Purpose: Autologous arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis access, with outcomes largely dependent on the surgeon’s experience. Nevertheless, few studies have been conducted on the learning curve of junior vascular surgeons in AVF creation. This study aims to address this by examining the development of surgical skills among junior vascular surgeons. Materials and Methods: A retrospective analysis was conducted on 100 patients who underwent autologous AVF procedures performed by five junior surgeons between January 2018 and December 2023. To establish the cutoff number of cases for the learning curve, we examined the cubic spline curve using the hazard ratio for primary failure. Results: The cutoff number for operation cases was 15.33, and we divided the analysis into a pre-learning curve period (≤15 cases of AVF) and a post-learning curve period (>15 cases of AVF). The 1-year primary patency rate for AVF during the post-learning curve period was 84.0%, which was higher than the 65.5% rate observed during the pre-learning curve period. In a subgroup analysis based on AVF type, the radiocephalic fistula patient group demonstrated a significant increase in 1-year primary patency in the post-learning curve period compared to that in the pre-learning curve period (80.0% vs. 43.0%, log-rank P=0.033). In contrast, there was no significant difference in the primary patency rates between the post- and pre-learning curve periods in the brachiocephalic fistula patient group (90.0% vs. 89.2%, log-rank P=0.930). Conclusion Junior vascular surgeons demonstrated improved primary AVF patency beyond the learning curve benchmark in 15 patients, with particularly notable enhancements in radiocephalic fistulas.

Purpose: Autologous arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis access, with outcomes largely dependent on the surgeon’s experience. Nevertheless, few studies have been conducted on the learning curve of junior vascular surgeons in AVF creation. This study aims to address this by examining the development of surgical skills among junior vascular surgeons. Materials and Methods: A retrospective analysis was conducted on 100 patients who underwent autologous AVF procedures performed by five junior surgeons between January 2018 and December 2023. To establish the cutoff number of cases for the learning curve, we examined the cubic spline curve using the hazard ratio for primary failure. Results: The cutoff number for operation cases was 15.33, and we divided the analysis into a pre-learning curve period (≤15 cases of AVF) and a post-learning curve period (>15 cases of AVF). The 1-year primary patency rate for AVF during the post-learning curve period was 84.0%, which was higher than the 65.5% rate observed during the pre-learning curve period. In a subgroup analysis based on AVF type, the radiocephalic fistula patient group demonstrated a significant increase in 1-year primary patency in the post-learning curve period compared to that in the pre-learning curve period (80.0% vs. 43.0%, log-rank P=0.033). In contrast, there was no significant difference in the primary patency rates between the post- and pre-learning curve periods in the brachiocephalic fistula patient group (90.0% vs. 89.2%, log-rank P=0.930). Conclusion Junior vascular surgeons demonstrated improved primary AVF patency beyond the learning curve benchmark in 15 patients, with particularly notable enhancements in radiocephalic fistulas.

Purpose: Autologous arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis access, with outcomes largely dependent on the surgeon’s experience. Nevertheless, few studies have been conducted on the learning curve of junior vascular surgeons in AVF creation. This study aims to address this by examining the development of surgical skills among junior vascular surgeons. Materials and Methods: A retrospective analysis was conducted on 100 patients who underwent autologous AVF procedures performed by five junior surgeons between January 2018 and December 2023. To establish the cutoff number of cases for the learning curve, we examined the cubic spline curve using the hazard ratio for primary failure. Results: The cutoff number for operation cases was 15.33, and we divided the analysis into a pre-learning curve period (≤15 cases of AVF) and a post-learning curve period (>15 cases of AVF). The 1-year primary patency rate for AVF during the post-learning curve period was 84.0%, which was higher than the 65.5% rate observed during the pre-learning curve period. In a subgroup analysis based on AVF type, the radiocephalic fistula patient group demonstrated a significant increase in 1-year primary patency in the post-learning curve period compared to that in the pre-learning curve period (80.0% vs. 43.0%, log-rank P=0.033). In contrast, there was no significant difference in the primary patency rates between the post- and pre-learning curve periods in the brachiocephalic fistula patient group (90.0% vs. 89.2%, log-rank P=0.930). Conclusion Junior vascular surgeons demonstrated improved primary AVF patency beyond the learning curve benchmark in 15 patients, with particularly notable enhancements in radiocephalic fistulas.

