In patients with chronic renal failure, a well-functioning vascular access is essential for hemodialysis treatment. Native arteriovenous fistula (AVF) is the first-choice of vascular access, due to a lower incidence of complications and better long-term patency as compared to prosthetic arteriovenous fistula. With the incidence ranging between 6-60%, AVF aneurysm (AAVF) is a common complication of native AVF. According to Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines, asymptomatic aneurysms are indicated for conservative treatment, but precise recommendations when and how to intervene in available guidelines are missing.

Several surgical (remodeling, resection and substitution, ligation) and endovascular techniques have been described in the AAVF treatment, but there is currently no prospective randomized study comparing these techniques.

In 2008, our team published the first experience with a new surgical method of AAVF treatment - aneurysmorrhaphy with external porous prosthesis (Provena©, BBraun). This therapy was validated in several studies and has shown a good long-term patency and a minimal incidence of complications.

AAVF aneurysmorrhaphy can be performed with or without an external porous prosthesis (Provena©, BBraun). The use of external prostheses reduces venous wall shear stress, turbulent flow, endothelial damage, and thrombus formation, which should improve vascular patency and reduce the risk of AVF re-aneurysm. So far, there is no prospective randomized study comparing the effect of external porous prosthesis on AVF patency and the incidence of postoperative complications.

Inclusion Criteria:

1. Signature of informed consent.
2. A male or female subject aged 18 or older.
3. A subject with a naive vascular access aneurysm indicated for surgical treatment.

Exclusion Criteria:

1. Patients with pseudoaneurysm of prosthetic vascular access
2. Patients with a vascular access infection