Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Limited data exist regarding the real-world practices and clinical outcomes in patients with ischemic heart failure with reduced left ventricular ejection fractions (LVEFs).Using nationwide registry data from South Korea, we aimed to investigate long-term outcomes and clinical practices, especially implantable cardioverter defibrillators (ICDs) implantation, in patients with reduced LVEFs at least 40 days after acute myocardial infarction (AMI). Of 13,056 patients with AMI between 2011 and 2015, we analyzed 350 (median age, 66 years [interquartile range, 56-75]) who had LVEFs <40% on follow-up transthoracic echocardiogram 40 days after the index event. The primary outcome was cardiac-cause mortality at 3 years. Secondary outcomes comprised major cardiovascular events as well as outcomes defined by the use of ICDs, cardiac resynchronization therapy defibrillators (CRT-Ds), and electrophysiology studies. Among 350 patients, 39 (11.1%) died from cardiac causes during 3 years of follow-up. Eleven (3.1%) were hospitalized for ventricular tachycardia. The rate of ICD or CRT-D implantation up to 3 years was 5.7% (20/350). Cox time-to-event analysis revealed older age, LVEF <30%, diabetes mellitus, and previous MI or revascularization as positively associated with cardiac death, whereas the use of statins and body weight <67 kg were negatively associated. This nationwide Korean registry demonstrated that only 5.7% of patients who had reduced LVEFs after 40 days of AMI underwent ICD implantations over 3 years. Considering the high mortality, concerted efforts are needed to improve clinical outcomes for patients who may have been candidates for ICD implantation.

Objectives: Allergic rhinitis (AR) is a chronic inflammation of the nasal mucosa triggered by environmental allergens. Although its pathophysiology has been extensively investigated, the influence of environmental aggravating factors—particularly combined pollutant exposure—remains insufficiently characterized. This study aimed to assess the impact of coexposure to PM2.5, formaldehyde, and Zn on allergic inflammation in a murine AR model and to delineate the associated immunological and histopathological responses. Methods: Female BALB/c mice were sensitized with ovalbumin (OVA) and challenged intranasally to induce AR. On days 21–24, the mice were exposed to PM2.5, formaldehyde, and Zn, either individually or in combination with OVA. Allergic symptoms were evaluated through behavioral observation, while immune responses were assessed by analyzing nasal and bronchoalveolar lavage fluids (NALF and BALF), serum immunoglobulin levels, nasal histopathology, and cytokine profiles. Results: Combined exposure to PM2.5, formaldehyde, and Zn significantly intensified allergic inflammation compared with single exposures. Coexposure to PM2.5 and Zn led to synergistic increases in total and OVA-specific immunoglobulin E levels, eosinophilic infiltration, nasal rubbing, sneezing, and Th2/Th17 cytokine levels in NALF and BALF. Histological analysis demonstrated epithelial thickening and goblet cell hyperplasia after combined exposure. Other combinations, including PM2.5 with formaldehyde, also produced additive or modestly amplified inflammatory responses. Conclusions Coexposure to PM2.5, formaldehyde, and Zn aggravated allergic inflammation in an OVA-induced murine model, with PM2.5+Zn yielding the strongest synergistic effects. These findings emphasize the role of pollutant–pollutant interactions in allergic airway diseases and highlight the need for further research to clarify long-term health effects and relevance to human disease.

Current ABO titration methods lack standardization and harmonization. We analyzed the consistency of ABO antibody titer testing among Korean laboratories and discussed future directions for standardization by analyzing external quality control data collected by the Korean Association of External Quality Assessment Service over 5 yrs (2019–2023). The analysis included the number of participating institutions and methods, as well as the proportion of acceptable results. To compare column agglutination technology (CAT) and tube methods, we created a normalized variable: ([log 2 titer of laboratory test result]–[mean of log 2 titer for the peer group]). The number of participating institutions and methods increased over time. The use of CAT methods expanded, whereas that of tube methods declined. The proportion of acceptable results ranged from 84.0% to 100%, with no significant differences between CAT and tube methods. An F-test revealed no significant variance differences among institutions using these methods. Tube methods demonstrated lower variance in anti-human globulin testing, and room temperature tube methods exhibited lower variance than that of CAT methods. Domestic laboratories demonstrated highquality performance in ABO antibody titer testing, with no significant differences in acceptable result rates or variance across methods. Continuous efforts toward standardization remain essential.

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.

Background: and Purpose Previous research on patients with acute ischemic stroke (AIS) has shown a 0.5% incidence of major gastrointestinal bleeding (GIB) requiring blood transfusion during hospitalization. The existing literature has insufficiently explored the long-term incidence in this population despite the decremental impact of GIB on stroke outcomes. Methods: We analyzed the data from a cohort of patients with AIS admitted to 14 hospitals as part of a nationwide multicenter prospective stroke registry between 2011 and 2013. These patients were followed up for up to 6 years. The occurrence of major GIB events, defined as GIB necessitating at least two units of blood transfusion, was tracked using the National Health Insurance Service claims data. Results: Among 10,818 patients with AIS (male, 59%; mean age, 68±13 years), 947 (8.8%) experienced 1,224 episodes of major GIB over a median follow-up duration of 3.1 years. Remarkably, 20% of 947 patients experienced multiple episodes of major GIB. The incidence peaked in the first month after AIS, reaching 19.2 per 100 person-years, and gradually decreased to approximately one-sixth of this rate by the 2nd year with subsequent stabilization. Multivariable analysis identified the following predictors of major GIB: anemia, estimated glomerular filtration rate <60 mL/min/1.73 m2 , and a 3-month modified Rankin Scale score of ≥4. Conclusion Patients with AIS are susceptible to major GIB, particularly in the first month after the onset of AIS, with the risk decreasing thereafter. Implementing preventive strategies may be important, especially for patients with anemia and impaired renal function at stroke onset and those with a disabling stroke.

