Background: DNA methylation is under investigation as an early diagnostic biomarker for cancers such as hepatocellular carcinoma (HCC). p21-activated protein kinase 1 (PAK1) demonstrates a high methylation tendency in HCC. We assessed the diagnostic and prognostic performance of PAK1 methylation in liver transplantation (LT) recipients with and without HCC. Methods: To assess PAK1 methylation, stored pretransplant blood samples from LT recipients were analyzed by droplet digital polymerase chain reaction. Results: This study included 274 patients with HCC and 100 control patients without the disease. Ten-year survival rates in the HCC and control groups were 60.5% and 80.6%, respectively (P=0.001). The 10-year HCC recurrence rate was 39.0%. Ten-year survival rates in the HCC recurrence and nonrecurrence groups were 13.3% and 91.2%, respectively (P<0.001); median PAK1 methylation levels in the control and HCC groups were 50.0 and 108.0 copies (P=0.102). The area under the receiver operating characteristic curve was 0.599, and the Youden J index was 0.199, indicating 57.9% sensitivity and 62.0% specificity at a cutoff of 78 copies. With a cutoff of 5 copies, sensitivity was 94.1% and specificity was 14.0%. The positive likelihood ratio was 1.09 and the negative likelihood ratio was 0.42, indicating diagnostic accuracy below α-fetoprotein and protein induced by vitamin K absence or antagonist-II. PAK1 cutoffs of 5 and 10 copies did not affect HCC recurrence, but a cutoff of 2 copies appeared associated with lower recurrence. Conclusions These data suggest that PAK1 methylation is not a clinically useful biomarker for HCC in LT recipients. New DNA methylation biomarkers are required for early diagnosis.

Purpose: Biliary atresia (BA) is a rare but progressive cholangiopathy and the leading cause of pediatric liver transplantation worldwide. The Korean Association of Pediatric Surgeons (KAPS) has conducted three national surveys (2001, 2011, and 2023) to assess long-term trends in the diagnosis, treatment, and outcomes of BA. This study provides a comparative analysis of the 2nd and 3rd national surveys, with reference to selected findings from the 1st survey. Methods: This study included 453 patients from the 3rd national survey (2011–2021) and 435 patients from the 2nd survey (2001–2010), all of whom underwent Kasai portoenterostomy. Data were collected via electronic case report forms from pediatric surgical centers nationwide. Comparisons were made regarding demographics, clinical features, diagnostic patterns, operative details, follow-up outcomes, and survival. Kaplan–Meier analysis was used to evaluate long-term survival. Results: The mean number of BA patients per year remained stable between surveys (43.5 in the 2nd, 41.18 in the 3rd), though centralization of care increased, with 61.5% of cases managed by two major institutions in the 3rd survey. The median age at surgery decreased, and the use of preoperative imaging (especially magnetic resonance cholangiopancreatography) increased. The 10-year native liver survival rate declined from 59.8% to 53.7%, while overall 10-year survival improved slightly (92.9% to 93.2%). Postoperative complications, such as cholangitis and liver failure, persisted but were better categorized. The 3rd survey also reported improved mortality (4.9%) and reduced follow-up loss (11.5%) compared to the 2nd survey. Conclusion While overall survival after Kasai operation has remained high and even improved, native liver survival has slightly declined. The findings reflect earlier diagnosis, more consistent diagnostic imaging, and increasing centralization of care. These trends underscore the importance of long-term nationwide data collection in guiding future strategies for BA management in Korea.

