[Analysis of the survival of permanent vascular access ports]

Complications arising from vascular access are major causes of morbidity in patients on renal replacement therapy. They contribute to frustration of health care providers and to high medical cost. To prevent failures in the future it will be helpful to identify the factors that are related to vascular access, malfunction. In a retrospective analysis we analysed the types, duration and primary patency rate of 1,033 permanent vascular access in 544 consecutive patients established during a 13-year period in a tertiary care hospital. Patient characteristics, incidence and risk factors related to vascular access failure were registered. In addition vascular access outcomes in patients who started haemodialysis with a catheter and in whom initial vascular access failure occurred were analysed separately. Forty-five per cent of patients required a central catheter at the start of HD, but 92% of them were being dialysed with an a-v fistula at the last observation. The total number of complications was 0.24 episodes per patient per year at risk, and the rate of thrombosis 0.1. A total of 52% of patients were dialysed throughout the observation period with their initial a-v fistula; 9.3% had more than three episodes of vascular access failure. The radiocephalic a-v fistula was the access with the best median duration, exceeding 7 years, but also the type that had the highest initial failure rate, i.e. 25% of patients and 13% of events. The brachiocephalic a-v fistula was the second most frequent type of vascular access, with a median duration of function of 3.6 years, in contrast the humerobasilar a-v fistula, lasted on average over 5 years. Average patency of the different types of grafts did not exceed 1 year, with the exception of the autologous saphenous graft with a median duration of function of 1.4 years. Patients with glomerulonephritis had the best function rates for their access, the median duration exceeding the duration of the study, whereas in half of diabetic patients it was less than 1 year. The duration of patency of the vascular access was twice as long in patients below age 65 years and in elderly males compared to elderly females. Patients who start HD with a catheter, as well as those with initial vascular access failure, have a higher rate of access failure in the subsequent course on renal replacement therapy. In conclusion, the radiocephalic and the brachiocephalic a-v fistula are the two types of vascular access with the longest duration of function, although a high rate of initial failure is seen with the radiocephalic a-v fistula. Age, female gender, presence of diabetic nephropathy, start of dialysis with a catheter, and failure to wait for initial maturation of vascular access are risk factors, and account for the majority of vascular access failure during renal replacement therapy.