1.Effects of the timing of testicular sperm retrieval on intracytoplasmic sperm injection outcomes
Tae Ho HWANG ; Jae Kyun PARK ; Dong Hyuk SHIN ; Won Hee LEE ; Ye Eun KIM ; Yohan HEO ; Tae Ho LEE ; Seung-Ryeol LEE ; Seung-Hun SONG
Clinical and Experimental Reproductive Medicine 2026;53(2):115-120
Objective:
This study aimed to evaluate reproductive outcomes according to the timing of testicular sperm retrieval.
Methods:
The study included 282 infertile couples divided into three groups: group A (freeze-thawed testicular sperm extraction [TESE] sperm, n=233), group B (fresh TESE sperm collected 1 day before ovum pickup, n=22), and group C (fresh TESE sperm collected on the same day as ovum pickup, n=27). The indications for TESE were surgically uncorrectable azoospermia or ejaculation failure, often accompanied by medical comorbidities such as diabetes mellitus and spinal cord injury. The outcome parameters assessed were fertilization rates, embryo quality, and clinical pregnancy rates.
Results:
The mean paternal age was 36.8±5.7 years, and the mean maternal age was 32.6±3.5 years. The mean duration of infertility was 2.9±1.8 years. The fertilization rates were 70.7%, 78.9%, and 73.0% for groups A, B, and C, respectively (p=0.047). The percentages of good-quality embryos were 68.2%, 65.3%, and 48.4%, respectively (p=0.007); specifically, the percentage of good-quality embryos was significantly lower in group C compared with the other two groups. Clinical pregnancy rates per transfer were similar at 51.1%, 50.0%, and 48.1% (p=0.958), with no differences observed in miscarriage rates.
Conclusion
Testicular sperm retrieval can be safely performed 1 day before ovum pickup, resulting in favorable fertility outcomes.
2.A Protocol of Korean JOint RegistrY for ALZheimer’s Treatment and Diagnostics (JOY-ALZ)
Geon Ha KIM ; Jung-Min PYUN ; Danbee KANG ; Sung Hoon KANG ; Seong-Ho KOH ; Jae Seung KIM ; So Young MOON ; Won-Jin MOON ; Young Ho PARK ; YongSoo SHIM ; Dong Won YANG ; Young Chul YOUN ; Young Hee JUNG ; Hanna CHO ; Hojin CHOI ; Jae-Sung LIM ; Kee Hyung PARK ; Seong Hye CHOI
Dementia and Neurocognitive Disorders 2026;25(1):25-41
Background:
and Purpose: To assess the long-term effectiveness, safety, and economic viability of recently approved Alzheimer’s disease (AD) therapies, as well as to evaluate the real-world application of novel diagnostics among AD patients with diverse comorbidities, comprehensive real-world data (RWD) analysis is essential. The Korean JOint RegistrY for ALZheimer’s Treatment and Diagnostics (JOY-ALZ) endeavors to create a registry of RWD derived from clinical practice on new diagnostic methods and therapeutic agents for AD introduced in Korea since 2021.
Methods:
Participants must fulfill all the following: 1) be at least 19 years old; 2) be actively receiving, scheduled to initiate, or undergoing evaluation for any AD disease-modifying treatment; 3) have completed amyloid positron emission tomography or cerebrospinal fluid AD immunoassay (a positive result is not essential for participation); 4) have a clinical classification of cognitively unimpaired, mild cognitive impairment, or probable AD dementia. Data generated during routine care is segmented into a minimum dataset, extended dataset, and research-only dataset requiring extra consent. Assessments encompass clinical, cognitive, functional, neurobehavioral, neuroimaging, and biomarker evaluations, in addition to systematic monitoring of new AD treatments and their safety.Data are collected and monitored at baseline, at semiannual intervals during the initial 2 years, and then annually up to 2034. To date, 46 medical centers will participate in JOY-ALZ.
Conclusions
JOY-ALZ is expected to promote understanding of the long-term clinical outcomes, safety, and cost-effectiveness of recently introduced diagnostics and treatments for AD, thereby supporting the progress of precision medicine in AD care and diagnosis.
3.Impact of COVID-19 on testicular torsion:A single-center retrospective study from a children’s hospital
Kota FUJIMOTO ; Beom Yong RHO ; Si Wook LEE ; Jae Ok BAEK ; Yong Seung LEE ; Sang Woon KIM
Investigative and Clinical Urology 2026;67(1):72-78
Purpose:
Testicular torsion is a urological emergency necessitating immediate surgical intervention. However, the altered medical environment during the coronavirus disease 2019 (COVID-19) pandemic posed several challenges and the current study aimed to analyze its effects on the treatment of pediatric testicular torsion cases.
