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

BACKGROUND/AIMS: This study assessed the antibiotic resistance organisms isolated from the blood and bile of acute cholangitis and evaluated risk factors associated with them and their impact on clinical outcomes. METHODS: The identities and antibiotic resistance profiles of bacteria isolated from 433 cases of acute cholangitis from 346 patients were analyzed. Risk factors and the outcomes of patients infected with them were assessed. RESULTS: Microorganisms were isolated from 266 of 419 blood cultures and 256 of 260 bile cultures. Isolates from bile and blood were identical in 71% of the cases. A total of 20 extended spectrum-beta-lactamase (ESBL)-producers and 4 carbapenemase-producing organisms were isolated from blood, and 34 ESBL-producers and 13 carbapenemase-producers were isolated from bile. Sixty-four (14.8%) cases were infected with any one of these bacteria isolated from blood or bile. Risk factors associated with them in blood were nosocomial infection and prior biliary intervention. In bile, indwelling biliary device was a risk factor associated with them. Antibiotic-resistant bacteria were associated with mortality, independent of other prognostic factors. CONCLUSIONS: ESBL or carbapenemase-producing bacteria were frequently isolated in acute cholangitis patients especially with prior biliary intervention and nosocomial infection. Isolation of antibiotic-resistant bacteria was an independent risk factor of mortality.
Bacteria ; Bacterial Proteins ; beta-Lactamases ; Bile ; Cholangitis ; Cross Infection ; Drug Resistance, Microbial ; Humans ; Risk Factors

BACKGROUND/AIMS: The aim of this study was to describe the types and causes of liver disease in patients from a single community hospital in Korea between April 2005 and May 2010. METHODS: A cohort of patients who visited the liver clinic of the hospital during the aforementioned time period were consecutively enrolled (n=6,307). Consistent diagnostic criteria for each liver disease were set by a single, experienced hepatologist, and the diagnosis of all of the enrolled patients was confirmed by retrospective review of their medical records. RESULTS: Among the 6,307 patients, 528 (8.4%) were classified as acute hepatitis, 3,957 (62.7%) as chronic hepatitis, 767 (12.2%) as liver cirrhosis, 509 (8.1%) as primary liver cancer, and 546 (8.7%) as a benign liver mass or other diseases. The etiologies in the acute hepatitis group in decreasing order of prevalence were hepatitis A (44.3%), toxic hepatitis (32.4%), other hepatitis viruses (13.8%), and cryptogenic hepatitis (9.1%). In the chronic hepatitis group, 51.2% of cases were attributed to viral hepatitis, 33.3% to nonalcoholic fatty liver disease, and 13.0% to alcoholic liver disease (ALD). Of the cirrhoses, 73.4% were attributable to viral causes and 18.1% to alcohol. Of the hepatocellular carcinoma cases, 86.6% were attributed to viral hepatitis and 11.6% to ALD. Among the benign tumors, hemangioma comprised 52.2% and cystic liver disease comprised 33.7%. CONCLUSIONS: Knowledge of the current status of the type and cause of liver disease in Korea may be valuable as a basis for evaluating changing trends in liver disease in that country.
Acute Disease ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Alcohol Drinking/adverse effects ; Carcinoma, Hepatocellular/epidemiology/etiology/pathology ; Chronic Disease ; Cohort Studies ; Fatty Liver/epidemiology ; Female ; Hepatitis/epidemiology ; Hepatitis, Viral, Human/complications/epidemiology ; Humans ; Liver Cirrhosis/epidemiology/etiology ; Liver Diseases/*diagnosis/epidemiology ; Liver Diseases, Alcoholic/complications/epidemiology ; Liver Neoplasms/epidemiology/etiology/pathology ; Male ; Middle Aged ; Prevalence ; Republic of Korea/epidemiology ; Retrospective Studies ; Young Adult