Ultrasound Monitoring to Detect Access Stenosis in Hemodialysis Patients: A Systematic Review

Tonelli, Marcello; James, Matthew; Wiebe, Natasha; Jindal, Kailash; Hemmelgarn, Brenda; Alberta Kidney Disease Network,

doi:10.1053/j.ajkd.2007.11.025

« Previous Next »American Journal of Kidney Diseases
Volume 51, Issue 4 , Pages 630-640, April 2008

Ultrasound Monitoring to Detect Access Stenosis in Hemodialysis Patients: A Systematic Review

Marcello Tonelli, MD, SM
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Division of Critical Care Medicine, University of Alberta, Edmonton, Alberta, Canada
- Institute of Health Economics, University of Alberta, Edmonton, Alberta, Canada
- Department of Public Health Sciences, University of Alberta, Edmonton, Alberta, Canada
- Address correspondence to Marcello Tonelli, MD, SM, 7-129 Clinical Science Bldg, 8440 112 St, Edmonton, Alberta T6B 2B7, Canada.
Matthew James, MD
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
Natasha Wiebe, MMath, PStat
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
Kailash Jindal, MD
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
Brenda Hemmelgarn, PhD, MD
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
Alberta Kidney Disease Network

Received 17 July 2007; accepted 13 November 2007. published online 07 March 2008.

Background

Observational studies indicate that routine measurements of access blood flow and use of Doppler ultrasound improve vascular access outcomes in hemodialysis patients, but randomized trials reached conflicting conclusions.

Study Design

Systematic review and meta-analysis.

Setting & Population

Adult hemodialysis patients with arteriovenous accesses. Selection Criteria for Studies: Randomized trials.

Intervention

Screening with access blood flow measurements or Doppler ultrasound.

Outcomes

Thrombosis, access loss, and resource use.

Results

Of 1,613 identified citations and abstracts, 69 full articles were retrieved, and 12 randomized controlled trials comparing access screening (using access blood flow– or ultrasound-based screening) with standard care in a total of 1,164 participants were included. In meta-regression, vascular access type was significantly associated with the relative risk of thrombosis associated with screening (P < 0.01), supporting the need to stratify analyses on access type. In the 4 trials that studied arteriovenous fistulas, access blood flow– or ultrasound-based screening significantly decreased the risk of access thrombosis (relative risk [RR], 0.47; 95% confidence interval [CI], 0.28 to 0.77; 360 participants; I² = 8%), but not the risk of fistula loss (RR, 0.65; 95% CI, 0.28 to 1.51, I² = 0%) or resource use. Conversely, no decrease in risk of thrombosis (RR, 0.94; 95% CI, 0.77 to 1.16; 446 participants; I² = 0%) or access loss (RR, 1.08; 95% CI, 0.83 to 1.40; I² = 0%) was identified in trials studying grafts.

Limitations

Overall trial quality was moderate to poor, many trials did not report all clinically or economically relevant outcomes, and statistical power generally was low.

Conclusions

There was no evidence that screening with access blood flow measurements or Doppler ultrasound is of benefit to patients with grafts. Access blood flow screening may prevent access thrombosis in arteriovenous fistulas, but may not reduce the risk of access loss or extent of resource use. These findings have implications for clinical practice guidelines and for future research.

Index Words: Hemodialysis, vascular access, diagnostic test, meta-analysis