We investigate the potentials and limitations of computational fluid dynamics (CFD) analysis of patient specific models from 3D angiographies. There are many technical problems in acquisition of proper vascular models, in pre-processing for making 2D surface and 3D volume meshes and also in post-processing steps for display the CFD analysis. We hope that our study could serves as a technical reference to validating other tools and CFD results.
Angiography ; Arteries ; Carotid Arteries ; Hemodynamics ; Humans ; Hydrodynamics

Background/Aims: We investigated the real-world effectiveness and safety of ustekinumab (UST) as induction treatment for Koreans with Crohn’s disease (CD). Methods: CD patients who started UST were prospectively enrolled from 4 hospitals in Korea. All enrolled patients received intravenous UST infusion at week 0 and subcutaneous UST injection at week 8. Clinical outcomes were assessed using Crohn’s Disease Activity Index (CDAI) scores at weeks 8 and 20 among patients with active disease (CDAI ≥150) at baseline. Clinical remission was defined as a CDAI <150, and clinical response was defined as a reduction in CDAI ≥70 points from baseline. Safety and factors associated with clinical remission at week 20 were also analyzed. Results: Sixty-five patients were enrolled between January 2019 and December 2020. Among 49 patients with active disease at baseline (CDAI ≥150), clinical remission and clinical response at week 8 were achieved in 26 (53.1%) and 30 (61.2%) patients, respectively. At week 20, 27 (55.1%) and 35 (71.4%) patients achieved clinical remission and clinical response, respectively. Twenty-seven patients (41.5%) experienced adverse events, with serious adverse events in 3 patients (4.6%). One patient (1.5%) stopped UST therapy due to poor response. Underweight (body mass index <18.5 kg/m2) (odds ratio [OR], 0.085; 95% confidence interval [CI], 0.014–0.498; P=0.006) and elevated C-reactive protein at baseline (OR, 0.133; 95% CI, 0.022–0.823; P=0.030) were inversely associated with clinical remission at week 20. Conclusions UST was effective and well-tolerated as induction therapy for Korean patients with CD.

In this report, we present a case of a patient with Philadelphia chromosome-positive (Ph+) B-cell acute lymphoblastic leukemia after renal transplantation. The patient, a 65-year-old man, had received a kidney transplantation 20 years prior to diagnosis with Ph+ precursor B-cell ALL. Because he was refractory to intensive chemotherapy and had refused to receive additional intensive chemotherapy, he was treated with imatinib and dexamethasone. While this patient experienced a complete hematologic and cytogenetic response, he did not show a complete molecular remission. Eighty days after imatinib combination therapy, the patient relapsed and died from intracerebral hemorrhage.
Aged ; B-Lymphocytes ; Benzamides ; Cerebral Hemorrhage ; Cytogenetics ; Dexamethasone ; Humans ; Kidney Transplantation ; Philadelphia ; Philadelphia Chromosome ; Piperazines ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Precursor Cells, B-Lymphoid ; Pyrimidines ; Imatinib Mesylate

PURPOSE: Computational flow dynamic (CFD) study has not been widely applied in intracranial artery stenosis due to requirement of high resolution in identifying the small intracranial artery. We described a process in CFD study applied to symptomatic severe intracranial (M1) stenosis before and after stenting. MATERIALS AND METHODS: Reconstructed 3D angiography in STL format was transferred to Magics (Materialise NV, Leuven, Belgium) for smoothing of vessel surface and trimming of branch vessels and to HyperMesh (Altair Engineering Inc., Auckland, New Zealand) for generating tetra volume mesh from triangular surface-meshed 3D angiogram. Computational analysis of blood flow in the blood vessels was performed using the commercial finite element software ADINA Ver 8.5 (ADINA R & D, Inc., Lebanon, MA). The distribution of wall shear stress (WSS), peak velocity and pressure in a patient was analyzed before and after intracranial stenting. RESULTS: Computer simulation of wall shear stress, flow velocity and wall pressure before and after stenting could be demonstrated three dimensionally by video mode according to flow vs. time dimension. Such flow model was well correlated with angiographic finding related to maximum degree of stenosis. Change of WSS, peak velocity and pressure at the severe stenosis was demonstrated before and after stenting. There was no WSS after stenting in case without residual stenosis. CONCLUSION: Our study revealed that CFD analysis before and after intracranial stenting was feasible despite of limited vessel wall dimension and could reveal change of WSS as well as flow velocity and wall pressure.
Angiography ; Arteries ; Atherosclerosis ; Blood Vessels ; Cerebral Arteries ; Characidae ; Computer Simulation ; Constriction, Pathologic ; Glycosaminoglycans ; Humans ; Lebanon ; Magic ; Stents

