Comparison of Two Under Knee Lower Limb Bypass Types:Endothelialised Prosthesis Versus Autologous Vein Graft

• Bypass permeability during 5 years after surgery, assessed trough Doppler echography
  

• Mortality and morbidity, primary and secondary permeability, quality of life, leg salvage, cost/benefit ratio.. All patients will be followed up at 1, 3, 6, and 12 months and each year during 5 years
  

Physiological vascular endothelium is an hemocompatible and thrombus resistant surface and none of the materials used for revascularisation owns these properties. The aim of this project is to improve the hemocompatibility of vascular prosthesis with a complete covering of their endoluminal surface with autologous endothelial cells. This strategy, that plans to associate an artificial component of synthetic origin and cellular component is a bioartificial vascular substitute concept. First results obtained by an austrian team are really encouraging (with more than 100 patients during last 10 years). Thus, the main objective of this study is to compare efficacy in terms of grafts with endothelialised PTFE prosthesis with great saphenous autologous vein graft for under knee arterial popliteal revascularisation of lower limbs.

This is a phase III, randomised equivalent trial. It is open labelled, with 2 parallel well balanced groups. Forty patients will be randomised. A short segment of the cephalic vein will be cut and some blood will be sampled in patients randomised in the ePTFE group. Endothelial cells of the cephalic vein will be isolated, cultured, with autologous serum, and then amplified before sowing of the internal face of PTFE prosthesis, previously covered with a biological glue clinically validated. Before prosthesis implantation, systematic quality controls will be performed. Implantation will be planned 3 weeks after venous sampling. Eventual failure of cellular culture or prosthesis covering will lead to an autologous vein graft. People randomised in the second group will receive an autologous saphenous vein graft.

The primary outcome is to demonstrate the equivalence of time dependent permeability rate between endothelialized PTFE and autologous vein graft. Equivalence between both technics would allow to preserve autologous saphenous vein for later distal bypasses (where it is the best technic) or for coronary bypasses.