Materials and Methods:
We retrospectively analyzed 47 pediatric patients diagnosed with testicular torsion at Severance Children's Hospital from 2009 to 2022. Patients were categorized into pre–COVID-19 (n=38) and COVID-19 (n=8) groups. Data were collected for each patient, and the differences between the two groups were statistically analyzed.
Results:
The patients’ median age was from 13 years (range, 1–19 years) to 13 years (range, 1–16 years) between the pre–COVID-19 and COVID-19 period (p=0.309). The analysis revealed a significant difference between the pre–COVID-19 and COVID-19 groups in the time from symptom onset to emergency department arrival (6.4 hours [0.7–120.0] vs. 20.0 hours [1.3–288.0], p=0.031) and the time from symptom onset to surgery start (19.5 hours [4.5–124.3] vs. 28.5 hours [6.1–293.4], p=0.047). The median postoperative size of the affected testis was 9.8 mL (range, 2.0–13.9 mL) during the COVID-19 period, compared to 1.6 mL (range, 0.1–7.3 mL) in pre–COVID-19 period (p=0.012). The testicular volume ratio (affected/unaffected) was used to evaluate outcomes across patients with varying ages and testicular sizes.
Conclusions
The current study shows that pandemic-related delays in treatment may worsen ischemic injury in testicular torsion, emphasizing the importance of timely intervention even during global crises.
4.Intraoperative Visual Evoked Potential Monitoring in Endoscopic Endonasal Surgery for Nonpituitary Adenoma Suprasellar Tumors
Young Nam KWON ; Hwa Reung LEE ; Myung Jae LEE ; Young Ung KIM ; Seung Woo KIM ; Ha Young SHIN ; Sung-Min KIM ; Ju Hyung MOON ; Jong Hee CHANG ; Eui Hyun KIM
Journal of Clinical Neurology 2026;22(2):221-228
Background:
and Purpose Intraoperative visual evoked potential (VEP) monitoring has been studied mainly in pituitary adenoma, while its role in nonpituitary suprasellar tumors has remained unclear. This study evaluated the predictive usefulness of intraoperative VEP monitoring during endoscopic endonasal surgery (EES) and aimed to identify optimal alarm criteria for visual outcomes.
Methods:
We retrospectively analyzed a cohort of 87 patients who underwent EES with intraoperative VEP monitoring between April 2021 and September 2023. Visual outcomes were evaluated preoperatively and at short-term (≤3 months) and long-term (12 months) followups, with visual deterioration at these time points defined as worsening of either visual acuity or the visual field. Reductions in the VEP amplitude were quantified using both the maximum intraoperative decrease and the final amplitude after recovery. Receiver operating characteristic (ROC) curve analyses were performed to identify the optimal alarm thresholds, and the sensitivity, specificity, positive predictive value, and negative predictive value were calculated for short-term and long-term visual deteriorations.
Results:
Short-term and long-term visual deteriorations were detected in 12 (9.2%) and 5 (3.8%) of the 130 analyzed eyes, respectively. ROC curve analyses identified ≥40% and ≥30% reductions in the N75–P100 amplitude as optimal alarm criteria for short-term and long-term visual deteriorations, respectively. A 30% reduction without intraoperative recovery demonstrated markedly higher sensitivity than the conventional 50% alarm threshold for short-term (58.3% vs. 33.3%) and long-term (80.0% vs. 20.0%) outcomes, while maintaining acceptable specificity (82.2% and 80.8%, respectively).
Conclusions
A 30% reduction in amplitude represents a more-sensitive and clinically relevant alarm threshold than a 50% reduction for intraoperative VEP monitoring during EES for nonpituitary suprasellar tumors. Incorporating both the magnitude and recovery pattern of VEP amplitude changes may improve the accuracy of predictions of long-term visual deterioration. However, the potential for false positives warrants cautious interpretation, and further studies are needed to validate the impact of intraoperative VEP monitoring on visual outcomes.
