[Sonographic findings in the diagnostic course of vascular access for hemodialysis]. / Sonographische Funktionsbeurteilung von Hämodialysefisteln.

BACKGROUND AND PURPOSE: Hemodialysis and related procedures require a reliable vascular access and the Brescia-Cimino shunt of the nondominant forearm has proven to be its most important form. Today, color Doppler sonography is regarded as the main method in the diagnosis of vascular access dysfunction. The aim of this study was to evaluate the impact of the Resistive Index (RI) of the fistula's feeding artery on the fistula's blood flow. PATIENTS AND METHODS: 47 patients with arteriovenous fistulas were investigated by means of color Doppler sonography. The fistulas' blood flow, morphological details and the RI of the arteries distal as well as proximal to the fistulas were determined. Furthermore, systolic blood pressure of the second and third fingers of both hands was measured. Comparisons were made between the fistula's blood flow and the RI of the feeding artery. RESULTS: On the arm of the fistulas, the proximal and distal RI and the systolic blood pressure were lower than on the contralateral arm. The blood flow of the upper arm fistulas was higher than that of the forearm fistulas due to a higher vascular diameter. No linear correlations existed between the RI and the fistula's blood flow. 50% of the forearm fistulas showed a proximal RI > or = 0.53 and a blood flow < 400 ml/min. CONCLUSION: The RI of the supplying artery of the forearm fistulas is a reliable value to detect insufficient blood flow. In such cases, further diagnostic procedures are necessary. Also, numerous influences on the measurement of the fistula's blood flow exist. Therefore, intraindividual investigations to evaluate the fistulas' further development are recommended to get better options for their control.