BIOMATERIAL APPLICATIONS - Advanced Biomaterials: Fundamentals, Processing, and Applications - page 526

15.3 APPLICATIONS IN MEDICINE, BIOLOGY, AND
ARTIFICIAL ORGANS
15.3.1 Cardiovascular Medical Devices
Cardiovascular medical devices (CMD) have been used for more than fi ve
decades for myriad applications that save, prolong, and enhance the quality of life.
Still, complications are associated with available CMD devices that cause signifi -
cant mortality rates, even years after implantation. Many different biomaterials
are used in cardiovascular applications depending on the specifi c application and
the design, for instance, carbon in heart valves and polyurethanes for pace maker
leads (Figure 15.1). Heart valve prostheses are used to replace dysfunctional
natural valves with substantial enhancement of both survival and quality of life.
Metallic cylindrical mesh stents are inserted via catheters and without surgery
during percutaneous transluminal coronary angioplasty (in which balloon is
threaded into a diseased vessel and infl ated, thereby deforming the atheroscle-
rotic plaque and partially relieving the vessel). These inventions revolutionized
the treatment of coronary artery disease and myocardial infarction. The synthetic
Figure 15.1. Various pacemaker component designs. Top: Three examples of titanium-
encased pulse generators. Connector blocks, which serve to attach the pacemaker to the pace-
maker lead, are shown at the top of each pulse generator. Bottom: Various types of insulated
endocardial and myocardial leads. Note that the lead shown at the center of the fi gure has a
silicone sewing pad and dacram mesh disk for implant fi xation. Adopted from chapter 1. over-
view of biomaterials and their use in medical devices, In: Handbook of materials for medical
devices. Ed. J. R. Davis, ASM International (USA), 2003 pp. 1 - 11 .