BACKGROUND: When a hemodialysis arteriovenous fistula (HAVF) is created, it is important to wait for venous dilatation and volume flow increase through the HAVF, a phenomenon called maturation. There is still some controversy as to the exact time required for this maturation to occur. OBJECTIVE: To evaluate the time required for HAVF maturation using ultrasound criteria. METHOD: From May 2004 through May 2005, 40 patients were prospectively selected. The sample was comprised of 23 men (57.5 %), mean age of 51.3±17.5 years, with indication of HAVF creation. Logic III® ultrasound with 10 MHz transducer probe was used for pre- and postoperative evaluation 7, 14, 21 and 28 days after the procedure. Criteria for maturation after the procedure were vein diameter larger than 4 mm and volume flow larger than 400 mL/min. RESULTS: Preoperative mean diameter was 3.24±1.43 and 3.71±1.37 mm for fist and elbow fistula, respectively. Final diameter of the fist HAVF was 5.01±0.87 mm (p = 0.006) and 6.15±1.16 mm for the elbow HAVF (p = 0.95). Flow volume in the 7th postoperative day was 493.63±257.49 and 976.33±332.90 mL/min, respectively, for the fist and elbow HAVF. At the end of the study, the value of 556.81±288.42 mL/min was calculated for the fist HAVF (p < 0.05) and 1,031.62±614.812 mL/min for the elbow HAVF. Based on both cut-off values, maturation occurred in 57.1% of the fist fistula and in 100% of the elbow fistula after the first week. After 4 weeks, 67.9% of the fist HAVF and 100% of the elbow HAVF presented maturation. CONCLUSION: Most elbow HAVF showed adequate diameter and flow volume for puncture 1 week after the procedure. For the fist fistula, gradual maturation occurred throughout the weeks, suggesting that these HAVF should be punctured 4 weeks after the surgery.
Fistula; arteriovenous; hemodialysis; color-flow Doppler ultrasound
