Dialysis patients presenting for angioplasty intervention for graft failure will be randomized to receive either Sirolimus or not receive Sirolimus (standard of care) to assess the time from primary failure or angioplasty intervention to second or next angioplasty intervention or graft failure.

This is a randomized control study to determine the feasibility of using sirolimus peri-angioplasty to compare the time from primary failure or angioplasty intervention to second or next angioplasty intervention or graft failure to a control group who would not have received Sirolimus

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.