Sirolimus Use in Angioplasty for Vascular Access Extension

Inclusion 1. hemodialysis patients referred for angioplasty for hemodialysis access stenosis through either access flow or clinical monitoring in either an AVF or AVG 2. \> 18 years of age. 3. Total white blood cell count \> 3 x 109 /L and platelet count \> 100.0 x 103/uL 4. Fasting triglycerides \< 4.0 mmol/L, fasting cholesterol \< 7.8 mmol/L while on optimal lipid lowering therapy. Exclusion Criteria: 1. A woman who is pregnant or breastfeeding 2. Active malignancy 3. Concomitant treatment with immunosuppressant medications 4. Active infection or treated for infection within the last 30 days 5. Pre-existing interstitial lung disease 6. Thrombocytopenia with platelets less than 100 109/L 7. Previous renal or other solid organ transplant 8. Preexisting liver failure 9. Life expectancy less than 6 months 10. Planned major surgery or major surgery within the last 6 months 11. History of malignancy within the previous 5 years (with the exception of adequately treated basal cell or squamous cell carcinoma of the skin). 12. Known history of any coronary intervention within the 6 months prior to current screening 13. Prior or current use of Sirolimus or any of its derivatives within 3 months prior to angioplasty 14. Active gastrointestinal disorder that may interfere with drug absorption 15. Known to be HIV positive or known active hepatitis B or C infection 16. Treatment with voriconazole, terfenadine, cisapride, astemizole, pimozide, or ketoconazole (known to interact with Sirolimus) that is not discontinued before starting Sirolimus treatment.