1.Multicenter evaluation of the PASS score as a negative predictive tool and the impact of inter-observer variability in pheochromocytoma and paraganglioma risk stratification
Sungyeon JUNG ; Hye-Ri SHIN ; Su-Jin SHIN ; Hee Young NA ; Soon-Won HONG ; So Yeon PARK ; Chan Kwon JUNG ; Kyeong Cheon JUNG ; Young Lyun OH ; Jae-Kyung WON
Journal of Pathology and Translational Medicine 2026;60(2):202-213
The Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) is widely used for risk stratification in pheochromocytoma and paraganglioma (PPGL), but its clinical utility is limited by inter-observer variability of its parameters and inconsistent predictive performance. Methods: We conducted a multicenter retrospective study of 1,518 patients with PPGL from five tertiary referral centers in Korea. Prognostic utility of PASS system was assessed using logistic regression, Kaplan-Meier analysis, and receiver operating characteristic (ROC) curve analysis. Inter-observer variability was inferred by comparing area under the ROC curve (AUCs) across institutions. Simplified PASS systems were developed based on multivariable analysis of key histopathological parameters. Results: The PASS system was a significant predictor of adverse events and recurrence-free survival. Although the PASS system demonstrated only modest discriminative ability (AUC, 0.673), it showed a high negative predictive value (NPV, 0.885), supporting its usefulness as a screening tool for benign behavior. However, there was significant inter-institutional variability in PASS performance (AUC; range, 0.513 to 0.727; p < .05). The 3-factor Simple PASS, which incorporates necrosis, spindling, and mitotic figures, exhibited less inter-observer variation. The 4-factor Simple PASS, which adds vascular invasion to the 3-factor model, also showed reduced inter-observer variability and improved AUC and NPV compared to the original PASS system. Conclusions: In this multicenter cohort, the PASS system demonstrated high NPV and screening potential, but significant inter-observer variability remains a challenge. Simplification of the PASS system and enhanced pathologist training may improve reproducibility and clinical utility in PPGL risk stratification.
2.Transition to a Primary Care–Centered Healthcare System: A Structural Reform for Korean Healthcare
Serng Bai PAK ; Sang-Hyun LEE ; Kyung-Hee CHO ; Juhwan OH ; Sang-il LEE ; Kunhee PARK ; Jae-Heon KANG ; Seung-Won OH ; Hee Gyung KANG ; Mihwa YOO
Korean Journal of Family Practice 2026;16(1):33-41
Korea’s healthcare system is at a critical juncture as rapid population aging, rising chronic disease burdens, and fragmented care expose the limits of a hospital-centered, fee-for-service model. Although policy discussions have long emphasized strengthening primary care and introducing a “family doctor” system, past reforms have focused mainly on expanding services or redefining professional roles, without establishing clear accountability, care continuity, or aligned payment mechanisms. Consequently, primary care remains weak and responsibility for comprehensive patient management is diffuse. This article argues that meaningful reform requires redefining the primary physician as an accountable manager of longitudinal, coordinated care within an integrated delivery and payment framework. Drawing on experiences from the United States, the United Kingdom, and several European countries, it identifies common features of successful primary care–oriented systems, including patient registration, team-based care, risk-adjusted payment, and explicit outcome accountability. Based on these insights, the authors propose a Korean primary physician model tailored to solo and small-group practices while fostering regional collaboration. Core elements include voluntary patient registration, multidisciplinary primary care teams, risk-stratified care management, regional care networks, and a mixed payment model combining per-member-per-month payments, shared savings, and performance-based incentives. The article emphasizes phased pilot testing focused on operational feasibility. Ultimately, transitioning to a primary care–centered system is presented as a strategic necessity for sustainability and improved care continuity.