PURPOSE: Image-based computational models with fluid-structure interaction (FSI) can be used to perform plaque mechanical analysis in intracranial artery stenosis. We described a process in FSI study applied to symptomatic severe intracranial (M1) stenosis before and after stenting. MATERIALS AND METHODS: Reconstructed 3D angiography in STL format was transferred to Magics for smoothing of vessel surface and trimming of branch vessels and to HyperMesh for generating tetra volume mesh from triangular surface-meshed 3D angiogram. Computational analysis of blood flow in the blood vessels was performed using the commercial finite element software ADINA Ver 8.5. The distribution of wall shear stress (WSS), peak velocity and pressure was analyzed before and after intracranial stenting. RESULTS: The wall shear stress distributions from Computational fluid dynamics (CFD) simulation with rigid wall assumption as well as FSI simulation before and after stenting could be compared. The difference of WSS between rigid wall and compliant wall model both in pre- and post-stent case is only minor except at the stenosis region. These WSS values were greatly reduced after stenting to 15~20 Pa at systole and 3~5 Pa at end-diastole in CFD simulation, which are similar in FSI simulations. CONCLUSION: Our study revealed that FSI simulation before and after intracranial stenting was feasible despite of limited vessel wall dimension and could reveal change of WSS as well as flow velocity and wall pressure.
Angiography ; Arteries ; Atherosclerosis ; Blood Vessels ; Cerebral Arteries ; Characidae ; Constriction, Pathologic ; Glycosaminoglycans ; Hydrodynamics ; Magic ; Stents ; Systole

Glycemic control is particularly important in hemodialysis (HD) patients with diabetes mellitus (DM). Although fasting blood glucose (FBG) level is an important indicator of glycemic control, a clear target for reducing mortality in HD patients with DM is lacking. Methods: A total of 26,162 maintenance HD patients with DM were recruited from the National Health Insurance Database of Korea between 2002 and 2018. We analyzed the association of FBG levels at the baseline health examination with the risk of all-cause and cause-specific mortality. Results: Patients with FBG 80–100 mg/dL showed a higher survival rate compared with that of other FBG categories (p < 0.001). The risk of all-cause mortality increased with the increase in FBG levels, and adjusted hazard ratios (HRs) were 1.10 (95% confidence interval [CI], 1.04–1.17), 1.21 (95% CI, 1.13–1.29), 1.36 (95% CI, 1.26–1.46), and 1.61 (95% CI, 1.51–1.72) for patients with FBG 100–125, 125–150, 150–180, and ≥180 mg/dL, respectively. The HR for mortality was also significantly increased in patients with FBG <80 mg/dL (adjusted HR, 1.14; 95% CI, 1.05–1.23). The analysis of cause-specific mortality also revealed a J-shaped curve between FBG levels and the risk of cardiovascular deaths. However, the risk of infection or malignancy-related deaths was not linearly increased as FBG levels increased. Conclusion: A J-shaped association was observed between FBG levels and the risk of all-cause mortality, with the lowest risk at FBG 80–100 mg/dL in HD patients with DM.

