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Polyurethane vascular prostheses decreases neointimal formation compared with expanded polytetrafluoroethylene
M G Jeschke1, V Hermanutz, S E Wolf
1University of Texas Medical Branch, Department of Surgery, Shriners Hospital for Children, Galveston, Tex 77550, USA.
Journal of Vascular Surgery
|January 12, 1999
Summary
Polycarbonate polyurethane (PU) vascular grafts demonstrated superior biocompatibility compared to expanded polytetrafluoroethylene (ePTFE) grafts. PU grafts showed faster endothelialization and reduced neointimal proliferation, suggesting improved performance in vascular reconstructions.
Area of Science:
- Biomaterials Science
- Vascular Surgery
- Regenerative Medicine
Background:
- Synthetic grafts are crucial for vascular reconstructions when autologous veins are unavailable.
- Current synthetic grafts, like expanded polytetrafluoroethylene (ePTFE), often lead to stenosis and thrombosis, particularly in small vessels.
- There is a need for synthetic vascular graft materials with improved biocompatibility and reduced adverse tissue responses.
Purpose of the Study:
- To compare the biocompatibility of porous, biodegradation-resistant polycarbonate polyurethane (PU) grafts against ePTFE grafts.
- To evaluate endothelialization rates and chronic intimal cell proliferation in PU versus ePTFE vascular grafts.
- To assess the potential of PU as a superior material for small vascular prostheses.
Main Methods:
- Abdominal aortic interposition grafts of PU (n=37) and ePTFE (n=32) were implanted in Sprague-Dawley rats.
- Grafts were explanted at multiple time points (1 day to 6 months) for evaluation using immunohistochemical, electron microscopic, and morphometric analyses.
- Cellular proliferation was assessed using Bromodeoxyuridine (BrdU) incorporation, with endothelial and smooth muscle cells identified via specific antibodies.
Main Results:
- Complete luminal endothelialization occurred significantly faster in PU grafts (4 weeks) compared to ePTFE grafts (24 weeks).
- Neointimal cell proliferation was substantially lower in PU grafts at 56 days and 6 months post-implantation compared to ePTFE.
- PU grafts exhibited significantly thinner neointima (3.2 ± 0.8 µm) at 6 months than ePTFE grafts (10.3 ± 3.1 µm).
Conclusions:
- Polycarbonate polyurethane small vascular prostheses promote accelerated luminal endothelialization.
- PU grafts demonstrate reduced chronic intimal proliferation and a thinner neointima compared to ePTFE grafts.
- Aliphatic-polycarbonate urethanes show promise as advantageous materials for vascular graft construction over traditional ePTFE.