1.Glymphatic System of the Brain: Anatomy, Physiology, and Clinical Implications
Min Young CHUN ; Seok Jong CHUNG ; Seong Ho JEONG
Journal of the Korean Neurological Association 2026;44(1):8-21
Cerebrospinal fluid (CSF) dynamics are increasingly recognized as central to brain waste clearance. Beyond the classical view of unidirectional CSF circulation, recent studies have identified the glymphatic system and meningeal lymphatic vessels as major complementary pathways. Glymphatic transport is driven by arterial pulsation, respiration, vasomotion, and strongly enhanced during slow-wave sleep. Advances in neuroimaging, including DTI-ALPS, EPVS quantification, contrast-enhanced magnetic resonance imaging (MRI), and ultrafast functional MRI, have enabled in vivo assessment of these mechanisms. Impaired glymphatic function has been linked to neurodegenerative and cerebrovascular diseases, highlighting its clinical relevance. Potential interventions range from lifestyle measures such as sleep optimization, exercise, and vascular risk control, to pharmacological and experimental strategies aiming to modulate CSF flow. These insights open new opportunities to target the glymphatic-lymphatic axis for the prevention and treatment of neurological disorders.
2.Clinical Outcomes Based on the Corneal Limbus–Scleral Tunnel Distance in Flanged Intrascleral Intraocular Lens Fixation
Dong Hyeon KIM ; Yu Min KIM ; Seong Yong JEONG ; Yong Koo KANG ; Dong Ho PARK ; Jae Rock DO
Journal of the Korean Ophthalmological Society 2026;67(4):103-109
Purpose:
To compare the anatomical and clinical outcomes based on the distance from the corneal limbus to the scleral tunnel in flanged intrascleral intraocular lens (IOL) fixation.
Methods:
We retrospectively analyzed the medical records of patients who underwent scleral fixation of flanged IOLs. Group 1 (54 eyes) had a distance of 2.1 mm from the corneal limbus to the scleral tunnel, and Group 2 (48 eyes) had a distance of 2.8 mm. We evaluated the best corrected visual acuity (BCVA), postoperative complications, IOL tilt and decentration, refractive prediction error (RPE), effective lens position, and iris-IOL distance.
Results:
The BCVA, postoperative complications, IOL tilt, and IOL decentration did not differ between the two groups (p > 0.05). The RPE showed a hyperopic shift in Group 1 and a myopic shift in Group 2 (Group 1: +0.24 ± 0.68 D, Group 2: -0.03 ± 0.43 D, p = 0.03). The iris-IOL distance was statistically longer in Group 1 compared to Group 2 (Group 1: 1.02 ± 0.40 mm, Group 2: 0.57 ± 0.32 mm, p = 0.02). The incidence of pupillary optic capture was significantly higher in Group 2 compared to Group 1 (Group 1; 0%, Group 2; 8.3%, p = 0.03).
Conclusions
It should be considered that a shorter distance from the corneal limbus to the scleral tunnel results in a postoperative hyperopic shift and reduces the incidence of pupillary optic capture when performing flanged intrascleral IOLs fixation.
3.A unified framework for postoperative complications after gastrectomy for gastric cancer: insights from the Korean Quality Improvement Platform in Surgery program
Jeong Ho SONG ; Chang Seok KO ; Han Hong LEE ; Hong Man YOON ; Hyoung-Il KIM ; In Gyu KWON ; Ji Yeon PARK ; Ji Yeong AN ; Jong Won KIM ; Mi Ran JUNG ; Sang-Il LEE ; Seong Ho KONG ; Sun-Hwi HWANG ; Yun-Suhk SUH ; Sang-Yong SON ; Sang-Uk HAN
Annals of Surgical Treatment and Research 2026;110(5):290-298
Purpose:
Postoperative complications following gastric cancer surgery significantly impact patient outcomes, yet standardized definitions for these events have not been consistently applied across institutions in Korea. This study aimed to develop a consensus-based, standardized complication classification system specific to gastrectomy for gastric cancer as part of the Korean Quality Improvement Platform in Surgery (K-QIPS) initiative.
