Management of true aneurysms of hemodialysis access fistulas.

OBJECTIVES: This study was designed to determine the clinical presentation, characteristics, and management of true aneurysms in dialysis access fistulas.
METHODS: Patients presenting with symptoms or functional arteriovenous fistula (AVF) problems and aneurysmal enlargement of the outflow vein were evaluated with duplex ultrasound scans. Dilatation to more than three times the native vessel diameter was considered aneurysmal. Pseudoaneurysms were excluded from the study. Patients' demographics, aneurysm characteristics (diameter, location, thrombus, association with stenosis, and outflow obstruction), symptoms, type of treatment, and follow-up were recorded.
RESULTS: Twenty-three patients with a mean age of 55 years were found to have 29 upper extremity aneurysms of the outflow vein on duplex ultrasound scan. Nine patients (39%) had radiocephalic, 11 patients (48%) had brachiocephalic, 2 patients (9%) had brachiobasilic, and 1 patient (4%) had radiobasilic arteriovenous fistula. The average aneurysm size was 3.3 cm and the mean time from fistula placement to treatment was 47.1 months. Four patients (17%) were asymptomatic and were repaired due to technical and mechanical problems with AVFs, including stenosis and lack of normal vein for cannulation, compromising continued use. Nineteen patients (83%) presented with symptoms, including pain (48%), skin changes (30%), venous hypertension (22%), steal syndrome (22%), and high output failure (9%). Four patients (17%) were found to have outflow vein stenosis, 2 patients (9%) had central venous stenosis, and 2 patients (9%) had central venous occlusion. In 13 patients (56%) who had a functioning kidney transplant, the fistula was ligated with or without aneurysm excision. Three of the 13 patients developed superficial phlebitis with 1 patient requiring surgical evacuation of a clot; the other 2 patients were managed conservatively. Two of the 13 patients required creation of new access due to renal transplant failure. In the remaining 10 patients, the aneurysm was treated and the fistula salvaged due to a persistent need for hemodialysis. The median follow-up of these patients was 19 months ranging from 8 to 25 months. Seven patients (30%) underwent excision and repair with the great saphenous vein and 3 patients (13%) had excision and repair with prosthetic material, 2 of which underwent central venous angioplasty and stenting. Two patients developed thrombosis of their repair requiring new access in the contralateral arm. Three patients needed secondary percutaneous interventions for anastomotic stenosis.
CONCLUSION: Although true aneurysms in patients with dialysis access are uncommon, significant complications may occur as a consequence of their presence. These complications can be treated and the fistulas can usually be salvaged.