This paper introduces the principle and procedure of integral hydro-forming technology for spherical vessels and the elastoplastic stress fields near weld seams. It also presents mechanical models of the angular disto...This paper introduces the principle and procedure of integral hydro-forming technology for spherical vessels and the elastoplastic stress fields near weld seams. It also presents mechanical models of the angular distortion area, which explains the circularization bending moment and the effect of spherodization in the angular distortion area during the process of hydro-bulging.展开更多
Background In the current era of transcatheter aortic valve replacement, there is renewed interest in balloon aortic valvuloplasty (BAV) and invasive hemodynarnic evaluation of aortic stenosis (AS). The current re...Background In the current era of transcatheter aortic valve replacement, there is renewed interest in balloon aortic valvuloplasty (BAV) and invasive hemodynarnic evaluation of aortic stenosis (AS). The current report aimed to study the invasive hemodynamics of se- vere AS patients treated with BAV as destination therapy and to identify factors associated with better hemodynamic outcome and prognosis. Methods From 2009 to 2012, 63 high risk elderly patients were treated with BAV as destination therapy for symptomatic severe AS and were all prospectively included in the study. Their hemodynamies were invasively evaluated during catheterization, pre- and post-BAV at the same session. All Post-BAV patients were regularly followed-up. Results The patients (82 ~ 6 years, 52% male) had post-BAV aortic valve area index (AVAi) significantly increased and mean pressure gradient (MPG) significantly reduced. During the follow-up of 0.9 (maximum 3.3) years, those with post-BAV AVAi 〈 0.6 cm2/m2 compared with the AVAi _〉 0.6 cm2/m2 group had significantly higher mortality (60% vs. 28%, log-rank P = 0.02), even after adjusting for age, gender, atrial fibrillation, chronic kidney disease, diabetes mellitus, coronary artery disease and EuroSCORE [HR: 5.58, 95% confidence interval (CI): 1.62-19.20, P = 0.006]. The only independent predictor of moderate AS post-BAV was the pre-BAV AVAi increase by 0.1cm^2/m^2 (OR: 3.81, 95% CI: 1.33-10.89, P = 0.01). Pre-BAV AVAi 〉 0.39 cm^2/m^2 could predict with sensitivity 84% and specificity 70% the post-BAV hemodynamic outcome. Conclusions BAV as destination therapy for severe AS offered immediate and significant hemodynamic improvement. The survival was significantly better when a moderate degree of AS was present.展开更多
文摘This paper introduces the principle and procedure of integral hydro-forming technology for spherical vessels and the elastoplastic stress fields near weld seams. It also presents mechanical models of the angular distortion area, which explains the circularization bending moment and the effect of spherodization in the angular distortion area during the process of hydro-bulging.
文摘Background In the current era of transcatheter aortic valve replacement, there is renewed interest in balloon aortic valvuloplasty (BAV) and invasive hemodynarnic evaluation of aortic stenosis (AS). The current report aimed to study the invasive hemodynamics of se- vere AS patients treated with BAV as destination therapy and to identify factors associated with better hemodynamic outcome and prognosis. Methods From 2009 to 2012, 63 high risk elderly patients were treated with BAV as destination therapy for symptomatic severe AS and were all prospectively included in the study. Their hemodynamies were invasively evaluated during catheterization, pre- and post-BAV at the same session. All Post-BAV patients were regularly followed-up. Results The patients (82 ~ 6 years, 52% male) had post-BAV aortic valve area index (AVAi) significantly increased and mean pressure gradient (MPG) significantly reduced. During the follow-up of 0.9 (maximum 3.3) years, those with post-BAV AVAi 〈 0.6 cm2/m2 compared with the AVAi _〉 0.6 cm2/m2 group had significantly higher mortality (60% vs. 28%, log-rank P = 0.02), even after adjusting for age, gender, atrial fibrillation, chronic kidney disease, diabetes mellitus, coronary artery disease and EuroSCORE [HR: 5.58, 95% confidence interval (CI): 1.62-19.20, P = 0.006]. The only independent predictor of moderate AS post-BAV was the pre-BAV AVAi increase by 0.1cm^2/m^2 (OR: 3.81, 95% CI: 1.33-10.89, P = 0.01). Pre-BAV AVAi 〉 0.39 cm^2/m^2 could predict with sensitivity 84% and specificity 70% the post-BAV hemodynamic outcome. Conclusions BAV as destination therapy for severe AS offered immediate and significant hemodynamic improvement. The survival was significantly better when a moderate degree of AS was present.