Methods:
As part of K-QIPS, a dedicated task force team (TFT) was formed with surgical experts from fourteen high-volume hospitals across Korea. The TFT conducted ten formal meetings to review existing literature and international guidelines, and incorporated findings from randomized controlled trials. The final complication list was developed through expert consensus and structured into a standardized framework. A Data Entry Manual was created to support consistent data collection by surgical clinical reviewers.
Results:
The TFT defined specific postoperative complications following gastrectomy for gastric cancer, including anastomotic leakage, duodenal stump leakage, pancreatic fistula, intra-abdominal and luminal bleeding, delayed gastric emptying, and internal hernia. Notably, internal hernia was described in standardized form for the first time. General complications were developed first and overlapped in part with the gastric cancer-specific list. The task force also produced a Data Entry Manual that provides practical instructions to ensure consistency and accuracy in complication reporting.
Conclusion
This nationwide consensus initiative established the first standardized complication classification system for gastric cancer surgery in Korea. The proposed definitions and data entry system are expected to improve complication reporting, enable multicenter research, support surgical quality benchmarking, and ultimately enhance patient outcomes.
4.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.
5.Correlation and Agreement Between Transcutaneous Oxygen Pressure and Toe Pressure in Patients with Diabetic Foot Ulcers
Kyu-Il LEE ; Yu-Kyeong YUN ; Seung-Kyu HAN ; Kyung-Chul MOON ; Sik NAMGOONG ; Seong-Ho JEONG ; Eun-Sang DHONG
Journal of Wound Management and Research 2026;22(1):14-20
Background:
Adequate tissue oxygenation is a key determinant of diabetic foot ulcer (DFU) outcomes. Though transcutaneous oxygen pressure (TcPO2) is the gold standard for evaluating tissue oxygenation, its limited availability restricts routine clinical use. Consequently, toe pressure is frequently utilized as a practical surrogate; however, the direct correlation between these two modalities has yet to be rigorously investigated. This study aimed to assess the correlation and agreement between TcPO2 and toe pressure in patients with DFUs.
Methods:
A retrospective review was conducted on 837 DFU patients who received simultaneous TcPO2 and toe pressure assessments. The correlation between the two tests was analyzed using the Pearson correlation coefficient, and agreement was evaluated using Bland–Altman analysis. To aid interpretation, a scatterplot and Bland–Altman plot were generated.
Results:
TcPO2 and toe pressure demonstrated a strong correlation (R=0.66; 95% confidence interval, 0.62 to 0.70; P<0.001). Bland–Altman analysis showed a mean bias of 26.9 mmHg (standard deviation of differences, 28.8 mmHg; 95% limits of agreement, −28.9 to 82.6 mmHg) between toe pressure and TcPO2, reflecting limited agreement and increased variability at higher perfusion levels.
Conclusion
TcPO2 and toe pressure are strongly correlated. However, they are not interchangeable, particularly in DFU patients with high tissue perfusion.
6.Part 1. Current Status of Hearing Loss Patients in Korea Using National Data: National Health Insurance Service- Database, 2010 to 2020
Junhun LEE ; Chul Young YOON ; Jiwon KIM ; In-Ki JIN ; Michelle J. SUH ; Wan-Ho CHO ; Hyo-Jeong LEE ; Seong Jun CHOI ; Dongchul CHA ; Kyung Ho PARK ; Soo Hee OH ; Young Joon SEO ; Tae Hoon KONG
Korean Journal of Otolaryngology - Head and Neck Surgery 2025;68(1):7-18
Background and Objectives:
Hearing loss significantly affects communication, psychosocial well-being, and quality of life. This study analyzes the National Health Insurance Service database to assess the trends and characteristics of hearing loss in South Korea from 2010 to 2020.Subjects and Method The database encompasses 97% of the Korean population, providing comprehensive data on medical history, prescriptions, and health examinations. The analysis used the World Health Organization’s ICD-10 definitions to categorize hearing loss types and examine their prevalence and incidence across various demographics over 11 years.
Results:
There was an overall annual increase of 4.62% in diagnosed cases of hearing loss, with the most significant rise among the elderly. The rate of increase accelerated from 3.32% between 2010 and 2014 to 6.49% between 2014 and 2020, corresponding with the improved hearing aid access facilitated by policy changes. Women showed a slightly higher increase than men. The data also indicated a consistent rise in abnormal hearing test results during health examinations, especially in older adults.