3.Closed reduction of midline palatal fracture using a palatal acrylic splint and interdental wiring: case report
Jae-Seung JUNG ; Kyung-Heun SON ; Hyo-jun KIM ; Ji-Su OH ; Seong-Yong MOON
Oral Biology Research 2026;50(1):4-
Midline palatal fractures compromise maxillary transverse stability and cause oro-nasal communication. We report a successful minimally invasive reconstruction based on AO CMF principles. A 60-year-old male with Le Fort II and midline palatal fractures following a fall exhibited nasal regurgitation. Associated facial fractures were managed conservatively, while the palatal fracture was addressed with a customized acrylic splint fabricated via model-based virtual surgery to restore pre-traumatic occlusion.Intraoperatively, segments were repositioned through manual reduction, followed by intermolar wire ligation and splint fixation. Nasal regurgitation resolved by postoperative day 4. Evaluation at 10 days confirmed anatomical arch width restoration. Stable occlusion was maintained throughout the 6-week splinting period. Closed reduction using customized splints and interdental ligation is an effective, minimally invasive alternative for managing midline palatal fractures, particularly when open reduction is challenging.
4.Impact of Low-Density Lipoprotein Cholesterol Levels on Atherosclerotic Vascular Changes: Analysis of Korean Treat Stroke to Target Trial
Sang Hee HA ; Jae-Chan RYU ; Sung Hee AHN ; Jae-Kwan CHA ; Sang Min SUNG ; Tae-Jin SONG ; Kyung Bok LEE ; Eung-Gyu KIM ; Yong-Won KIM ; Ji Hoe HEO ; Man Seok PARK ; Kyusik KANG ; Byung-Chul LEE ; Keun-Sik HONG ; Oh Young BANG ; Jei KIM ; Jong S. KIM
Journal of Stroke 2026;28(2):330-333
5.Early Onset, High Comorbidity Burden, and Regional Disparities of CADASIL:A Nationwide Cohort Study in South Korea
Ju-Yeun LEE ; Minwoo LEE ; Jae-Sung LIM ; Mi Sun OH ; Kyung-Ho YU ; Young Eun KIM ; Hyeo-Il MA ; Yun Jin KIM ; Jong Ho PARK ; Young Hee JUNG
Journal of Clinical Neurology 2026;22(2):172-182
Background:
and Purpose To compare the epidemiological and clinical features of the rare patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) with age- and sex-matched controls in a nationwide cohort from South Korea.
Methods:
This observational cohort study analyzed newly diagnosed CADASIL patients aged at least 20 years and matched controls using data from the National Health Information Database for 2004–2022. The cumulative incidence of CADASIL was assessed by age and sex, and compared between regions. Neurologic and systemic diseases were compared between the CADASIL and control groups.
Results:
The study analyzed 816 CADASIL patients and 816 age- and sex-matched controls aged 56.8±15.2 years (mean±standard deviation), among whom 48.3% were male. The cumulative incidence of CADASIL was 1.86 per 100,000 people (95% confidence interval [CI]=1.85– 1.87 per 100,000), and peaked at 60–69 years of age. In terms of regional distribution, the incidence was highest for Jeju, at 39.67 per 100,000 (95% CI 37.84–41.49 per 100,000). Neurologic diseases were more frequent in CADASIL patients, including Alzheimer’s disease (33.1% vs.20.0%), vascular dementia (84.9% vs. 5.0%), epilepsy (34.6% vs. 15.9%), stroke (70.7% vs. 27.6%), parkinsonism (18.9% vs. 11.0%), and depression (60.8% vs. 44.9%). Systemic diseases such as diabetes mellitus (78.9% vs. 68.9%) were also more common in CADASIL patients, while cancer (27.9% vs. 38.7%) and myocardial infarction (10.0% vs. 13.6%) were less common than in controls. The onset ages of all diseases were lower in CADASIL patients.
Conclusions
This study has provided a precise nationwide estimate of the CADASIL incidence and its regional distribution in South Korea. CADASIL patients showed higher incidence rates and earlier onsets of diverse clinical manifestations.
