Effect of the veins histopathological characteristics and preexisting medical conditions on arteriovenous fistula maturation and primary patency in patients with end-stage renal disease: an observational, prospective study.

We assessed the veins histopathological characteristics and preexisting medical conditions before arteriovenous fistula (AVF) creation, and their correlation with AVF outcome and primary patency in patients with end-stage renal disease (ESRD). In this observational, prospective, mono-center study in Romania, patients with artery and venous diameters =2 mm and =2.5 mm, respectively, were enrolled. Vein specimens were harvested at AVF creation and evaluated by Hematoxylin and Eosin, Masson's trichrome and Orcein stainings, in terms of intimal hyperplasia, elastic fibers disposition, medial hypertrophy and smooth muscle cell disorganization and fibrosis (graded from mild to severe). Venous diameters and blood flow one÷two-months post-AVF creation, AVF maturation at dialysis start, two-year primary patency were assessed. Of 115 examined patients, 50 were enrolled and underwent AVF creation. Of six (12%) patients with no vein morphological changes, 11 (22%) with mild histopathological changes, 19 (38%) with moderate and 14 (28%) with severe histopathological changes, four (67%), eight (73%), 17 (89%) and 12 (86%), respectively, had mature AVF. Regardless of histopathological characteristics, non-mature AVF were recorded in older patients and with smaller venous diameter. One÷two-months post-AVF creation, in all patients with mature AVF, venous diameter and ultrasonographic blood flow were similar. Two years post-AVF creation, 26 patients had functional AVF; non-functional AVFs were recorded more likely in women and functional AVFs were most likely located on forearm. The veins histopathological modifications may not negatively influence AVF maturation in ESRD patients. AVF maturation failure may most likely be related to age and venous diameter at AVF creation.