1.Molecular Epidemiology of Extended-spectrum β-Lactamase-producing Escherichia coli in South Korea: A Korean Global Antimicrobial Resistance Surveillance System Report
Dokyun KIM ; SungYoung LEE ; Jun Sung HONG ; Min Hyuk CHOI ; Hyun Soo KIM ; Young Ree KIM ; Young Ah KIM ; Young UH ; Kyeong Seob SHIN ; Jeong Hwan SHIN ; Jeong Su PARK ; Kyoung Un PARK ; Soo Hyun KIM ; Jong Hee SHIN ; Jungsik YU ; Seok Hoon JEONG
Annals of Laboratory Medicine 2026;46(1):72-82
Background:
Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is among the most important multidrug-resistant pathogens causing bloodstream infections (BSIs).Cefotaximase (CTX-M) enzymes are the most common and highly diverse ESBL family in E.coli. CTX-M-15 in group CTX-M-1 and CTX-M-14 in group CTX-M-9 are the most extensively disseminated enzymes. Multidrug-resistant E. coli strains complicate empirical therapy and increase healthcare burden globally and in Korea. We investigated the molecular epidemiology, sequence types (STs), and ESBL genotypes of E. coli bloodstream isolates in Korea and identified clinical risk factors for cefotaxime resistance.
Methods:
We collected all non-duplicated isolates of E. coli and related clinical information from patients with BSIs at eight sentinel hospitals in the Korean Global Antimicrobial Resistance Surveillance System (Kor-GLASS) collection network during 2017–2021. Duplicate isolates were removed to ensure representativeness of the data. Antimicrobial susceptibility was tested using disk diffusion tests, and multilocus sequence typing and betalactamase genotyping were performed.
Results:
Among 9,232 E. coli blood isolates, resistance rates to cefotaxime and ceftazidime were 36.4% and 11.4%, respectively. Among the clinical factors, age > 65 yrs (adjusted odds ratio [aOR], 1.36), hospital-origin infection (aOR, 2.55), and admission type (intensive care unit [ICU] vs. general ward; aOR, 1.34) were significant cefotaxime resistance risk factors. ST131 was the most prevalent among cefotaxime-resistant E. coli (64.8%, 2,180/3,363), followed by ST1193 (5.3%, N = 177), and ST69 (5.1%, N = 170).ST131, ST648, ST405, and ST410 cefotaxime-resistant E. coli isolates frequently harbored blaCTX-M-15, whereas ST1193 and ST68 showed a high proportion of blaCTX-M-27 carriers, and most ST457 and ST5150 isolates carried blaCTX-M-55.
Conclusions
Continuous monitoring of ESBL-producing E. coli is required to prevent further dissemination, guide empirical therapy, inform infection control policies, and ensure early detection of multidrug-resistant clones with the potential for widespread transmission.
2.Comparative Outcomes of No-Touch Radiofrequency Ablation Versus Tumor-Puncture Microwave Ablation for Small Hepatocellular Carcinoma
Jae Hyun KIM ; Sae-Jin PARK ; Dong Jin CHUNG ; Hyun Pyo HONG ; Jeong Kyong LEE ; Chang Jin YOON ; Jeong Min LEE
Korean Journal of Radiology 2026;27(1):34-47
Objective:
This study aimed to compare the therapeutic outcomes of no-touch (NT) radiofrequency ablation (RFA) vs. tumorpuncture microwave ablation (MWA) in the treatment of single hepatocellular carcinomas (HCCs) measuring ≤3 cm.
Materials and Methods:
This multicenter retrospective study included 304 patients who underwent either NT-RFA (n = 144) or MWA (n = 160) for a single HCC measuring ≤3 cm. Comparative analyses were conducted for the overall cohort, while 81 patients per group were matched using propensity score matching (PSM). The analyzed outcomes included technical success, primary technique efficacy, local tumor progression (LTP), and major complications. Cumulative LTP was estimated using Kaplan–Meier analysis and compared using the log-rank text, while the rate of ablative margin ≥5 mm and ablation time were compared using Chi-squared and Mann–Whitney U tests, respectively.
