The paper presents a simple alternative adhesion method for fabricating spherical particle based complex undercuts for interlocking the laminate polymer composites.

This study indicates a sufficient annular fixation force of the tested transcatheter mitral valve implantation valved stent prototypes. Therefore, these mitral valved stents demonstrate a new type of mitral valved stent design.

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Background and Aim of the Study: Aortic hemodynamics influence the integrity of the vessel wall and cardiac afterload. The aim of this study was to compare hemodynamics distal to biological (BV) and mechanical aortic valve (MV) replacements by in vitro 4D Flow MRI excluding confounding factors of in-vivo testing potentially influencing hemodynamics. Methods: Two BV (Perimount MagnaEase [Carpentier-Edwards], Trifecta [Abbott]) and two MV (On-X [CryoLife], prototype trileaflet valve) were scanned in a flexible aortic phantom at 3T using a recommended 4D Flow MR sequence. A triphasic aortic flow profile with blood-mimicking fluid was established. Using GTFlow (Gyrotools), area and velocity of the ejection jet were measured. Presence and extent of sinus vortices and secondary flow patterns were graded on a 0 to 3 scale.Results: A narrow, accelerated central ejection jet (Area = 27 ± 7% of vessel area, Velocity = 166 ± 13 cm/s; measured at sinotubular junction) was observed in BV as compared to MV (Area = 53 ± 13%, Velocity = 109 ± 21 cm/s). As opposed to MV, the jet distal to BV impacted the outer curvature of the ascending aorta and resulted in large secondary flow patterns (BV: n = 4, grades 3, 3, 2, 1; MV: n = 1, grade 1). Sinus vortices only formed distal to MV. Although physiologically configured, they were larger than normal (grade 3). Conclusions: In contrast to mechanical valves, biological valve replacements induced accelerated and increased flow patterns deviating from physiological ones. While it remains speculative whether this increases the risk of aneurysm formation through wall shear stress changes, findings are contrasted by almost no secondary flow patterns and typical, near-physiological sinus vortex formation distal to mechanical valves. K E Y W O R D S 4D Flow MRI, aorta and great vessels, cardiovascular research, valve repair/replacement CONFLICT OF INTERESTS Prof. Sievers holds the patent for the tricuspid mechanical valve, US9775708 B2. Dr. Fujita recieved lecture fees from Edwards Lifesciences. Dr. Oechtering recieved lecture fees from Abbott Laboratories. The other authors do not have conflict of interests. AUTHOR CONTRIBUTIONS Concept/design, experiments, analysis and interpretation, drafting article, and approval of the article: THO. Concept/design, experiments, analysis and interpretation, critical revision of article, and approval of the article: MS, KS, TS, MS, AP, and BF. Concept/design, experiments, critical revision of article, and approval of the article: CA. Concept/design, analysis and interpretation, critical revision of article, and approval of the article: HB and SE. Concept/design, critical revision of article, and approval of the article: HHS. Concept/ design, analysis and interpretation, drafting article, critical revision of article, and approval of the article: AF.ORCID Thekla H. Oechtering Additional supporting information may be found online in the Supporting Information section. How to cite this article: Oechtering TH, Sieren M, Schubert K, et al. In vitro 4D Flow MRI ev...

Background: Even after decades of intensive research, an ideal heart valve prosthesis remains elusive. Shortcomings of conventional devices include reduced durability of bioprostheses and the thrombogenicity of mechanical substitutes, necessitating anticoagulation and resulting in imperfect hemodynamics. Here we present in vivo results of a novel mechanical heart valve prosthesis aiming for freedom from anticoagulation.Methods: Four female sheep had their aortic valves replaced using the novel mechanical heart valve (size 21 mm), with no postoperative anticoagulation treatment. This trileaflet heart valve was designed with the pivots in the systolic central flow. Hemodynamics, biochemistry, hematology, and macroscopy and microscopy were studied at 90 days in 2 sheep and at 1 year in the other 2 sheep.Results: Mean (<6 mm Hg) and peak (<10 mm Hg) aortic transvalvular gradients remained low during the study period. Aortic regurgitation was trivial, and central traces were only rarely observed. The rate of thrombotic events was very low, with none macroscopically and microscopically visible thrombotic material on the device. Biochemistry and hemotology were unchanged without hemolysis. In 3 sheep, the fibrous pannus and mitral leaflet were partially folded over the edge of the annular body. Apart from organic/inorganic deposits on the leaflets after 1 year, the ultrastructurally evaluated leaflets were similar to those of nonimplanted controls. Conclusions:The preliminary in vivo results of this novel anticoagulation-free aortic mechanical heart valve are promising with excellent hemodynamics and a very low risk of thrombotic events. (JTCVS Open 2021;7:76-88) Novel trileaflet mechanical heart valve explanted after 375 days in a sheep model.