Functional patency rates of arteriovenous fistula of a retrospective cohort study from one of the biggest centers in Canada

Abstract

Background: The main barriers to arterio-venous fistula (AVF) utilization are primary failure, long maturation duration, and low secondary patency rates.

Methods: In this retrospective cohort study, primary, secondary, functional primary, and functional secondary patency rates were calculated and compared between two age groups (< 75 years and > = 75 years) and between radiocephalic (RC-) and upper arm (UA-) AVFs, and factors determining the duration of functional secondary patency were evaluated.

Results: Between 2016 and 2020, 206 predialysis patients whose AVFs had been created previously initiated renal replacement treatment. RC-AVFs comprised 23.3% and were created after favorable analysis of the forearm vasculature. Overall, the primary failure rate was 8.3, and 84.7% started hemodialysis with a functioning AVF. Functional secondary patency rates of primary AVFs were better with RC-AVFs [1,3 and 5 year rates of 95.8, 81.9 and 81.9% versus 83.4, 71.8 and 59.2% for UA-AVFs (log rank p: 0.041)]. There was no difference between the two age groups for any of the AVF outcomes assessed. Among patients whose AVF was abandoned, 40.3% had gone on to have a second fistula created. This was significantly less likely in the older group (p < 0.01).

In conclusion: (1) UA-AVFs were placed more commonly than RC-AVFs; (2) a selection bias existed whereby RC-AVFs were only created after favorable forearm vasculature was demonstrated or suspected; (3) superior functional secondary patency rates were observed with RC-AV's, perhaps stemming from this selection bias; (4) the elderly were more likely to have only one AVF creation attempt.

Keywords: Arteriovenous fistula; Hemodialysis; Patency; Primary failure.