Results:
Technical success was achieved in 98.6% (142/144) and 100% (160/160) of in the NT-RFA and MWA patients, respectively before PSM (P = 0.224), and 98.8% (80/81) and 100% (81/81) after PSM (P = 1.000). The primary technique efficacies were 98.6% (142/144) and 100% (160/160) before PSM (P = 0.224), and 97.5 % (79/81) and 100% (81/81) after PSM (P = 0.497), respectively. The 1-, 2-, and 3-year cumulative LTP rates were 1.4%, 1.4%, and 2.3%, respectively, for NTRFA and 5.1%, 8.6%, and 8.6%, respectively, for MWA before PSM (P = 0.013). After PSM, the corresponding rates were 0%, 0%, and 0% for NT-RFA, and 7.6%, 10.4%, and 10.4% for MWA (P = 0.006). Major complications were not observed. NT-RFA achieved a higher proportion, with an ablative margin ≥5 mm (88.7% [126/142] vs. 71.9% [115/160]; P < 0.001), but required longer ablation times (median, 10.0 vs. 6.0 min; P < 0.001).
Conclusion
NT-RFA showed superior local tumor control compared to MWA, despite greater procedural complexity and longer ablation times.
3.Effect of weight reduction on liver volume in living liver donors with steatosis: a retrospective cohort study
Kwangpyo HONG ; Kwang-Woong LEE ; Su young HONG ; Sola LEE ; Hyun Hwa CHOI ; Jiyoung KIM ; Jaewon LEE ; Jae-Yoon KIM ; Jeong-Moo LEE ; Suk Kyun HONG ; YoungRok CHOI
Annals of Surgical Treatment and Research 2026;110(4):273-280
Purpose:
Weight reduction (WR) can reduce liver volume, affecting the graft-to-recipient weight ratio (GRWR). This study aimed to evaluate the decrease in liver volume after WR and analyze risk factors affecting liver volume reduction in potential liver donors with steatosis.
Methods:
We retrospectively reviewed data of 147 potential liver donors with steatosis who participated in a WR program prior to liver transplantation between January 2016 and December 2021. Total liver volume (TLV) was measured using CT and MRI. Risk factors for large liver volume reduction (≥10%) were analyzed using multivariate logistic regression.
Results:
Ninety-seven donors (66.0%) underwent donor hepatectomy after WR. Liver volumes showed a statistically significant decrease (from 1,399.6 ± 315.4 mL to 1,283.6 ± 271.2 mL, P < 0.05). Thirty-eight donors (42.7%) showed large liver volume reduction. There was a more significant reduction in weight, AST, and ALT in the large liver volume reduction group than in the small liver volume reduction group (all P < 0.05). WR percentage and ALT abnormalities were independent risk factors for large liver volume reduction (odds ratio, 1.184 [95% confidence interval, 1.054–1.329] and odds ratio, 5.502 [95% confidence interval, 1.660–18.229], respectively; all P < 0.05).
Conclusion
Potential liver donors with 7% or more WR or ALT abnormality require liver volume/GRWR remeasurement after WR to ensure adequate graft size and prevent small-for-size syndrome.
4.Development of an artificial intelligence-based prediction platform for early recurrence of resectable pancreatic cancer after curative surgery–toward future use as an indication for neoadjuvant treatment: a retrospective multicenter cohort study
So Jeong YOON ; Sung Hyun KIM ; Hongbeom KIM ; Sang Hyun SHIN ; Jin Seok HEO ; Seung Soo HONG ; Chang Moo KANG ; Kyung Sik KIM ; Ho Kyoung HWANG ; In Woong HAN
Annals of Surgical Treatment and Research 2026;110(2):76-83
Purpose:
Neoadjuvant treatment (NAT) is now the standard for borderline resectable pancreatic cancer (RPC) and is being considered for RPC. Early recurrence after curative surgery in RPC is often seen as a treatment failure, prompting considerations for NAT. Our goal was to develop an artificial intelligence (AI)-based predictive model utilizing preoperatively available factors to forecast early recurrences of resected RPC.
