1.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.
2.Artificial intelligence-based personalized oncological outcome prediction model for upper urinary tract urothelial carcinoma after radical nephroureterectomy: A development and multicenter validation
Hyun Young LEE ; Hwanik KIM ; Bumjin LIM ; Dalsan YOU ; Cheryn SONG ; In Gab JEONG ; Jun Hyuk HONG ; Bumsik HONG ; Hanjong AHN ; Seung-hwan JEONG ; Ja Hyeon KU ; Jungyo SUH
Investigative and Clinical Urology 2026;67(1):15-23
Purpose:
To develop and validate an artificial intelligence (AI)-based personalized outcome prediction model for upper-urinary tract urothelial carcinoma patients undergoing radical nephroureterectomy.
Materials and Methods:
Data from patients who underwent radical nephroureterectomy between 2010 and 2020 across three hospitals were retrospectively analyzed. A model was developed using one tertiary center’s data and externally validated with data from two other hospitals. An AI model using XGBoost as risk estimator and bootstrapped Weibull Accelerated Failure Time model for 10-year survival probability was employed. Hyperparameter tuning used Optuna method. Model efficacy was assessed using concordance index, average Brier score, D-calibration, and six-month interval time-dependent area under the curve (AUC).
Results:
Of 1,039 patients, 627 qualified after excluding 50 with neoadjuvant chemotherapy. Model development used 564 patients (507 training, 57 test) with 9:1 stratified random split, plus 63 for internal validation and 362 for external validation. Significant parameters included preoperative glomerular filtration rate (p<0.001), hydroureteronephrosis (p=0.013), pathological N stage (p<0.001), concurrent carcinoma in situ (p<0.001), disease progression (p<0.001), and survival rate (p<0.001). Disease-free survival (DFS) model’s concordance index: internal validation 0.789, external validations 0.734 and 0.771. Overall survival (OS) model’s concordance index: internal validation 0.819, external validations 0.780 and 0.771. Mean time-dependent AUC was 0.66–0.77 for DFS and 0.67–0.80 for OS during 10-year periods.
Conclusions
AI-based model effectively predicts disease-free and OS outcomes for upper-urinary tract urothelial carcinoma patients with post-radical nephroureterectomy, showcasing robust performance across multicenter settings.
3.Prognostic Factors and Cancer-Specific Survival of Surgically Managed Renal Cell Carcinoma With Venous Thrombus: A 30-Year Experience at a Tertiary Referral Center
Hyun Young LEE ; Yunjoong KIM ; Bumjin LIM ; Dalsan YOU ; Cheryn SONG ; In Gab JEONG ; Bumsik HONG ; Jun Hyuk HONG ; Hanjong AHN ; Jungyo SUH
Journal of Urologic Oncology 2024;22(1):52-58
Purpose:
This study investigated the prognostic factors and cancer-specific survival (CSS) of patients who had renal cell carcinoma (RCC) with venous thrombus and underwent radical nephrectomy with thrombectomy (RNTx).
Materials and Methods:
From January 1990 to December 2022, we retrospectively reviewed the medical records of patients diagnosed with RCC with venous thrombus who underwent RNTx at a single tertiary medical center. Univariate and multivariable Cox proportional hazard regression analyses were conducted to identify significant prognostic factors affecting CSS. A Kaplan-Meier model was used to calculate CSS rates at 1, 3, and 5 years after RNTx.
Results:
We included 262 patients in the final analysis (median age, 59 years) with a median follow-up of 28 months. The 1-, 3-, and 5-year CSS rates were 84.1%, 62.5%, and 46.4%, respectively. Multivariable analysis revealed that pathologic T4 stage (hazard ratio [HR], 3.711; 95% confidence interval [CI], 1.599–8.611, p=0.002), pathologic N1 stage (HR, 2.371; 95% CI, 1.231–4.567; p=0.01), sarcomatoid differentiation (HR, 1.89; 95% CI, 1.027–3.477; p=0.041), and tumor necrosis (HR, 2.993; 95% CI, 1.132–7.914; p=0.027) were associated with CSS.
Conclusions
Approximately one-third of all RCC patients with venous thrombus remained disease-free, and half survived 5 years after RNTx. Sarcomatoid differentiation and the presence of tumor necrosis in pathology predicted poorer CSS outcomes in our study. Further retrospective studies are required to validate these findings.
