The SIR-POBA Bypass Trial

Inclusion Criteria * Age at least 18 years * Informed consent with signature * Rutherford category 2 or 3 (in terms of lifestyle-limiting moderate or severe claudication symptomatology) or chronic critical ischemia (Rutherford 4-6) * Venous bypass stenosis requiring intervention * Confirmed inflow * At least 1 crural outflow vessel Exclusion Criteria: * Pregnant or lactating women * Active infection or sepsis * Patients currently participating in another clinical trial * Unconfirmed inflow * Intolerance to sirolimus * Coagulopathy * Radiotherapy * Patients on immunosuppressive therapy * Non-dialysis renal insufficiency (eGFR \< 45 ml/min/1.73m2) * Use of potent CYP3A4 and/or P-gp inhibitors (such as ketoconazole, Voriconazole, itraconazole, erythromycin, telithromycin, or clarithromycin) or strong CYP3A4 and/or P-gp inducers (such as rifampin or rifabutin).