The effectivity of imaging modalities in the management of dysfunctional hemodialysis fistulas

PURPOSE: The role of color Doppler ultrasonography (CDUS) and multislice computed tomography (MDCT) in diagnosis of arteriovenous fistula disfunctions and comparision of the two methods? diognostic efficiencyMATERIALS AND METHODS: Between december 2009 and november 2011, RDUS and MDCT was performed to 41 patients preliminary diagnosed as AVF disfunction and referred to our clinic. According to acquired data, patients were directed to DSA or surgery for treatment.All patients? CDUS and MDCT examination findings and DSA and surgery results were compared. Imaging findings of CDUS and MDCT were assessed and Wilcoxson signed rank test was used for statistical analysis of these two methods? diagnostic efficiency.SIGNS: 64 segmental area lesions (35 stenosis, 12 thrombosis, 12 aneurysm, 3 pseudoaneurysm, 2 seromas) were found in 41 patients with AVF disfunction included in our study. When DSA or surgery is accepted as gold standart, CDUS has 85.9% sensitivity, 99.2% specificity and MDCT has 96.8% sensitivity, 99.6% specificity in diagnosis of all vascular lesions resulting AVF disfunction.In detecting stenosis resulting AVF disfunction; CDUS has 74.2% sensitivity, 90.6% specificity, 89.6% positive predictive value, 76.3% negative prediktif value and 82.6% accuracy. MDCT has 97.1% sensitivity, 93.7% specificity, 94.4% positive predictive value, 96.7% negative prediktive value and 95.4 % accuracy in detecting stenosis.In detecting thrombosis, aneurysm and pseudoaneurisms, accuracy of CDUS and MDCT was 100%. In rare extravasculer lesions like seroma, CDUS has high success rates whereas MDCT has relatively lower.In detecting central venous stenosis , RDUS has 20% sensitivity (p=0.046) whereas MDCT has 100% sensitivity and accuracy.RESULT: MDCT, a minimal invasive imaging method, , can be an alternative to DSA in diagnosis and treatment planning of AVF disfunctions. After vascular mapping with MDCT, higher accuracy is achieved by adding CDUS in only suspected patients and extravasculer lesions. Especially in central venous stenosis, MDCT should be used because of high effieciency.