[Monitoring therapeutic arteriovenous fistulas in chronic hemodialysis patients. Value of the continuous Doppler test combined with real-time echotomography]. / Surveillance des fistules artério-veineuses thérapeutiques chez des hémodialysés chroniques. Intérêt de l'examen au Doppler continu couplé à l'examen échotomographique en temps réel.

Continuous doppler investigation of functioning of therapeutic arteriovenous fistula is a well-established routine. The availability for the last few years of high frequency (10 mg/Hz) real-time ultrasound has enabled visualization of superficial arteries and veins. Total afferent and efferent branches of these therapeutic fistulae can be visualized. Examination should therefore include continuous doppler recordings combined with real-time ultrasound of both transverse and sagittal sections of the different arteries and veins participating in the fistula. The indication for examination is clinical in cases with low or high output or during the immediate postoperative period to detect early thrombosis.

[Echographic study in the exploration of supra-aortic trunks. Comparative study with doppler velocimetry and their respective roles in functional vascular explorations]. / Examen échographique dans l'exploration des troncs supra-aortiques. Etude comparée à l'examen vélocimétrique doppler et leur place respective dans les explorations fonctionnelles vasculaires.

Over the last six months, 1,311 doppler examinations of the supra-aortic trunks have been performed with confrontation doppler, ultrasound, arteriography and intra-operative examination according to the cases. We studied these cases with the following questions in mind: Does real time ultrasound of the supra-aortic trunks give more valuable information than the classical doppler examination? Is the diagnosis simplified? Is the therapeutic management altered? We are able to conclude: 1. In the case of a mildly stenotic plaque (less than 50%), the doppler examination gives an acoustic and graphic representation which is rich and not differentiated for stenoses of between 10% and 50%, which corresponds to an ultrasound plaque of 1 mm to 4-5 mm: the ultrasound supports the diagnosis. 2. However, in stenoses greater than 50%, there is good correlation between the doppler examination, ultrasound and arteriography. Ultrasound enables the exact extent of the plaque to be visualised in sagittal and transverse planes. It can diagnose aneurysmal lesions and suggest ulcerated lesions. 3. Finally, the doppler examination seems to be indispensable in cases of pre-thrombosis or fresh thrombosis of the carotid. Ultrasound can be negative at this early stage.