Abstract: Objective This study was designed to determine the clinical presentations, characteristics, and management of true aneurysms in dialysis access fistula. Methods Patients presenting arteriovenous ? fistula (AVF) functional problems or symptoms and aneurysmal enlargement of the outf low vein were reviewed.
Dilatation to more than three times of the native vessel diameter was considered to be aneurysm. Pseudoaneurysms were excluded from the study. Patients’demographics, aneurysm characteristics (location, diameter, thrombus, association with stenosis, and outf low obstruction), symptoms, type of treatment, and followup data were recorded. Results Fifty-two patients were found to have aneurysms of the outf low vein in upper extremities, accounting for 2.44% (52/2,131) of all hemodialysis access related complications. The average aneurysm size was 3.12±1.24cm, and the mean time from fistula establishment to presence of aneurysm was 24±20 months. Aneurysms located in cannulation areas in 23 patients (44.23%), along the venous outflow tract in 15 patients (28.85%), and in the juxta-anastomotic areas in 14 patients (26.92%). 7 patients (14.46%) were asymptomatic and the aneurysms were repaired for normal outlook. 45 patients (86.54%) were symptomatic, including skin changes (25%), venous hypertension (11.54%), high-output heart failure (11.54%), insufficient
blood flow (11.54%), steal syndrome (9.62%), limited area for cannulation (7.69%), infections (5.77%),and rupture with hemorrhage (3.85%). 9 patients (19.25%) presented vein stenosis in cannulation areas, 2 patients (3.85%) had venous outflow tract stenosis/occlusion not in the cannulation vein, and 4 patients (7.69%)
had central venous stenosis/occlusion. In the 5 patients with well- functional transplantation kidney, fistulawere ligated and the aneurysms were excised. In 30 patients, a new fistula at the same side or at opposite side was created with or without aneurysm excision. In 9 patients with stenosis at the aneurysm site, outflow tract venous angioplasty was conducted. In 3 patients with central venous stenosis/occlusion, angioplasty or stenting was used. In 5 patients with higher flow in fistula, banding aimed to restrict blood flow in the fistula was conducted. The immediate success rate was 98.08% without severe complications. Conclusion True aneurysm of autologous AVF is uncommon developing later after fistula creation with various clinical manifestations. This complication can be treated individually according to aneurysm site and vascular condition of the patient.

Key words: Arteriovenous fistula, true aneurysms, clinical manifestion, management