Methods:
This study included 469 patients who underwent surgery for RPC between 2011 and 2019. Clinicopathologic and oncologic data were retrospectively reviewed. Preoperative variables, including laboratory data and imaging findings, were collected. Early recurrence was defined as recurrence occurring within a year after surgery. Deep neural networks were then used to select variables by assessing their importance. A new model predicting early recurrence of RPC was subsequently developed.
Results:
Of the patients evaluated, 199 (42.4%) experienced early recurrence. The predictive model included 14 preoperative variables: CA 19-9, preoperative pancreatitis, serum albumin, platelet count, lymphocyte count, the American Society of Anesthesiologists physical status classification, tumor size, monocyte count, age, body mass index, CRP, hemoglobin, WBC count, and CEA. The area under the curve for the model was 0.786 in the training set and 0.734 in the test set.
Conclusion
We developed an AI-based model to predict the early recurrence of RPC using preoperative parameters. By identifying patients at risk of early recurrence, optimal individualized treatments such as NAT can be considered. Future prospective studies are crucial to establish clear indications for NAT in RPC.
5.A pilot study on microbial dynamics in drainage fluid during trauma recovery
Hyun-Hee HONG ; Tae-Hwan KIM ; Dowan KIM ; Jungchul KIM ; Younggoun JO ; Yunchul PARK ; Euisung JEONG ; Naa LEE ; Hyunseok ROH ; Hyunseok JANG ; Su-Man KIM
Annals of Surgical Treatment and Research 2026;110(5):347-358
Purpose:
Drainage fluid may serve as a biologically informative indicator of immune and infectious status during postsurgical recovery after trauma. However, microbiome shifts in drainage fluid associated with clinical resilience have not yet been characterized. This study aimed to investigate microbial dynamics in drainage fluid across the intensive care unit (ICU) and ward recovery phases in Korean trauma patients.
Methods:
A total of 25 drainage and 10 stool samples were collected from 10 trauma patients who underwent abdominal surgery at a regional trauma center. Microbial composition was analyzed using 16S ribosomal RNA amplicon sequencing.Alpha and beta diversity were compared between sample types and recovery stages. Linear mixed-effects models were used to identify recovery-associated taxa while adjusting for clinical variables, and predicted metabolic pathways were assessed using PICRUSt2.
Results:
Drainage fluid harbored distinct microbial communities independent of the intestinal microbiota. Shared taxa between drainage and stool increased significantly in patients with bowel injury, suggesting microbial translocation.Seven genera and 5 species showed significantly decreased abundance during the ward stage, with Modestobacter and Blastococcus tunisiensis demonstrating the highest discriminative ability between recovery stages (area under the curve = 0.721). Predicted metabolic pathways related to fatty acid degradation, amino acid degradation, and pro-inflammatory processes were more active during the ICU stage.
Conclusion
These findings provide preliminary evidence that drainage fluid microbiome profiles may reflect recovery dynamics following trauma, supporting its potential utility for microbiome-based monitoring and biomarker discovery in trauma surgery.
6.Real-World Efficacy of Intravesical Gemcitabine for BCG-Unresponsive Non–muscle-Invasive Bladder Cancer
Hye Won LEE ; Eui Hyun JUNG ; Kyung Hwan KIM ; Hong Koo HA ; Jong Jin OH ; Seok Ho KANG ; Seung-hwan JEONG ; Hyeong Dong YUK ; Ji Eun HEO ; Won Sik HAM ; Eu Chang HWANG ; Seung Il JUNG ; Wan SONG ; Bumjin LIM ; Bumsik HONG ; Byung Chang JEONG ; Ho Kyung SEO
Cancer Research and Treatment 2026;58(2):591-602
Purpose:
This study aimed to report the real-world outcomes of intravesical gemcitabine for bacillus Calmette–Guérin (BCG)–unresponsive, high-risk, non–muscle-invasive bladder cancer (HR-NMIBC) in Korean patients who were unable or unwilling to undergo radical cystectomy (RC).
