title: Medial fibrosis, vascular calcification, intimal hyperplasia, and arteriovenous fistula maturation.
abstract: BACKGROUND
  Arteriovenous fistulas (AVFs) for hemodialysis frequently fail to mature because of inadequate dilation or early stenosis. The pathogenesis of AVF nonmaturation may be related to pre-existing vascular pathologic states: medial fibrosis or microcalcification may limit arterial dilation, and intimal hyperplasia may cause stenosis.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  Patients with chronic kidney disease (N = 50) undergoing AVF placement.
  
  
  METHODS
  Medial fibrosis, microcalcification, and intimal hyperplasia in arteries and veins obtained during AVF creation.
  
  
  METHODS
  AVF nonmaturation.
  
  
  RESULTS
  AVF nonmaturation occurred in 38% of patients despite attempted salvage procedures. Preoperative arterial diameter was associated with upper-arm AVF maturation (P = 0.007). Medial fibrosis was similar in patients with nonmaturing and mature AVFs (60% ± 14% vs 66% ± 13%; P = 0.2). AVF nonmaturation was not associated with patient age or diabetes, although both variables were associated significantly with severe medial fibrosis. Conversely, AVF nonmaturation was higher in women than men despite similar medial fibrosis in both sexes. Arterial microcalcification (assessed semiquantitatively) tended to be associated with AVF nonmaturation (1.3 ± 0.8 vs 0.9 ± 0.8; P = 0.08). None of the arteries or veins obtained at AVF creation had intimal hyperplasia. However, repeated venous samples obtained in 6 patients during surgical revision of an immature AVF showed venous neointimal hyperplasia.
  
  
  CONCLUSIONS
  Single-center study.
  
  
  CONCLUSIONS
  Medial fibrosis and microcalcification are frequent in arteries used to create AVFs, but do not explain AVF nonmaturation. Unlike previous studies, intimal hyperplasia was not present at baseline, but developed de novo in nonmaturing AVFs.
authors: Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL, USA. mdallon@uab.edu
authors: Michael
authors: M
authors: Allon
authors: Silvio
authors: S
authors: Litovsky
authors: Carlton J
authors: CJ
authors: Young
authors: Mark H
authors: MH
authors: Deierhoi
authors: Jeremy
authors: J
authors: Goodman
authors: Michael
authors: M
authors: Hanaway
authors: Mark E
authors: ME
authors: Lockhart
authors: Michelle L
authors: ML
authors: Robbin
mesh_terms: D000328:Adult; D000368:Aged; D001158:Arteries / Q000473:pathology*; D001166:Arteriovenous Shunt, Surgical; D002214:Capsules; D004548:Elasticity; D005260:Female; D005355:Fibrosis; D006801:Humans; D006965:Hyperplasia; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000628:therapy*; D017539:Tunica Intima / Q000473:pathology; D017540:Tunica Media / Q000473:pathology*
chemical_list: D002214:Capsules