Native arteriovenous fistula: preoperative evaluation.

Duplex sonography recently has been recognized as an objective and noninvasive method to assess morphological and functional parameters of vessels that could predict arteriovenous fistula (AVF) patency and time of adequate maturation. To prospectively study prognostic indicators of native AVFs, forearm arteries and veins of patients with end-stage renal disease were examined by duplex sonography before AVF construction. Several anatomic parameters, including feeding artery internal diameter (IDA), resistance index (RI), and arterial blood flow (Q(A)) before and at reactive hyperemia (RH) and internal diameter of the vein (IDV) before and after proximal vein compression (PVC), were measured. Measurements of the feeding artery were repeated at different periods after native AVF construction. One hundred sixteen patients were included on the study. The primary patency rate (successful constructed AVF) of native AVFs was 80.2%. In this group, mean values for IDA were 0.264 cm; RI at RH, 0.50; and Q(A), 54.5 mL/min. IDV increased after PVC for 59.3%. In the group with failed AVFs (19.8%), mean IDA was 0.162 cm; RI at RH, 0.70; and Q(A), 24.1 mL/min. IDV increased after PVC for only 12.4%. Patency rates after surgery in a group with IDAs greater than 0.16 cm was 93%, and with IDAs of 0.16 cm or less, 32%. In a group with RIs at RH less than 0.7, the patency rate was 95.3%, and with RIs of 0.7 or greater, 38.7%. An AVF feeding artery Q(A) of 300 mL/min was achieved in the group with IDAs greater than 0.16 cm, those with RIs at RH less than 0.7 after 1 week, those with IDAs of 0.16 cm or less between 3 and 8 weeks, and those with RIs of 0.7 or greater between 8 and 12 weeks. This study shows that duplex sonography may provide useful data on preoperative morphological and functional characteristics of vessels used for AVF construction. Increase in IDA, Q(A), RI at RH, and IDV after PVC are important to predict AVF primary patency rate. Based on these measurements, the most adequate location for AVF construction, as well as time of optimal AVF development, can be determined, particularly for patients at greater risk for primary failure, such as the elderly and patients with diabetes. Copyright 2002 by the National Kidney Foundation, Inc.