1.Factors affecting worsening intracranial injuries in pediatric patients with mild traumatic brain injury
Nu Ri BAIK ; Jin Seong CHO ; Jae-Hyug WOO ; Jae Ho JANG ; Woo Sung CHOI ; Yong Su LIM ; Jea Yeon CHOI
Pediatric Emergency Medicine Journal 2026;13(2):58-64
Purpose:
The clinical utility of routine repeat computed tomography (CT) in pediatric patients with mild traumatic brain injury (TBI) remains controversial. We aimed to identify factors associated with worsening intracranial injury (ICI) on repeat CT in pediatric patients with mild TBI.
Methods:
This retrospective study included patients aged 0–18 years with mild TBI (Glasgow Coma Scale score 13–15) who presented to an emergency department in South Korea from January 2017 through December 2023. Patients were included if they underwent an initial CT within 24 hours of injury and a repeat CT within 72 hours. Worsening ICI was defined as an increase in hemorrhage size or the development of new lesions on repeat CT. Clinical characteristics, injury mechanisms, and CT findings were compared between patients with and without the worsening ICI. Multivariable logistic regression was performed to identify independent predictors of worsening ICI on repeat CT.
Results:
A total of 212 patients were included, of whom 48 (22.6%) showed worsening ICIs on repeat CT (i.e., worsening group). The worsening group showed higher median values of age and length of hospital stay, as well as higher percentages of initial Glasgow Coma Scale of 14, motorcycle/bicycle injury, intensive care unit hospitalization, and abnormalities on initial CT (including skull fracture, epidural hemorrhage, subdural hemorrhage, and pneumocephalus), compared with their counterparts. The regression model showed subdural hemorrhage (odds ratio, 4.99 [95% confidence interval, 2.08–11.96]), epidural hemorrhage (4.04 [1.73–9.44]), and motorcycle/bicycle as the injury mechanism (2.94 [1.14–7.59]) as the predictors.
Conclusion
In pediatric mild TBI, motorcycle/bicycle accidents and the presence of hemorrhages on initial CT may be associated with worsening ICI on repeat CT. These findings support a risk-stratified approach, in which repeat imaging is selectively considered for high-risk patients to reduce unnecessary radiation exposure.
2.Nerve Root Herniation Due to Delayed Dural Tear Following Unilateral Laminotomy for Bilateral Decompression With Lumbar Discectomy Using Unilateral Biportal Endoscopy
Sang Hyub LEE ; Jae-Won JANG ; Yong Eun CHO ; Choon Keun PARK
Journal of Minimally Invasive Spine Surgery and Technique 2026;11(Suppl 1):S109-S115
This case report describes a delayed dural tear with subsequent nerve root herniation following unilateral laminotomy for bilateral decompression (ULBD) combined with lumbar discectomy using unilateral biportal endoscopy (UBE). A 31-year-old woman underwent UBE ULBD with lumbar discectomy via a left-sided approach for extremely severe L4–5 central canal stenosis with a central disc herniation. No dural tear occurred intraoperatively; however, the dorsal dura was extremely thinned and translucent, with the nerve roots faintly visible through the thecal sac. Following the initial operation, the patient’s symptoms improved, and she was discharged without complications. One week later, the patient developed recurrent severe radiating pain in the left leg. Follow-up magnetic resonance imaging (MRI) revealed cerebrospinal fluid (CSF) leakage and findings suspicious for nerve root herniation. Revision surgery was performed to reduce the herniated nerve root and repair the dural tear. After revision surgery, the patient’s symptoms improved, and postoperative MRI obtained 1 week later showed no evidence of CSF leakage. During 6 months of follow-up, no further complications were observed. Delayed dural tear with nerve root herniation is rare but clinically significant, and revision surgery is often unavoidable. Prophylactic reinforcement may be advisable when translucent, thinned dura is encountered.
3.Impact of COVID-19 on the Profitability of General Hospitals in Korea
Jun Young PARK ; Tae Hyun KIM ; Suk-Yong JANG ; Sang Gyu LEE
Journal of Preventive Medicine and Public Health 2026;59(1):46-55
Objectives:
This study was performed to quantify the impact of coronavirus disease 2019 (COVID-19) on hospital profitability in Korea by analyzing changes in the medical revenue-to-profit ratio (MRPR) and net income before reserve fund allocation (NIBR) before and after the pandemic onset. Additionally, it examined how financial outcomes varied by hospital ownership, geographic location, and type (secondary or tertiary), providing insights into the financial resilience of various hospital types during public health crises.
