RESUMO
OBJECTIVE: To investigate the significance of inflow artery and cephalic vein diameters on predicting patency of radiocephalic and brachiocephalic arteriovenous fistulas (AVFs). DESIGN: Single centre study with retrospective analysis of prospectively collected data between November 2010 and July 2015. METHODS: A detailed history and physical examination was undertaken, including age, gender, history and duration of haemodialysis, cause of chronic kidney disease, and the presence of comorbidities/risk factors. Pre-operative arterial and venous upper extremity mapping was performed and inner vessel diameter was recorded, using a tourniquet for the veins. Outcome measures included AVF use (functionality), primary, primary assisted, secondary, and functional secondary patency. RESULTS: One hundred and thirty five AVFs (57 and 78 radiocephalic and brachiocephalic AVFs, respectively) were constructed and followed up for 5 years. A cephalic vein diameter <4.3 mm (lower three quartiles) was the single independent predictor of inferior secondary and also functional secondary patency of radiocephalic AVFs (p = .02, HR 11.2, 95% CI 1.44-90.9). A brachial artery diameter ≤4.1 mm (lowest quartile) was an independent predictor of AVF functionality (57% vs. 83% for larger arteries, p = .017), and inferior primary, primary assisted, secondary, and functional secondary patency of brachiocephalic AVFs (primary assisted patency 21.9% vs. 55.9% at 3 years, p = .001/log-rank test, HR 3.1, p = .002/Cox regression). The presence of lower extremity PAD or use of dual antithrombotics was also independently associated with an inferior secondary patency. The number of risk factors (brachial artery diameter ≤4.1 mm, PAD, and use of dual antithrombotics) demonstrated risk stratification capabilities for functional secondary patency. CONCLUSIONS: Among patients undergoing radiocephalic AVFs, a tourniquet derived cephalic vein diameter <4.3 mm was the single independent predictor of inferior secondary and functional secondary patency. Among patients undergoing brachiocephalic AVFs, all patency rates were inferior in the presence of a brachial artery diameter ≤4.1 mm and secondary patency was inferior in the presence of multiple risk factors.