The prognostic value of blood-flow measurements during construction of arteriovenous fistulae.

The most common route of access in haemodialysis is the conventional radio-cephalic fistula at the wrist. Some patients are better suited for a graft procedure, however. In order to select the most appropriate approach preoperative assessment of the veins is important. Certain observations made at operation may also be helpful. We have measured the vessel sizes and estimated blood flow before and after establishment of the fistula. 36 radio-cephalic fistulae were made in a series of patients not selected with regard to the condition of the veins, in order to find characteristics indicating a poor prognosis for the fistula. There were 8 early failures (22%), and another fistula ceased to function within 6 months. We found that a fistula flow of less than 40 ml/min immediately after construction was associated with a 70% risk of early failure, and no fistulae with such a flow rate survived 6 months. Neither vessel diameters nor preoperative blood flow in the radial artery influenced the risk of early failure.