Is there a place for duplex screening of brachial artery in haemodialysis patients with vascular access?

Background: Vascular access (VA) stenosis with subsequent thrombosis remain s one of the major causes of morbidity and hospitalization in haemodialysis patients. The present cross-sectional study was planned in order to analyz e the usefulness of brachial artery duplex ultrasound for detection and pre diction of vascular access stenoses. Methods: Color duplex ultrasound(Apogee Cx 200, sectorial probe 7.5 MHz) wa s used to obtain the anatomical pattern of the VA and flow velocity wavefor ms of the brachial artery in 77 non-selected VA (47 Ciminio-Brescia fistula e and 30 PTFE grafts). In each VA, the resistance index (RI), the mean bloo dflow rate (el and the bloodflow ratio index (QI) (QI = VA flow rate/contra lateral flow rate) were calculated at the level of the brachial artery. The sensitivity and specificity of these brachial Doppler parameters were calc ulated for the detection of VA stenosis. In normal VA, positive (PPV) and n egative predictive (NPV) values were calculated for the development of clin ical stenotic complications 3 months post ultrasound examination. Results: Thirteen of the 77 VA (17%) were identified as stenosed by duplex ultrasound and confirmed by fistulography and/or during surgical exploratio n. The best screening tests for VA stenosis detection were a er threshold < 4.0 with a sensitivity and specificity of 69 and 69% and an RI > 0.55 with a sensitivity and specificity of 62 and 66%, respectively. In the VA consi dered as normal by ultrasound, the prediction of subsequent stenosis within three months post-ultrasound examination gave a PPV of only 18% and 19% fo r RI and el, respectively NPV for RI and el were 90% and 88%. Conclusions: While Doppler ultrasound is a useful non-invasive test Sor the detection of prevalent VA stenosis, our results do not confirm that abnorm al brachial Doppler flow parameter can predict short term development of VA stenosis.