November 22, 2011 — The question remains whether patency rates for heparin-bonded polytetrafluoroethylene (PTFE) grafts are better than traditional PTFE bypasses; whether these types of grafts should be used in all lower extremity bypass situations is also a question.
These questions were addressed at the 38th annual VEITH Symposium in New York City. Edward Y. Woo, M.D., associate professor of surgery, division of vascular surgery and endovascular therapy of Hospital of the University of Pennsylvania, made the presentation.
Lower extremity bypasses fail for a large number of reasons; the prominent ones include thrombus formation, progression of vascular disease, and intimal hyperplasia. Prosthetic grafts coated with heparin have been suggested as a possible way to address the mechanisms that lead to graft failure.
Woo reviewed the data around the Gore Propaten Vascular Graft. This graft has the Carmeda BioActive Surface heparin immobilization that allows for long-term heparin binding. Sustained heparin bioactivity has been shown in graft explants from an in vivo canine model after 12 weeks and a human graft explant out to three years.
Woo recently published a study that demonstrated excellent rates of patency for the Propaten graft in all positions. The rates surpassed historical patency rates for traditional PTFE grafts. However, Woo said, “There are some precautions to keep in mind. In patients who have heparin-induced thrombocytopenia (HIT), these grafts should not be used as the presence of heparin on the graft will worsen the HIT. In patients who demonstrate HIT after the procedure or have a suspicion of HIT, the management is more difficult.”
“The decision of explanting a Propaten graft in a patient that develops HIT will have to be made on a case by case basis,” concluded Woo.
Woo reported that he moved to using Propaten grafts in all positions where PTFE would be placed because of the improved patency rates.
For more information: www.veithpress.org
April 17, 2024 
