Prostheses, heart valves

Pericardial prostheses Heart valve prosthesis made with hxed bovine pericardial tissue. 

Medical Alerts (examples hearing aids, prosthesis, heart valves, eyeglasses, artificial hips) ... 

Cardiovascular Blood vessel prosthesis Heart valve Catheter Pacemaker Dacron, Teflon , polyurethane Reprocessed tissue, stainless steel, carbon Silicone rubber. Teflon, polyurethane Polyurethane, silicone rubber, platinum electrodes... 

Shoulder joint prosthesis Heart valve prosthesis... 

Reul, H., Steinseifer, U., Knoch, M., and Rau, G. 1995. Development, manufacturing and validation of a single leaflet mechanical heart valve prosthesis. /. Heart Valve Dis. 4 513-519. 

Aortic aneurysm, prosthetic heart valve, vascular or orthopedic prosthesis... 

Even with this somewhat stricter definition, there is room for discretion. A sportsman who takes an occasional puff of a bronchodilator for exercise-induced asthma but is otherwise asymptomatic may be considered eligible by some. Individuals who have undergone surgery for a congenital condition and are in excellent health may or may not be suitable. Thus, an asymptomatic patient with a hip prosthesis who is taking no medication may be acceptable whereas an equally healthy individual with a prosthetic heart valve should be excluded from a study involving a cannula because of the risk, however remote, of endocarditis. Clearly, whatever definition of a healthy volunteer is used, sensible clinical judgement is still required. 

Siloxane-containing devices have also been used as contact lenses, tracheostomy vents, tracheal stents, antireflux cuffs, extracorporeal dialysis, ureteral stents, tibial cups, synovial fluids, toe joints, testes penile prosthesis, gluteal pads, hip implants, pacemakers, intra-aortic balloon pumps, heart valves, eustachian tubes, wrist joints, ear frames, finger joints, and in the construction of brain membranes. Almost all the siloxane polymers are based on various polydimethylsiloxanes. 

Cribier A, Eltchaninoff H, Tron C, et al. Early experience with percutaneous transcatheter implantation of heart valve prosthesis for the treatment of end-stage inoperable patients with calcific aortic stenosis. J Am Coll Cardiol 2004 43(4) 698-703. 

Pretreatment of patients undergoing dental extractions who have implanted prosthetic devices, such as artificial heart valves, to prevent seeding of prosthesis. 

The application of polymeric materials in medicine is a fairly specialized area with a wide range of specific applications and requirements. Although the total volume of polymers used in this application may be small compared to the annual production of polyethylene, for example, the total amount of money spent annually on prosthetic and biomedical devices exceeds 16 billion in the United States alone. These applications include over a million dentures, nearly a half billion dental fillings, about six million contact lenses, over a million replacement joints (hip, knee, finger, etc.), about a half million plastic surgery operations (breast prosthesis, facial reconstruction, etc.), over 25,000 heart valves, and 60,000 pacemaker implantations. In addition, over AO,000 patients are on hemodialysis units (artificial kidney) on a regular basis, and over 90,000 coronary bypass operations (often using synthetic polymers) are performed each year (]J. 

The ideal heart valve prosthesis has not yet been designed and probably will never exist. An ideal valve should have the following characteristics ... 

The flow velocity, shear stress and pressure fields in the immediate vicinity of a given heart valve prosthesis design are directly related to the fluid dynamic characteristics of the prosthesis. Therefore, detailed in vitro fluid dynamic studies should help predict potential problems and complications that may arise in vivo with different designs of prosthetic heart valves. 

More R.B. and Silver M.D. 1990. Pyrolitic carbon prosthetic heart valve occluder wear in vitro results for the Bjork-Shiley prosthesis. J. Appl. Biomater. 1 267-278. 

FIGURE 44.1 A caged-ball heart valve prosthesis. (Courtesy of Baxter Health Care, Irvine, CA.)... 

FIGURE 44.2 (a) Photograph of a typical tilting disc valve prosthesis. (Courtesy of Medtronic Heart Valves,... 

FIGURE 44.4 A tri-leaflet heart valve prosthesis under development. Costa Mesa, CA.)... 

