RESUMO
Objective To reduce the thrombosis probability and hemolysis risk of the meglev left ventricular assist device (LVAD), so as to increase the efficiency of blood supply. Methods The influences of the pump outlet diameter, exit angle, fillet size between the outlet and the inner wall of the pump, as well as gap between the rotor and the shell on internal flow field of the pump were studied by using the computational fluid dynamics (CFD) method, so as to optimize the internal structure and improve the hydrodynamic performance of the pump. Results Compared with pump of the previous generation, the maximum wall shear stress (WSS) of the pump inner wall, the maximum WSS of the pump rotor, the area with WSS >200 Pa were reduced by 23.6%, 47.4%, 76.2%, respectively, while the outlet flow was increased by 14.4%. Conclusions For the meglev LVAD of the new generation, its internal blood flow tended to be smooth, and the hemodynamic performance of blood flow was improved comprehensively. The research findings provide references for optimization design of the meglev LVAD and related experimental researches in the future.
RESUMO
Objective To explore the clinical application value of transcatheter arterial chemoembolization (TACE) combined with CT-guided percutaneous acetic acid injection (PAI) in treatment of huge hepatocellular carcinoma (HCC). Methods Forty-three patients with huge HCC were randomly divided into two group. Twenty-one patients in group A underwent routine one course for TACE (three times), and the interval of TACEs was one month. Twenty-two patients in group B underwent TACE combined with PAI, and CT-guided PAI was performed once a week since 2-3 weeks after first TACE, and one course included 6-9 times of PAI. Postoperative follow-up was conducted (including AFP, the size of tumor, etc.). One course of treatment was repeated in case of tumor recurred. Results At the 1st month after treatment, no statistical difference was found of AFP positive rate between two groups. Statistical difference of total effective rate was found between two groups (38.10% vs 77.27%). The 1-, 2- and 3-year survival rate In group A was 47.62%, 23.81% and 9.52%, respectively, while in group B was 81.82%, 54.55% and 36.36%, respectively, and significant differences were found between the two groups for the same period. Conclusion TACE combined with PAI is safe and more effective than TACE alone in the treatment of huge HCC.