Sustained Thromboresistant Bioactivity with Reduced Intimal Hyperplasia of Heparin-Bonded Polytetrafluoroethylene Propaten Graft in a Chronic Canine Femoral Artery Bypass Model

Ann Vasc Surg. 2018 May;49:295-303. doi: 10.1016/j.avsg.2017.09.017. Epub 2017 Nov 29.

Abstract

Background: Bypass graft thrombosis remains a significant mode of failure in prosthetic graft revascularization. The purpose of this investigation was to evaluate the long-term thromboresistant effect of heparin-bonded expanded polytetrafluoroethylene (ePTFE) graft using Carmeda BioActive Surface technology in a canine model.

Methods: Bilateral femorofemoral artery bypass grafts with ePTFE grafts were performed in 25 adult grayhound dogs. In each animal, a heparin-bonded ePTFE graft (Propaten, WL Gore) was placed on one side, whereas a control nonheparin graft was placed on the contralateral side. The graft patency was assessed at 1, 6, 12, 18, and 24 months (n = 5 per group) following the bypass. Heparin bioactivity of the graft material was analyzed. The effect of intimal hyperplasia was also assessed.

Results: All bypass grafts were patent at 1 month. Significantly greater patency rates were noted in the Propaten group compared to the control group at 12, 18, and 24 months, which were 84%, 80%, and 80% vs. 55%, 35%, and 20%, respectively (P < 0.02). There was a significant reduction in the anastomotic neointimal area and neointimal cell proliferation in Propaten grafts compared with control grafts at all groups between 6 and 24 months (P < 0.05). Heparin bioactivity as measured by antithrombin binding assay was demonstrated in the Propaten graft between 1 and 24 months. Mean heparin activities on Propaten grafts ranged from 26.3 ± 6.4 pmol/cm2 to 18.4 ± 8.7 pmol/cm2 between 1 and 24 months, which were significantly greater than the control group (P < 0.001). Differences between mean heparin activities of explanted Propaten graft samples at the various time points were nonsignificant (P > 0.05).

Conclusions: Heparin-bonded ePTFE graft provides a thromboresistant surface and reduced anastomotic intimal hyperplasia at 2 years. The stable heparin bioactivity of the Propaten graft confers an advantage in long-term graft patency.

MeSH terms

  • Animals
  • Anticoagulants / administration & dosage*
  • Blood Vessel Prosthesis Implantation / adverse effects
  • Blood Vessel Prosthesis Implantation / instrumentation*
  • Blood Vessel Prosthesis*
  • Coated Materials, Biocompatible*
  • Dogs
  • Femoral Artery / drug effects
  • Femoral Artery / pathology
  • Femoral Artery / physiopathology
  • Femoral Artery / surgery*
  • Graft Occlusion, Vascular / etiology
  • Graft Occlusion, Vascular / pathology
  • Graft Occlusion, Vascular / physiopathology
  • Graft Occlusion, Vascular / prevention & control*
  • Heparin / administration & dosage*
  • Hyperplasia
  • Models, Animal
  • Neointima*
  • Polytetrafluoroethylene*
  • Prosthesis Design
  • Thrombosis / etiology
  • Thrombosis / pathology
  • Thrombosis / physiopathology
  • Thrombosis / prevention & control*
  • Time Factors
  • Vascular Patency / drug effects

Substances

  • Anticoagulants
  • Coated Materials, Biocompatible
  • Polytetrafluoroethylene
  • Heparin