Key Points
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Mechanical prostheses are evident on chest radiography. Their position is readily determined.
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Older models of mechanical prostheses were radiographically obvious due to the greater ferrous metal content. More contemporary models contain less ferrous metal and are less apparent. The occluder elements of older models are also more readily seen; occluder elements of newer mechanical prostheses are less evident but are apparent if seen end-on.
Mechanical Prostheses
Most often, mechanical valve prostheses ( Table 9-1 ) are inserted into the aortic and the mitral positions. Many different models have been made over the 40 years of valve replacement surgery, but currently the great majority that are inserted are bileaflet hemidisk models. However, there are many older types and models still in situ, and therefore it is necessary to have an appreciation of the different types. Mechanical prostheses are evident principally because of their radiopaque sewing rings, and for some models, radiographically evident struts, cages, or occluders. The more ferrous or other metallic material within the prosthesis, the more radiographically evident the prosthesis; current mechanical prostheses contain little ferrous or metallic material and are much less radiographically evident by comparison.
TABLE 9-1
Mechanical Prosthetic Heart Valves
| VALVES | OCCLUDERS | HOUSING/SEWING RING |
|---|---|---|
| Bileaflet Occluders | ||
| Sorin | ||
| CarboMedics Standard | Bileaflet, radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 78°; Closing: 35° | Radiopaque titanium pyrolytic carbon over graphite ring/thick sewing ring |
| CarboMedics Aortic “R” series | Bileaflet, radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 78°; Closing: 35° | Radiopaque titanium pyrolytic carbon over graphite ring |
| CarboMedics Top Hat | Bileaflet, radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 78°; Closing: 35° | Supra-annular/radiopaque titanium pyrolytic carbon over graphite ring |
| CarboMedics Mitral mechanical | Bileaflet, radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 78°; Closing: 35° | Radiopaque titanium pyrolytic carbon over graphite ring/very thick sewing ring |
| CarboMedics Optiform Mitral | Bileaflet, radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 78°; Closing: 35° | Radiopaque titanium pyrolytic carbon over graphite ring |
| Monoleaflet Allcarbon | Bileaflet, radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 60°; Closing: 0° | Radiopaque titanium pyrolytic carbon over graphite ring |
| Bicarbon | Bileaflet, radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 80° | Radiopaque titanium pyrolytic carbon over graphite ring |
| Bicarbon Slimline | Bileaflet, radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 80° | Radiopaque titanium pyrolytic carbon over graphite ring |
| Bicarbon Overline | Bileaflet, radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 80° | Supra-annular/radiopaque titanium pyrolytic carbon over graphite ring |
| Medtronic | ||
| Medtronic-Hall (mechanical prosthesis) | Radiopaque tungsten-containing single tilting disk with a central hole. Central curved radiopaque titanium guidepost. Opening: 70-75° | Radiopaque titanium-containing housing ring |
| Medtronic-Hall Easy-Fit | Radiopaque tungsten-containing single tilting disk with a central hole. Central curved radiopaque titanium guidepost. Opening: 70-75° | Supra-annular/radiopaque titanium-containing housing ring |
| Advantage | Bileaflet, radiopaque occluders. Opening: 86° | NA |
| Advantage Supra | Bileaflet, radiopaque occluders. Opening: 86° | Supra-annular |
| (Carpentier) Edwards | ||
| Edwards Mira (mechanical prosthesis) | Bileaflet occluders Opacity not known. Opening: 80° | Radiopaque tungsten-titanium |
| St. Jude Medical Biocor | ||
| Standard | Bileaflet, radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 85°; closing: 35° | Nonradiopaque pyrolytic carbon over graphite ring/thick sewing ring |
| Masters | Radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 85°; closing: 35° | Nonradiopaque pyrolytic carbon over graphite ring/thick sewing ring |
| Masters HP (Hemodynamic Plus) | Radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 85°; closing: 35° | Supra-annular, nonradiopaque pyrolytic carbon over graphite ring/thick sewing ring |
| Regent | Radiopaque tungsten-impregnated pyrolytic carbon over graphite. Opening: 85°; closing: 35° | Supra-annular, nonradiopaque pyrolytic carbon over graphite ring/thick sewing ring |
| Bileaflet (Other) | ||
| Triflo (mecahnical prosthesis) | Bileaflet | NA |
| CarboMedics Orbis Universal | NA | NA |
| St. Jude Medical Masters | NA | NA |
| St. Jude Medical HP | NA | NA |
| CarboMedics “R” Series Aortic | NA | NA |
| Sorin Bicarbon | NA | NA |
| ATS Open Pivot (mechanical bileaflet) | Bileaflet, nonradiopaque pyrolytic carbon. Opening: 85° | Nonradiopaque pyrolytic carbon |
| On-X | Bileaflet, nonradiopaque pyrolytic carbon. Opening: 85° | Nonradiopaque pyrolytic carbon |
| Single (Nontilting) Disk | ||
| Beall-Surgitool | Nonopaque flat plastic occluders | NA |
| Cooley-Cutter | Radiopaque single faceted domed disk | Densely radiopaque housing with four densely radiopaque pronglike struts that do not close at the top |
| Single Tilting Disk | ||
| Björk-Shiley | Single tilting disk with a central radiopaque rim. Opening: 60°; closing: 0° | Densely radiopaque housing with two densely radiopaque bridgelike struts |
| Björk-Shiley Convexoconcave (BCC60) | Single tilting disk with a central radiopaque rim. Opening: 60°; closing: 0° | Densely radiopaque housing with two densely radiopaque bridgelike struts |
| Björk-Shiley Convexoconcave (BCC70) | Single tilting disk with a central radiopaque rim. Opening: 70°; closing: 0° | Densely radiopaque housing with two densely radiopaque bridgelike struts |
| Björk-Shiley Monostrut | Single tilting disk with a central radiopaque rim. Opening: 60°; closing: 0° | Densely radiopaque housing with two densely radiopaque struts; one bridge shaped and the other a post |
| Omnicarbon | Single tiling disk; pyrolytic carbon/graphite. Opening: 80°; closing: 0° | Radiopaque titanium, includes small struts/flanges that hold the occluder and are visible |
| Koehler Ultracor | Radiopaque single tilting disks. Aortic with opening of 73° and mitral with opening of 68°; closing angle unknown | NA |
| Lillehei-Kaster | Radiopaque single tilting disk | Radiopaque housing with two radiopaque fanglike struts |
| Omniscience | Radiopaque single tilting disk | Radiopaque housing and flanges |
| Aortech UltraCor | Radiopaque single tilting disk | Radiopaque housing and wire struts |
| Bicer | Single tilting disk | Radiopaque housing and wire struts |
| Sorin Monocast | Single tilting disk | Radiopaque housing and wire struts |
| Ball-in-Cage | ||
| Starr-Edwards | Radiopaque (barium-containing) silastic ball; radiopaque alloy cage | Radiopaque post; cage domed at the top |
| Smeloff-Cutter | Silastic ball | Radiopaque post; cage (open at the top) |
| McGovern-Crombie | Silastic ball | Radiopaque post; cage (open at the top) |
| Debakey-Surgitool | Radiopaque steel ball | Radiopaque post; cage domed at the top |
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