Randomized comparison of 6-mm straight grafts versus 6- to 8-mm tapered grafts for brachial-axillary dialysis access

Abstract

The results of this study show an advantage in terms of primary and assisted primary patency rates, and complication rate for upper arm grafts with diameter 6 mm to 8 mm over grafts with 6-mm diameter in a patient population younger than 70 years without diabetes. The finding of a similar secondary patency rate in both groups is probably due to the surveillance program with sequential measurement of access flow and prompt surgical treatment of stenosis. However, we needed twice the number of rescue procedures in 6-mm grafts to achieve a similar patency rate as with large-bore grafts. These study results must be carefully evaluated, taking into consideration the small number of patients and the selected patient population.

Neointimal hyperplasia associated with synthetic hemodialysis grafts

“…Limited clinical studies suggested that 8- to 6-mm tapered grafts improved primary patency rate and decreased complications, compared with 6-mm straight grafts. Further studies are required to confirm these observations 152,153. Yet another approach is to create a cuffed geometry made of ePTFE at the venous anastomosis to reduce regional turbulence, as venous cuffs seems to be beneficial in the arterial–arterial bypass ePTFE graft setting.…”

The effect of location and configuration on forearm and upper arm hemodialysis arteriovenous grafts

“…6,8,15,[19][20][21] Although prosthetic AVGs are often placed in the upper extremity, they vary with respect to location, configuration, material, feeding artery, and draining vein. 1,[4][5][6][7]15,[22][23][24][25][26][27] The optimal graft location (upper arm or forearm) and graft configuration (straight or looped) are unknown. 5,28,29 Placement of an fAVG has the advantage of preserving upper arm veins for a future upper arm access site and may increase the suitability of upper arm veins for future upper arm AVF.…”

Prevention of neointimal hyperplasia associated with modified stretch expanded polytetrafluoroethylene hemodialysis grafts (Gore) in an experimental preclinical study in swine

“…4 The elements which take part in the development of NH (␣-smooth muscle actin positive cells derived from adventitial fibroblasts, extracellular matrices, a variety of growth factors and neovascularization) are well known, [5][6][7] but the true cause of the activation of these components remains unclear and is still under debate. Actually, NH prevention strategies (mechanical design of the graft, [8][9][10][11][12] biological reagents, [13][14][15] small-molecule drugs 16 ) have not produced the expected results essentially because they have not intervened on the initial causes. Using synthetic vascular prostheses in AVGs, most commonly made from expanded polytetrafluoroethylene (ePTFE), the first observation we could make was that the flow induced vein-wall vibration at the anastomosis site 17 where there was also large mismatch compliance between the vein and the graft wall.…”