Background/Aims: Peroral cholangioscopy (POC) has been used to assess intrahepatic duct (IHD) lesions but with a limited role. A new multibending (MB) ultraslim endoscope has been designed to improve POC performance. We evaluated the usefulness of POC using the MB ultraslim endoscope for the management of IHD lesions. Methods: Between March 2017 and March 2020, 22 patients underwent direct POC using the MB ultraslim endoscope for IHD lesions documented by previous imaging or cholangiopancreatography. The primary outcome was technical success of POC, and secondary outcomes were technical success of POC-guided interventions, median procedure time, and POC-related adverse events. Results: The technical success rate for POC using the MB ultraslim endoscope for IHD lesions was 95.5% (21/22). Free-hand insertion was successful in 95.2% (20/21). The overall technical success rate for POC-guided intervention was 100% (21/21), including nine diagnostic and 12 therapeutic procedures (eight direct stone removal and four intraductal lithotripsies). The median procedure time was 29 minutes (range, 9 to 79 minutes). There were no procedure-related adverse events. Conclusions Direct POC using the MB ultraslim endoscope allows direct visualization of IHD lesions and may be useful for diagnosis and therapeutic management in selected patients.

Objective: : We performed an expanded multi-ethnic meta-analysis to identify associations between inflammation-related loci with intracranial aneurysm (IA) susceptibility. This meta-analysis possesses increased statistical power as it is based on the most data ever evaluated. Methods: : We searched and reviewed relevant literature through electronic search engines up to August 2022. Overall estimates were calculated under the fixed- or random-effect models using pooled odds ratio (OR) and 95% confidence intervals (CIs). Subgroup analyses were performed according to ethnicity. Results: : Our meta-analysis enrolled 15 studies and involved 3070 patients and 5528 controls including European, Asian, Hispanic, and mixed ethnic populations. Of 17 inflammation-related variants, the rs1800796 locus (interleukin [IL]-6) showed the most significant genome-wide association with IA in East-Asian populations, including 1276 IA patients and 1322 controls (OR, 0.65; 95% CI, 0.56–0.75; p=3.24×10-9) under a fixed-effect model. However, this association was not observed in the European population (OR, 1.09; 95% CI, 0.80–1.47; p=0.5929). Three other variants, rs16944 (IL-1β), rs2195940 (IL-12B), and rs1800629 (tumor necrosis factor-α) showed a statistically nominal association with IA in both the overall, as well as East-Asian populations (0.01Conclusion : Our updated meta-analysis with increased statistical power highlights that rs1800796 which maps on the IL-6 gene is associated with IA, and in particular confers a protective effect against occurrence of IA in the East-Asian population.

Although technological advances and clinical studies on stem cells have been increasingly reported in stroke, research targeting hemorrhagic stroke is still lacking compared to that targeting ischemic stroke. Studies on hemorrhagic stroke are also being conducted, mainly in the USA and China. However, little research has been conducted in Korea. In reality, stem cell research or treatment is unfamiliar to many domestic neurosurgeons. Nevertheless, given the increased interest in regenerative medicine and the increase of life expectancy, attention should be paid to this topic. In this paper, we summarized pre-clinical rodent studies and clinical trials using stem cells for hemorrhagic stroke. In addition, we discussed results of domestic investigations and future perspectives on stem cell research for a better understanding.

