The Role of Doppler Ultrassonography in Significant and Borderline Stenosis Definition

Abstract

Background: The definition of significant stenosis (SS) remains controversial. Methods: We retrospectively reviewed 1,040 consultations. SS was defined in the presence of clinical and echo-Doppler (DDU) criteria: Qa <500 mL/min or Qa decrease >25%; RI >0.7 in the feeding artery or absolute minimal luminal stenosis diameter <2.0 mm. Stenosis without any additional criteria were considered borderline stenosis (BS). Results: Two hundred twenty-one arteriovenous fistulas (AVFs) were included: 58.8% had SS, 18.6% had BS, and 22.6% had no dysfunctional access (ND). SS had a significantly higher thrombotic events than BS and ND (13.1 vs. 4.4%, p = 0.018). The annual thrombosis rate was 0.007, 0.037, and 0.004 in the ND, SS, and BS, respectively. AVF cumulative survival at 5 years was significantly lower in SS (89.5%) compared to BS (100%) and ND (97.4%; p = 0.03). BS had an HR for AVF failure of 1.1, p = 0.955, while the SS presented an HR of 5.9, p = 0.09. Conclusion: AVF clinical monitoring with additional DDU criteria appear to be appropriate for therapeutic referral.