Conclusion
The study highlights an increasing trend in hearing loss diagnoses, driven by an aging population and enhanced detection facilitated by policy changes. These findings emphasize the need for continuous monitoring and targeted health policies to manage hearing loss effectively, offering valuable insights for global health management and policy development.
7.Part 2. Current Status of Hearing Disability and Hearing Rehabilitation Devices in Korea Using National Data: NHIS-Database, 2010 to 2020
Junhun LEE ; Chul Young YOON ; Jiwon KIM ; In-Ki JIN ; Michelle J. SUH ; Wan-Ho CHO ; Hyo-Jeong LEE ; Seong Jun CHOI ; Dongchul CHA ; Kyung Ho PARK ; Soo Hee OH ; Young Joon SEO ; Tae Hoon KONG
Korean Journal of Otolaryngology - Head and Neck Surgery 2025;68(3):94-104
Background and Objectives:
This study aims to analyze trends in hearing disability and the use of hearing rehabilitation devices (hearing aids and cochlear implants) in South Korea over the past 11 years (2010-2020) using data from the National Health Insurance Service (NHIS).Subjects and Method Data were extracted from the NHIS database, covering approximately 97% of the South Korean population. Patients diagnosed with hearing loss were classified using ICD-10 codes. The data were analyzed to determine trends in hearing disability, hearing aid prescriptions, and cochlear implant usage by age, gender, and types and causes of hearing loss.
Results:
The number of hearing disability patients increased from 170900 in 2010 to 362738 in 2020, with an annual growth rate of 7.95%. The highest increase was observed in the ≥60 age group, with an annual growth rate of 11.04%. Hearing aid prescriptions rose from 4966 in 2010 to 11974 in 2020, showing a 10.45% annual increase. Females showed a higher growth rate in both hearing disability and hearing aid prescriptions compared to males. Cochlear implant prescriptions also increased, particularly among older adults.
Conclusion
The study highlights a significant rise in hearing disability and the use of hearing aids and cochlear implants in South Korea, especially among the elderly. The findings underscore the importance of early diagnosis and intervention for hearing loss and the need for policy improvements to enhance accessibility and affordability of hearing rehabilitation services. Additional strategies are needed to ensure appropriate hearing rehabilitation for those not yet receiving adequate care.
8.Neuroblastoma: A 2020 Survey Conducted by the Korean Association of Pediatric Surgeons
Hee-Beom YANG ; Soo Min AHN ; Min Jeng CHO ; Yong-Hoon CHO ; Soo Jin Na CHOI ; Yoon Mi CHOI ; Jae Hee CHUNG ; Seok Joo HAN ; In Geol HO ; Jeong HONG ; Kyong IHN ; Yeon Jun JEONG ; Eunyoung JUNG ; Dae Youn KIM ; Hae-Young KIM ; Ki Hoon KIM ; Seong Chul KIM ; Soo-Hong KIM ; Eun-Jung KOO ; Hyun Hee KWON ; Yong Jae KWON ; Nam-Hyuk LEE ; Ju Yeon LEE ; Sanghoon LEE ; Jung-Man NAMGOONG ; Chaeyoun OH ; Jung-Tak OH ; Jin Young PARK ; Junbeom PARK ; Jeong-Meen SEO ; Jae Ho SHIN ; Hyun Beak SHIN ; Joohyun SIM ; Jiyoung SUL ; Joon Kee YOUN ; Hyun-Young KIM
Advances in Pediatric Surgery 2025;31(2):66-76
Purpose:
To report a nationwide survey on neuroblastoma conducted by the Korean Association of Pediatric Surgeons (KAPS) in 2020.
Methods:
The clinical data of pediatric patients diagnosed with and treated for neuroblastoma from 2005 to 2019 in 19 hospitals of KAPS members were collected. Survival and prognostic factor analyses were performed using the log rank test and Cox proportional hazard analysis. A p-value <0.05 was considered significant.
Results:
A total of 669 patients with neuroblastoma were registered for the study. The results were presented and discussed at the 36th annual meeting of the KAPS, which was held in Seoul on August 21, 2020.
Conclusion
This study provides information on patient demographics, prognostic outcomes, and comprehensive treatment outcomes for neuroblastoma. The study is expected to be an important reference for improving pediatric surgeons’ understanding and treatment of neuroblastoma.
9.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.
10.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.

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