Background/Aims: Nonalcoholic fatty liver disease (NAFLD) is closely related to gut-microbiome. There is a paucity of research on which strains of gut microbiota affect the progression of NAFLD. This study explored the NAFLD-associated microbiome in humans and the role of Lactobacillus in the progression of NAFLD in mice. Methods: The gut microbiome was analyzed via next-generation sequencing in healthy people (n=37) and NAFLD patients with elevated liver enzymes (n=57). Six-week-old male C57BL/6J mice were separated into six groups (n=10 per group; normal, Western, and four Western diet + strains [109 colony-forming units/g for 8 weeks; L. acidophilus, L. fermentum, L. paracasei, and L. plantarum]). Liver/body weight ratio, liver pathology, serum analysis, and metagenomics in the mice were examined. Results: Compared to healthy subjects (1.6±4.3), NAFLD patients showed an elevated Firmicutes/Bacteroidetes ratio (25.0±29.0) and a reduced composition of Akkermansia and L. murinus (P<0.05). In the animal experiment, L. acidophilus group was associated with a significant reduction in liver/body weight ratio (5.5±0.4) compared to the Western group (6.2±0.6) (P<0.05). L. acidophilus (41.0±8.6), L. fermentum (44.3±12.6), and L. plantarum (39.0±7.6) groups showed decreased cholesterol levels compared to the Western group (85.7±8.6) (P<0.05). In comparison of steatosis, L. acidophilus (1.9±0.6), L. plantarum (2.4±0.7), and L. paracasei (2.0±0.9) groups showed significant improvement of steatosis compared to the Western group (2.6±0.5) (P<0.05). Conclusions Ingestion of Lactobacillus, such as L. acidophilus, L. fermentum, and L. plantarum, ameliorates the progression of nonalcoholic steatosis by lowering cholesterol. The use of Lactobacillus can be considered as a useful strategy for the treatment of NAFLD.

Purpose: Atypical teratoid/rhabdoid tumor (ATRT) is a highly aggressive malignancy with peak incidence in children aged less than 3 years. Standard treatment for central nervous system ATRT in children under the age of 3 years have not been established yet. The objective of this study was to analyze characteristics and clinical outcomes of ATRT in children aged less than 3 years. Materials and Methods: A search of medical records from seven centers was performed between January 2005 and December 2016. Results: Forty-three patients were enrolled. With a median follow-up of 90 months, 27 patients (64.3%) showed at least one episode of disease progression (PD). The first date of PD was at 160 days after diagnosis. The 1- and 3-year progression-free survivals (PFS) were 51.2% and 28.5%, respectively. The 1- and 3-year overall survivals were 61.9% and 38.1%, respectively. The 3-year PFS was improved from 0% in pre-2011 to 47.4% in post-2011. Excluding one patient who did not receive any further therapy after surgery, 27 patients died due to PD (n=21), treatment-related toxicity (n=5), or unknown cause (n=1). In univariate analysis, factors associated with higher 3-year PFS were no metastases, diagnosis after 2011, early adjuvant radiotherapy, and high-dose chemotherapy (HDCT). In multivariate analysis, the use of HDCT and adjuvant radiotherapy remained significant prognostic factors for PFS (both p < 0.01). Conclusion Aggressive therapy including early adjuvant radiotherapy and HDCT could be considered to improve outcomes of ATRT in children under the age of 3 years.

Purpose: Atypical teratoid/rhabdoid tumor (ATRT) is a highly aggressive malignancy with peak incidence in children aged less than 3 years. Standard treatment for central nervous system ATRT in children under the age of 3 years have not been established yet. The objective of this study was to analyze characteristics and clinical outcomes of ATRT in children aged less than 3 years. Materials and Methods: A search of medical records from seven centers was performed between January 2005 and December 2016. Results: Forty-three patients were enrolled. With a median follow-up of 90 months, 27 patients (64.3%) showed at least one episode of disease progression (PD). The first date of PD was at 160 days after diagnosis. The 1- and 3-year progression-free survivals (PFS) were 51.2% and 28.5%, respectively. The 1- and 3-year overall survivals were 61.9% and 38.1%, respectively. The 3-year PFS was improved from 0% in pre-2011 to 47.4% in post-2011. Excluding one patient who did not receive any further therapy after surgery, 27 patients died due to PD (n=21), treatment-related toxicity (n=5), or unknown cause (n=1). In univariate analysis, factors associated with higher 3-year PFS were no metastases, diagnosis after 2011, early adjuvant radiotherapy, and high-dose chemotherapy (HDCT). In multivariate analysis, the use of HDCT and adjuvant radiotherapy remained significant prognostic factors for PFS (both p < 0.01). Conclusion Aggressive therapy including early adjuvant radiotherapy and HDCT could be considered to improve outcomes of ATRT in children under the age of 3 years.

