Coaxial double-tubular compliant arterial graft prosthesis: time-dependent morphogenesis and compliance changes after implantation.
In order to reduce the compliance mismatch between the native artery and the artificial graft, we have developed a coaxial double-tubular compliant graft, using multiply micropored segmented polyurethane (SPU) thin films, which mimics the relationship between the intraluminal pressure and vessel internal diameter (P-D) of the native artery (termed "J" curve). The graft was coaxially assembled by inserting a high-compliance inner tube with a heparin-immobilized photocured gelatin coating layer into a low-compliance outer tube with a photocured hydrophilic polymer coating layer. Twenty-eight coaxial double-tubular compliant grafts were implanted into the canine common carotid arteries in an end-to-end fashion for up to 12 months. The overall patency rate was 86% (24/28), and neither rupture nor aneurysmal formation was observed. A neoarterial wall was formed via transanastomotic and transmural tissue ingrowth, resulting in neoarterial tissue formation on the luminal surface and into the intertubular space of the double-tubular graft, accompanied by mainly myofibroblasts and inflammatory cells in the early stage and endothelialization and collagen-rich extracellular matrices in the late stage of implantation. Surrounding-tissue adhesion with the outer tube was prevented by the hydrophilic polymer coating. Although the J curve of the implanted prototype model was preserved 1 month after implantation, the impaired J curves were observed because of tissue ingrowth and tissue adhesion between the outer surface of the inner tube and the surrounding tissues 3 and 6 months after implantation. At 12 months after implantation, however, the implanted coaxial double-tubular graft exhibited high compliance due to biodegradation of the SPU films.
Department of Biomedical Engineering, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
Hiromichi
H
Sonoda
Keiichi
K
Takamizawa
Yasuhide
Y
Nakayama
Hisataka
H
Yasui
Takehisa
T
Matsuda
D000818:Animals; D001011:Aorta / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods; D017536:Carotid Artery, Common / Q000601:surgery* / Q000648:ultrastructure; D004285:Dogs; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D009024:Morphogenesis; D009131:Muscle, Smooth, Vascular / Q000601:surgery; D011474:Prosthesis Design; D013499:Surface Properties; D017539:Tunica Intima / Q000601:surgery / Q000648:ultrastructure