Repeated Failure of Arterio-Venous Haemodialysis Access: (Causes and possible solutions)

Background: In 1960, Quinton and Scribner developed an external shunt that allowed for repeated access to the circulation, making chronic hemodialysis a viable option for treating end-stage renal disease. Patients may now be kept on dialysis for decades because to the improvement of vascular access methods and equipment. Aim of study: To evaluate the most possible causes behind repeated arteriovenous (AV) access failure in ESRD patients. Patients and methods: This retrospective, non-randomized study was carried out at the vascular surgery department of Al-Azhar University hospitals(Al-Hussein and Sayed Glaal Hospitals). Results: Access thrombosis comes first as a cause of access failure where it is responsible for 41% of all failed accesses. Among the cases of access thrombosis 25.5% were associated with access stenosis, 10.5% with hypotension, and 2.5% with external compression. The commonest cause of access stenosis was hypotension (14%) followed by hypotension together with central venous stenosis (4.5%) and then central venous stenosis alone (2.5%). Failure of maturation comes next to access thrombosis and it is responsible for 35% of all access failures. Among the cases of failure of maturation 16% were due to small vein diameter (less than 2.5 mm), 9% associated with hypotension, and 7% with hypotension together with central venous stenosis. Conclusion: Management of repeated AV access failure needs changing the attitude of vascular surgeons to be more conservative and based on access salvage protocols (access preservation); directed to correction of early access failure and the predisposing factors behind it.