GENETICALLY ENGINEERED MAMMALIAN CELLS COULD IMPROVE THE BIOCOMPATIBILITY OF IMPLANTABLE CARDIOVASCULAR DEVICES

Abstract

patients’ acceptance and become popular in cardiac surgical practices. Because most centres have limited experiencewith this approach,we summarised the clinical profiles in patients undergoing endoscopic vessel harvest (EVH). Methods. Between March 2001 and October 2005, 1005 patients (705 male, 301 female) with a mean age of 67.2 (range 28–89) underwent EVH of the saphenous vein for coronary artery bypass surgery, peripheral artery reconstruction and miscellaneous conditions. The EVH was performed using the Vasoview system (Guidant, Menlo Park, CA) under the assistance of carbon dioxide (CO2) insufflation. Results. Technical success was achieved in 98% of cases. Two saphenous veins were discarded due to obvious vein injury. The mean harvest time was 45min. The mean harvest times for the first 50 cases and last 200 cases were 68 and 23min, respectively. Ninety-eight percent of patients had only saphenous vein harvested from thighs; only 2% patients had saphenous vein harvested from legs. Postoperative wound complications occurred in 36 patients. There were 19 wound dehiscences or poor healing, 16 wound infections and 1 overlying skin necrosis. Overall, 18 subsequent revisionswere required for these complications. Therewere detectable air embolisms in 143 patients, self-limited wound haematoma in 25 patients, and numbness in the saphenous nerve territory in 169 patients. Methods. To improve the biocompatibility of implantable cardiovascular devices our group investigated cellular linings to modulate biological properties of device surfaces. For this purpose different tissue types were harvested, isolated and expanded in tissue culture. The biological performance of mammalian cells were characterised and assessed. Tissue culture cells were genetically engineered to create an endothelial like cell lining for the blood-contacting surfaces of cardiovascular devices. Cardiovascular devices were coated with a genetically engineered cell lining and their mechanical performance and biological properties were assessed in vitro and in vivo. Data were compared with mathematical models and numerical methods to study diffusion-mediated and stress-induced growth and adhesion of tissue culture cells under normal and sheer stress conditions. Conclusion. Genetically engineered mammalian tissue culture cells have provided an adherent, nonthrombogenic cell lining for implantable cardiovascular devices and were comparable to mathematical modelling. The data gained from this interdisciplinary research project may lead to novel ways of improving the biocompatibility of implantable cardiovascular devices, which in turn may reduce the incidence of complications associated with their use and at last improve the treatment of cardiovascular diseases. Conclusion. EVH of the saphenous vein is a valid alternative to open saphenectomy, providing excellent surgical results, and should be the standard of care for saphenous vein harvest.