Methods:
We conducted a longitudinal analysis using publicly available financial disclosure data from 243 general hospitals in Korea (2016–2022). We then performed a quadrant analysis to classify hospitals based on changes in MRPR and NIBR, identifying patterns of financial impact. For inferential analysis, we employed linear mixed-effects models incorporating a difference-in-differences framework, enabling estimation of both time-varying and hospital-specific effects.
Results:
Following the onset of COVID-19, MRPR declined significantly, reaching −10.62% in 2020. NIBR initially dropped but later increased, reaching 21.09 billion Korean won per 100 beds in 2022. Quadrant analysis revealed substantial heterogeneity in financial responses, with national/public hospitals experiencing the most severe MRPR decline, whereas educational foundation and medical corporation hospitals displayed stronger financial recovery. Regression results confirmed significant interactions between outcomes after COVID-19 onset and hospital ownership type, indicating differential financial impacts across hospital categories.
Conclusions
The findings highlight the uneven financial effects of COVID-19 on Korean hospitals, emphasizing the importance of targeted government financial support. Policy measures should prioritize structural financial reforms to ensure hospital sustainability beyond short-term crisis management.
4.Nitric Oxide Production Inhibitory Terpenylated Coumarins from Ailanthus altissima
Beom Kyun AN ; Jae Sang HAN ; Joon Su JANG ; Yong Beom CHO ; Mi Kyeong LEE ; Bang Yeon HWANG
Natural Product Sciences 2026;32(1):44-49
LC-MS/MS-based molecular networking was used to guide the targeted isolation of terpenylated coumarins from the barks of Ailanthus altissima. Five known terpenylated coumarins (1–5), along with two simple coumarins (6 and 7), were isolated from the CH 2 Cl 2 -soluble fraction. Their structures were determined using spectroscopic techniques, including 1D and 2D NMR and LC-HR-MS/MS. Notably, altissimacoumarins C (1), F (3), and H (4) demonstrated potent inhibition of LPS-induced nitric oxide production in RAW 264.7 macrophages, with IC50 values of 36.1, 27.9, and 11.2 μM, respectively. These results demonstrate the antiinflammatory properties of A. altissima, supporting its possible application in treating inflammatory disorders.
5.Individualized strategy of treatment for ruptured abdominal aortic aneurysm using causal inference model: a retrospective observational study
Youngki SOHN ; Youngje WOO ; Sangkyun MOK ; Eunju JANG ; Ki-Yoon MOON ; Sun Cheol PARK ; Sang Seob YUN ; Jang Yong KIM
Annals of Surgical Treatment and Research 2026;110(4):259-272
Purpose:
This study was performed to predict individualized treatment strategies in ruptured abdominal aortic aneurysm (rAAA) by estimating the survival benefit of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) based on anatomical and physiological features using a causal inference model.
Methods:
This retrospective study included 45 patients with de novo rAAA who underwent EVAR or OSR between 2012 and 2024. Thirty-three variables were analyzed. The model estimated individualized treatment effects (ITE) for 30-day survival.Model interpretability was assessed using Shapley Additive Explanations (SHAP) analysis. Five-fold cross-validation, receiver operating characteristic (ROC) analysis, and calibration plots were used for model evaluation. A clinical decision tree was developed to derive simplified decision rules.
Results:
The mean ITE was 0.22 ± 0.42, with 33% of patients classified as OSR-benefit candidates. SHAP analysis revealed that suprarenal angle, infrarenal angle, iliac anatomy, and proximal neck characteristics strongly influenced treatment effects. However, some predictors, such as low hemoglobin and systolic blood pressure favoring OSR, conflicted with clinical intuition. ROC analysis showed an area under the curve of 1.00, but calibration suggested overfitting due to a small sample size. Treatment-matched patients had a higher 30-day mortality rate than mismatched patients, suggesting potential bias or unmeasured confounding. The decision tree identified clinically relevant features but displayed structural inconsistencies and impractical cutoff values due to the limited sample size.
Conclusion
The X-learner model demonstrated the feasibility of individualized treatment prediction in rAAA but suffered from overfitting and limited generalizability. Validation with larger multicenter cohorts is necessary to confirm clinical applicability.
6.Deep learning-based classification of superficial femoral arterial lesions: a pilot study
Yo Sep LEE ; Choongmin KIM ; Youngje WOO ; Jang Yong KIM
Annals of Surgical Treatment and Research 2026;110(2):92-103
Purpose:
This study evaluated the feasibility of detecting peripheral arterial lesions in plane-reconstructed lower extremity CT angiograms using object detection algorithms.
