan, 301 (0.6%) patients with multiple lung cysts were enrolled in this study. Of enrolled patients, 24 (8.0%) were diagnosed with BHD. In patients with BHD, 95.8% exhibited bilateral cysts, and 83.3% showed basal predominance. The cysts’ maximal diameter averaged 32.1 mm (interquartile range, 26.5 to 43.5). Additionally, 95.8% of patients with BHD had diverse cyst sizes and morphologies. Multivariate logistic regression analysis revealed that bilateral cysts (odds ratio [OR], 12.393; 95% confidence interval [CI], 1.613 to 274.682; p=0.038), basal predominance (OR, 8.511; 95% CI, 2.252 to 39.392; p=0.002), maximum diameter (OR, 1.053; 95% CI, 1.009 to 1.108; p=0.032), and diversity of morphology (OR, 19.513; 95% CI, 2.833 to 398.119; p=0.010) were significant factors associated with BHD diagnosis. A multivariate prediction model for BHD diagnosis demonstrated a sensitivity of 95.83%, a specificity of 81.22%, and an area under the receiver operating characteristic curve of 0.951 (95% CI, 0.914 to 0.987). Conclusion Distinguishing features of lung cysts from other cystic lung diseases include bilateral cysts, basal dominance, large size, and irregular shape.

Purpose: The purpose of this study was to compare the effectiveness of pericapsular nerve group (PENG) block with periarticular multimodal drug injection (PMDI) on postoperative pain management and surgical outcomes in patients who underwent total hip arthroplasty (THA). We hypothesized that PENG block with PMDI would exhibit superior effects on postoperative pain control after THA compared to PMDI alone. Materials and Methods: From April 2022 to February 2023, 58 patients who underwent THA were randomly assigned into two groups: PENG block with PMDI group (n=29) and PMDI-only group (n=29). Primary outcomes were postoperative numeric rating scale (NRS) at rest and during activity at 6, 24, and 48 hours postoperatively. Secondary outcomes were postoperative complications (nausea and vomiting), Richards-Campbell Sleep Questionnaire (RCSQ) score, length of hospital stay, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, Harris Hip Score (HHS), and total morphine usage after surgery. Results: There was no significant difference in postoperative pain for either resting NRS or active NRS. Postoperative nausea and vomiting, RCSQ score, length of hospital stay, WOMAC index, HHS, and total morphine usage exhibited no significant differences between the two groups. Conclusion Both groups showed no significant differences in postoperative pain and clinical outcomes, indicating that the addition of PENG block to PMDI does not improve pain management after applying the posterolateral approach of THA. PMDI alone during THA would be an efficient, fast, and safe method for managing postoperative pain. This article was registered with ClinicalTrials.gov (Gov ID: NCT05320913).

Purpose: The immunological response and adverse effects of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) in patients receiving coronavirus disease-2019 (COVID-19) vaccines remain unclear. We aimed to evaluate the effects of these vaccines on AAV disease activity. Materials and Methods: We reviewed the medical records of 52 patients with AAV who had received at least second doses of the COVID-19 vaccine and evaluated their immunogenicity by measuring the anti-spike (S) antibody (Ab) titer levels using the Roche Elecsys® immunoassay. Responses to the Birmingham Vasculitis Activity Score (BVAS) tool and 36-Item Short Form Survey before and after vaccination were obtained to assess AAV disease activity. Vaccine reactivity was measured using a standardized questionnaire. Results: We enrolled 52 patients with AAV. No differences were found between those who received second and third doses of vaccination in terms of AAV type, disease activity, vaccine type, or the use of immunosuppressive agents, including steroids. The median anti-S Ab titer was 3967.0 after third doses compared to 419.0 after second doses (p=0.001). Except for mycophenolate mofetil (MMF), when immunosuppressants were administered in conjunction with steroids, the Ab titer was higher after the third vaccination than that after the second dose. The BVAS remained unchanged before and after second and third doses. No life-threatening adverse events were reported. Conclusion Although COVID-19 vaccine may not produce sufficient antibodies in patients taking MMF, the vaccine did not exacerbate disease activity or cause severe side effects. Therefore, COVID-19 vaccines should be considered in patients with AAV.

Background: Acute respiratory failure (ARF) is the leading cause of hospitalization and is associated with in-hospital mortality. This study aimed to elucidate the epidemiology and clinical outcomes of ARF. Methods: We retrospectively screened patients admitted to three hospitals in South Korea between January 2018 and December 2022. We included individuals aged 18 years, diagnosed with either type 1 ARF (arterial oxygen partial pressure [PaO2] <60 mm Hg) or type 2 ARF (arterial carbon dioxide partial pressure (PaCO2) >45 mm Hg) with a pH of <7.35, or diagnosed with the combined-type ARF. Results: Among the 768,700 hospitalized patients, 33,278 (4.3%) developed ARF. The most common cause of ARF was sepsis (15,757 patients, 47.3%), and the most frequent comorbidity was malignancy (15,403 patients, 43.6%). Among ARF patients, 15,671 (47.1%) required intensive care unit transfer, while 8,980 (27.0%) experienced in-hospital mortality. Over 5 years, the proportion of ARF patients aged 80 years and older has shown a consistent annual increase (coefficient, 0.085 and Ptrend <0.001). Concurrently, the in-hospital mortality rate exhibited an upward trend, increasing from 25.5% in 2018 to 29.3% in 2022 (coefficient, 1.017 and Ptrend<0.001). Among the respiratory support methods used for patients with ARF over the 5-year period, high-flow nasal cannula usage steadily increased (coefficient, 4.137 and Ptrend<0.001), whereas the use of invasive mechanical ventilation declined (coefficient, –0.983 and Ptrend<0.001). Conclusions ARF frequency and in-hospital mortality rates are increasing, driven by various etiologies. Despite these trends, research on the epidemiology and individualized treatments for older patients is limited, highlighting the need for nationwide prospective multicenter studies.

