title: Pre-existing and Postoperative Intimal Hyperplasia and Arteriovenous Fistula Outcomes.
abstract: BACKGROUND
  The contribution of intimal hyperplasia (IH) to arteriovenous fistula (AVF) failure is uncertain. This observational study assessed the relationship between pre-existing, postoperative, and change in IH over time and AVF outcomes.
  
  
  METHODS
  Prospective cohort study with longitudinal assessment of IH at the time of AVF creation (pre-existing) and transposition (postoperative). Patients were followed up for up to 3.3 years.
  
  
  METHODS
  96 patients from a single center who underwent AVF surgery initially planned as a 2-stage procedure. Veins and AVF samples were collected from 66 and 86 patients, respectively. Matched-pair tissues were available from 56 of these patients.
  
  
  METHODS
  Pre-existing, postoperative, and change in IH over time.
  
  
  RESULTS
  Anatomic maturation failure was defined as an AVF that never reached a diameter > 6mm. Primary unassisted patency was defined as the time elapsed from the second-stage surgery to the first intervention.
  
  
  METHODS
  Maximal intimal thickness in veins and AVFs and change in intimal thickness over time.
  
  
  RESULTS
  Pre-existing IH (>0.05mm) was present in 98% of patients. In this group, the median intimal thickness increased 4.40-fold (IQR, 2.17- to 4.94-fold) between AVF creation and transposition. However, this change was not associated with pre-existing thickness (r(2)=0.002; P=0.7). Ten of 96 (10%) AVFs never achieved maturation, whereas 70% of vascular accesses remained patent at the end of the observational period. Postoperative IH was not associated with anatomic maturation failure using univariate logistic regression. Pre-existing, postoperative, and change in IH over time had no effects on primary unassisted patency.
  
  
  CONCLUSIONS
  The small number of patients from whom longitudinal tissue samples were available and low incidence of anatomic maturation failure, which decreased the statistical power to find associations between end points and IH.
  
  
  CONCLUSIONS
  Pre-existing, postoperative, and change in IH over time were not associated with 2-stage AVF outcomes.
authors.affiliation: DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL.
authors.forename: Marwan
authors.initials: M
authors.lastname: Tabbara
authors.affiliation: DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Duque
authors.affiliation: DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL.
authors.forename: Laisel
authors.initials: L
authors.lastname: Martinez
authors.affiliation: DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Escobar
authors.affiliation: Department of Mathematics and Statistics, Florida International University, Miami, FL.
authors.forename: Wensong
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Epidemiology and Public Health, University of Miami, Coral Gables, FL.
authors.forename: Yue
authors.initials: Y
authors.lastname: Pan
authors.affiliation: DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL.
authors.forename: Natasha
authors.initials: N
authors.lastname: Fernandez
authors.affiliation: DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL.
authors.forename: Omaida C
authors.initials: OC
authors.lastname: Velazquez
authors.affiliation: Renal Service, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Edgar A
authors.initials: EA
authors.lastname: Jaimes
authors.affiliation: Section of Interventional Nephrology, Leonard M. Miller School of Medicine, University of Miami, Miami, FL.
authors.forename: Loay H
authors.initials: LH
authors.lastname: Salman
authors.affiliation: DeWitt Daughtry Family Department of Surgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL. Electronic address: rvazquez@med.miami.edu.
authors.forename: Roberto I
authors.initials: RI
authors.lastname: Vazquez-Padron
mesh_terms: D001166:Arteriovenous Shunt, Surgical; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000150:complications / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology*; D011446:Prospective Studies; D016896:Treatment Outcome; D017539:Tunica Intima / Q000473:pathology*
keywords: AVF creation; AVF transposition; Intimal hyperplasia (IH); anatomic maturation failure; arteriovenous fistula (AVF); end-stage renal disease (ESRD); failure; hemodialysis; histology; intimal thickness; outcomes; primary unassisted patency; stenosis; vascular access; vascular pathology