Methods:
We retrospectively collected 1,241 contrast-enhanced lower extremity CT images from patients with peripheral arterial disease. One-stage (YOLOv5: v5s, v5m, v5l, v5x) and 2-stage (Faster R-CNN) detectors were used to classify stent, stenosis, and occlusion. A one-by-one comparison between manual test image annotations and algorithmic detection results was conducted to evaluate model performance and errors. Performance was evaluated by mean average precision (mAP@.5) and precision-recall curves.
Results:
Among YOLOv5 models, v5l showed the highest overall accuracy (77% mAP@.5). While stent classification was excellent (≥ 96.9% mAP@.5 in YOLOv5 and 99.8% in Faster R-CNN), classification accuracies for stenosis (53.8%–58.7% in YOLOv5 vs. 37.2% in Faster R-CNN) and occlusion (69%–80.9% in YOLOv5 vs. 67.7% in Faster R-CNN) were moderate.Stenosis was frequently missed, resulting in high false-negative rates. Occlusions at arterial bifurcations were often not detected, and stent edges were misclassified as occlusions. Overfitting emerged in some YOLOv5 models beyond 75 epochs.
Conclusion
This pilot study supports the feasibility of applying object detection algorithms as a preliminary step toward developing clinical decision support tools for peripheral arterial disease. Further refinements, including additional training data and more granular lesion annotation, are essential for improved classification of stenosis and occlusion.
7.Clinical Outcomes and Use of Implantable Cardioverter-Defibrillator in Ischemic Heart Failure Patients with Reduced Ejection Fraction:A Retrospective Observational Study
Kyung Hoon CHO ; Ki Hong LEE ; Yong-Kyu LEE ; Seok OH ; Yongwhan LIM ; Joon Ho AHN ; Seung Hun LEE ; Dae Young HYUN ; Min Chul KIM ; Doo Sun SIM ; Young Joon HONG ; Ju Han KIM ; Youngkeun AHN ; Jang Hoon LEE ; Joo-Yong HAHN ; Yu-Ri KIM ; Nam Sik YOON ; Hyung Wook PARK ; Weon KIM ; Myung Ho JEONG ;
Chonnam Medical Journal 2026;62(2):55-63
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.
8.Treatment Outcomes of the Inferior Meatus Augmentation Procedure With Autologous Costal Cartilage for Empty Nose Syndrome
Clinical and Experimental Otorhinolaryngology 2026;19(1):79-85
Objectives:
. Empty nose syndrome (ENS) is a rare postoperative complication that can develop following turbinate surgery. Here, we present our clinical experience and a comprehensive analysis of the inferior meatus augmentation procedure with autologous costal cartilage (IMAP-ACC) as a treatment for ENS.
Methods:
. We retrospectively reviewed the medical records of patients diagnosed with ENS who underwent IMAP-ACC at a tertiary referral center between November 2015 and November 2023. Symptom improvement was evaluated using the Empty Nose Syndrome 6-Item Questionnaire (ENS6Q) score before and after the procedure. In addition, perioperative complications and instances of revision surgery were systematically examined.
Results:
. Of the 32 patients who underwent IMAP-ACC, clinical analysis included 20 patients (16 men, 4 women) with a mean age of 39.1±11.5 years and a mean follow-up duration of 61.2±28.8 months. The mean ENS6Q score significantly improved from 17.5±5.3 preoperatively to 9.1±6.0 at the final follow-up (P<0.001). In a subgroup analysis of 16 patients with available early follow-up data, significant reductions in ENS6Q scores were observed both at early follow-up (7.8±5.7) and long-term follow-up (8.6±6.5), compared to the preoperative value (18.2±5.6). Across all 32 patients, nasal obstruction was the most common perioperative complication (34.4%), necessitating reoperation in four patients (12.5%). The majority of complications were effectively managed with a conservative approach.
Conclusion
. IMAP-ACC has proven to be a valuable and durable treatment option for patients with ENS, demonstrating sustained symptom improvement over extended follow-up periods.
