The Outcomes of Arteriovenous Fistula Cannulated From Different Direction.

The Outcomes of Arteriovenous Fistula (AVF) Cannulated From Different Direction in Maintenance Hemodialysis Patients.

The investigators hypothesis that aneurysms and stenoses will be decreased if the direction of inserted arterial needle were same as the direction of blood flow, when compared to the opposite direction puncture.

Native arteriovenous fistula (AVF) is the preferred access for hemodialysis, and cannulation technique is very important factors affect the outcomes of AVF. Rope-ladder cannulation is one kind of the standard puncture techniques which is used commonly in maintenance hemodialysis (MHD) patients. There are many complications for rope-ladder cannulation, such as venous aneurysm and vascular stenosis, which may induce AVF dysfunction. For the venous outflow way, there always be aneurysm followed by stenoses at the sites of needle connected with the arterial line in rope-ladder cannulation patients. The investigators hypothesis that the directions of inserted arterial needles should affect the AVF outcomes. The present prospective study will compare the outcomes of AVF between the puncture direction at arterial needle sites same as blood flow and opposite to blood flow.

Inclusion Criteria:

• MHD patients with autogenous AVF.
• Newly setup AVF in 3 months.
• Fore- or Upper arm AVF.
• Flow of >800ml/min detected by using the ultrasound dilution technique.

Exclusion Criteria:

• AVF after neoplasty.
• Arteriovenous grafts.
• Anticipated live time less than one year.
• Patients whose concurrent illnesses, disability, or geographical residence would hamper attendance at required study visit.