Despite an older dialysis population, the proportion and survival of arteriovenous fistulas (AVFs) in Danish dialysis patients has not changed over a 39-year period. This is the main conclusion of a national cohort study published online in The Journal of Vascular Access (JVA). Authors Kristine Lindhard (Herlev Hospital, Herlev, Denmark) and colleagues suggest that this is probably because of increased awareness of AVF as the first choice of vascular access and improved surveillance, surgery and repair.
Lindhard et al write that the age and number of comorbidities in the haemodialysis population has increased over time, which, they hypothesise, may influence the construction and survival of AVFs. In the present study, the research team explored the incidence and survival of AVFs between 1977 and 2015 by conducting a retrospective cohort study based on Danish registries, including incidence haemodialysis patients.
The authors note that the registries included 10,187 arteriovenous accesses (AVFs and arteriovenous grafts) and 4,201 central venous catheters (CVCs). Writing in JVA, they report seeing no significant difference in the proportion of AVFs during the 39 years. In addition, they found that age and renal diagnosis did not influence the proportion of AVFs, and that patients with CVCs were found to have a significantly higher prevalence of comorbidities.
Another key finding was that AVF survival remained stable during the 39 years. Lindhard and colleagues add that the first constructed AVF had the best survival, 35% still functioning after 15 years. Factors such as brachiocephalic AVF (odds ratio [OR], 2.46; 95% confidence interval [CI], 2.29–2.65), female sex (OR, 1.17; 95% CI, 1.1–1.25) and diabetic nephropathy (OR, 1.21; 95% CI, 1.12–1.3) increased the risk of AVF failure, the authors detail.
In the discussion of their findings, the authors highlight some key strengths of their study, including the large sample size, long observation period of 39 years and the high data completeness in the Danish registries. However, they also acknowledge certain limitations. For example, the Danish Nephrology registry was first complete after 1 January 1990 and some dialysis treatments before this time may not have been registered. Another limitation is the lack of data on previous CVC history, medication and time to cannulation.