Changes in venous histology in chronic hemodialysis patients.

Because most hemodialysis access fails at the venous side, we studied samples of brachial vein obtained during access creation in 15 patients with end-stage renal disease who gave consent. Veins were examined by computer-assisted histomorphometry, and the results correlated with the patients' clinical data. The mean venous medial width was 239 +/- 31 microm, and mean intimal width was 6.0 +/- 0.9 microm. Mean venous medial width was 358 +/- 74 microm and mean venous intimal width was 9.2 +/- 1.2 microm in the 4 patients who had been undergoing dialysis more than 6 months, compared with 196 +/- 23 microm and 4.9 +/- 0.8 microm, respectively, in the 11 patients undergoing dialysis less than 6 months (P < 0.01). The number of months undergoing hemodialysis correlated well with venous medial width (r = 0.79; P < 0.001). Correlation between number of months undergoing dialysis and intimal width did not reach statistical significance. Medial and intimal widths of the 4 patients with diabetes were not significantly different from those of the patients without diabetes. Serum parathyroid hormone level did not correlate with either medial or intimal venous width. We conclude there may be changes in the veins of hemodialysis patients with time that cause thickening of layers, even in veins not directly used for access. This may affect the creation or survival of subsequent vascular accesses.