Abstract: Objective  To investigate the clinicopathological characteristics of type I autologous arteriovenous fistula (AVF) stenosis in uremic patients.  Methods  A total of 39 patients who underwent AVF reconstructive surgery for type I stenosis were enrolled in this study. Their clinical data were collected. The stenotic venous tissue cut during the reconstructive surgery and the venous tissue stored during the first AVF constructive surgery were pathologically compared, including HE and masson staining, and immunohistochemistry using antibodies against CD133, CD31, CD68, CD206, iNOS and CD56 to identify the cell types.  Results  The mean age of the 39 patients was 52.7±4.4 years old, 62% were male, and diabetic kidney disease accounted for 43.6% of the patients. HE and Masson staining of the stenotic venous tissues demonstrated typical neointimal hyperplasia (NIH). Pearson correlation analysis showed that NIH was positively correlated with serum phosphorus (r=0.381, P=0.026) and negative correlated with neutrophil count (r=-0.360, P=0.031), but not with serum calcium (r=-0.269, P=0.097) and parathyroid hormone (r=0.007, P=0.971). Immunohistochemical staining showed that positive staining of CD31, CD133, CD206, iNOS, CD68 and CD56 were found in the NIH area in stenotic venous tissues.  Conclusions   Histopathological staining showed an eccentric NIH in the venous tissues from type I AVF stenosis. The thickness of the intimal layer correlated with serum phosphorus level and neutrophil count. Immunohistochemistry showed the presence of abnormally arranged intimal cells, endothelial progenitor cells, M1 and M2 macrophages, and NK cells in NIH areas.

Key words: Uremia, Arteriovenous fistula, Stenosis, Neointimal hyperplasia