5.Clinical Practice Guideline for the Prehospital Stage of Acute Stroke : III. Initial Decision for Primary Treatment in Subarachnoid Hemorrhage
Jae Sang OH ; Jong Min LEE ; Hong Suk AHN ; Jung-Jae KIM ; Kyoung Min JANG ; Gi-Yong YUN ; Jang Hun KIM ; Dongwook SEO ; Hyeong Jin LEE ; Yuna JO ; Jinwoo JEONG ; Kyoung-Chul CHA ; Yong Soo CHO ; Su Jin KIM ; Jongkyu PARK ; Won-Sang CHO ; Hoon KIM ; Young Woo KIM ; Seung Hun SHEEN ; Sang Weon LEE ; Jae Whan LEE ; Tae Gon KIM ; Sung-kon HA ; Sukh Que PARK ; Dae-Won KIM ; Soon Chan KWON
Journal of Korean Neurosurgical Society 2026;69(1):35-50
Subarachnoid hemorrhage (SAH) is a stroke subtype with high mortality and poor functional outcomes. Prompt occlusion of a ruptured aneurysm at an early stage is crucial to prevent rebleeding, which can result in even higher mortality and more severe disabilities. The most critical initial decision in SAH management is the choice of treatment method with surgical clipping or endovascular coiling. We aimed to develop an evidence-based clinical guideline to select the optimal initial treatment in patients with SAH. We developed this guideline based on evidence from systematic reviews and meta-analyses via a de novo process. A systematic literature review was conducted across four databases (MEDLINE, Embase, Cochrane, and KoreaMed) to answer two population, intervention, comparison, outcome questions comparing clipping and coiling. The risk of bias was assessed using ROB 2.0 and the Newcastle-Ottawa Scale. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagrams and meta-analyses were generated for functional outcome and mortality. We included six randomized control trials (RCTs) and 58 observational studies. Meta-analysis of RCTs showed that coiling improved functional outcomes compared to clipping (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.86–0.97). No significant mortality difference was observed in RCTs (OR, 1.38; 95% CI, 0.91–2.09), but non-RCTs favored clipping for reduced mortality (OR, 0.77; 95% CI, 0.69–0.86). However, it is difficult to generalize these findings to all clinical situations, as patients with SAH have a highly variable clinical course. Final treatment decision should be tailored to the individual patient’s status, including aneurysm location, morphology, and the expertise available at the treatment center. Such decisions are best made by specialists such as a board-certified physician and should be explained to the patient and their caregivers, along with the rationale for selecting the most appropriate treatment at the given hospital. Korea has many certified endovascular neurosurgeons, cerebrovascular surgeons, and certified cerebrovascular centers. Proper selection of the most suitable treatment method by certified physicians and centers would greatly benefit patient outcomes and healthcare professionals.
6.Clinical Practice Guidelines for the Prehospital Stage of Acute Stroke in Korea II : Transport Decisions for Patients with Acute Ischemic Stroke
Jae Sang OH ; Yuna JO ; Jong Min LEE ; Hong Suk AHN ; Jung-Jae KIM ; Kyoung Min JANG ; Gi-Yong YUN ; Jang Hun KIM ; Dongwook SEO ; Hyeong Jin LEE ; Jinwoo JEONG ; Kyoung-Chul CHA ; Yong Soo CHO ; Su Jin KIM ; Jongkyu PARK ; Won-Sang CHO ; Hoon KIM ; Young Woo KIM ; Seung Hun SHEEN ; Sang Weon LEE ; Jae Whan LEE ; Tae Gon KIM ; Sung-kon HA ; Sukh Que PARK ; Soon Chan KWON
Journal of Korean Neurosurgical Society 2026;69(1):23-34
The mothership (MS) model, where patients are directly transferred to a thrombectomy-capable center, and the drip-and-ship (DS) model, where thrombolysis is initiated at the nearest primary stroke center before transfer for thrombectomy, are the primary transport modes for patients with stroke. We aimed to establish guidelines for selecting the appropriate transfer strategy based on emergent large vessel occlusion (LVO). We developed this guideline based on evidence from systematic reviews and meta-analyses via a de novo process. A systematic literature review was conducted across four databases (MEDLINE, Embase, Cochrane, and KoreaMed) to answer three Population, Intervention, Comparison, and Outcome questions comparing MS and DS models. The risk of bias was assessed using the Newcastle-Ottawa Scale. Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagrams and meta-analyses were generated for functional outcomes, mortality, and successful recanalization. Twenty-six non-randomized controlled studies showed that the MS model improved good functional outcomes by approximately 14% compared with the DS model (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.00–1.30). Fifteen studies reported that mortality in the MS and DS models showed no significant differences (OR, 0.97; 95% CI, 0.84–1.11). Twenty-four studies revealed no significant difference in successful recanalization between the MS and DS models (OR, 0.87; 95% CI, 0.68–1.10). The MS model should be considered first to improve the functional outcome of patients with LVO. However, if thrombectomy cannot be performed immediately after thrombolysis, or if a thrombectomy-enabled hospital is not nearby, the DS model should be considered by stroke specialists depending on transportation time and regional factors. We suggest a mixed approach with the DS model based on specific circumstances or regions to ensure the optimum treatment of patients with acute ischemic stroke (AIS). Appropriate transport for patients with LVO improves the prognosis of AIS.
