PRESERVATION OF VASCULAR ACCESS

Preservation of vascular access is critical in the long-term successfu l management of hemodialysis patients. Dialysis access abnormalities a re the most common cause of hospitalization in this patient group, and access problems can increase the morbidity and cost involved in the c are of these patients. Native fistulas are preferable to synthetic gra fts because of longer survival and a lower complication rate. Venous o utflow stenosis is the most common site of obstruction in a failing gr aft. The pathophysiology of access failure is poorly understood, but i t seems to be related to intimal hyperplasia in the native vessel down stream from the anastomosis. The stimulation of local growth factors b y needle puncture may also play a role, An assessment of access adequa cy includes careful physical examination, laboratory evaluation, and u ltimately, angiography. Measurements of recirculation and venous press ure are commonly used to screen for access dysfunction, and their appr opriate use will lower the incidence of graft loss in dialysis units. Treatment is usually either angioplasty or surgery, with some centers having success with thrombolytic therapy. New techniques such as ather ectomy and stent placement may prove to be beneficial, but this requir es further study.