Permacol interposition graft as an alternative to vein in contaminated wounds using a rabbit model

Vascular injuries are common in trauma and often involve massive soft tissue injury and segmental arterial loss. Current practice uses either autogenous vein or polytetrafluorethylene (PTFE) for interposition grafting in arterial injuries. Decision making between autogenous or synthetic conduit pivots around the physiological state of the trauma patient. Vein is known to increase operative times in an already physiologically depleted patient, whereas synthetic graft can be simply pulled from the shelf. However, when used in contaminated wounds, PTFE is prone to chronic infection and subsequent graft failure. An alternative synthetic conduit resistant to infection would be ideal for such situations. Permacol (Tissue Science Laboratories, Inc, Andover, MA), a biosynthetic material, has demonstrated resistance to bacterial contamination in contaminated hernia repairs. When fashioned into a tubular structure, this material may be useful as an alternative vascular conduit in contaminated trauma wounds.

New Zealand white rabbits were randomized to one of 4 groups: Permacol graft (P) without bacterial contamination (n = 9), Permacol graft with bacterial contamination (CP; n = 9), autogenous vein graft without bacterial contamination (V; n = 9), or autogenous vein with bacterial contamination (CV; n = 9). All groups then underwent interposition grafting of the right common carotid artery. Grafts were contaminated by applying Staphylococcus aureus (1 × 10(5) colonies/0.1 mL) directly to the exposed surface of the graft on completion of the arterial repair. Each graft was then excised at day 42, and segments were collected for histologic evaluation, bacterial counts, and real-time polymerase chain reaction.

Of the 36 rabbits used in this study, 3 animals in the CV group died within 72 hr of surgery. There was no difference in early mortality between P and V (0% vs. 0%; P = 1.0); however, early mortality was higher in the CV compared with the CP group (33% vs. 0%; P = 0.023). At 42 days, histologic evaluation of graft patency demonstrated no difference between P and V (67% vs. 33%; P = 0.157); however, patency was higher in CP than CV (56% vs. 12%; P = 0.040). In addition, no difference was found between the 2 contaminated groups in regard to the number of bacteria present on each graft material.

Permacol as an interposition graft is a feasible alternative to vein in a contaminated setting and shows resistance to infection in a rabbit model. Future studies are needed to evaluate this material in larger animal models.