7.Lordosis Distribution Index in an Asymptomatic Elderly Population : The Role of Lower and Upper Lumbar Lordosis According to Individual Pelvic Incidence and Roussouly Type
Seung-Jae HYUN ; Sanghyun HAN ; Youngbae B. KIM
Journal of Korean Neurosurgical Society 2026;69(1):92-99
Objective:
: This study aimed to elucidate the normative upper lumbar lordosis (ULL) and lower LL (LLL) based on individual pelvic and spinal morphology within an asymptomatic elderly population.
Methods:
: Whole spine standing radiographs were obtained from asymptomatic elderly populations who had not undergone previous spinal surgery. The LL, LLL and ULL were measured. Pelvic incidence (PI), upper lumbar distribution index (ULDI), and lower LDI were calculated. Pearson correlation and linear regression analyses were performed, and the mean value for each parameter was obtained according to PI subgroup (PI <40°, 40°≤ PI <50°, 50°≤ PI <60°, and 60°≤ PI) and “theoretical” Roussouly type.
Results:
: Overall, data from 150 male were retrospectively collected in the study, with an average age of 64.1±6.4 years. The mean height was 167.0±5.5 cm, weight was 67.3±9.8 kg, and body mass index was 24.1±3.1 kg/m2. The average LL was -57.5°±9.0°, LLL was -39.7°±6.8°, and PI was 48.6°±8.6°. Pelvic tilt (PT) tended to increase with ULL, PI-LL, PI-ULL, PI-LLL, and ULDI and decrease with LLL and LDI. However, PT was not significantly related to LL. The mean ULDI and LDI were 30.4%±11.7% and 69.7%±11.7%, respectively. The differences between PI and LL (PI-LL) and between PI and LLL (PI-LLL) were -8.9°±8.0° and 9.0°±9.3°, respectively. As PI increased from low (<40°) to high (≥60°), ULDI increased significantly from 25.9% to 38.9%, while LDI decreased from 74.1% to 61.1%. Additionally, LDI varied by Roussouly type, ranging from 62.6% to 81.0%. The LDIs of Roussouly types 1 and 4 were significantly higher and lower, respectively, than those of types 2 and 3 (p<0.001).
Conclusion
: As PI and Roussouly type increase, the contribution of ULL to overall LL rises, reaching up to 38.9%. Conversely, LLL substantially impacts LL in patients with a low PI and those classified as Roussouly type 1. PT is significantly related to LLL instead of LL according to PI.
8.Surgical management of intrahepatic cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma: a narrative review of principles, technical nuances, and emerging strategies
Woohyung LEE ; Kwang Pyo HONG ; Jae Hoon LEE ; Mirang LEE ; Minkyu SUNG ; Seung Jae LEE ; Ki Byung SONG ; Dae Wook HWANG ; Song Cheol KIM
Journal of Liver Cancer 2026;26(1):19-28
Intrahepatic cholangiocarcinoma (CCA) is the second most common primary liver cancer after hepatocellular carcinoma (HCC). However, combined HCC-CCA is a rare malignancy exhibiting hepatocytic and cholangiocytic differentiation. For both tumors, R0 resection with regional lymph node dissection remains the only potentially curative treatment. Nevertheless, key aspects of surgical management remain controversial. In this narrative review, we synthesize contemporary evidence on the surgical management of intrahepatic CCA and combined HCC-CCA. We summarize current data on lymphadenectomy, safety, and oncologic comparability of minimally invasive vs. open surgery, and integration of liver hypertrophy techniques for major hepatectomy. We also review the emerging clinical experience with immune checkpoint inhibitor-based chemoimmunotherapy as a neoadjuvant treatment and conversion surgery for advanced disease. We highlight persisting knowledge gaps and propose practical perspectives to support individualized surgical planning for this heterogeneous disease.
9.Molecular determinants of outcome to gemcitabine, cisplatin, and nab-paclitaxel in patients with advanced biliary tract cancer
Daeseong KIM ; Nam Suk SIM ; Seonjeong WOO ; Min Hwan KIM ; Choong-kun LEE ; Seung Soo HONG ; Sung Hyun KIM ; Ho Kyoung HWANG ; Chang Moo KANG ; Woo Jung LEE ; Jung Hyun JO ; Taek CHUNG ; Sohyun HWANG ; Beodeul KANG ; Jung Sun KIM ; Chang-Il KWON ; Sangwoo KIM ; Hong Jae CHON ; Chang Gon KIM ; Young Nyun PARK ; Hye Jin CHOI
Clinical and Molecular Hepatology 2026;32(2):721-736
Background/Aims:
Biliary tract cancer (BTC) is a rare malignancy with poor prognosis. We investigated genomic determinants of clinical benefit from gemcitabine, cisplatin, and nab-paclitaxel (GAP) versus gemcitabine and cisplatin (GC) in advanced BTC.