Background/Aims: Recently, the European Society of Gastrointestinal Endoscopy (ESGE) proposed criteria for “difficult biliary cannulation” during endoscopic retrograde cholangiopancreatography (ERCP). This study aimed to investigate the clinical relevance of the ESGE criteria from the perspective of post-ERCP pancreatitis (PEP). Methods: An ERCP database was prospectively maintained between November 2014 and December 2015 across six teaching hospitals in South Korea. The ESGE criteria (biliary cannulation time, the number of cannulation attempts, and inadvertent pancreatic duct [PD] manipulation) were recorded in this database as well as other technical factors. Logistic regression analysis was used to identify risk factors for PEP. Then, the PEP prediction model was investigated using decision tree analysis. Results: We analyzed 1,067 consecutive patients with naïve papilla. The overall rate of PEP was 6.6%. Multivariate analysis revealed that female sex (odds ratio [OR], 1.860; 95% confidence interval [CI], 1.124 to 3.078), a selective biliary cannulation duration >5 minutes (OR, 3.282; 95% CI, 1.641 to 6.566), and inadvertent PD manipulation (OR, 2.614; 95% CI, 1.480 to 4.617) were significant factors affecting PEP. Decision tree analysis revealed that biliary cannulation time (χ2 =49.857, p<0.001) and inadvertent PD manipulation (χ2 =8.556, p=0.010) were decisive factors. PEP occurred in 3.9%, 11.8%, and 16.2% of patients with biliary cannulation duration lasting 3 to 5 minutes, >5 minutes, and >5 minutes with inadvertent PD manipulation, respectively. Conclusions Biliary cannulation time and inadvertent PD manipulation could be relevant indicators of PEP, and 5 minutes might be used as a cutoff value for the implementation of the rescue cannulation technique.

Background/Aims: Recently, the European Society of Gastrointestinal Endoscopy (ESGE) proposed criteria for “difficult biliary cannulation” during endoscopic retrograde cholangiopancreatography (ERCP). This study aimed to investigate the clinical relevance of the ESGE criteria from the perspective of post-ERCP pancreatitis (PEP). Methods: An ERCP database was prospectively maintained between November 2014 and December 2015 across six teaching hospitals in South Korea. The ESGE criteria (biliary cannulation time, the number of cannulation attempts, and inadvertent pancreatic duct [PD] manipulation) were recorded in this database as well as other technical factors. Logistic regression analysis was used to identify risk factors for PEP. Then, the PEP prediction model was investigated using decision tree analysis. Results: We analyzed 1,067 consecutive patients with naïve papilla. The overall rate of PEP was 6.6%. Multivariate analysis revealed that female sex (odds ratio [OR], 1.860; 95% confidence interval [CI], 1.124 to 3.078), a selective biliary cannulation duration >5 minutes (OR, 3.282; 95% CI, 1.641 to 6.566), and inadvertent PD manipulation (OR, 2.614; 95% CI, 1.480 to 4.617) were significant factors affecting PEP. Decision tree analysis revealed that biliary cannulation time (χ2 =49.857, p<0.001) and inadvertent PD manipulation (χ2 =8.556, p=0.010) were decisive factors. PEP occurred in 3.9%, 11.8%, and 16.2% of patients with biliary cannulation duration lasting 3 to 5 minutes, >5 minutes, and >5 minutes with inadvertent PD manipulation, respectively. Conclusions Biliary cannulation time and inadvertent PD manipulation could be relevant indicators of PEP, and 5 minutes might be used as a cutoff value for the implementation of the rescue cannulation technique.