[Evaluation of anticoagulant effect and predicted dose of low molecular weight heparin in hemodialysis by anti-â ©a factor activity].

The purpose of this study was to explore the reasonable dose of low molecular weight heparin (LMWH) in hemodialysis (HD) and the strategy of preventing extracorporeal circuit coagulation (ECC). A retrospective case-control study included patients who used LMWH for anticoagulation during maintenance hemodialysis (MHD) in the Hemodialysis Center of Beijing Hospital from December 2020 to January 2021. Basic data such as weight, height, basic kidney disease, dialysis age and anti-Ⅹa factor activity before, during and after dialysis were collected. A total of 46 patients were enrolled in this study, including 5 patients in coagulation group (10.9%) and 41 patients in non-coagulation group (89.1%). The anti-Ⅹa factor activity reached its peak at 0.5 h after the start of HD. The level of anti-Ⅹa factor was incorporated into the receiver operating characteristic curve (ROC curve). The results showed that the area under the ROC curve (AUC) was 0.802 (95% confidence interval: 0.651-0.54, P=0.029), and the cutoff was 0.31 IU/ml (sensitivity 1, specificity 0.683). It is suggested that the body surface area should be used as the basis to estimate the anticoagulant dose of LMWH in HD, and the activity of HD 4 h anti-Ⅹa factor ≤0.31 IU/ml, which is of diagnostic value for ECC. In addition, the results of binary logistic regression analysis showed that dialysis age was an independent risk factor for ECC (OR value 1.319, 95%CI 1.052-1.654, P=0.017). In summary, this study reveals that dialysis age may be a risk factor for ECC and that the activity of HD 4 h anti-Ⅹa factor ≤0.31 IU/ml can be used as a potential diagnostic cut-off point for ECC in HD patients, which provides a scientific basis for monitoring strategies to prevent blood coagulation in HD filters.

Application of High-Resolution C-Arm CT Combined with Streak Metal Artifact Removal Technology for the Stent-Assisted Embolization of Intracranial Aneurysms.

BACKGROUND AND PURPOSE: Metal artifacts from coils and stents limit the level of detail in C-arm CT images of stent attachment and coiling attenuation in the aneurysm neck. We evaluated the utility of high-resolution C-arm CT combined with streak metal artifact removal technology for stent-assisted embolization of intracranial aneurysms. MATERIALS AND METHODS: From October 2017 to July 2018, the First Affiliated Hospital of Zhengzhou University treated 107 patients with intracranial aneurysms (118 aneurysms in total) with stent-assisted embolization. Conventional C-arm CT and high-resolution C-arm CT scanning of the stented area were performed during and after treatment. 3D images were reconstructed with and without streak metal artifact removal techniques. Subsequently, the image quality was compared. The reconstructed images indicated the stent deployment degree and packing density. Follow-up assessments included clinical and angiographic outcomes and complications. RESULTS: In total, 118 aneurysms were successfully embolized using 118 stents. Image quality was significantly higher (P < .05) with high-resolution C-arm CT combined with streak metal artifact removal reconstruction. Streak metal artifact removal reconstruction and 2D angiography at working angles showed incomplete deployment of 6 stents and incomplete aneurysm embolization of 15 patients, which were subsequently resolved. One case of hemorrhage was noted postoperatively. Follow-up of 93 patients at 6-13 months indicated 3 cases of aneurysm recurrence. CONCLUSIONS: High-resolution C-arm CT combined with the streak metal artifact removal technique effectively reduced metal artifacts from stents and coils during aneurysm embolization. This method can help physicians determine the extent of stent deployment and the packing density of coils and thus potentially reduce complications and aneurysm recurrence.