Methods:
Clinical and genomic data using TruSight Oncology 500 were analyzed from patients treated with GAP (N=198) or GC (N=89) as first-line therapy.
Results:
With a median follow-up of 33.0 months, GAP modestly improved progression-free survival (PFS) (hazard ratio [HR] 0.764; 95% confidence interval [CI] 0.591–0.989) without significant overall survival (OS) difference compared to GC. Genomic profiling revealed frequent alterations in TP53 (35.2%), KRAS (16.4%), SMAD4 (10.5%), and TNFRSF14 (10.5%), involving RTK/RAS (44.3%), TP53 (41.8%), and PI3K (20.2%) pathways. Single-gene mutations did not predict treatment benefit. However, pathway-level analysis identified PI3K pathway activation as significantly associated with inferior PFS (HR 2.148; 95% CI 1.478–3.124) and OS (HR 2.096; 95% CI 1.413–3.109) in patients receiving GAP, an effect not observed with GC. Importantly, GAP conferred clinical benefit only in patients without PI3K pathway activation, while no survival advantage was seen in those with such alterations (Pinteraction=0.023 for PFS, Pinteraction=0.003 for OS). Similar results were obtained in the independent validation cohort treated with GAP (N=103) or GC (N=64) for BTC.
Conclusions
Genomic profiling using next-generation sequencing identified PI3K pathway activation as key molecular determinant that differentiates patient outcomes between GAP and GC treatments in advanced BTC.
10.Acute Heart Failure Across the Ejection Fraction Spectrum: Phenotypes, Management, and Outcomes From Nationwide KorHF III Registry
Huijin LEE ; Eung Ju KIM ; Seong Woo HAN ; Seong-Mi PARK ; Hyung-Seop KIM ; Myung-Chan CHO ; Hyo-Suk AHN ; Mi-Seung SHIN ; Seok-Jae HWANG ; Jin-Ok JEONG ; Dong Heon YANG ; Junho HYUN ; Jin Oh CHOI ; Hae-Young LEE ; Byung-Su YOO ; Seok-Min KANG ; Dong-Ju CHOI ; Hyun-Jai CHO ;
International Journal of Heart Failure 2026;8(1):43-55
Background and Objectives:
Clinical characteristics and outcomes in acute heart failure (AHF) vary by phenotype. We assessed phenotype-specific features, treatment patterns, and outcomes in a nationwide Korean cohort.
Methods:
The Korean Heart Failure III registry prospectively enrolled 7,351 AHF admissions at 47 hospitals. Among 6,777 patients with available left ventricular ejection fraction (EF), phenotypes were defined as heart failure with reduced EF (HFrEF, ≤40%), mildly reduced EF (HFmrEF,41–49%), or preserved EF (HFpEF, ≥50%). The primary endpoint was a 12-month composite of all-cause death or heart transplantation, evaluated from index admission and, among hospital survivors, from discharge. We used inverse probability weighting (multinomial generalized boosted models with stabilized, trimmed weights) and weighted Cox proportional-hazards models to estimate hazard ratios (HRs).
Results:
Phenotype distribution was 58.9% HFrEF, 13.6% HFmrEF, and 27.5% HFpEF. Crude 12-month composite rates from index admission were 13.4% (HFrEF), 12.7% (HFmrEF), and 16.8% (HFpEF). After weighting, from index admission, HFmrEF (HR, 0.892; 95% confidence interval [CI], 0.731–1.088) and HFpEF (HR, 1.101; 95% CI, 0.939–1.291) did not differ from HFrEF; from discharge, HFpEF had modestly higher risk (HR, 1.207; 95% CI, 1.008–1.445) whereas HFmrEF did not (HR, 1.039; 95% CI, 0.844–1.279). Hyponatremia and chronic kidney disease were consistent adverse markers, while angiotensin-converting enzyme inhibitor/ angiotensin II receptor blocker use at discharge was protective.
Conclusions
Across the EF spectrum, phenotypes showed distinct profiles and risk. Postdischarge risk was modestly higher in HFpEF, supporting phenotype-tailored care and systematic discharge optimization in Korean patients with AHF.

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