Purpose: This study aims to investigate and compare the incidence, demographic characteristics, clinical manifestations, preoperative diagnostic methods, anatomical classifications, associated anomalies, operative treatments, and postoperative outcomes of patients with intestinal atresia treated by the members of the Korean Association of Pediatric Surgeons (KAPS) through three nationwide surveys. Methods: KAPS conducted 3 national surveys in 1998, 2010, and 2024 to examine the patients diagnosed with intestinal atresia. In preparation for the survey, we developed a customized case registration form to obtain data on patient sex, birth weight, gestational age, clinical manifestations, preoperative diagnostic methods, anatomical types, associated anomalies, operative treatments, and postoperative outcomes. Authorized KAPS members completed the case registration form. Results: The first, second, and third national surveys included 218, 222, and 236 individuals diagnosed with intestinal atresia, respectively. The male-to-female ratios were 1.5:1, 1.1:1, and 1.1:1, respectively. The first, second, and third national surveys revealed that 34.3%, 43.3%, and 53.4% of patients were born before 37 weeks of gestation, respectively. Additionally, 28.7%, 32.0%, and 40.7% of patients had a birth weight under 2,500 g. In the third national survey, duodenoduodenostomy was the most common procedure, performed in 70 out of 82 patients diagnosed with duodenal atresia. Resection and anastomosis were the main surgical procedures conducted in 47 out of 54 cases of jejunal atresia and 74 out of 92 cases of ileal atresia. The mortality rates in the first, second, and third national surveys were 13.8%, 3.6%, and 1.3% respectively, with the lowest rate observed in the third national survey. Conclusion These national surveys offer valuable insights into the current state of intestinal atresia, including specific surgical interventions and postoperative outcomes in South Korea. For pediatric surgeons aiming to enhance their understanding of intestinal atresia and its treatment options, these surveys could be an indispensable resource and guide.

Background: A decellularized liver scaffold (DLS) is a three-dimensional acellular extracellular matrix created by removing cellular components from liver tissue. Hepatocellular carcinoma (HCC) organoids represent a useful experimental model. Methods: HCC organoids from patient-derived xenografts (PDX), liver organoids, and HepG2 cells were expanded by cultivation within a murine DLS. Results: HCC and liver organoids were generated from HCC PDX and human liver tissues, respectively. Expression levels of hepatocyte paraffin 1 (HepPar1), epithelial cell adhesion molecule (EpCAM), alpha-fetoprotein, keratin-7, and keratin-19 were detected in normal liver tissue, HCC tissue, HCC PDX, and HCC organoids. Fifteen murine DLSs were created, and the complete absence of liver cells was confirmed histologically by Masson trichrome and periodic acid–Schiff staining. Culture of HCC organoids in the DLS resulted in the expansion of numerous HCC cells scattered throughout the DLS framework. Keratin-7 expression was abundant, indicating widely dispersed progenitor cells. In contrast, cultivation of HepG2 cells within the DLS resulted in sparse cell distribution throughout the scaffold. Human hepatocyte organoids could not be cultivated successfully within the murine DLS framework. Conclusions The DLS collagen framework facilitates the proliferation of HCC organoids. Thus, cultivating HCC organoids within a DLS appears to represent an effective method for rapid cell expansion, although it was ineffective for HepG2 cells and liver organoids. Further studies are required to validate the biological and oncological equivalence between seeded HCC organoids and those rapidly expanded within a DLS.

Purpose: The coronavirus disease 2019 (COVID-19) pandemic has caused patients to suffer from various physical and psychological symptoms and social challenges, but the impact was harder for those COVID-19 patients receiving treatment in single-room isolation wards in South Korea. This study aimed to investigate resilience, anxiety, depression, and sleep quality of those patients and the relationships between those variables, and explore the patients’ experience of resilience during the COVID-19 treatment in single-room isolation wards. Methods: This study employed a mixed-methods approach, collecting quantitative data through surveys and qualitative data through semistructured interviews conducted between May and October 2022. Quantitative surveys encompassing disease-specific and demographic information, visual analog scales to assess anxiety, depression, and sleep quality, and the Connor–Davidson resilience scale were administered to patients (N = 153). Qualitative thematic analyses were conducted following interviews with a subset of patients (N = 13) belonging to the high-resilience group. Results: Resilience exhibited a negative correlation with anxiety and depression, while showing a positive correlation with sleep quality. Factors affecting resilience include having a spouse, educational attainment, and depression. The qualitative thematic analysis results were categorized into: (1) facing the reality of being isolated in a room; (2) struggling to accept and adapt to isolation; and (3) seeking connections in isolation. Conclusions This research sheds light on the challenges faced by individuals in isolation and underscores the crucial role of resilience in overcoming such challenges. The resilience observed in these patients is grounded in both interpersonal and profound spiritual connections. These findings underscore the necessity for nurses to develop customized strategies to alleviate the impacts of social isolation.

