Post-Approval Study for the FLAIR Endovascular Stent Graft

The purpose of this study is to confirm the long-term safety and effectiveness of the FLAIR Endovascular Stent Graft for treatment of stenoses at the venous anastomosis of ePTFE or other synthetic arteriovenous (AV) access grafts.

The purpose of the study is to compare efficacy data on subjects randomized to treatment with percutaneous transluminal angioplasty (PTA) and the FLAIR™ Endovascular Stent Graft versus subjects randomized to treatment with PTA only.

Eligibility Criteria:
Inclusion Criteria:

* Subject must be either a male or non-pregnant female greater than or equal to 21 years of age
* Subject is willing to comply with the protocol requirements and can be contacted by telephone
* Subject has a synthetic AV access graft located in an arm that has been implanted for greater than or equal to 30 days and has undergone at least one successful dialysis session prior to the index procedure
* Angiographic evidence (per the institution's standard) is available to indicate that the subject has a stenosis greater than or equal to 50% located at the graft-vein anastomosis of subject's synthetic AV access graft
* The target lesion is estimated to be less than or equal to 7 cm in length (by angiography)
* The entire target lesion is located within 7 cm of the graft-vein anastomosis, as verified by angiography, such that approximately 1 cm of the FLAIR™ Endovascular Stent Graft will extend into non-diseased vein and approximately 1 cm but no more than 2 cm of the FLAIR™ Endovascular Stent Graft will extend into the non-diseased AV graft
* Full expansion of an appropriately sized angioplasty balloon, in the operator's judgment, can be achieved during primary angioplasty
* Graft diameter at the deployment site is between 5 mm and 8 mm as verified by angiography

Exclusion Criteria:

* The subject has a life expectancy of \< 25 months.
* The target lesion has had a corresponding thrombosis treated less than or equal to 7 days prior to the index procedure.
* A previously placed stent and/or stent graft located in the treatment area is present. Treatment area includes the entire target lesion and 1 cm of landing zone into both non-diseased AV graft and non-diseased vein.
* The subject has an infected AV access graft or uncontrolled systemic infection.
* The presence of additional lesion(s) in the access circuit less than or equal to 3 cm from the edges of the target lesion that was treated less than or equal to 30 days prior to index procedure.
* The presence of additional lesion(s) in the access circuit \> 3 cm from the edges of the primary lesion that are greater than or equal to 30% stenosed. Note: Subjects may be included if the additional lesions(s) can be successfully treated with a final residual stenosis of \< 30% prior to the index procedure.
* The location of the target lesion would require that the FLAIR™ Endovascular Stent Graft be deployed fully across the elbow joint (radiographically identified by a combination of the humeroulnar joint and the humeroradial joint).
* The location of the target lesion would require that the FLAIR™ Endovascular Stent Graft cross an angle (between the inflow vein and synthetic AV access graft) that is \> 90 degrees.
* The subject has an uncontrolled blood coagulation disorder.
* The subject has a known allergy or sensitivity to contrast media which cannot be adequately pre-medicated.
* The subject has a known hypersensitivity to nickel-titanium.
* Subjects who are currently enrolled or who plan to enroll in other investigations that conflict with follow-up testing or confounds data in this trial.