Background and Objectives: The Valsalva test, although commonly utilized to assess the Eustachian tube function, is limited by drawbacks such as inconsistent pressure increases in the nasal cavity. Thus we introduced the “Popper test,” a tympanic membrane inflation test using the automatic middle ear inflation device known as middle ear inflation device (MEID), to explore its viability as an alternative to the Valsalva test.Subjects and Method We sampled 80 ears from patients between June 1, 2023, and August 1, 2023. Each patient underwent both the Valsalva and Popper tests using the MEID. Participants were divided into three categories: the “unable” group (patients who could not follow the Valsalva maneuver) and the “successful” and “unsuccessful” groups (patients whose attempts at the Valsalva or Popper tests either successed or failed). Success or failure was determined using an otoscope to assess the bulging of the tympanic membrane. Results: Of the 68 ears with normal middle ear pressure, 30.9% (21 ears) showed an inability to perform the Valsalva test, 45.6% (31 ears) successfully inflated the tympanic membrane via the Valsalva test, and 23.5% (16 ears) failed. Conversely, the Popper test resulted in an 88.2% (60 ears) success rate for inflating the tympanic membrane, with only 11.8% (8 ears) failing. Conclusion Variability observed in the Valsalva test outcomes may be attributed to individual differences and the instructor’s technique. MEID, as utilized in the Popper test, offers a promising alternative to the Valsalva test, potentially enhancing the reliability by minimizing individual variation. However, the diagnostic performance may be dependent on the properties of the MEID.

This study explores the development, roles, and key initiatives of the Regional Environmental Health Centers in Korea, detailing their evolution through four distinct phases and their impact on environmental health policy and local governance. It chronicles the establishment and transformation of these centers from their inception in May 2007, through four developmental stages. Originally named Environmental Disease Research Centers, they were subsequently renamed Environmental Health Centers following legislative changes. The analysis includes the expansion in the number of centers, the transfer of responsibilities to local governments, and the launch of significant projects such as the Korean Children’s Environmental Health Study (Ko-CHENS ). During the initial phase (May 2007–February 2009), the 10 centers concentrated on research-driven activities, shifting from a media-centered to a receptor-centered approach. In the second phase, prompted by the enactment of the Environmental Health Act, six additional centers were established, broadening their scope to address national environmental health issues. The third phase introduced Ko-CHENS, a 20-year national cohort project designed to influence environmental health policy by integrating research findings into policy frameworks. The fourth phase marked a decentralization of authority, empowering local governments and redefining the centers' roles to focus on regional environmental health challenges. The Regional Environmental Health Centers have significantly evolved and now play a crucial role in addressing local environmental health issues and supporting local government policies. Their capacity to adapt and respond to region-specific challenges is essential for the effective implementation of environmental health policies, reflecting geographical, socioeconomic, and demographic differences.

Purpose: We investigated the results of endoscopic fenestration for deeply located intracranial cysts (DLICs), risk factors for reoperation, and symptom improvement. Materials and Methods: We included 51 patients with DLICs who underwent endoscopic fenestration between November 2006 and October 2022. The median age was 5±20 years (6 days–67 years), and 36 (70.6%) patients were aged <20 years. The male-tofemale ratio was 1.3:1. The ventriculoscope was used to fenestrate the cysts, which had diameters under 4.5 mm. The volume of DLICs was measured separately on serial magnetic resonance imaging, and the patients were followed up for 32±40 months. Results: The mean preoperative volume of DLICs was 63.5±87.4 cm, 3 , which decreased to 23.7±56.2 cm 3postoperatively, with a 45.4%±32.1% decrease rate in 32 months. All DLICs were approached appropriately, avoiding the eloquent areas. Overall, 39 (76.5%) patients showed symptom improvement after a single operation, which was preserved without recurrence, whereas 12 (23.5%) underwent a second operation [shunting (17.6%) or repeating the endoscopic fenestration (5.9%)] owing to symptom aggravation and recurrent cysts. Patients aged <12 months showed 7.4 times more re-operation rate (p>0.046) and 7.4 times less symptom improvement (p=0.038) compared to those with older age. Females showed 6.5 times more re-operation rate (p=0.037) and 7.1 times less symptom improvement (p=0.027) than males. No patients experienced complications such as cerebrospinal fluid leakage, postoperative hemorrhage, or infection. Conclusion Endoscopic surgery is feasible for the treatment of DLICs. Female sex and age <12 months are risk factors for re-operation and less symptom improvement.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background and Objectives: Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment. Methods: A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years. Results: The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization. Conclusions For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Heart failure (HF) is a major cause of mortality and morbidity in South Korea, imposing substantial physical, emotional, and financial burdens on patients and society. Despite the high burden of symptom and complex care needs of HF patients, palliative care and hospice services remain underutilized in South Korea due to cultural, institutional, and knowledge-related barriers. This position statement from the Korean Society of Heart Failure emphasizes the need for integrating palliative and hospice care into HF management to improve quality of life and support holistic care for patients and their families. By clarifying the role of palliative care in HF and proposing practical referral criteria, this position statement aims to bridge the gap between HF and palliative care services in South Korea, ultimately improving patient-centered outcomes and aligning treatment with the goals and values of HF patients.

Purpose: This study aimed to report the results of Korean Antimicrobial Resistance Monitoring System (KARMS) for uncomplicated cystitis (UC) in 2023. Materials and Methods: KARMS was established for the surveillance of antimicrobial resistance in urinary tract infections with the cooperation of Korean nationwide medical centers. Data from patients with UC have been collected in the web-based KARMS database. Demographic data, uropathogen distribution, and antimicrobial susceptibility of representative pathogens were analyzed. Results: A total of 885 patients’ data were collected in KARMS database. The mean patient age was 56.39±18.26 years. The number of postmenopausal and recurrent cystitis were 530 (61.1%) and 102 (11.5%), respectively. Escherichia coli was the most frequently identified uropathogen (654/871, 75.1%). Regarding antimicrobial susceptibility, 94.9% were susceptible to fosfomycin, 90.5% to nitrofurantoin, 58.4% to ciprofloxacin, 83.6% to cefotaxime, and 100.0% to ertapenem. ESBL positivity was 13.7% (96/702), and significantly higher in tertiary hospital (23.1%, p<0.001), postmenopausal (15.9%, p=0.044), and recurrent cystitis (24.7%, p=0.001).Fluoroquinolone resistance was significantly higher in tertiary hospital (47.4%, p=0.001), postmenopausal (44.9%, p<0.001), and recurrent cystitis (59.8%, p<0.001). In addition, postmenopausal (odds ratio [OR] 1.96, 95% confidence interval [CI] 1.38–2.77, p<0.001) and recurrent cystitis (OR 2.37, 95% CI 1.44–3.92, p=0.001) were associated with increased fluoroquinolone resistance. Conclusions These data provide information on the distribution of uropathogen and the status of antimicrobial resistance in UC of South Korea. In addition, KARMS will be a useful reference in the future through the continuous surveillance system construction over the years.