6.Macro-Aspartate Aminotransferase Elevation in a Patient with Chronic Hepatitis B
Nae-Yun HEO ; Jae-Hoon KIM ; Seungha PARK ; Joon Hyuk CHOI ; Tae Oh KIM ; Jin LEE ; Yong Eun PARK ; Kyung Ran JUN
The Korean Journal of Gastroenterology 2026;86(2):122-127
Although aspartate aminotransferase (AST) is a serum marker of hepatocellular damage in chronic hepatitis, it is difficult to interpret very high AST levels with concurrent low alanine aminotransferase (ALT) levels. Macro-AST is an immunoglobulin-AST complex that can present as aberrant high enzymatic activity without significant inflammation in the liver. Two patients with chronic hepatitis B presented with disproportionate AST elevations. Their plasma samples were precipitated with polyethylene glycol (PEG) and stored at 4°C for macro-AST determinations. In Case 1, PEG precipitation showed 100% removal of AST activity, and refrigerated storage resulted in a ~70% decline over seven days, confirming macro-AST. In Case 2, both tests showed minimal changes, suggesting that macro-AST was unlikely. The AST levels normalized after antiviral therapy, suggesting immune-active hepatitis as the probable cause, but the other contributing factors could not be completely excluded. The abrupt decrease in AST activity after PEG precipitation and during refrigeration storage suggests that relatively high AST values compared to ALT might be attributed to the presence of macro-AST.These non-invasive methods for detecting macroenzymes might help the patient avoid unnecessary further work-ups.
7.Serial KL-6 Changes in PD-1/PD-L1 Inhibitor-Related Pneumonitis in Non-small Cell Lung Cancer: A Single-Center Prospective Pilot Study
Jae Kyeom SIM ; Juwhan CHOI ; Sung Won CHANG ; Sang Hyuk KIM ; Jee Youn OH ; Kyung Hoon MIN ; Gyu Young HUR ; Hwan Seok YONG ; Jae Jeong SHIM ; Sung Yong LEE
Tuberculosis and Respiratory Diseases 2026;89(2):257-265
Background:
Programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) inhibitors are effective treatments for non-small cell lung cancer (NSCLC), but their use can lead to severe pneumonitis. This study aims to evaluate the utility of Krebs von den Lungen-6 (KL-6) for predicting and diagnosing PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients.
Methods:
We conducted a prospective observational study at a university-affiliated tertiary hospital in Korea from February 2022 to June 2023. Baseline KL-6 levels were measured immediately before initiating PD-1/PD-L1 inhibitor therapy. In patients who developed pneumonitis, KL-6 levels were monitored every 1–2 weeks from the onset of pneumonitis. For patients without pneumonitis, KL-6 levels were measured every 6 weeks. We compared clinical characteristics and serial KL-6 levels between the pneumonitis and non-pneumonitis groups.
Results:
Eighteen patients were enrolled, with 11 developing pneumonitis. Baseline KL-6 levels did not significantly differ between the two groups (261 U/mL in the pneumonitis group vs. 373 U/mL in the non-pneumonitis group, p=0.375). In the pneumonitis group, KL-6 levels generally showed an upward trend, with a median of 412 U/mL at pneumonitis onset. Conversely, KL-6 levels in the non-pneumonitis group showed no clear overall change.
Conclusion
In this pilot study, baseline KL-6 was not clearly linked to PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients. However, increases in KL-6 levels post-baseline were more frequently observed in patients who developed pneumonitis, including cases of all-cause pneumonitis.
8.A Comparative Study of Three National Surveys on Biliary Atresia by the Korean Association of Pediatric Surgeons
Yeon Jun JEONG ; Dayoung KO ; Hyunhee KWON ; Ki Hoon KIM ; Dae Yeon KIM ; Soo-Hong KIM ; Wontae KIM ; Hae-Young KIM ; Hyun Young KIM ; Seong Chul KIM ; Younghyun NA ; Jung-Man NAMGOONG ; So Hyun NAM ; Junbeom PARK ; Jinyoung PARK ; Tae-Jun PARK ; Jeong-Meen SEO ; Ji-Young SUL ; Joonhyuk SON ; Hyun Beak SHIN ; Joohyun SIM ; Soo Min AHN ; Hee Beom YANG ; Jung-Tak OH ; Chaeyoun OH ; Joong Kee YOUN ; Sanghoon LEE ; Ju Yeon LEE ; Kyong IHN ; Hye Kyung CHANG ; Eunyoung JUNG ; Jae Hee CHUNG ; Yu Jeong CHO ; Yun Mee CHOE ; Soo Jin Na CHOI ; Seok Joo HAN ; In Geol HO ; Ji-Won HAN
Advances in Pediatric Surgery 2025;31(2):47-58
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.