Purpose: This study aimed to evaluate senior baccalaureate nursing students’ knowledge and visual differentiation ability for the pressure injury classification system (PICS) and incontinence-associated dermatitis (IAD). Methods: A cross-sectional survey was conducted using a paper-based questionnaire with 120 senior baccalaureate nursing students in South Korea. Data were collected using a knowledge test (KT) and a visual differentiation tool (VDT) based on 21 photographs with clinical information related to PICS and IAD. Results: Students had relatively high KT scores (62.6%), and low VDT scores (35.6%). Critical issues in this study were nursing students’ lack of an adequate visual differentiation ability to accurately assess the stage of pressure injury and IAD and their higher level of confusion in identifying unstageable, deep tissue injuries, and IAD compared to stage 1-4 injuries. Satisfaction with education (r=.20, p<.05) and exposure to various teaching methods (r=.21, p<.05) exhibited significant correlations with higher VDT scores. Conclusion The findings of this study suggest that increasing students’ satisfaction with their education and applying various teaching methods can contribute to the improvement of visual differentiation ability in PICS.

Objective: Automated breast ultrasound (ABUS) is a relevant imaging technique for early breast cancer diagnosis and is increasingly being used as a supplementary tool for mammography. This study compared the performance of ABUS and handheld ultrasound (HHUS) in detecting and characterizing the axillary lymph nodes (LNs) in patients with breast cancer. Materials and Methods: We retrospectively reviewed the medical records of women with recently diagnosed early breast cancer (≤ T2) who underwent both ABUS and HHUS examinations for axilla (September 2017–May 2018). ABUS and HHUS findings were compared using pathological outcomes as reference standards. Diagnostic performance in predicting any axillary LN metastasis and heavy nodal-burden metastases (i.e., ≥ 3 LNs) was evaluated. The ABUS-HHUS agreement for visibility and US findings was calculated. Results: The study included 377 women (53.1 ± 11.1 years). Among 385 breast cancers in 377 patients, 101 had axillary LN metastases and 30 had heavy nodal burden metastases. ABUS identified benign-looking or suspicious axillary LNs (average, 1.4 ± 0.8) in 246 axillae (63.9%, 246/385). According to the per-breast analysis, the sensitivity, specificity, positive and negative predictive values, and accuracy of ABUS in predicting axillary LN metastases were 43.6% (44/101), 95.1% (270/284), 75.9% (44/58), 82.6% (270/327), and 81.6% (314/385), respectively. The corresponding results for HHUS were 41.6% (42/101), 95.1% (270/284), 75.0% (42/56), 82.1% (270/329), and 81.0% (312/385), respectively, which were not significantly different from those of ABUS (P ≥ 0.53). The performance results for heavy nodal-burden metastases were 70.0% (21/30), 89.6% (318/355), 36.2% (21/58), 97.3% (318/327), and 88.1% (339/385), respectively, for ABUS and 66.7% (20/30), 89.9% (319/355), 35.7% (20/56), 97.0% (319/329), and 88.1% (339/385), respectively, for HHUS, also not showing significant difference (P ≥ 0.57). The ABUS–HHUS agreement was 95.9% (236/246; Cohen’s kappa = 0.883). Conclusion Although ABUS showed limited sensitivity in diagnosing axillary LN metastasis in early breast cancer, it was still useful as the performance was comparable to that of HHUS.

Purpose: This study provides insights into the prevalence at birth, clinical characteristics, and outcomes of gastroschisis and omphalocele in Korea over the past decade, addressing the lack of localized data despite advanced healthcare capabilities. Methods: The study retrospectively analyzed data from 20 pediatric surgical centers in Korea from January 2012 to December 2021, including 269 patients diagnosed with gastroschisis or omphalocele. Data variables included gender, gestational age, birth weight, associated anomalies, type of defect, surgical interventions, and outcomes. Results: The study covered 269 patients, with 80 gastroschisis and 189 omphalocele cases. Gastroschisis prevalence at birth remained stable at 2.15 per 100,000 live births, while omphalocele increased to 5.08 per 100,000. Both conditions had similar gender ratios (0.95). Gastroschisis patients had lower birth weights (2,463.90±505.50 g) and smaller head circumferences (31.97±1.86 cm) compared to omphalocele patients (2,757.65±761.24 g, 32.78±2.64 cm). Omphalocele cases had more associated anomalies, especially cardiovascular issues. Prenatal diagnosis rates were high: 93.7% for gastroschisis and 86.4% for omphalocele. About 96.3% of gastroschisis and 84.1% of omphalocele patients were born in their treatment hospitals. Gastroschisis patients underwent surgery sooner (average 3.5 days) and started feeding later (16.5 days) than omphalocele patients (average 56.5 days to surgery, 6.6 days to start feeding). Hospital stays and follow-up durations were similar, averaging around 782.6 days for gastroschisis and 800.3 days for omphalocele patients. Survival rates were 89.7% for gastroschisis and 87.1% for omphalocele. Conclusion The study highlights the need for early diagnosis, centralized care, and specialized surgical approaches to optimize outcomes for gastroschisis and omphalocele patients in Korea. Enhanced prenatal screening and surgical protocols are recommended to improve these patients' prognosis.

