Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Prospective, Multi Center, Study to Evaluate the Safety and Efficacy of the VasQ External Support Device for Brachiocephalic Arteriovenous Fistula
Brief Summary: This study is a prospective, multi center, randomized, controlled study of the VasQ in arteriovenous fistulas. The VasQ constraints and directs the geometrical parameters of the fistula as well as the vascular diameter and gradient in the vicinity of the AV shunt. These geometrical constraints direct flow and influence hemodynamics, and hence minimize turbulence and promote laminar flow. The device is designed to improve short term maturation and long term patency of the fistula. The VasQ is a permanent implant intended for use as a subcutaneous arteriovenous conduit support for vascular access.


Options:
A: 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 of enrollment, or current dialysis dependence
* A new or planned arteriovenous (AV) graft placed in any location for the purpose of hemodialysis. (Any type of graft material and any configuration of the access is acceptable).
* The patient is expected to stay at a participating dialysis facility for at least 6 months.
* 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 of the study.
* The presence of ongoing bleeding.
* The presence of a known bleeding disorder (e.g., hemophilia or von Willebrand's disease).
* Recent bleeding episode requiring transfusion within 12 weeks of entry.
* The presence of acute ulcer disease. Acute ulcer disease is defined as a new diagnosis of peptic disease including esophagitis, gastritis, or ulcer or the initiation of treatment with proton pump inhibitors, H2 blockers or therapy for Helicobacter pylori within 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 other antiplatelet agents other than aspirin.
* Current uncontrolled hypertension with systolic blood pressure in excess of 200 mm Hg or 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 or bleeding 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.
B: Inclusion Criteria:

1. Age of at least 18 years.
2. Life expectancy of at least 6 months.
3. Diagnosis of Chronic Kidney Disease (CKD).
4. Planned creation of a new radiocephalic arteriovenous fistula (AVF)-revision of an existing AVF is not eligible.
5. Ability to understand and comply with the requirements of the entire study and to communicate with the study team.
6. Written informed consent using a document that has been approved by the Institutional Review Board (IRB).
7. If female and of childbearing potential (premenopausal and not surgically sterile) must have a negative serum pregnancy test at the screening visit (Visit 1) and be willing to use contraception from the time of the screening visit to 2 weeks following study drug administration. Acceptable methods of birth control include abstinence, barrier methods, hormones, or intra uterine device.

Exclusion Criteria:

1. Malignancy or treatment for malignancy within the previous 12 months with the exception of the following cancers if they have been resected: localized basal cell or squamous cell skin cancer, or any cancer in situ.
2. Presence of any significant medical condition that might significantly confound the collection of safety and efficacy data in this study.
3. Previous treatment with PRT 201.
4. Treatment with any investigational drug within the previous 30 days or investigational antibody therapy within the previous 90 days prior to signing informed consent.
C: Inclusion Criteria:

* Primary arteriovenous fistulas

  * Brachiocephalic
  * Radiocephalic (both proximal and distal)
* \>18 yrs old
* Diabetics and smokers will be eligible for inclusion

Exclusion Criteria:

* All complex vascular access procedures

  * Re-do brachiocephalic and radiocephalic fistulas
  * Brachiobasilic fistulas
  * Prosthetic grafts
* Cardiovascular dysfunction

  * Hypotension (systolic \<90)
  * Obstructive Cardiomyopathy
  * Severe Aortic stenosis (gradient \>40mmhg)
  * Confirmed myocardial infarction within the last 6 months
* Marked anaemia (Hb\<8)
* Migraine
* Medications

  * Sildenafil
  * Pre-existing nitrate use
* Nitrate allergy
* Closed-angle glaucoma
* Chronically raised intra-cranial pressure
* History of hypothyroid disease
* \< 18 years old
D: Inclusion Criteria:

* Patients referred for creation of a new brachiocephalic fistula who consent to take part in the study.
* Aged \> 18
* Male and female participants
* Patients willing and able to attend follow up visits over a period of 6 months

Exclusion Criteria:

* Patients who require revision surgery.
* Having had previous arteriovenous fistula surgery is not a contraindication to recruitment provided the new procedure is not revision surgery
* Target arteries smaller than 3 mm in diameter
* Target vein smaller than 3 mm in diameter
* Stenotic veins on the side of surgery as diagnosed on pre-op ultrasound
* Patients with prior central venous stenosis or obstruction on the side of surgery
* Depth of vein greater than 8 mm (on US) on side of surgery
* Known coagulation disorder
* Prior steal
* Known allergy to nitinol
* Life expectancy less than 6 months
* Inability to give consent and/or comply with the study follow up schedule
* Women of child bearing age

Answer: D