Materials and Methods:
This retrospective study included 131 patients (median age, 69 years; 88.5% men) treated with intravesical gemcitabine for BCG-unresponsive HR-NMIBC at nine centers between May 2019 and April 2022. The primary endpoint was 1-year recurrence-free survival (RFS). The secondary endpoints included factors influencing RFS, progression-free survival (PFS), cystectomy- free survival, cancer-specific survival (CSS), overall survival (OS), and safety. Survival analysis was performed using the Kaplan-Meier method, and risk factors for recurrence were assessed using Cox regression models.
Results:
Patients were followed up for a median duration of 25 months, with carcinoma in situ (CIS) in 41.9% of the patients. The 1-year and 2-year RFS rates were 68% and 42%, while the 1-year and 2-year PFS rates were 87% and 77%, respectively. No significant factors influencing RFS were identified. Seventeen patients underwent RC during a median follow-up of 16 months, with the condition in three patients progressing to muscle-invasive disease on final pathological analysis. The 2-year CSS and OS rates were 98% and 97%, respectively. Intravesical gemcitabine was well-tolerated, with only seven patients (5.3%) unable to complete the full induction course.
Conclusion
Our research highlights the potential of intravesical gemcitabine as a viable bladder-sparing treatment option for BCG-unresponsive HR-NMIBC, providing real-world evidence on its safety, efficacy, and tolerability.
7.Detection Ability of Quality of Life Changes and Responsiveness of the KOQUSS-40 and the EORTC QLQ-C30/STO22 in Patients Who Underwent Gastrectomy: A Prospective Comparative Study
Bang Wool EOM ; Keun Won RYU ; Ji Yeong AN ; Yun-Suhk SUH ; In CHO ; Sung Geun KIM ; Ji-Ho PARK ; Hoon HUR ; Hyung-Ho KIM ; Sang-Hoon AHN ; Sun-Hwi HWANG ; Hong Man YOON ; Ki Bum PARK ; Hyoung-Il KIM ; In-Gyu KWON ; Han-Kwang YANG ; Byoung-Jo SUH ; Sang-Ho JEONG ; Tae-Han KIM ; Oh Kyoung KWON ; Hye-Seong AHN ; Ji Yeon PARK ; Ki Young YOON ; Myoung Won SON ; Seong-Ho KONG ; Young-Gil SON ; Geum Jong SONG ; Jong Hyuk YUN ; Jung-Min BAE ; Do Joong PARK ; Sol LEE ; Jun-Young YANG ; Kyung Won SEO ; You-Jin JANG ; So Hyun KANG ; Joongyub LEE ; Hyuk-Joon LEE ;
Cancer Research and Treatment 2026;58(1):221-231
Purpose:
The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ).
Materials and Methods:
A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire.
Results:
Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ.
Conclusion
KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.
8.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.
9.Postoperative Readmission Is Associated With Worse Oncologic Outcomes After Radical Cystectomy for Bladder Cancer: A Multicenter Study of 3,972 Patients
Jungwon PARK ; Jong Ho PARK ; Sangchul LEE ; Seung-Hwan JEONG ; Ja Hyeon KU ; Kyung Hwan KIM ; Jong Kil NAM ; Bumjin LIM ; BumSik HONG ; Wook NAM ; Sung Gu KANG ; Seok Ho KANG ; Tae Gyun KWON ; Tae-Hwan KIM ; Jieun HEO ; Won Sik HAM ; Geehyun SONG ; Ho Kyung SEO ; Wan SONG ; Hyun Hwan SUNG ; Byong Chang JEONG ; Jong Jin OH
Journal of Urologic Oncology 2026;24(1):69-78
Purpose:
Radical cystectomy (RC) is associated with substantial postoperative morbidity, and unplanned readmission remains common despite advances in perioperative management. However, the association between postoperative readmission due to complications and oncologic outcomes after RC for bladder cancer has not been clearly defined. We evaluated the impact of postoperative readmission on overall survival (OS) and cancer-specific survival (CSS) after RC for bladder cancer.
