[An unexpected bottleneck].

This is a clinical case concerning an uremic female patient who presented with an important oedema in the omolateral left arm, after the creation of an AV fistula. All the diagnostic procedures including the ultrasound color-Doppler were irrelevant. The patient was positive for a subclavian venous stenosis which was completely unexpected. This clinical case questions how useful it is in indirectly evaluating flow meters by ultrasound color-Doppler in the work-up of central venous steno-occlusions.