Background: Chromosomal alterations serve as diagnostic and prognostic markers in acute leukemia. Given the evolving landscape of chromosomal abnormalities in acute leukemia, we previously studied these over two periods. In this study, we investigated the frequency of these abnormalities and clinical trends in acute leukemia in Korea across three time periods. Methods: We retrospectively analyzed data from 1,787 patients with acute leukemia (319 children and 1,468 adults) diagnosed between 2006 and 2020. Conventional cytogenetics, FISH, and multiplex quantitative PCR were used for analysis. The patient groups were divided according to the following three study periods: 2006–2009 (I), 2010–2015 (II), and 2016–2020 (III). Results: Chromosomal aberrations were detected in 92% of patients. The PML::RARA translocation was the most frequent. Over the 15-yr period, chromosomal aberrations showed minimal changes, with specific fusion transcripts being common among patients.ALL was more prevalent in children than in adults and correlated significantly with the ETV6::RUNX1 and RUNX1::RUNX1T1 aberrations. The incidence of ALL increased during the three periods, with PML::RARA remaining common. Conclusions The frequency of chromosomal abnormalities in acute leukemia has changed subtly over time. Notably, the age of onset of adult AML has continuously increased. Our results may help in establishing diagnoses and clinical treatment strategies and developing various molecular diagnostic platforms.

Background: Deceased donor liver transplantation (DDLT) and living donor liver transplantation (LDLT) are employed to address highly urgent patients, including those with acute liver failure (ALF), acute-on-chronic liver failure (ACLF), or critical cirrhosis. This study compares outcomes between LDLT and DDLT patients with ALF, ACLF, or critical cirrhosis in highly urgent LDLT (HU-LDLT) applications. Methods: This study conducted a retrospective analysis of the Korean Network for Organ Sharing (KONOS) data, which included 391 consecutive HU-LDLT applications from 2017 to 2021. Results: The proportion of DDLT was 15.1% (n=59) within the cohort of HU-LDLT applications. The prevalence of hepatorenal syndrome, duration of pre-transplant intensive care unit (ICU) care, incidence of pre-transplant continuous renal replacement therapy, and median model for end-stage liver disease scores were significantly greater and prolonged in DDLT patients compared to LDLT patients. Statistical analysis revealed no significant differences in postoperative complications or overall survival between the two groups. In the multivariate analysis, only pre-transplant ventilator care emerged as a significant predisposing factor for mortality. Conclusion The present study indicates that LDLT is a viable option, yielding comparable perioperative and long-term outcomes to DDLT for HU patients, which can encourage living liver donation to overcome organ shortages in HU patients.

Purpose: We aimed to identify changes in surgical indications in patients with ulcerative colitis (UC) in the biologics era in a single tertiary center. Methods: In this retrospective observational study, 108 patients with UC who underwent abdominal surgery for UC at Seoul National University Hospital from 2000 to 2021 were included. We compared the total number of patients undergoing UC before and after the introduction of biologic therapy. Results: Of the 108 patients with UC (male, 59 and female, 49; mean age, 46.8 years), 30 (27.8%) underwent surgery for neoplasms and 78 (72.2%) for medical intractability without neoplasms. The duration between diagnosis and surgery varied significantly (126.00 months vs. 60.50 months, P = 0.001). A significant difference was also noted in the surgical indications according to time (P = 0.02). Between 2000 and 2010, 12 patients (19.4%) underwent surgery for UC with neoplasms and 50 (80.6%) for UC without neoplasms, while between 2011 and 2021, 18 (39.1%) and 28 patients (60.9%) underwent surgery for UC with and without neoplasms, respectively. Conclusion Since 2011, when biological agents were covered by insurance in South Korea, there has been a relative increase in the incidence of surgical indications for neoplasia cases. Focusing on closely monitoring individuals with longterm UC for neoplasms is necessary.

It is difficult to determine a cause of bile duct stricture and dilatation. Eosinophilic cholangitis, a rare benign condition, may be one cause of bile duct stricture and dilatation. It can be evaluated using various methods of histopathology, radiographs, endoscopy, and hematologic findings. Treatment generally involves steroid therapy which can lead to improvement. This case report will discuss eosinophilic cholangitis, emphasizing that while it can easily be overlooked but should be considered in differential diagnoses.

The development and implementation of a systematic program evaluation framework is critical for improving the quality of the undergraduate medical education. At Yonsei University College of Medicine, we established the following five evaluation domains that encompass various aspects of educational experiences: (1) preclinical curriculum; (2) clinical curriculum; (3) educational environment, resources, and systems; (4) performance of students and graduates and program outcomes; and (5) implementation and outcomes of the curriculum. Specific evaluation indicators were designed within these domains and validated through the Delphi technique, which integrated expert opinions. In total, 98 indicators were identified across five domains. These indicators will function as a comprehensive tool for assessing medical education programs. The proposed evaluation framework addresses both shortand long-term educational changes, facilitating systematic monitoring, continuous quality improvement of curricula, and better outcomes for students. As this framework is grounded in the unique context of the institution, it is appropriate for a comprehensive evaluation of interactions at various educational stages. Furthermore, it may serve as a strategic foundation for identifying areas that require improvement, ensuring that the curriculum aligns with current medical education standards and practices. The framework’s structured approach and continuing evaluation processes may make it possible to obtain essential data for ongoing development, potentially contributing to a robust system for quality improvement in medical education. The findings of this study are expected to serve as a valuable reference for developing similar evaluation frameworks in other medical schools.