Purpose: Autologous arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis access, with outcomes largely dependent on the surgeon’s experience. Nevertheless, few studies have been conducted on the learning curve of junior vascular surgeons in AVF creation. This study aims to address this by examining the development of surgical skills among junior vascular surgeons. Materials and Methods: A retrospective analysis was conducted on 100 patients who underwent autologous AVF procedures performed by five junior surgeons between January 2018 and December 2023. To establish the cutoff number of cases for the learning curve, we examined the cubic spline curve using the hazard ratio for primary failure. Results: The cutoff number for operation cases was 15.33, and we divided the analysis into a pre-learning curve period (≤15 cases of AVF) and a post-learning curve period (>15 cases of AVF). The 1-year primary patency rate for AVF during the post-learning curve period was 84.0%, which was higher than the 65.5% rate observed during the pre-learning curve period. In a subgroup analysis based on AVF type, the radiocephalic fistula patient group demonstrated a significant increase in 1-year primary patency in the post-learning curve period compared to that in the pre-learning curve period (80.0% vs. 43.0%, log-rank P=0.033). In contrast, there was no significant difference in the primary patency rates between the post- and pre-learning curve periods in the brachiocephalic fistula patient group (90.0% vs. 89.2%, log-rank P=0.930). Conclusion Junior vascular surgeons demonstrated improved primary AVF patency beyond the learning curve benchmark in 15 patients, with particularly notable enhancements in radiocephalic fistulas.

Purpose: Autologous arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis access, with outcomes largely dependent on the surgeon’s experience. Nevertheless, few studies have been conducted on the learning curve of junior vascular surgeons in AVF creation. This study aims to address this by examining the development of surgical skills among junior vascular surgeons. Materials and Methods: A retrospective analysis was conducted on 100 patients who underwent autologous AVF procedures performed by five junior surgeons between January 2018 and December 2023. To establish the cutoff number of cases for the learning curve, we examined the cubic spline curve using the hazard ratio for primary failure. Results: The cutoff number for operation cases was 15.33, and we divided the analysis into a pre-learning curve period (≤15 cases of AVF) and a post-learning curve period (>15 cases of AVF). The 1-year primary patency rate for AVF during the post-learning curve period was 84.0%, which was higher than the 65.5% rate observed during the pre-learning curve period. In a subgroup analysis based on AVF type, the radiocephalic fistula patient group demonstrated a significant increase in 1-year primary patency in the post-learning curve period compared to that in the pre-learning curve period (80.0% vs. 43.0%, log-rank P=0.033). In contrast, there was no significant difference in the primary patency rates between the post- and pre-learning curve periods in the brachiocephalic fistula patient group (90.0% vs. 89.2%, log-rank P=0.930). Conclusion Junior vascular surgeons demonstrated improved primary AVF patency beyond the learning curve benchmark in 15 patients, with particularly notable enhancements in radiocephalic fistulas.

BACKGROUND: Although kidney transplantation outcomes have improved dramatically after using calcineurin inhibitors (CNIs), CNI toxicity continues to be reported and the mechanism remains uncertain. Here, we investigated the neurotoxicity of CNIs by focusing on the viability of glioma cells.METHODS: Glioma cells were treated with several concentrations of CNIs for 24 hours at 37℃ and their cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.RESULTS: Exposure to 0, 0.25, 0.5, 2.5, 5.0, and 10.0 mM concentrations respectively showed 100%, 64.3%, 61.3%, 68.1%, 62.4%, and 68.6% cell viability for cyclosporine and 100%, 38.6%, 40.8%, 43.7%, 37.8%, and 43.0% for tacrolimus. The direct toxic effect of tacrolimus on glioma cell viability was stronger than that of cyclosporine at the same concentration.CONCLUSION: CNIs can cause neurological side effects by directly exerting cytotoxic effects on brain cells. Therefore, we should carefully monitor the neurologic symptoms and level of CNIs in kidney transplant patients.
Animals ; Brain ; Calcineurin Inhibitors ; Calcineurin ; Cell Survival ; Cyclosporine ; Glioma ; Humans ; Kidney ; Kidney Transplantation ; Neurologic Manifestations ; Rats ; Tacrolimus

