The application area of biportal endoscopic spine surgery (BESS) is gradually expanding. Compared with conventional fusion surgery, transforaminal interbody fusion (TLIF) using BESS (BESS-TLIF) has the advantages of less bleeding, minimal postoperative pain, and faster recovery. This technical note highlights its application in managing complex conditions such as scar tissue adhesion, altered anatomy, and implant removal, common in reoperations. The method focuses on precise dissection, endoscopic visualization, and careful tissue handling to ensure effective decompression and stabilization. Three representative cases, including reoperations for recurrent disc herniation, adjacent segment disease (ASD) following prior fusion, and ASD with nonunion of the prior fusion site requiring fusion extension, were described. All three cases exhibited clinical improvement following surgery. BESS is an effective and safe method for spinal revision surgery not only in simple decompression surgery but also in cases that required fusion surgery. As BESS is advancing, its role in complex spinal surgeries is expected to expand, potentially setting new standards in minimally invasive spine surgery.

Background: Hemolysis is an important preanalytical factor that influences laboratory test results. Because arterial blood gas analysis (ABGA) is performed using whole blood, it is difficult to visually check whether a specimen is hemolyzed, and even blood gas analyzers cannot detect hemolysis. However, there is insufficient consensus on the parameters that are influenced by hemolyzed specimens. This study aimed to determine the effect of hemolysis on ABGA results. Methods: One hundred residual arterial blood specimens were collected from Severance Hospital between March and April 2022. Samples were aliquoted into three groups for mechanical hemolysis. Hemolysis was induced using 16-, 22-, and 26-gauge needles and measured using the Profile pHOx Ultra Blood Gas Analyzer (Nova Biomedical, USA). The remaining blood was centrifuged, and the hemolysis index was determined using the plasma. Results: Among the parameters, pH and K increased, whereas pCO 2 , Na,Ca 2+ , and HCO 3− decreased. The values of Hb, Mg2+ , and Hct did not change with the degree of hemolysis, although there was a difference between the two groups. The values of pCO 2 , Hb, K, and Ca 2+ increased as the degree of hemolysis increased, with % biases exceeding the desirable bias. Conclusions This study confirmed that hemolysis significantly influences pH, pCO 2 , and K. Therefore, when clinical findings and blood gas analysis results are inconsistent, clinicians should be cautious of spurious hemolysis when interpreting the results.

Background: Hemolysis is an important preanalytical factor that influences laboratory test results. Because arterial blood gas analysis (ABGA) is performed using whole blood, it is difficult to visually check whether a specimen is hemolyzed, and even blood gas analyzers cannot detect hemolysis. However, there is insufficient consensus on the parameters that are influenced by hemolyzed specimens. This study aimed to determine the effect of hemolysis on ABGA results. Methods: One hundred residual arterial blood specimens were collected from Severance Hospital between March and April 2022. Samples were aliquoted into three groups for mechanical hemolysis. Hemolysis was induced using 16-, 22-, and 26-gauge needles and measured using the Profile pHOx Ultra Blood Gas Analyzer (Nova Biomedical, USA). The remaining blood was centrifuged, and the hemolysis index was determined using the plasma. Results: Among the parameters, pH and K increased, whereas pCO 2 , Na,Ca 2+ , and HCO 3− decreased. The values of Hb, Mg2+ , and Hct did not change with the degree of hemolysis, although there was a difference between the two groups. The values of pCO 2 , Hb, K, and Ca 2+ increased as the degree of hemolysis increased, with % biases exceeding the desirable bias. Conclusions This study confirmed that hemolysis significantly influences pH, pCO 2 , and K. Therefore, when clinical findings and blood gas analysis results are inconsistent, clinicians should be cautious of spurious hemolysis when interpreting the results.

Background: Ensuring reference material (RM) commutability is crucial for evaluating measurement traceability in order to standardize laboratory tests. However, commutability assessment is not routinely performed. We assessed whether RMs prepared following CLSI C37-A guidelines could be used without assessing commutability by evaluating their commutability for four lipid measurements using the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and CLSI EP14 protocols. Methods: We analyzed total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in frozen sera from 20 individuals and 11 RMs, prepared by the Korea Disease Control and Prevention AgencyLaboratory Standardization Project (per CLSI C37-A), using six routine measurement procedures (MPs). Regression equations and 95% prediction intervals derived from single-donor sera were analyzed following CLSI EP14. The IFCC protocol was used to assess differences in inter-MP biases between RM and clinical samples. The effect of the TG concentration on commutability was evaluated by analyzing biases between MP results and reference procedure-assigned values. Results: RMs were commutable for most MP pairs for TC and TG. Commutability for HDL-C and LDL-C varied across RMs, with RM10 and RM11 showing higher TG levels (2.38 and 2.95 mmol/L, respectively) and lower commutability. Increased bias percentages from assigned values were observed for RMs with higher TG levels. Conclusions RMs prepared per CLSI C37-A were commutable with most MP pairs for TC and TG. Elevated TG levels affected HDL-C and LDL-C commutability, highlighting the need to consider TG concentrations during RM preparation and assess commutability to standardize laboratory tests.

