Arteriovenous fistula (AVF) monitoring and surveillance

An arteriovenous fistula (AVF) is created by direct anastomosis between an artery and adjacent vein which leads to flow of blood from artery directly into the vein. A well functioning and patent AVF is essential for optimum delivery of hemodialysis and hence it is important to assess the AVF for any signs of loss of patency (stenosis/thrombosis) on a regular basis. Methods of AVF monitoring include physical examination and other features like difficulty in AVF cannulation due to poor blood flow, clot aspiration or prolonged bleeding from the AVF site post hemodialysis. Methods of AVF surveillance include access blood flow, venous pressure and Doppler ultrasound etc. Both physical examination and investigations have complimentary role in this field and it is necessary that adequate stress is given on monitoring on a continuous basis. Access blood flow and intra-access pressures have role in confirming any abnormal physical examination finding.