BACKGROUND: Although kidney transplantation outcomes have improved dramatically after using calcineurin inhibitors (CNIs), CNI toxicity continues to be reported and the mechanism remains uncertain. Here, we investigated the neurotoxicity of CNIs by focusing on the viability of glioma cells. METHODS: Glioma cells were treated with several concentrations of CNIs for 24 hours at 37℃ and their cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. RESULTS: Exposure to 0, 0.25, 0.5, 2.5, 5.0, and 10.0 mM concentrations respectively showed 100%, 64.3%, 61.3%, 68.1%, 62.4%, and 68.6% cell viability for cyclosporine and 100%, 38.6%, 40.8%, 43.7%, 37.8%, and 43.0% for tacrolimus. The direct toxic effect of tacrolimus on glioma cell viability was stronger than that of cyclosporine at the same concentration. CONCLUSION CNIs can cause neurological side effects by directly exerting cytotoxic effects on brain cells. Therefore, we should carefully monitor the neurologic symptoms and level of CNIs in kidney transplant patients.

BACKGROUND/AIMS: The distribution of hepatitis C virus (HCV) genotypes varies geographically. In Korea, genotypes 1 and 2 comprise more than 90% of HCV infections, while genotype 6 is very rare. This study compared the clinical and epidemiological characteristics of patients with genotype 6 HCV infection with those infected with HCV genotypes 1 and 2. METHODS: This was a prospective, multicenter HCV cohort study that enrolled 1,173 adult patients, of which 930 underwent HCV genotype analysis, and only 9 (1.0%) were found to be infected with genotype 6 HCV. The clinical and epidemiological parameters of the genotypes were compared. RESULTS: The patients with genotype 6 HCV had a mean age of 41.5 years, 77.8% were male, and they had no distinct laboratory features. A sustained virologic response (SVR) was observed in four (67%) of six patients who received antiviral therapy. Risk factors such as the presence of a tattoo (n=6, 66.7%), more than three sexual partners (n=3, 33.3%), and injection drug use (n=3, 33.3%) were more common among genotype 6 patients than among genotypes 1 or 2. CONCLUSIONS: The epidemiology and treatment response of patients infected with genotype 6 HCV differed significantly from those with genotypes 1 or 2, warranting continuous monitoring.
Adult ; Antiviral Agents/therapeutic use ; Asian Continental Ancestry Group ; Cohort Studies ; Female ; Genotype ; Hepacivirus/*genetics ; Hepatitis C, Chronic/*diagnosis/drug therapy/epidemiology ; Humans ; Liver/pathology ; Male ; Middle Aged ; Prospective Studies ; RNA, Viral/blood ; Republic of Korea ; Risk Factors ; Sexual Behavior ; Substance-Related Disorders/complications ; Tattooing

The publisher wishes to apologize for incorrectly displaying the author (Jung-Ho Han) name. We correct his name from Jung-Ho Han to Joung-Ho Han.

There are several antigenic variants of Orientia tsutsugamushi. The 56-kDa type-specific antigen (TSA) is responsible for the antigenic variation. Nucleotide sequences of the 56-kDa TSA obtained from 44 eschar samples of Korean scrub typhus patients and from 40 representative strains retrieved from the GenBank database were analyzed phylogenetically. Clinical patient data were assessed based on the genotyping results. Of the 44 nucleotide sequences, 32 (72.7%) clustered with the Boryong genotype, which is the major genotype in Korea. Eleven nucleotide sequences (25%) clustered with the Kawasaki genotype, not identified in Korea until 2010. One nucleotide sequence was consistent with the Karp genotype. The clinical course of the patients infected with each genotype showed no differences. Diagnostic performance of the immunofluorescence assay (IFA) using the 56-kDa TSA from Gilliam, Karp and Boryong as test antigens were not different for the Boryong and Kawasaki genotypes. Although Boryong is still the predominant genotype, the results suggest that Kawasaki genotype is quite prevalent in Chungbuk province of Korea.
Aged ; Bacterial Proteins/*genetics/metabolism ; Base Sequence ; DNA, Bacterial/analysis ; Databases, Genetic ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Open Reading Frames ; Orientia tsutsugamushi/*classification/isolation & purification ; Phylogeny ; Republic of Korea ; Scrub Typhus/diagnosis/metabolism/*microbiology ; Sequence Analysis, DNA