Arteriovenous Fistulas Not Always the Best Option
Despite low infection rates, AVFs have a high risk of maturation failure and abandonment.
Arteriovenous fistula (AVF) is widely regarded as the optimal form of vascular access for hemodialysis patients, but some new studies shed light on when AVFs are a less attractive option.
In a paper published online ahead of print in the European Journal of Vascular Endovascular Surgery, Jeffrey Lawson, MD, PhD, of Humacyte in Morrisville, North Carolina, and collaborators reported results from a meta-analysis of 318 studies spanning 20 years that involved 62,712 accesses. Despite low infection rates, AVFs displayed a high risk of maturation failure and abandonment. Only 26% of AVFs were mature by 6 months and 21% were abandoned. The average time to maturation was 3.5 months, and 66% of patients required a bridging catheter.
AVFs created in the United States were abandoned more frequently than in other developed nations (27% vs 16%). Higher abandonment rates were found among women than men (43% vs 33%). AVFs placed in patients initiating dialysis endured longer than those placed in established patients. With regard to location, accesses placed in the upper arm were abandoned less than those in the forearm (16% vs. 23%).
Infections occurred in 4.1% of patients, which is twice the rate found in a similar meta-analysis by Jehad Almasri, MD, and colleagues published in the Journal of Vascular Surgery (2016;64:236-243). In the present analysis, the rate per 100 access days was 0.018 for infections overall, 0.020 for access-site infections, and 0.025 for bacteremia/bloodstream infections.
With regard to patency, at 1 year, primary unassisted, primary assisted (i.e., with surgical and endovascular procedures), and secondary rates were 64%, 73%, and 79%, respectively. The 2-year rates found by Dr Lawson's team agreed with the meta-analysis by Dr Almasri's team: primary unassisted patency (51% vs 55%, respectively) and secondary patency (70% vs 63%, respectively).
“An important tradeoff arising from aggressive efforts to maximise AVF use is prolonged catheter dependence and a high frequency of catheter-related bacteraemia,” Jan Tordoir, MD, PhD, of Maastricht University Medical Centre in Maastricht, the Netherlands, commented in an accompanying editorial. “These complications are often viewed as an acceptable short-term price for achieving a long-term gain, namely an AVF with a high secondary patency.”
Dr Tordoir suggested that pre-operative ultrasonographic vessel examination and vascular access training centers of excellence might better identify appropriate patients for AVF placement and reduce AVF failure.
Another study published online ahead of print in the Journal of Vascular Surgery examined vascular access types and health-related quality of life (HRQOL), an important measure associated with mortality. Of 77 HD patients, 62.3% had AVF, 23.4% tunneled dialysis catheter (TDC), and 14.3% arteriovenous graft (AVG). Natalie Domenick Sridharan, MD, MSc, and colleagues at the University of Pittsburgh reported significantly greater satisfaction with AVF compared with TDC and AVG (77% vs 56% vs 55%, respectively), as measured by the Vascular Access Questionnaire. HRQOL, as assessed using the Short Form Health survey, was “highly dependent on access satisfaction,” with greater access satisfaction associated with better HRQOL.
Factors predicting dissatisfaction included being on dialysis for less than 1 year, more access-related hospital admissions, and placement of an AVG or TDC. AVG users seemed most dissatisfied by how the access interfered with social functioning. TDC patients complained less about pain, bleeding, swelling, and bruising, and more about dialysis-related complications, such as their vascular access not working, difficulty with its care, and fears of hospitalization or access replacement.
Nonetheless, Dr Sridharan's team pointed out that AVF is not the best option for everyone. “The results of our analysis contribute to the evolving view that some patients, particularly elderly patients and those with multiple comorbidities who are likely to have poor fistula maturation rates or may never use a fistula owing to the competing risk of mortality, may be appropriate for AVG or even consideration of ‘destination' TDC,” they wrote. “These patients may benefit from an access that provides maximal functionality and decreased hospitalizations, improving their access satisfaction and thus positively impacting their HRQOL.”
Bylsma LC, Gage SM, Reichert H, Dahl SLM, Lawson JH. Arteriovenous fistulas for haemodialysis: A systematic review and meta-analysis of efficacy and safety outcomes. Eur J Vasc Endovasc Surg 2017;1e10. doi: 10.1016/j.jvs.2017.05.131
Tordoir JHM. Commentary on “Arteriovenous fistulas for haemodialysis: A systematic review and meta-analysis of efficacy and safety outcomes.” Eur J Vasc Endovasc Surg 2017.
Domenick Sridharan N, Fish L, Yu L, et al. The associations of hemodialysis access type and access satisfaction with health-related quality of life. J Vas Surg. doi: 10.1016/j.jvs.2017.05.131