Purpose: This study examined the status of arthroscopic shoulder surgery in ambulatory settings by analyzing a single institutional database. Materials and Methods: Three hundred and eight arthroscopic shoulder surgeries performed between June 2022 and March 2023 were reviewed retrospectively. Propensity score matching (1-to-2) was performed between the day surgery group and the inpatient group according to sex, age, tear size, and interscalene nerve block (ISNB). Finally, 59 patients in the day surgery group and 118 patients in the inpatient group were matched. The indications of the day surgery were pre-determined according to the American Society of Anesthesiologists classification I or II, and the patient's social, medical, and surgical factors were thoroughly analyzed to define the target group of the day surgery. Complications related to voiding difficulty were prevented by classifying the patients using the International Prostate Symptom Score (IPSS) before surgery, and preventive medications were prescribed in the higher-risk patients with an IPSS of more than 7. To reduce postoperative pain, ISNB and patient-controlled analgesia (PCA) were applied to all patients during the study period, while day surgery patients received an additional bolus injection (5 cc of 0.375% ropivacaine+5 cc of normal saline) before discharge instead of continuous ISNB PCA. This study compared the postoperative pain assessments at discharge and on postoperative days 1, 2, and 14, as well as the total volume of saline irrigation, surgical time, and complications between the day surgery and inpatient groups. Results: The visual analogue scale for pain (pVAS) at the time of surgery were comparable in the day surgery group (4.1±1.5) and inpatient surgery group (4.1±1.1), with no significant difference between them (p=0.35). Similarly, the postoperative pVAS at 1, 2, and 14 days postoperatively was similar in the two groups (all p>0.05). The surgical-related factors, such as the total volume of saline irrigation and surgical time, were similar in the two groups. Furthermore, there was no significant difference in postoperative complications between the two groups (all p>0.05). Conclusion These results show that arthroscopic shoulder surgery in ambulatory settings is a safe alternative to inpatient surgery.

Background and Objectives: Among various emerging catheter-based treatments for severe tricuspid regurgitation (TR), the spacer device can reduce the regurgitation orifice without manipulating the valve leaflet. However, its clinical application has been hampered by traumatic anchoring to the myocardium and the coaxial alignment of the balloon resulting in insufficient TR reduction. This study aimed to evaluate the early-stage safety, technical feasibility, and preliminary efficacy of the novel atraumatic vertical spacer in patients with isolated severe TR. Methods: All procedures were guided by fluoroscopy and transthoracic echocardiography.The maximum device placement time with an inflated balloon was 24 hours. Changes in the amount of TR, right ventricular function, and patient hemodynamics were measured during balloon deployment. Results: A total of 7 patients (median age 74), underwent successful device implantation without procedure-related complications. During balloon inflation (median 25 minutes), there were no symptoms or signs indicative of TR intolerance. TR was reduced by 1 grade or greater in all patients, with 2 patients exhibiting a reduction of 3 grades, from torrential TR to a moderate degree. Mild TR after balloon inflation was achieved in 3 patients with baseline severe TR. The TR reduction observed during initial balloon deployment was sustained during the subsequent balloon maintenance period. Conclusions The Pivot-balloon procedure was safe, technically feasible, and effective in reducing TR in patients with severe TR. No periprocedural complications or adverse cardiovascular events were reported during device placement with TR reduction observed in all patients. However, longer-term follow-up is needed to confirm safety and treatment effect.

ABO/RhD-mismatch transfusions are frequently encountered in clinical practice, so a systematic and thorough understanding of these events is necessary. In the case of ABO minor-incompatible transfusions, it is important to consider the possibility of hemolytic transfusion reactions because of the reaction between the ABO antibodies in the blood product and the patient’s red blood cells. For platelet products, the risk is approximately 1 in 9,000.In ABO major-incompatible transfusions, red blood cell products are contraindicated, but plasma or platelet products may be allowed in situations such as blood product shortages. In RhD major-incompatible transfusions, the use of Rh immunoglobulin to prevent alloimmunization may be considered depending on the patient’s clinical status and the availability of blood products. In the case of RhD major-incompatible red blood cell transfusions, however, such prevention is difficult to apply in Korea. ABO/RhD-mismatch transfusion may also affect the long-term outcomes of patients, in addition to immediate hemolytic transfusion reactions. Therefore, decisions must be made based on the patient’s clinical situation considering the benefits and potential risks.

This report provides a summary of the 2024 survey results on the external quality assessment (EQA) scheme for the general transfusion medicine test and the general transfusion antibody test programs in Korea. Proficiency testing materials were prepared at the Asan Medical Center for bi-annual distribution to participating laboratories. The accuracy rates and number of participating laboratories for the bi-annual EQAs were: ABO typing, 99.6%–99.9% (n=944, n=945); RhD typing, 99.9%–100.0% (n=929, n=930);crossmatching, 95.0%–99.2% (n=825, n=825); unexpected antibody scre ening, 99.5%–100.0% (n=363, n=367); direct antiglobulin test (DAT) using a polyspecific reagent, 99.3%–100.0% (n=296, n=299); DAT using an antiimmunoglobulin G monospecific reagent, 100.0% (n=74, n=72); and DAT using an anti-C3d monospecific reagent, 98.6%–100.0% (n=72, n=71). The 2024 EQA scheme for the transfusion medicine program has improved and maintained the standards of the participating laboratories.