Morphological changes in the cephalic vein of renal failure patients before arterio -venous fistula [AVF] creation

ABSTRACT

Hemodialysis vascular access dysfunction currently is a major clinical problem. Although arteriovenous fistulae [AVFe] are the preferred form of permanent dialysis access, it continues to have significant problems with early AVF failure. Although inadequate dilatation of the venous segment was believed to have a role in early AVF failure, the exact pathogenesis of early AVF failure is unknown despite the magnitude of the clinical problem. To study the pre-existing morphological changes in the wall of the cephalic vein before AVF creation. The study was conducted in Tanta University Hospital at time period from May to December 2007. After informed consent, biopsy specimens were taken from 40 cephalic veins of chronic renal failure [CRF] patients during creation of AVFs for hemodialysis. Another 5 normal cephalic vein specimens were taken from patients with upper limbs stab injuries as a control group. Sections were prepared and stained with haematoxylin and eosin [H and E], Mallory's trichrome and elastic Van Gieson's stains. Compared with normal cephalic vein, all pre-access cephalic veins showed, generalized thickening of the vein walls due to intimal hypertrophy and increase in collagenous tissue in the media. Other changes as complete loss of internal elastic lamina, disruption of endothelial cell layer, and atrophy of the muscle layer were also found. Most of the apparently normal cephalic veins of the renal failure patients showed morphological abnormalities when examined histologically at the time of AVF creation. This might influence the outcome of fistulae in terms of future stenosis and failure. Future diagnostic modality and therapy to address this problem will be needed to target this pathogenic pathway