Inclusion Criteria:  CKD and ESRD patients on hemodialysis, in whom native arteriovenous fistula operation is needed  both sexes are included. age group from 15-80years upper limb arteriovenous fistula only. native arteriovenous fistula. surgically succeeded AVF  Exclusion Criteria:  we will exclude:  patients refused to be in the research. Patients with AVF not in the upper limbs. Patient of age less than 15years and above 80years. patients with synthetic grafts.