Purpose: The Korean Association of Pediatric Surgeons (KAPS) conducts annual nationwide surveys on various aspects of pediatric surgical diseases, with the results being discussed during KAPS’s annual spring meetings. Methods: KAPS conducted two national surveys, in 1995 and 2016, to investigate esophageal atresia (EA) with or without tracheoesophageal fistula (TEF). The authors analyzed data from these surveys to identify differences or changes in the annual occurrence, demographic characteristics, clinical presentation, preoperative diagnostic methods, anatomical type, associated anomalies, surgical treatment, and postoperative outcomes among patients with EA/TEF treated by KAPS members. Results: The first and second national surveys included 148 and 211 patients with EA/TEF, respectively. Excessive salivation was the most prevalent clinical symptom in both surveys. Type C was the most common form of EA/TEF in both surveys. The first survey included 126 patients, all of whom underwent open surgery. In the second survey, 152 (78.4%) of 194 patients underwent open surgery, while 34 (17.5%) underwent thoracoscopic surgery. Primary esophageal repair was performed on 96 (76.2%) of 126 patients in the first survey and on 160 (82.5%) of 194 patients in the second survey. Anastomotic strictures developed in 21.4% and 32.5% of patients, anastomotic leakage in 22.2% and 10.3%, recurrent fistula in 2.4% and 4.2% during the first and second surveys, respectively. The respective survival rates for group A were 90.2% and 98.3% in the first and second surveys. For group B, the rates were 73.9% and 98.1%, and for group C, they were 34.5% and 68.1%, respectively, according to the Waterston classifications. Conclusion These nationwide surveys provide comprehensive information on the status, detailed treatment, and outcomes for Korean pediatric patients with EA/TEF. They are anticipated to be an invaluable resource and guide for pediatric surgeons seeking to expand their knowledge on EA/TEF and its treatment options.

Purpose: Several predictive models have been developed to predict the pathological complete response (pCR) after neoadjuvant chemotherapy (NAC); however, few are broadly applicable owing to radiologic complexity and institution-specific clinical variables, and none have been externally validated. This study aimed to develop and externally validate a machine learning model that predicts pCR after NAC in patients with breast cancer using routinely collected clinical and demographic variables. Methods: The electronic medical records of patients with advanced breast cancer who underwent NAC before surgical resection between January 2017 and December 2020 were reviewed. Patient data from Seoul National University Bundang Hospital were divided into training and internal validation cohorts. Five machine learning techniques, including gradient boosting machine (GBM), support vector machine, random forest, decision tree, and neural network, were used to build predictive models, and the area under the receiver operating characteristic curve (AUC) was compared to select the best model. Finally, the model was validated using an independent cohort from Seoul National University Hospital. Results: A total of 1,003 patients were included in the study: 287, 71, and 645 in the training, internal validation, and external validation cohorts, respectively. Overall, 36.3% of the patients achieved pCR. Among the five machine learning models, the GBM showed the highest AUC for pCR prediction (AUC, 0.903; 95% confidence interval [CI], 0.833–0.972).External validation confirmed an AUC of 0.833 (95% CI, 0.800–0.865). Conclusion Commonly available clinical and demographic variables were used to develop a machine learning model for predicting pCR following NAC. External validation of the model demonstrated good discrimination power, indicating that routinely collected variables were sufficient to build a good prediction model.