ABSTRACT
Severe acute respiratory infection caused by a novel coronavirus(SARS-CoV-2), WHO named COVID-19, is the major clinical concern globally. Both the world health organization and the National Health Commission have issued interim guidelines and management strategy for the diagnosis and treatment of COVID-19. These comprehensive guidelines establish the basic norms for the clinical practice. However, cardiovascular diseases have their special pathophysiological characteristics. The surgical treatment strategies for emergency and critical cardiovascular diseases requires specific recommendations or guidelines. From 16 January to 12 February 2020, the department of cardiovascular surgery in Wuhan Union Hospital had performed 15 emergency cardiovascular operations. The perioperative success rate is 100%. Based on our clinical practice, we summarized the relevant experience as a complement to the WHO and National Health Commission guidelines, hope to provide references for the cardiovascular surgeons.
ABSTRACT
Objective To establish and evaluate 3 kinds of minimally-invasive valve implantation model in vivo.Methods A novel tissue engineered heart valve(TEHV) manufactured by branched polyethylene glycol cross-linked acellular porcine valve and a minimally-invasive valve implantation system according to the design of Corevalve revalving system were adopted.After anesthesia,18 adult male goats were randomly divided into 3 groups: the ulrasound-directed orthotropic group (group A,n =6),angiography-directed orthotropic group (group B,n =6) and direct-released heterotopic group (group C,n =6),and all received minimally-invasive valve implantation orthotropically or heterotopically.4 weeks later,the valvular function was evaluated by CTA and/or echocardiography.Results All 3 kinds of caprine model were successfully constructed.The operation success rate of each group was A: 66.7％,B: 50.0％ and C: 100.0％,respectively(multiple x2 analysis,group A and B P ＞0.05; group A and C,group B and C,P ＜0.05).The operation-time of each group was A: (79 ± 18) min,B:(61 ±23) min,C: (45 ± 15) min(one-way ANOVA,P ＜0.05).The survival rate at4 weeks was A: 100％,B: 100％ and C: 83.3％ (multiple x2 analysis,P ＞ 0.05).Echocardiography and CTA proved the short-term function of implanted TEHV was satisfactory.Conclusion All 3 kinds of caprine valve implantation model can be established without cardiopulmonary bypass and blood transfusion.The devices and equipments required in group A is relatively simple,but the procedure cost longer time for it is hard to determine the right position by ultrasound.The application of angiography made the positioning much easier in group B while the procedure had to be performed in specific operation room with angiographic apparatus.Group C did rely on neither special equipments nor complex operation,but the valve leaflets cannot work normally,so this model was only suitable for testing in vivo characteristics such as biocompatiblities.
ABSTRACT
The purpose of this study was to fabricate decelluarized valve scaffold modified with polyethylene glycol nanoparticles loaded with transforming growth factor-β1 (TGF-β1), by which to improve the extracellular matrix microenvironment for heart valve tissue engineering in vitro. Polyethylene glycol nanoparticles were obtained by an emulsion-crosslinking method, and their morphology was observed under a scanning electron microscope. Decelluarized valve scaffolds, prepared by using trypsinase and TritonX-100, were modified with nanoparticles by carbodiimide, and then TGF-β1 was loaded into them by adsorption. The TGF-β1 delivery of the fabricated scaffold was measured by asing enzyme-linked immunosorbent assay. Whether unseeded or reseeded with myofibroblast from rats, the morphologic, biochemical and biomechanical characteristics of hybrid scaffolds were tested and compared with decelluarized scaffolds under the same conditions. The enzyme-linked immunosorbent assay revealed a typical delivery of nanoparticles. The morphologic observations and biological data analysis indicated that fabricated scaffolds possessed advantageous biocompatibility and biomechanical property beyond decelluarized scaffolds. Altogether this study proved that it was feasible to fabricate the hybrid scaffold and effective to improve extracellular matrix microenvironment, which is beneficial for an application in heart valve tissue engineering.