Unfortunately some of the stents currently used occlude either immediately or over time, which can lead to organ failure, morbidity and death. A recent advancement in stent design has heparin bonded to the stent surface which prevents clot from forming. This new design has been shown to help maintain stent patency in other parts of the body. The investigators believe it may do the same for FEVAR patients. The proposed study is a 20-patient pilot to assess the safety of substituting a heparin bonded stent graft for FEVAR branches over a period of one year. Patients who are deemed eligible for FEVAR by a UHN multidisciplinary vascular conference will be recruited to the study. All the branches in their FEVAR will use the Viabahn BX stent in place of the current standard of care stent. They will then be followed per the standard of care for one year. Adverse events will be recorded and the rate of occlusion will be assessed based on CT imaging.