A NEW, SMALL-VESSEL PROSTHESIS

THE OBJECTIVE OF THIS PROGRAM IS TO DEVELOP A NEW PROSTHESIS FOR THE REPLACEMENT OF VESSELS SMALLER THAN 6 MM DIAMETER. THE PROSTHESIS EMPLOYS A POLYURETHANE FIBRIL MICROPOROUS TEXTURED SURFACE AT THE BLOOD INTERFACE DESIGNED TO GENERATE A PSEUDONEOINTIMA (PNI) FROM BLOOD FLOWING OVER THE SURFACE. THE NEW MICROPOROUS SURFACE IS APPLIED ON A SUBSTRATE WHOSE COMPLIANCE IS APPROXIMATELY MATCHED TO A COMPARABLY SIZED ARTERY. THE TEXTURED SURFACE WILL ALSO BE APPLIED TO THE EXTERIOR OFTHE GRAFT TO PROMOTE TISSUE ATTACHMENT AND MAINTAIN THE COMPLIANCE OF THE GRAFT IN A PHYSIOLOGIC RANGE FOLLOWING HEALING OF THE PERIGRAFT TISSUES. IT IS POSTULATED THAT COMPLIANCE MISMATCH IS AT LEAST IN PART RESPONSIBLE FOR THE INTIMAL HYPERPLASIA THAT IS FREQUENTLY SEEN AT THE ANASTOMOTIC SITES WITH CONVENTIONAL PROSTHESES. BY LESSENING INTIMAL HYPERPLASIA, IMPROVED PATENCY MAY RESULT. TO EVALUATE THE NEW PROSTHESIS, A SERIES OF SIX GRAFTS ARE TO BE IMPLANTED IN THE CAROTID ARTERIES OF ADULT DOGS. NONCOMPLIANT GRAFTS WILL BE IMPLANTED CONTRALATERALLY AS A CONTROL. AFTER 8 WEEKS, THE ANIMALS ARE TO BE SACRIFICED. THE COMPLIANCE OF THE GRAFT IS TO BE MEASURED IN SITU, AND THE IMPLANTS REMOVED FOR HISTOPATHOLOGIC ANALYSIS. THE COMPOSITION, STRUCTURE, AND THICKNESS OF THE PNI FROM BOTH GROUPS WILL BE COMPARED, AND THE ANASTOMOTIC SITES WILL BE EXAMINED FOR EVIDENCE OF DIMINISHED INTIMAL HYPERPLASIA RESULTING FROM THE NEW PROSTHESIS DESIGN.