Background: Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients. Methods: We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates. Results: Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively). Conclusion Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.

Background: Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients. Methods: We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates. Results: Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively). Conclusion Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.

The application area of biportal endoscopic spine surgery (BESS) is gradually expanding. Compared with conventional fusion surgery, transforaminal interbody fusion (TLIF) using BESS (BESS-TLIF) has the advantages of less bleeding, minimal postoperative pain, and faster recovery. This technical note highlights its application in managing complex conditions such as scar tissue adhesion, altered anatomy, and implant removal, common in reoperations. The method focuses on precise dissection, endoscopic visualization, and careful tissue handling to ensure effective decompression and stabilization. Three representative cases, including reoperations for recurrent disc herniation, adjacent segment disease (ASD) following prior fusion, and ASD with nonunion of the prior fusion site requiring fusion extension, were described. All three cases exhibited clinical improvement following surgery. BESS is an effective and safe method for spinal revision surgery not only in simple decompression surgery but also in cases that required fusion surgery. As BESS is advancing, its role in complex spinal surgeries is expected to expand, potentially setting new standards in minimally invasive spine surgery.

Background: Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients. Methods: We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates. Results: Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively). Conclusion Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.

The application area of biportal endoscopic spine surgery (BESS) is gradually expanding. Compared with conventional fusion surgery, transforaminal interbody fusion (TLIF) using BESS (BESS-TLIF) has the advantages of less bleeding, minimal postoperative pain, and faster recovery. This technical note highlights its application in managing complex conditions such as scar tissue adhesion, altered anatomy, and implant removal, common in reoperations. The method focuses on precise dissection, endoscopic visualization, and careful tissue handling to ensure effective decompression and stabilization. Three representative cases, including reoperations for recurrent disc herniation, adjacent segment disease (ASD) following prior fusion, and ASD with nonunion of the prior fusion site requiring fusion extension, were described. All three cases exhibited clinical improvement following surgery. BESS is an effective and safe method for spinal revision surgery not only in simple decompression surgery but also in cases that required fusion surgery. As BESS is advancing, its role in complex spinal surgeries is expected to expand, potentially setting new standards in minimally invasive spine surgery.

Background: Barriers to treatment with intravenous thrombolysis (IVT) for patients with acute ischemic stroke (AIS) in South Korea remain incompletely characterized. We analyze a nationwide prospective cohort to determine patient-level features associated with delayed presentation and non-treatment of potential IVT-eligible patients. Methods: We identified consecutive patients with AIS from 01/2011 to 08/2023 from a multicenter and prospective acute stroke registry in Korea. Patients were defined as IVT candidates if they presented within 4.5 hours from the last known well, had no lab evidence of coagulopathy, and had National Institute of Health Stroke Scale (NIHSS) ≥ 4. Multivariable generalized linear mixed regression models were used to investigate the associations between their characteristics and the IVT candidates or the use of IVT among the candidates. Results: Among 84,103 AIS patients, 41.0% were female, with a mean age of 69 ± 13 years and presentation NIHSS of 4 [interquartile range, 1–8]. Out of these patients, 13,757 (16.4%) were eligible for IVT, of whom 8,179 (59.5%) received IVT. Female sex (adjusted risk ratio [RR], 0.90; 95% confidence interval [CI], 0.86–0.94) and lower years of education (adjusted RR, 0.90; 95% CI, 0.84–0.97 for 0–3 years, compared to ≥ 13 years) were associated with a decreased likelihood of presenting as eligible for IVT after AIS; meanwhile, young age (adjusted RR, 1.12; 95% CI, 1.01–1.24 for ≤ 44 years, compared to 75–84 years) was associated with an increased likelihood of being an IVT candidate. Among those who were eligible for IVT, only age was significantly associated with the use of IVT (adjusted RR, 1.09; 95% CI, 1.03–1.16 for age 65–74 and adjusted RR, 0.83; 95% CI, 0.76–0.90 for ≥ 85 years, respectively). Conclusion Most patients with AIS present outside IVT eligibility in South Korea, and only 60% of eligible patients were ultimately treated. We identified increased age, female sex and lower education as key features on which to focus interventions for improving IVT utilization.