Diagnostic accuracy of Color Doppler Ultrasound in determining arteriovenous fistula stenosis
Keywords:Arteriovenous fistula, Dialysis, Doppler, Ultrasound
Objective: To determine the diagnostic accuracy of color Doppler ultrasound in determining arteriovenous fistula stenosis.
Methodology: A descriptive, Cross-sectional study was conducted at Radiology Department, Jinnah Hospital, Lahore from November 2014 to March 2016. A total 105 patients with 20-70 years of age having recent mature fistulas of more than 12 weeks were included. Patients with acute hemodialysis, receiving hemodialysis through AV graft and hemodynamically unstable patients were excluded. All the patients underwent blood flow and luminal diameter measurement of AV fistula by color Doppler ultrasound. After this, Digital Subtraction Angiography (DSA) was performed and results of Color Doppler Ultrasound (CDS) were correlated with DSA which was taken as the gold standard. Linear regression was used for analysis. P and r2 values calculated for each of these.
Results: Mean age of the patients was 42.08 ± 11.90 years. Out of these 105 patients, 73 (69.52%) were males and 32 (30.48%) were females with a ratio of 2.28:1. CDS detected AVF stenosis in 64 (60.95%) patients, out of which, 58 were True Positive and 06 were False Positive. Among 41 CDS negative patients, 30 were False Negative and 11 were True Negative. Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CDS for the detection of AVF stenosis, taking DSA as the gold standard was 84.06%, 83.33%, 90.62%, 73.17%, and 83.81% respectively.
Conclusion: Color Doppler ultrasonography is a highly sensitive and accurate non-invasive modality for detecting AVF stenosis, and should be used routinely in order to reduce invasive digital subtraction angiography.