4.2023 Korean sexually transmitted infections guidelines for non-gonococcal bacterial infection (chlamydia, syphilis, etc.) by the Korean Association of Urogenital Tract Infection and Inflammation
Joongwon CHOI ; Jin Bong CHOI ; Sangrak BAE ; Chan Ho LEE ; Yu Seob SHIN ; Dalsan YOU ; Joo Yong LEE ; Seung-Ju LEE ; Kyu Won LEE
Investigative and Clinical Urology 2024;65(2):115-123
Non-gonococcal sexually transmitted infections (STIs) include chlamydia, syphilis, and chancroids. Chlamydia is the most common STI caused by Chlamydia trachomatis and is mainly transmitted through sexual intercourse or vertical transmission at birth. Although symptoms are mostly absent or mild, untreated chlamydial infections in females can lead to pelvic inflammatory disease, chronic pelvic pain, and infertility due to the narrowing of fallopian tubes. Syphilis is caused by Treponema pallidum and is divided into phase I, phase II, latent syphilis, and phase III. The incidence of syphilis, including congenital syphilis, has significantly increased in the United States in recent years. The chronic status of this disease can significantly increase morbidity and potentially affect almost all body organs, which, in rare cases, can lead to death. Additionally, untreated maternal syphilis can lead to fetal death and fatal congenital infections in newborns. Chancroid is an STI caused by Haemophilus ducreyi, and its prevalence is gradually decreasing in Korea and worldwide. The symptoms include shallow genital ulcers with suppurative granulomatous inflammation and tender inguinal lymphadenopathy. Chancroids can be differentiated from syphilitic chancres based on their appearance. In contrast to painless chancres, chancroids are painful. Ureaplasma urealyticum, Ureaplasma parvum, and Mycoplasma hominis are considered symbiotic bacteria.Infections caused by these bacteria are usually not considered STIs and do not require treatment unless they are suspected of being associated with infertility. This article presents the 2023 Korean STI guidelines for non-gonococcal bacterial infections.
5.Risk factors for failing to complete gemcitabine–cisplatin neoadjuvant chemotherapy in muscle invasive bladder cancer patients
Homin KANG ; Jungyo SUH ; Dalsan YOU ; In Gab JEONG ; Bumsik HONG ; Jun Hyuk HONG ; Hanjong AHN ; Bumjin LIM
Investigative and Clinical Urology 2024;65(3):256-262
Purpose:
We evaluated the risk factors associated with failure to complete gemcitabine–cisplatin (GP) neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC).
Materials and Methods:
In total, 231 patients with MIBC treated with NAC before undergoing radical cystectomy between 2013 and 2022 participated in this study. Logistic regression analysis was performed to assess the relationship between the likelihood of incomplete NAC and clinical and demographic variables, including age, sex, hypertension (HTN), diabetes mellitus (DM), prechemotherapy glomerular filtration rate, clinical T stage, clinical N stage, and body mass index (BMI).
Results:
Of 231 patients, 209 (90.5%) and 22 (9.5%) completed and discontinued the NAC course, respectively. The mean age was 66.13±9.15, 65.63±9.07, and 70.86±8.66 years for the total sample, continuation, and discontinuation groups, respectively (p=0.010). No significant inter-group differences in sex, HTN, height, weight, BMI, pre-chemotherapy glomerular filtration rate, clinical T stage, or clinical N stage were observed. According to the results of the multivariable analysis, age (odds ratio [OR] 1.076, 95% confidence interval [CI] 1.013–1.143, p=0.018) and the presence of DM (OR 2.541, 95% CI 1.028–6.281, p=0.043) were significantly associated with NAC discontinuation.
Conclusions
Thus, older age and presence of DM are potential risk factors for GP NAC discontinuation in patients with MIBC.Further studies are required to validate our findings and develop strategies to minimize the rate of GP NAC discontinuation in this population.
6.Efficacy and Safety of Human Bone Marrow-Derived Mesenchymal Stem Cells according to Injection Route and Dose in a Chronic Kidney Disease Rat Model
Han Kyu CHAE ; Nayoung SUH ; Myong Jin JANG ; Yu Seon KIM ; Bo Hyun KIM ; Joomin AUM ; Ha Chul SHIN ; Dalsan YOU ; Bumsik HONG ; Hyung Keun PARK ; Choung-Soo KIM
International Journal of Stem Cells 2023;16(1):66-77
Background and Objectives:
We compared the efficacy and safety of human bone marrow-derived mesenchymal stem cells (hBMSC), delivered at different doses and via different injection routes in an animal model of chronic kidney disease.