9.Surveillance of avian influenza viruses in migratory wild birds in South Korea, 2019–2025
Jae Kyung LEE ; Min Beom KIM ; Seo Hyeon KIM ; Song Hwi JEONG ; HaanWoo SUNG ; Hyung-Kwan JANG ; Kang-Seuk CHOI ; Daesung YOO ; Se-Hee AN ; Gyeong-Beom HEO ; Yong-Myung KANG ; Youn-Jeong LEE ; Kwang-Nyeong LEE ; Young Ju LEE
Journal of Veterinary Science 2026;27(2):07-2025
Objective:
We investigated the distribution of AI viruses in fecal samples from wild bird habitats (and nearby poultry-farm areas) surveyed between September and March from 2019 to 2025 and identified associated epidemiological risk factors.
Methods:
Samples were screened for influenza A (M, H5, H7) genes using real-time reverse transcription polymerase chain reaction (PCR), subjected to virus isolation in embryonated chicken eggs, and subtyped by PCR and sequencing. Host species were identified through DNA barcoding. Relative risks (RRs) with 95% confidence intervals were estimated for province, month, and waterfowl density.
Results:
Overall prevalence of HPAI and low pathogenic AI (LPAI) virus was 0.10% and 3.21%, respectively. HPAI virus was continuously isolated since 2020–2021, except 2019– 2020, while LPAI prevalence steadily increased (3.01%–4.35%). Twelve hemagglutinin (H1–H12) subtypes were identified in 1,722 isolates, and H3 (16.5%) was the most prevalent, followed by H5 (11.1%) and H7 (5.2%). LPAI H5N3 (55.7%) and H7N7 (75.5%) were the predominant H5 and H7 subtypes, respectively. Detection was higher in western coastal provinces, and higher mallard/spot-billed duck density and sampling in September– December were associated with increased risk.
Conclusions
and Relevance: Continued surveillance of migratory-bird habitats can provide early warning of HPAIV incursions and support targeted biosecurity measures in high-risk regions and seasons.
10.Clinical Practice Guideline for the Prehospital Stage of Acute Stroke : III. Initial Decision for Primary Treatment in Subarachnoid Hemorrhage
Jae Sang OH ; Jong Min LEE ; Hong Suk AHN ; Jung-Jae KIM ; Kyoung Min JANG ; Gi-Yong YUN ; Jang Hun KIM ; Dongwook SEO ; Hyeong Jin LEE ; Yuna JO ; Jinwoo JEONG ; Kyoung-Chul CHA ; Yong Soo CHO ; Su Jin KIM ; Jongkyu PARK ; Won-Sang CHO ; Hoon KIM ; Young Woo KIM ; Seung Hun SHEEN ; Sang Weon LEE ; Jae Whan LEE ; Tae Gon KIM ; Sung-kon HA ; Sukh Que PARK ; Dae-Won KIM ; Soon Chan KWON
Journal of Korean Neurosurgical Society 2026;69(1):35-50
Subarachnoid hemorrhage (SAH) is a stroke subtype with high mortality and poor functional outcomes. Prompt occlusion of a ruptured aneurysm at an early stage is crucial to prevent rebleeding, which can result in even higher mortality and more severe disabilities. The most critical initial decision in SAH management is the choice of treatment method with surgical clipping or endovascular coiling. We aimed to develop an evidence-based clinical guideline to select the optimal initial treatment in patients with SAH. We developed this guideline based on evidence from systematic reviews and meta-analyses via a de novo process. A systematic literature review was conducted across four databases (MEDLINE, Embase, Cochrane, and KoreaMed) to answer two population, intervention, comparison, outcome questions comparing clipping and coiling. The risk of bias was assessed using ROB 2.0 and the Newcastle-Ottawa Scale. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagrams and meta-analyses were generated for functional outcome and mortality. We included six randomized control trials (RCTs) and 58 observational studies. Meta-analysis of RCTs showed that coiling improved functional outcomes compared to clipping (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.86–0.97). No significant mortality difference was observed in RCTs (OR, 1.38; 95% CI, 0.91–2.09), but non-RCTs favored clipping for reduced mortality (OR, 0.77; 95% CI, 0.69–0.86). However, it is difficult to generalize these findings to all clinical situations, as patients with SAH have a highly variable clinical course. Final treatment decision should be tailored to the individual patient’s status, including aneurysm location, morphology, and the expertise available at the treatment center. Such decisions are best made by specialists such as a board-certified physician and should be explained to the patient and their caregivers, along with the rationale for selecting the most appropriate treatment at the given hospital. Korea has many certified endovascular neurosurgeons, cerebrovascular surgeons, and certified cerebrovascular centers. Proper selection of the most suitable treatment method by certified physicians and centers would greatly benefit patient outcomes and healthcare professionals.

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