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.