Glycemic control is particularly important in hemodialysis (HD) patients with diabetes mellitus (DM). Although fasting blood glucose (FBG) level is an important indicator of glycemic control, a clear target for reducing mortality in HD patients with DM is lacking. Methods: A total of 26,162 maintenance HD patients with DM were recruited from the National Health Insurance Database of Korea between 2002 and 2018. We analyzed the association of FBG levels at the baseline health examination with the risk of all-cause and cause-specific mortality. Results: Patients with FBG 80–100 mg/dL showed a higher survival rate compared with that of other FBG categories (p < 0.001). The risk of all-cause mortality increased with the increase in FBG levels, and adjusted hazard ratios (HRs) were 1.10 (95% confidence interval [CI], 1.04–1.17), 1.21 (95% CI, 1.13–1.29), 1.36 (95% CI, 1.26–1.46), and 1.61 (95% CI, 1.51–1.72) for patients with FBG 100–125, 125–150, 150–180, and ≥180 mg/dL, respectively. The HR for mortality was also significantly increased in patients with FBG <80 mg/dL (adjusted HR, 1.14; 95% CI, 1.05–1.23). The analysis of cause-specific mortality also revealed a J-shaped curve between FBG levels and the risk of cardiovascular deaths. However, the risk of infection or malignancy-related deaths was not linearly increased as FBG levels increased. Conclusion: A J-shaped association was observed between FBG levels and the risk of all-cause mortality, with the lowest risk at FBG 80–100 mg/dL in HD patients with DM.

Glycemic control is particularly important in hemodialysis (HD) patients with diabetes mellitus (DM). Although fasting blood glucose (FBG) level is an important indicator of glycemic control, a clear target for reducing mortality in HD patients with DM is lacking. Methods: A total of 26,162 maintenance HD patients with DM were recruited from the National Health Insurance Database of Korea between 2002 and 2018. We analyzed the association of FBG levels at the baseline health examination with the risk of all-cause and cause-specific mortality. Results: Patients with FBG 80–100 mg/dL showed a higher survival rate compared with that of other FBG categories (p < 0.001). The risk of all-cause mortality increased with the increase in FBG levels, and adjusted hazard ratios (HRs) were 1.10 (95% confidence interval [CI], 1.04–1.17), 1.21 (95% CI, 1.13–1.29), 1.36 (95% CI, 1.26–1.46), and 1.61 (95% CI, 1.51–1.72) for patients with FBG 100–125, 125–150, 150–180, and ≥180 mg/dL, respectively. The HR for mortality was also significantly increased in patients with FBG <80 mg/dL (adjusted HR, 1.14; 95% CI, 1.05–1.23). The analysis of cause-specific mortality also revealed a J-shaped curve between FBG levels and the risk of cardiovascular deaths. However, the risk of infection or malignancy-related deaths was not linearly increased as FBG levels increased. Conclusion: A J-shaped association was observed between FBG levels and the risk of all-cause mortality, with the lowest risk at FBG 80–100 mg/dL in HD patients with DM.

Glycemic control is particularly important in hemodialysis (HD) patients with diabetes mellitus (DM). Although fasting blood glucose (FBG) level is an important indicator of glycemic control, a clear target for reducing mortality in HD patients with DM is lacking. Methods: A total of 26,162 maintenance HD patients with DM were recruited from the National Health Insurance Database of Korea between 2002 and 2018. We analyzed the association of FBG levels at the baseline health examination with the risk of all-cause and cause-specific mortality. Results: Patients with FBG 80–100 mg/dL showed a higher survival rate compared with that of other FBG categories (p < 0.001). The risk of all-cause mortality increased with the increase in FBG levels, and adjusted hazard ratios (HRs) were 1.10 (95% confidence interval [CI], 1.04–1.17), 1.21 (95% CI, 1.13–1.29), 1.36 (95% CI, 1.26–1.46), and 1.61 (95% CI, 1.51–1.72) for patients with FBG 100–125, 125–150, 150–180, and ≥180 mg/dL, respectively. The HR for mortality was also significantly increased in patients with FBG <80 mg/dL (adjusted HR, 1.14; 95% CI, 1.05–1.23). The analysis of cause-specific mortality also revealed a J-shaped curve between FBG levels and the risk of cardiovascular deaths. However, the risk of infection or malignancy-related deaths was not linearly increased as FBG levels increased. Conclusion: A J-shaped association was observed between FBG levels and the risk of all-cause mortality, with the lowest risk at FBG 80–100 mg/dL in HD patients with DM.