Methods:
and Results: A total of ninety 12-week-old rats underwent 5/6 nephrectomy and randomized among nine groups: sham, renal artery control (RA-C), tail vein control (TV-C), renal artery low dose (RA-LD) (0.5×10 6 cells), renal artery moderate dose (RA-MD) (1.0×10 6 cells), renal artery high dose (RA-HD) (2.0×10 6 cells), tail vein low dose (TV-LD) (0.5×10 6 cells), tail vein moderate dose (TV-MD) (1.0×10 6 cells), and tail vein high dose (TV-HD) (2.0×10 6 cells). Renal function and mortality of rats were evaluated after hBMSC injection. Serum blood urea nitrogen was significantly lower in the TV-HD group at 2 weeks (p<0.01), 16 weeks (p<0.05), and 24 weeks (p<0.01) than in the TV-C group, as determined by one-way ANOVA. Serum creatinine was significantly lower in the TV-HD group at 24 weeks (p<0.05). At 8 weeks, creatinine clearance was significantly higher in the TV-MD and TV-HD groups (p<0.01, p<0.05) than in the TV-C group. In the safety evaluation, we observed no significant difference among the groups.
Conclusions
Our findings confirm the efficacy and safety of high dose (2×10 6 cells) injection of hBMSC via the tail vein.
7.Therapeutic Effect of Three-Dimensional Cultured Adipose-Derived Stem Cell-Conditioned Medium in Renal Ischemia-Reperfusion Injury
Yu Seon KIM ; Joomin AUM ; Bo Hyun KIM ; Myoung Jin JANG ; Jungyo SUH ; Nayoung SUH ; Dalsan YOU
International Journal of Stem Cells 2023;16(2):168-179
Background and Objectives:
We evaluated the effect of adipose-derived stem cell-derived conditioned medium (ADSC-CM) on the renal function of rats with renal ischemia-reperfusion injury (IRI)-induced acute kidney injury.
Methods:
and Results: Forty male Sprague‐Dawley rats were randomly divided into four groups: sham, nephrectomy control, IRI control, ADSC-CM. The ADSC-CM was prepared using the three-dimensional spheroid culture system and injected into renal parenchyme. The renal function of the rats was evaluated 28 days before and 1, 2, 3, 4, 7, and 14 days after surgical procedures. The rats were sacrificed 14 days after surgical procedures, and kidney tissues were collected for histological examination. The renal parenchymal injection of ADSC-CM significantly reduced the serum blood urea nitrogen and creatinine levels compared with the IRI control group on days 1, 2, 3, and 4 after IRI. The renal parenchymal injection of ADSC-CM significantly increased the level of creatinine clearance compared with the IRI control group 1 day after IRI. Collagen content was significantly lower in the ADSC-CM group than in the IRI control group in the cortex and medulla. Apoptosis was significantly decreased, and proliferation was significantly increased in the ADSC-CM group compared to the IRI control group in the cortex and medulla. The expressions of anti-oxidative makers were higher in the ADSC-CM group than in the IRI control group in the cortex and medulla.
Conclusions
The renal function was effectively rescued through the renal parenchymal injection of ADSC-CM prepared using a three-dimensional spheroid culture system.
8.Risk Factors Leading to Radical Cystectomy in Patients Who Had Undergone Nephroureterectomy
Janghui LEE ; Bumjin LIM ; Dalsan YOU ; In Gab JEONG ; Cheryn SONG ; Jun Hyuk HONG ; Choung-Soo KIM ; Hanjong AHN ; Bumsik HONG
Korean Journal of Urological Oncology 2021;19(4):271-280
Purpose:
To identify the risk factors leading to radical cystectomy in patients who had undergone nephroureterectomy (NUx).
Materials and Methods:
We retrospectively reviewed the medical records of patients with upper tract urothelial carcinoma who underwent NUx during 2011–2019 and excluded patients with metastatic cancer. In total 646 patients were included in this study; of these, 532 had no previous bladder cancer history. Follow-up was performed every 3 months for 2 years after NUx was administered, and recurrence was confirmed using cystoscopy, urine cytology, computed tomography, and chest radiography. Bladder recurrence was confirmed through biopsy, urine cytology, or radiologic examination. Univariate and multivariate Cox regression analyzes were performed for statistical analysis of risk factors leading to radical cystectomy in patients undergoing NUx.
