Please select the eligibility criteria that correspond to the clinical trial below.
Title: Effect of Isometric Preoperative Exercise on Vascular Caliber and the Maturation of Autologous Arteriovenous Fistulas. Randomized Clinical Trial
Brief Summary: A good vascular access (VA) is vital for hemodialysis (HD) patients. The start of HD with autologous arteriovenous fistula (AVF) means higher survival, lower sanitary costs and complications. The distal forearm AVF is known as the best option but not all patients are good candidates for this surgery, and there is a primary failure rate between 20 and 50% published in literature.

The choice of the optimal AVF for each patient is conditioned mainly by the anatomical and hemodynamic characteristics of the artery and the vein chosen to perform the anastomosis. These characteristics can be modified by performing physical exercise Some vascular access guidelines suggest the performance of isometric exercises in the pre and postoperative period of the AVF confection. However, there is very little data in literature on the possible efficacy of preoperative exercise, although small published observational studies point to an improvement in the venous and arterial caliber. Regarding the postoperative exercises, they do seem to improve maturation, however the degree of evidence in literature is low and there is no consensus on the exercise protocol to follow.

We present an open-label, multicenter, prospective, controlled and randomized study in order to evaluate the usefulness of preoperative isometric exercise (PIE) in pre-dialysis patients or in prevalent HD with indication of performing a new AVF. The randomization will be 1: 1, one group of patients will perform PIE for 8 weeks and the other group of patients will be a control group. The main purpose will be to evaluate if there is a lower rate of primary failure in the PIE group compared with control group.


Options:
A: Inclusion Criteria:

* Patients with Chronic Kidney Disease (CKD) stage 4 or 5;
* In conservative or dialysis treatment;
* Medical indication of arteriovenous fistula as an achievement of HD.

Exclusion Criteria:

* Cognitive impairment or changes that hinder understanding, realization of activities and interpretation of the issues;
* a history of making FAV in both upper limbs or some other type of vascular surgery in upper limbs, with some type of vascular access in upper limbs or in nearby regions;
* to develop some kind of manual work with heavy loads;
* Trauma-orthopedic lesions in the cervical, shoulder, elbow, wrist and untreated (or) hand;
* Signs of thrombophlebitis and hypoplasia / agenesis of the upper limbs.
B: Inclusion Criteria:

* Informed consent signature.
* Age between 18 and 89 years.
* Patients with advanced chronic kidney disease, stages IV-V, in pre-dialysis or prevalent HD patients, requiring new AVF.

Exclusion Criteria:

* Absence of adequate arteries and veins to allow autologous AVF. (The minimum gauges that will be considered in order to perform an autologous AVF are: artery caliber equal or greater than 1.6 mm and vein caliber equal or greater than 1,8 mm with a compressor).
* Diagnosis of coagulopathy or hemoglobinopathy of any cause.
* Patients who urgently need an AVF without the possibility of being 8 weeks on the surgical waiting list.
* Impossibility to perform the physical exercise protocol due to physical or mental disabilities or lack of social support.
C: Inclusion Criteria:

* Age exceeding the age of majority (18 years of age).
* Chronic renal failure with a calculated GFR (MDRD equation) less than or equal to 20 ml/min
* Eligible for creation of an arteriovenous fistula for the purpose of hemodialysis.
* The subject is expected to stay within driving distance of study site for at least 4 months.
* The subject's physician(s) will allow the patient to participate.
* Ability to give informed consent.

Exclusion Criteria:

* Unstable angina.
* Uncontrolled hypertension (resting blood pressure \>170 systolic or \>100 diastolic).
* Musculoskeletal or neurologic problem that prevents arm exercise.
* Currently functioning arteriovenous access in the same arm as the planned new fistula.
* Subjects who are eligible to participate in the ongoing DAC fistula trial.
* Planned new access surgery in less than 6 weeks
* Anticipated non-compliance with medical care based on physician judgment.
* Patient refusal.
D: Inclusion Criteria:

1. Chronic Kidney failure patients with eGFR less than 20mls/min
2. Chosen Hemodailysis as their modality of renal replacement therapy

Exclusion Criteria:

1. Potential fistula vein diameter less than 3mm (with application of tornique) on initial vein mapping
2. Known left ventricular ejection fraction of less than 20% on Echocardiogram
3. Previous stroke effecting the AV fistula arm
4. Calcified brachial or radial arteries and/or duplex evidence of stenosis of \>50%

Answer: B