Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Paravalvular sealing pf percutaneous heart valves
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...
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Division of Cardiothoracic Surgery
2022
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613306850639872 |
|---|---|
| access_status_str | Open Access |
| author | Conradie, David Gideon |
| author2 | Bezuidenhout, Deon |
| author_browse | Bezuidenhout, Deon Conradie, David Gideon |
| author_facet | Bezuidenhout, Deon Conradie, David Gideon |
| author_sort | Conradie, David Gideon |
| collection | Thesis |
| description | 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] |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/36648 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:34:03.682Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2022 |
| publishDateRange | 2022 |
| publishDateSort | 2022 |
| publisher | Division of Cardiothoracic Surgery |
| publisherStr | Division of Cardiothoracic Surgery |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/36648 Paravalvular sealing pf percutaneous heart valves Conradie, David Gideon Bezuidenhout, Deon De Villiers, Jandre Biomaterials 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] 2022-07-14T10:44:04Z 2022-07-14T10:44:04Z 2019 2022-07-14T10:43:23Z Master Thesis Masters MSc http://hdl.handle.net/11427/36648 eng application/pdf Division of Cardiothoracic Surgery Faculty of Health Sciences |
| spellingShingle | Biomaterials Conradie, David Gideon Paravalvular sealing pf percutaneous heart valves |
| thesis_degree_str | Master's |
| title | Paravalvular sealing pf percutaneous heart valves |
| title_full | Paravalvular sealing pf percutaneous heart valves |
| title_fullStr | Paravalvular sealing pf percutaneous heart valves |
| title_full_unstemmed | Paravalvular sealing pf percutaneous heart valves |
| title_short | Paravalvular sealing pf percutaneous heart valves |
| title_sort | paravalvular sealing pf percutaneous heart valves |
| topic | Biomaterials |
| url | http://hdl.handle.net/11427/36648 |
| work_keys_str_mv | AT conradiedavidgideon paravalvularsealingpfpercutaneousheartvalves |