9.Comparative Analysis of National Surveys of Intestinal Atresia: A Retrospective Study by the Korean Association of Pediatric Surgeons
Jinyoung PARK ; Dayoung KO ; Eun-jung KOO ; Hyunhee KWON ; Ki Hoon KIM ; Dae Yeon KIM ; Seong Chul KIM ; Soo-Hong KIM ; Wontae KIM ; HaeYoung KIM ; Hyun-Young KIM ; So Hyun NAM ; Jung-Man NAMGOONG ; Junbeom PARK ; Taejin PARK ; Min-Jung BANG ; Jeong-Meen SEO ; Ji-Young SUL ; Joonhyuk SON ; Joohyun SIM ; Soo Min AHN ; Hee-Beom YANG ; Jung-Tak OH ; Chaeyoun OH ; Joong Kee YOUN ; Sanghoon LEE ; Ju Yeon LEE ; Kyong IHN ; Hye Kyung CHANG ; Yeon Jun JEONG ; Eunyoung JUNG ; Jae Hee CHUNG ; Min Jeong CHO ; Yun-Mee CHOE ; Seok Joo HAN ; In Geol HO ; Jeong HONG
Advances in Pediatric Surgery 2025;31(1):8-15
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.
10.Leveraging augmented reality for dynamic guidance in 3-dimensional laparoscopic and robotic liver surgery:a prospective case series study
Moon Young OH ; Kyung Chul YOON ; Hyoun-Joong KONG ; Taesoo JANG ; Yeonjin CHOI ; Junki KIM ; Jae-Yoon KIM ; YoungRok CHOI ; Young Jun CHAI
Annals of Surgical Treatment and Research 2025;109(1):44-52
Purpose:
Accurate anatomical knowledge and precise visualization are critical during liver surgery. We developed augmented reality (AR) software that overlays digital 3-dimensional (3D) models onto laparoscopic or robotic views, providing real-time visual aids for surgical navigation during 3D laparoscopic and robotic liver surgeries. This study assesses the accuracy of manual registration and the subjective perception of this AR software by the operator.
Methods:
Ten consecutive patients undergoing 3D laparoscopic or robotic liver surgery from December 2023 to February 2024 were selected for application of the AR software during surgery. Manual registration accuracy was quantified postregistration using the Dice similarity coefficient (DSC) to compare the stereoscopic and virtual liver images. A 6-question operator survey, using a 5-point Likert scale, was administered after each surgery to evaluate the software’s helpfulness in clinical settings.
Results:
Seven males and 3 females (mean age, 62.4 ± 6.4 years) underwent liver surgery (3D laparoscopic, 5; robotic, 5).Surgical procedures included 4 right hemihepatectomies, 1 extended left hemihepatectomy, 1 left lateral sectionectomy, and 4 segmentectomies. The mean tumor size was 4.4 ± 2.2 cm (range, 1.0–7.5 cm). The mean DSC was 0.912 ± 0.052 (range, 0.879–0.954). The operator rated registration alignment favorably before (mean score, 3.9 ± 1.1) and after mobilization (mean score, 4.1 ± 1.2). The software was reported as very helpful overall (mean score, 4.2 ± 0.8), and in locating blood vessels (4.2 ± 0.6) and tumors (4.3 ± 0.7).
Conclusion
Clinical application of the AR software during 3D laparoscopic and robotic liver surgery is feasible, with favorable registration accuracy and high operator perception of helpfulness.

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