title: Effects of wall shear stress in venous neointimal hyperplasia of arteriovenous fistulae.
abstract: OBJECTIVE
  An arteriovenous fistulae (AVF) is the preferred vascular access for maintenance haemodialysis patients. Its dysfunction is often due to venous stenosis, which is mainly caused by neointimal hyperplasia. Additionally, haemodynamic forces, especially wall shear stress (WSS), as a mechanical stimuli to venous wall have a significant role in neointimal hyperplasia. The purpose of this study was to evaluate the association between WSS and neointimal hyperplasia.
  
  
  METHODS
  An 'end-to-side' AVF was created between the right femoral artery and vein of canines. Canines were killed at 7 and 28 days post-surgery. The velocity and WSS in the three-dimensional computational model of AVF were simulated using computational fluid dynamics (CFDs). The four typical sites of the vein evaluated in this study, chosen according to the haemodynamic analysis, included the arteriovenous anastomosis (A-V), the juxta-anastomotic segment (J-V), the juxta-ligation segment (L-V) and the proximal vein (P-V). The specimens were haematoxylin-eosin stained and the intima-media thickening was then measured.
  
  
  RESULTS
  Neointimal hyperplasia was more obvious in the inner wall of the J-V and L-V (low-and-disturbed WSS) sites compared with the P-V and A-V sites, and the outer wall of the L-V and J-V segments (high or laminar WSS) (P < 0.01).
  
  
  CONCLUSIONS
  In this study, we described the haemodynamic condition in the AVF and found that neointimal hyperplasia predisposed to occur in the inner wall of venous segment near the anastomosis. We also found that not only the neointimal hyperplasia has a strong inverse correlation with WSS levels, but also is related to flow patterns.
authors.affiliation: Department of Kidney Disease and Blood Purification, Institute of Urology & Key Laboratory of Tianjin, The Second Hospital of Tianjin Medical University, Tianjin, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Jia
authors.forename: Lihua
authors.initials: L
authors.lastname: Wang
authors.forename: Fang
authors.initials: F
authors.lastname: Wei
authors.forename: Haibo
authors.initials: H
authors.lastname: Yu
authors.forename: Hongye
authors.initials: H
authors.lastname: Dong
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Lu
authors.forename: Guijiang
authors.initials: G
authors.lastname: Sun
authors.forename: Haiyan
authors.initials: H
authors.lastname: Chen
authors.forename: Jia
authors.initials: J
authors.lastname: Meng
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Ruining
authors.initials: R
authors.lastname: Zhang
authors.forename: Xueqing
authors.initials: X
authors.lastname: Bi
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.forename: Haiyan
authors.initials: H
authors.lastname: Pang
authors.forename: Aili
authors.initials: A
authors.lastname: Jiang
mesh_terms: D000818:Animals; D001166:Arteriovenous Shunt, Surgical; D001783:Blood Flow Velocity / Q000502:physiology; D004285:Dogs; D005263:Femoral Artery / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005268:Femoral Vein / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006965:Hyperplasia; D058426:Neointima / Q000473:pathology* / Q000503:physiopathology; D033081:Shear Strength / Q000502:physiology; D013314:Stress, Mechanical; D017539:Tunica Intima / Q000473:pathology* / Q000503:physiopathology; D014655:Vascular Resistance / Q000502:physiology
keywords: arteriovenous fistulae; venous neointimal hyperplasia; wall shear stress