Paravalvular sealing pf percutaneous heart valves
| dc.contributor.advisor | Bezuidenhout, Deon | |
| dc.contributor.advisor | De Villiers, Jandre | |
| dc.contributor.author | Conradie, David Gideon | |
| dc.date.accessioned | 2022-07-14T10:44:04Z | |
| dc.date.available | 2022-07-14T10:44:04Z | |
| dc.date.issued | 2019 | |
| dc.date.updated | 2022-07-14T10:43:23Z | |
| dc.description.abstract | Paravalvular regurgitation (PVR), which frequently occurs after transcatheter aortic valve replacements (TAVR) can lead to adverse clinical consequences and has been shown to correlate to an increased late mortality and morbidity. Quantification, graduation and testing for PVR has proven challenging and a standardized method for pre-clinical testing is still sought. Commercial transcatheter heart valves (THV's) rely on sealing skirts made from treated pericardium or polyethylene terephthalate (PET) fabrics. The current study was aimed at developing novel electrospun skirts for the minimization of PVR in THV's. Thermoplastic polyurethane (TPU) was electrospun onto mandrels and several techniques (CO2 - laser, ultra-sonic, solvent and conductive heat bonding) used to attach the scaffolds to pre-coated TAVR stents. Attachment strength was modelled by finite element analysis (FEA) of stents in the crimped and expanded conditions and empirically determined by physical pull-off tests. PVR was evaluated for four different skirt designs (1× single layer “FLAT” and 3× double layers: Forward Flow Filling “FFF”, No Filling “NF” and Back Flow Filling “BFF”) using a pulse duplicator fitted with perforated mounting rings. Optimization of solution, process and environmental parameters yielded scaffolds with average fibre diameters of 3.17 ± 0.64 μm and average pore sizes 9.52 ± 6.90 μm. Tensile strength was found to be similar in the direction perpendicular to collector rotation [Abstract incomplete due to DSpace NOT being able to accommodate some formulas and equations in the abstract, BS] | |
| dc.identifier.apacitation | Conradie, D. G. (2019). <i>Paravalvular sealing pf percutaneous heart valves</i>. (). ,Faculty of Health Sciences ,Division of Cardiothoracic Surgery. Retrieved from http://hdl.handle.net/11427/36648 | en_ZA |
| dc.identifier.chicagocitation | Conradie, David Gideon. <i>"Paravalvular sealing pf percutaneous heart valves."</i> ., ,Faculty of Health Sciences ,Division of Cardiothoracic Surgery, 2019. http://hdl.handle.net/11427/36648 | en_ZA |
| dc.identifier.citation | Conradie, D.G. 2019. Paravalvular sealing pf percutaneous heart valves. . ,Faculty of Health Sciences ,Division of Cardiothoracic Surgery. http://hdl.handle.net/11427/36648 | en_ZA |
| dc.identifier.ris | TY - Master Thesis AU - Conradie, David Gideon AB - Paravalvular regurgitation (PVR), which frequently occurs after transcatheter aortic valve replacements (TAVR) can lead to adverse clinical consequences and has been shown to correlate to an increased late mortality and morbidity. Quantification, graduation and testing for PVR has proven challenging and a standardized method for pre-clinical testing is still sought. Commercial transcatheter heart valves (THV's) rely on sealing skirts made from treated pericardium or polyethylene terephthalate (PET) fabrics. The current study was aimed at developing novel electrospun skirts for the minimization of PVR in THV's. Thermoplastic polyurethane (TPU) was electrospun onto mandrels and several techniques (CO2 - laser, ultra-sonic, solvent and conductive heat bonding) used to attach the scaffolds to pre-coated TAVR stents. Attachment strength was modelled by finite element analysis (FEA) of stents in the crimped and expanded conditions and empirically determined by physical pull-off tests. PVR was evaluated for four different skirt designs (1× single layer “FLAT” and 3× double layers: Forward Flow Filling “FFF”, No Filling “NF” and Back Flow Filling “BFF”) using a pulse duplicator fitted with perforated mounting rings. Optimization of solution, process and environmental parameters yielded scaffolds with average fibre diameters of 3.17 ± 0.64 μm and average pore sizes 9.52 ± 6.90 μm. Tensile strength was found to be similar in the direction perpendicular to collector rotation [Abstract incomplete due to DSpace NOT being able to accommodate some formulas and equations in the abstract, BS] DA - 2019 DB - OpenUCT DP - University of Cape Town KW - Biomaterials LK - https://open.uct.ac.za PY - 2019 T1 - Paravalvular sealing pf percutaneous heart valves TI - Paravalvular sealing pf percutaneous heart valves UR - http://hdl.handle.net/11427/36648 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/36648 | |
| dc.identifier.vancouvercitation | Conradie DG. Paravalvular sealing pf percutaneous heart valves. []. ,Faculty of Health Sciences ,Division of Cardiothoracic Surgery, 2019 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/36648 | en_ZA |
| dc.language.rfc3066 | eng | |
| dc.publisher.department | Division of Cardiothoracic Surgery | |
| dc.publisher.faculty | Faculty of Health Sciences | |
| dc.subject | Biomaterials | |
| dc.title | Paravalvular sealing pf percutaneous heart valves | |
| dc.type | Master Thesis | |
| dc.type.qualificationlevel | Masters | |
| dc.type.qualificationlevel | MSc |