FIGURE 44.7 Typical bioprostheses (a) Hancock porcine bioprosthesis (courtesy of Medtronic Heart Valves, Minneapolis, MN) (b) PhotoFbc a pericardial prosthesis. (Courtesy of Sulzer-CarboMedics, Inc., Austin, TX.)... 

Bona, G., Rinaldi, S., and Vallana, F. 1997. Design characteristics of the BICARBON bileaflet heart valve prosthesis. In Surgery for Acquired Aortic Valve Disease. Piwnica, A. and Westaby, S. Eds., ISIS Medical Media, Oxford, pp. 392-396. 

Chandran, K.B., Kim, S.-H., and Han, G. 1991a. Stress distribution on the cusps of a polyurethane trileaflet heart valve prosthesis in the closed position. J. Biomech. 24 385-395. 

Cheon, G.J. and Chandran, K.B. 1994. Transient behavior analysis of a mechanical monoleaflet heart valve prosthesis in the closing phase. Am. Soc. Mech. Eng. J. Biomech. Eng. 116 452-459. 

M. Herold, H.B. Lo, H. Reul, et al.. The Helmholtz-Institute tri-leaflet-polyurethane-heart valve prosthesis design, manufacturing and first in-vitro and in-vivo results, in H. Planck, I. Syre, M. Dauner, G. Egbers (Eds.), Polyurethanes in Biomedical Engineering, vol. II, Elsevier Science, Amsterdam, 1987, pp. 231-256. 

I. Gallo, In vivo experimental assessment of polytetrafluoroethyl-ene trileaflet heart valve prosthesis, J. Thorac. Cardiovasc. Surg. 99 (1990) 1074-1081. 

T. Mackay, D. Wheatley, G. Bernacca, A. Fisher, C. Hindle, New polyurethane heart valve prosthesis design, manufacture and evaluation, Biomaterials 17 (19) (1996) 1857-1863. 

After implantation, the surface of the prosthesis is the first component to come into contact with the surrounding biological milieu. Therefore, surface characteristics play an important role in controlling the course of subsequent biological reactions. Antifouling materials are materials that can resist protein adsorption or microbial adhesion [205,206]. Hence, they have potential applications as surface coatings on implantable devices such as heart valves and hip joint prostheses to minimize biofihn formation and subsequent device-associated infections. 

P. Pibarot, J.G. Dumesnil, Prosthetic heart valves selection of the optimal prosthesis and long-term management. Circulation 119 (2009) 1034-1048. 

P. Bloomfield, Choice of heart valve prosthesis. Heart 87 (2002) 583-589. 

J. Groetzner, B. Klosterhalfen, B. J. Messmer, Introduction of a flexible polymeric heart valve prosthesis with special design fa- mitral posiuon, CirculaUon 108 (2003) 134-139. 

Polyurethanes Ligament replacements, heart valve prostheses, vascular graft prostheses, breast prosthesis, catheter, cannulae films, tubing... 

However, in the last decade the main application of bacterial cellulose has been in the biomedical materials field [13,46,55-57], Due to its unique nanostructure and properties, microbial cellulose is a nattnal candidate for numerous medical and tissue-engineered apphcations. In fact, much work has already been focused on designing ideal biomedical devices from BNC, such as artificial skin, blood vessels, cornea, urethra, bone, cartilage, porcine knee menisci, and heart valve prosthesis as well as deliveries of drug, hormone and protein [58-62], Figure 2,5 illustrates some of the prospects for the various biomedical applications of BNC-based materials. 

Jiang H, Campbell G, Boughner D, Wan W, Quantz M (2004) Design and manufacture of a polyvinyl alcohol (PVA) cryogel tri-leafiet heart valve prosthesis. Med Eng Phys 26 269-277... 

Mohammadi H, Boughner D, Millon LE, Wan WK (2009) Design and simulation of a poly (vinyl alcohol)-bacterial cellulose nanocomposite mechanical aortic heart valve prosthesis. Proc Inst Mech Eng H 223 697-711... 

Key words textile valve prosthesis, percutaneous valve surgery, noninvasive valve replacement, trans-catheter heart valve, polyester fiber scaffold. 

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