High-Porosity expanded polytetrafluoroethylene grafts with omentum wrap for portal vein replacement: Intermediate results

The purpose of this study was to examine the intermediate (6-month) patency and healing characteristics of high-porosity expanded polytetrafluoroethylene (ePTFE) grafts with and without omentum wrap in a dog portal vein replacement model, compared with short-term (1-month) results. The grafts, either wrapped by omentum or not, were placed as portal vein replacements in 22 mongrel dogs. After 1 and 6 months, the grafts were retrieved and examined for patency and subjected to pathology study. Although the short-term patency rate in all grafts was 100%, regardless of the presence or absence of omentum wrap, the intermediate patency of high-porosity ePTFE without omentum wrap was very poor (20%). On the other hand, high-porosity ePTFE with omentum wrap had an intermediate patency rate of 100%. At 6 months, the high-porosity ePTFE grafts with omentum wrap were completely healed. The pseudointima was entirely replaced by thin fibrous tissue, with complete endothelial-like cell coverage throughout the graft. This result suggests that high-porosity ePTFE with omentum wrap could be a suitable prosthetic alternative to autogenous vein graft in portal vein reconstruction.