Antibiotic-coated ePTFE decreases graft colonization and neointimal hyperplasia.
BACKGROUND
Synthetic vascular conduits used in traumatic or infected fields have a high failure rate leading to catastrophic consequences including amputation and death. Although efforts to coat vascular grafts with antibiotics have had varying results, we developed a novel coating technique for expanded-polytetrafluoroethylene (ePTFE), which has proven to be effective in vitro. Thus, we hypothesized that the coated grafts would resist infection and have decreased neointimal hyperplasia when used in vivo in a large animal model.


METHODS
Minocycline and rifampin suspended in a mixture of methacrylates were coated onto a 3cm segment of 6mm ePTFE (Bard, Tempe, AZ). An antibiotic-coated (ABX), adhesive-coated (AC), or control (C) ePTFE graft was then placed as an end-to-side graft into the left iliac artery of a male mongrel pig. Sterile saline or innoculum containing 3x10(8)Staphylococcus aureus (SA) or Staphylococcus epidermidis (SE) was then placed directly on the graft and the reflected peritoneum re-approximated to confine the bacteria. After 6 wk, the graft was harvested, cultured, and morphometric analyses of neointimal hyperplasia were performed.


RESULTS
Twenty-seven pigs had grafts placed (9 ABX, 9 AC, 9 C) and harvested. Of the nine grafts exposed to SA, the uncoated and adhesive-coated grafts averaged greater than 50,000 colonies of SA while the antibiotic-coated grafts averaged less than 50 colonies. Although not statistically significant, neointimal hyperplasia was decreased by 15% to 20% when using an ABX graft in an infected field.


CONCLUSIONS
The coated grafts appeared to decrease NIH formation although not significantly in this small pilot study. The methacrylate antibiotic-coated ePTFE graft did provide resistance to infection when used in infected fields.
Fischer
Peter E
PE
Department of Surgery, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA. pfischer@utmem.edu
Schroeppel
Thomas J
TJ
Fabian
Timothy C
TC
deRijk
Waldemar G
WG
Edwards
Norma M
NM
Magnotti
Louis J
LJ
Doty
Daniel H
DH
Croce
Martin A
MA
D000269:Adhesives / Q000008:administration & dosage; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D001807:Blood Vessel Prosthesis / Q000382:microbiology*; D020099:Coated Materials, Biocompatible; D004195:Disease Models, Animal; D006965:Hyperplasia / Q000517:prevention & control; D008297:Male; D008689:Methacrylates / Q000008:administration & dosage; D008855:Microscopy, Electron, Scanning; D008911:Minocycline / Q000008:administration & dosage; D010865:Pilot Projects; D011138:Polytetrafluoroethylene; D016459:Prosthesis-Related Infections / Q000382:microbiology / Q000517:prevention & control*; D012293:Rifampin / Q000008:administration & dosage; D013203:Staphylococcal Infections / Q000382:microbiology / Q000517:prevention & control*; D013211:Staphylococcus aureus; D013212:Staphylococcus epidermidis; D013552:Swine
D000269:Adhesives; D000900:Anti-Bacterial Agents; D020099:Coated Materials, Biocompatible; D008689:Methacrylates; D011138:Polytetrafluoroethylene; D008911:Minocycline; D012293:Rifampin