LAUSR

Objectives: Each year, >35,000 children are born in the United States with congenital heart defects. A vascular conduit is commonly used in the surgical repair of these defects. However, no currently available vascular conduit provides the potential for growth. For children with congenital heart diseases, this means having to undergo repeated operations due to the limitations of current vascular conduits. Pediatric patients with congenital cardiovascular defects would benefit greatly from an expandable conduit. To address this issue, PECA Labs has developed a novel expanded polytetrafluoroethylene vascular conduit with the capability of being radially expanded via balloon catheterization. We have shown previously that this novel expanded polytetrafluoroethylene material maintains its mechanical properties after expansion (Fig). Methods: In the described study, a systematic biocompatibility and chemical characterization was conducted to investigate the clinical viability of this novel expandable conduit material. The material is also undergoing proof-of-concept testing in a large-animal aortic replacement model. Pyrogenicity was tested in a rabbit model to determine the levels of chemical pyrogens in the material. New Zealand White rabbits were injected with the material extracts, and their temperature was monitored for 3 hours. Cytotoxicity was evaluated in vitro by culturing mouse fibroblast CCL-1 cells with the material and quantifying cell viability after 24 hours. Hemocompatibility was determined with a hemolysis test using rabbit blood. Whole rabbit blood was cultured with material extracts for 3 hours. Samples were then centrifuged to collect the supernatant to test for free hemoglobin. Additional testing, including irritation testing, the genotoxicity, and hemodynamics is currently ongoing. Implantation of the material in a 14-day rabbit implantation study is ongoing to determine the systemic toxicity of the material. Results: The results from testing have thus far have illustrated the biocompatibility of this expandable conduit material. The expandable material is considered nonpyrogenic and meets the requirements of the Pyrogen Test, ISO 10993-11 guidelines. The material also meets the requirements to be nonhemolytic according to ASTM F756 guidelines and is not considered to have a cytotoxic potential based on ISO 10993-5 guidelines. Large-animal proof-of-concept testing and chemical characterization testing is currently underway, and results will be collected over the next 2 months. Conclusions: Thus far, this study represents successful safety verification of this material and is a critical step toward clinical translation,