Randomization and Masking
Using a computer-generated list for each site, permuted block randomization was applied with block sizes of 8 patients assigned in a 1:1 fashion to either endovascular treatment with the ZILVER PTX stent or BYPASS surgery with synthetic graft. Each site received closed envelopes that were opened only after the patient signed the informed consent. Once a treatment was assigned, crossover was not permitted. Patients assigned to the ZILVER PTX group were considered enrolled when successful lesion passage was achieved and diagnostic angiography confirmed that all angiographic inclusion criteria were met. Patients assigned to the BYPASS group were considered enrolled when they were treated as intended.