Results:
Lymphovascular invasion (LVI) (hazard ratio [HR], 4.728; 95% confidence interval [CI], 1.463–15.570; p=0.011), previous transurethral resection of bladder tumor history (HR, 3.825; 95% CI, 1.164–12.571; p=0.027), and intravesical recurrence (IVR) within 6 months (HR, 3.733; 95% CI, 1.091–12.778; p=0.036) in patients undergoing NUx are predictors of radical cystectomy implementation. In a multivariate analysis of patients without bladder cancer history, bladder recurrence was identified as a predictor of radical cystectomy implementation, if it occurred within 6 months of NUx (HR, 8.608; 95% CI, 1.545–47.976; p=0.014).
Conclusions
LVI and IVR within 6 months and previous bladder cancer history are factors that can predict the need for radical cystectomy after NUx. Even in patients without bladder cancer history, early bladder recurrence within 6 months is a major predictor of radical cystectomy.
9.Utility of Urinalysis as a Follow-up Surveillance Tool in Nonmuscle Invasive Bladder Cancer
Minuk PARK ; Bumjin LIM ; Dalsan YOU ; In Gab JEONG ; Cheryn SONG ; Bumsik HONG ; Choung-Soo KIM ; Hanjong AHN ; Jun Hyuk HONG
Korean Journal of Urological Oncology 2021;19(4):244-251
Purpose:
To evaluate the association between microscopic hematuria (MH) detected by surveillance urinalysis and cancer recurrence in nonmuscle invasive bladder cancer (NMIBC) patients.
Materials and Methods:
A total of 1,082 NMIBC patients who underwent transurethral resection of bladder tumor (TURB) procedures at Asan Medical Center between January 2017 and December 2019 were included. We retrospectively reviewed the follow-up data for these cases including cystoscopy, urinalysis, and urine cytology. The association between urine testing and cancer recurrence was assessed by both univariable and multivariable logistic regression analysis.
Results:
The study patients had a median age of 68 years (interquartile range, 60–75 years) and comprised 898 men and 184 women. Among the 1,428 TURB procedures conducted in this series, 548 of the lesions (38.4%) were diagnosed as low-grade and 880 (61.6%) as highgrade cancers. A total of 3,309 follow-up cystoscopies were conducted during the study period and were divided into high-grade (HG) (2,011 cases) and low-grade (LG) (1,298 cases) groups according to the latest TURB pathology. MH was found to have a statistically significant association with NMIBC recurrence in both the LG (odds ratio [OR], 1.57; 95% confidence interval [CI], 1.107–2.223; p=0.011) and HG (OR, 1.90; 95% CI, 1.434–2.517; p<0.001) groups.
Conclusions
Urinalysis during follow-up may provide important information on cancer recurrence in NMIBC patients.
10.Construction of a Retrospective Cohort to Observe 10-Year Urologic Cancer Treatment Trends at the Biggest Medical Center of South Korea
Se Young CHOI ; Ho Heon KIM ; Bumjin LIM ; Jong Won LEE ; Young Seok KIM ; Jeong Kon KIM ; Jae Lyun LEE ; Yong Mee CHO ; Dalsan YOU ; In Gab JEONG ; Cheryn SONG ; Jun Hyuk HONG ; Choung-Soo KIM ; Hanjong AHN ; Bumsik HONG
Korean Journal of Urological Oncology 2021;19(4):232-243
Purpose:
To construct a urologic cancer database using a standardized, reproducible method, and to assess preliminary characteristics of this cohort.
Materials and Methods:
Patients with prostate, bladder, and kidney cancers who were enrolled with diagnostic codes in the electronic medical record (EMR) at Asan Medical Center from 2007–2016 were included. Research Electronic Data Capture (REDCap) was used to design the Asan Medical Center-Urologic Cancer Database (AMC-UCD). The process included developing a data dictionary, applying branching logic, mapping clinical data warehouse structures, alpha testing, clinical record summary testing, creating “standards of procedure,” importing data, and entering data. Descriptive statistics were used to identify rates of surgeries and numbers of patients.
Results:
Clinical variables (n=407) were selected to develop a data dictionary from REDCap. In total, 20,198 urologic cancer patients visited our institution from 2007–2016 (bladder cancer, 4,616; kidney cancer, 5,750; prostate cancer, 10,330). The overall numbers of patients and surgeries increased over time, with robotic surgeries rapidly growing over a decade. The most common treatment for urologic cancer was surgery, followed by chemotherapy and radiation therapy.
Conclusions
Using a standardized method, the AMC-UCD fosters multidisciplinary research. This constructed database provides access to clinical statistics to effectively assist research. Preliminary data should be refined through EMR chart review. The successful organization of data from 2007–2016 provides a framework for future periods of investigation and prospective models.

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