Vascular access for hemodialysis and cardiovascular complications.

Native arterio-venous fistula (AVF), is the first choice of the vascular access for hemodialysis treatment. In comparison with other vascular accesses such as prosthetic arterio-venous graft or permanent central venous catheter, AVF has shown a significant reduction in cardiovascular mortality. It needs, of course, an appropriate blood flow that provides a flow of 400-800 mL/min in the distal seat and a flow of 800-1500 ml/min in the proximal seat. As a consequence, the creation of AVF may be associated with changes in blood flow, pulmonary pressure and cardiac output. All these haemodynamic changes may not have any cardiac consequences, or they could lead to congestive heart disease particularly when the blood flow of AVF is greater than 2000 ml/min. For this reason, the patient's cardiac status should determine the choice of dialysis and the type of vascular access. Cardiac function monitoring is essential, particularly when dealing with patients at high risk for congestive heart disease and AVF in the proximal seat. Vascular access reduction surgery may be effective in some cases, otherwise a suitable alternative could be that of closing AVF. However, the likely side effects that can be generated by closing arterio-venous AVF such as a sudden increase of venous peripheral systemic should be taken into account.