Vascular devices

Utilization of cell-specific peptide sequences in biomaterials enables the selective adhesion of certain cell types, even in the presence of a mixture of many cell types. As mentioned earlier, REDV promotes the adhesion of endothelial cells, but not other vascular cell types (Hubbell et al., 1991). This selectivity has great potential for endothelialization of vascular devices, where the growth of an endothelial cells, but not fibroblasts or smooth muscle cells, is desired. Another peptide sequence, KRSR, has been shown to selectively promote the adhesion of osteoblasts, which is useful in the rational design of better dental and orthopedic biomaterials (Dee et al., 1998). 

Paris, E., et al.. Innovations and deviations in therapeutic vascular devices, in S. Dumitriu, Polymeric Biomaterials. New York Marcel Dekker. 1994, pp. 245-275. 

The production of compliant absorbable films with modulated absorption and strength loss profiles to allow for their use in a wide range of applications as vascular devices or components — more specifically the use of these devices in sealing punctured blood vessels (Chapter 10)... 

B.D. Wilson, C.C. Gibson, L.K. Sorensen, M.Y. Guilhermier, M. Clinger, L.L. Kelley, et al.. Novel approach for endothelializing vascular devices understanding and exploiting elastin-endothelial interactions, Ann. Biomed. Eng. 39 (2011) 337-346. 

Acknowled ents The authors would like to thank Jack Mac Griffis MS for his expert consultation in vascular devices. The authors would tdso like to thank Kurt Jacobus Ph.D., Carl Frick Ph.D., Alicia M. Ortega, Sean Dixon, Jordan Rakes, and Jhordtin Gil for their support and careful review of this work. 

The radical biomediator NO is a natural modulator of several processes contributing to postangiplasty restenosis. At present, NO supplementation represents a unique and potentially powerful approach to help control restenosis, either alone or as a pharmaceutical adjunct to a vascular device (Janero and Ewing 2000). 

Vascular grafts are tubular devices implanted throughout the body to replace blood vessels which have become obstmcted by plaque, atherosclerosis, or otherwise weakened by an aneurysm. Grafts are used most often in peripheral bypass surgery to restore arterial blood flow in the legs. 

Blood Access Devices. An investigational device called the Osteoport system allows repeated access to the vascular system via an iatraosseous iafusion directiy iato the bone marrow. The port is implanted subcutaneously and secured iato a bone, such as the iUac crest. Medications are adrninistered as ia any conventional port, but are taken up by the venous sinusoids ia the marrow cavity, and from there enter the peripheral circulation (8). 

Polyurethanes as Biomaterials. Much of the progress in cardiovascular devices can be attributed to advances in preparing biostable polyurethanes. Biostable polycarbonate-based polyurethane materials such as Corethane (9) and ChronoFlex (10) offer far-reaching capabiUties to cardiovascular products. These and other polyurethane materials offer significant advantages for important long-term products, such as implantable ports, hemodialysis, and peripheral catheters pacemaker interfaces and leads and vascular grafts. 

Impla.nta.ble Ports. The safest method of accessing the vascular system is by means of a vascular access device (VAD) or port. Older VAD designs protmded through the skin. The totally implanted ports are designed for convenience, near absence of infection, and ease of implantation. Ports allow dmgs and fluids to be deUvered directiy into the bloodstream without repeated insertion of needles into a vein. The primary recipients of totally implanted ports are patients receiving chemotherapy, bolus infusions of vesicants, parenteral nutrition, antibiotics, analgesics, and acquired immune disease syndrome (AIDS) medications. 

The worldwide market for vascular grafts was approximately 150 million and growing at about 5% annuaUy as of 1995. The vascular graft area has tremendous market potential in development of smaU-diameter grafts of 3—4 mm for coronary bypass surgery. The total market for the intra-aortic baUoon pump, a cardiac-assist device, is ca 80 million worldwide. About 75,000 patients were supported by these baUoon pumps in 1994. This market is thought to have peaked. 

Self-expanding stents with a higher radial force (e.g., WingSpan, Boston Scientific Corp.) will probably play a key role in acute stroke cases related to intracranial atherosclerotic disease. Antegrade flow is essential for the maintenance of vascular patency, as particularly evident in patients with severe proximal stenoses who commonly develop rethrombosis after vessel recanalization. Furthermore, stenting of the proximal vessels may be required in order to gain access to the intracranial thrombus with other mechanical devices or catheters. In a recent series, 23 of 25 patients (92%) with acute n = 15) or subacute n = 10) ICA occlusions were successfully revascularized with this technique. " ... 

Acute myocardial infarction Angiopathy Aortic aneurysm Aortic balloon assist devices Giant hemangiomas Peripheral vascular disease Postcardiac arrest Prosthetic devices Raynaud s syndrome Infectious Arbovirus Aspergillus Candida albicans Cytomegalovirus Ebola virus... 

Two sets of blood cultures should be obtained, because two sets of cultures are required to rule out contamination. At least one should be drawn percutaneously and one drawn through each vascular access device, unless the device was recently (less than 48 hours) inserted. 

Pulmonary artery catheter An invasive device used to measure hemodynamic parameters directly, including cardiac output and pulmonary artery occlusion pressure calculated parameters include stroke volume and systemic vascular resistance. 

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