Vascular access for haemodialysis--an epidemiological study of the Catalan Renal Registry.

Background. Vascular access (VA) continues to cause problems in a proportion of haemodialysis (HD) patients. VA complications are a major cause of hospitalization, with the resulting financial consequences and human suffering. The purpose of the study was to assess the types and duration of function of different modalities of VA in Catalunya and to relate them to treatment characteristics, to study the characteristics of patients who necessitated more than four VAs and to describe the factors associated with the start of HD using a catheter. Methods. The Catalan Renal Registry, using a questionnaire, sampled the data of all patients alive on December 31, 1997 (n=3073). Data were analysed using the X 2 test, ANOVA and logistic regression. Results. In 85.8% of HD patients in Catalunya, an AV fistula was used, in 8.5% a vascular graft and in 5.6% a catheter. In 48% of incident HD patients in 1997, a catheter was necessary due to lack of an AV fistula. The use of grafts increases with progressive time on dialysis, reaching > 10% amongst patients on dialysis for >7 years. The average time of function for AV fistula was 4 years, for grafts 2 years and for catheters 9 months. A total of 39.1% of patients required only one VA during the entire time on HD, 29.9% two, 14.4% three, and 16.5% four or more. The duration of VA function decreases with age. In patients with autosomal dominant polycystic kidney disease and glomerulonephritis, the duration of VA function exceeds 4 years; it is 3 years in patients with vascular disease and 25 months in diabetic patients. Conclusions. The most frequent modality of VA used in Catalunya is the AV fistula. It is used more frequently in male than in female patients. Approximately half of the patients have no VA at the time of start of renal replacement therapy. Age, duration of dialysis treatment and diabetes have an adverse effect on the duration of VA function. Repeated VA failure concerns a minority of patients.