Materials and Methods:
We retrospectively analyzed 3,972 patients who underwent RC for bladder cancer in a multicenter cohort. Postoperative readmission was defined as unplanned hospitalization within 90 days postsurgery due to surgery-related complications. Survival outcomes were assessed using the Kaplan-Meier method and compared using the log-rank test. Univariable and multivariable Cox proportional hazards regression analyses were performed to identify independent predictors of OS and CSS.
Results:
Among the study population, 916 patients (23.1%) experienced postoperative readmission. Baseline and perioperative characteristics were generally comparable between patients with and without readmission. Kaplan-Meier analyses demonstrated significantly worse OS and CSS among patients who experienced postoperative readmission (both log-rank p<0.001). In multivariable analyses adjusting for clinicopathological factors, postoperative readmission remained independently associated with worse OS (hazard ratio [HR], 1.654; 95% confidence interval [CI], 1.464–1.868; p<0.001) and CSS (HR, 1.761; 95% CI, 1.509–2.055; p<0.001).
Conclusion
Postoperative readmission within 90 days after RC was independently associated with inferior long-term oncologic outcomes. These findings suggest the importance of strategies aimed at preventing postoperative complications and subsequent readmission.
10.Radical Nephrectomy and Thrombectomy Without Cardiopulmonary Bypass for Level IV Venous Thrombus Renal Cell Carcinoma: Feasibility and Technical Tips
Dong-Hoon LIM ; Hyun Young LEE ; Bumjin LIM ; Jung Kwon KIM ; Cheryn SONG ; Dalsan YOU ; In Gab JEONG ; Jun Hyuk HONG ; Bumsik HONG ; Hanjong AHN ; Jun Gyo GWON ; Jungyo SUH
Journal of Urologic Oncology 2026;24(1):50-59
Purpose:
This study evaluated the feasibility of radical nephrectomy and thrombectomy without cardiopulmonary bypass (CPB) in patients with renal cell carcinoma (RCC) and level IV venous tumor thrombus, compared with CPB-assisted surgery.
Materials and Methods:
This retrospective cohort study analyzed patients with RCC and level IV venous tumor thrombus who underwent surgery at a single center between 2014 and 2020. Feasibility of non-CPB surgery was assessed by comparing perioperative safety-related outcomes, overall survival (OS), and progression-free survival (PFS) between the non-CPB and CPB groups. Perioperative outcomes included operative time, blood loss, severe complications (Clavien-Dindo classification grade ≥III), intensive care unit (ICU) stay, and mortality. Kaplan-Meier analysis and generalized Wilcoxon tests were used to compare survival outcomes.
Results:
A total of 16 patients met eligibility criteria: 5 underwent surgery without CPB, and 11 underwent CPB-assisted surgery. Median operative time was similar between the CPB and non-CPB groups (490 minutes vs. 480 minutes, p=0.650). Compared with the CPB group, blood loss was lower in the non-CPB group (4000 mL vs. 1080 mL, p=0.333). Severe complications occurred in 36.4% of CPB patients and 0% of non-CPB patients (p=0.245). ICU stay was comparable between the non-CPB and CPB groups (2 days vs. 3 days, p=0.356). OS did not differ significantly between groups (p=0.180), whereas PFS was longer in the non-CPB group (p=0.041).
Conclusions
Radical nephrectomy and thrombectomy without CPB appears feasible and may be associated with lower perioperative morbidity and blood loss without compromising oncologic outcomes. Non-CPB surgery should be considered in selected patients with level IV venous tumor thrombus when technically feasible.

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