Aggrenox Prevention of Access Stenosis

Inclusion criteria:

• Age 18-21 depending on state regulations

• Life expectancy of at least six months

• Chronic renal failure with anticipated start of hemodialysis within six months ofenrollment, or current dialysis dependence

• A new or planned arteriovenous (AV) graft placed in any location for the purpose ofhemodialysis. (Any type of graft material and any configuration of the access isacceptable).

• The patient is expected to stay at a participating dialysis facility for at least 6months.

• The patient's physician(s) will allow the patient to participate.

• Ability to give informed consent.

Exclusion Criteria:

• Women must not be pregnant, breastfeeding, or plan to be pregnant during the course ofthe study.

• The presence of ongoing bleeding.

• The presence of a known bleeding disorder (e.g., hemophilia or von Willebrand'sdisease).

• Recent bleeding episode requiring transfusion within 12 weeks of entry.

• The presence of acute ulcer disease. Acute ulcer disease is defined as a new diagnosisof peptic disease including esophagitis, gastritis, or ulcer or the initiation oftreatment with proton pump inhibitors, H2 blockers or therapy for Helicobacter pyloriwithin three months prior to obtaining consent.

• Known allergy or adverse reaction to Aggrenox or any of its study components (dipyridamole and aspirin).

• Required use of warfarin, dipyridamole, non-steroidal antiinflammatory drugs or otherantiplatelet agents other than aspirin.

• Current uncontrolled hypertension with systolic blood pressure in excess of 200 mm Hgor diastolic blood pressure in excess of 115 mm Hg.

• Baseline platelet count less than 75,000/mm3.

• Known advanced liver disease with decompensated cirrhosis, jaundice, ascites orbleeding varices.

• Current problem with substance abuse.

• Concurrent participation in another medical intervention trial.

• Anticipated non-compliance with medical care based on physician judgment.

• Patient refusal.