title: Effect of preoperative sonographic mapping on vascular access outcomes in hemodialysis patients.
abstract: BACKGROUND
  Current DOQI guidelines encourage placing arteriovenous (AV) fistulas in more hemodialysis patients. However, many new fistulas fail to mature sufficiently to be usable for hemodialysis. Preoperative vascular mapping to identify suitable vessels may improve vascular access outcomes. The present study prospectively evaluated the effect of routine preoperative vascular mapping on the type of vascular accesses placed and their outcomes.
  
  
  METHODS
  During a 17-month period, preoperative sonographic evaluation of the upper extremity arteries and veins was obtained routinely. The surgeons used the information obtained to plan the vascular access procedure. The types of access placed, their initial adequacy for dialysis, and their long-term outcomes were compared to institutional historical controls placed on the basis of physical examination alone.
  
  
  RESULTS
  The proportion of fistulas placed increased from 34% during the historical control period to 64% with preoperative vascular mapping (P < 0.001). When all fistulas were assessed, the initial adequacy rate for dialysis increased mildly from 46 to 54% (P = 0.34). For the subset of forearm fistulas, the initial adequacy increased substantially from 34 to 54% (P = 0.06); the greatest improvement occurred among women (from 7 to 36%, P = 0.06) and diabetic patients (from 21 to 50%, P = 0.055). In contrast, the initial adequacy rate of upper arm fistulas was not improved by preoperative vascular mapping (59 vs. 56%, P = 0.75). Primary access failure was higher for fistulas than grafts (46.4 vs. 20.6%, P = 0.001), but the subsequent long-term failure rate was higher for grafts than fistulas (P < 0.05). Moreover, grafts required a threefold higher intervention rate (1.67 vs. 0.57 per year, P < 0.001) to maintain their patency. The overall effect of this strategy was to double the proportion of patients dialyzing with a fistula in our population from 16 to 34% (P < 0.001).
  
  
  CONCLUSIONS
  Routine preoperative vascular mapping results in a marked increase in placement of AV fistulas, as well as an improvement in the adequacy of forearm fistulas for dialysis. This approach resulted in a substantial increase in the proportion of patients dialyzing with a fistula in our patient population. Fistulas have a higher primary failure rate than grafts, but have a lower subsequent failure rate and require fewer procedures to maintain their long-term patency.
authors.affiliation: Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, 1900 University Boulevard S., THT 647, Birmingham, AL 35294, USA. mallon@nrtc.uab.edu
authors.forename: M
authors.initials: M
authors.lastname: Allon
authors.forename: M E
authors.initials: ME
authors.lastname: Lockhart
authors.forename: R Z
authors.initials: RZ
authors.lastname: Lilly
authors.forename: M H
authors.initials: MH
authors.lastname: Gallichio
authors.forename: C J
authors.initials: CJ
authors.lastname: Young
authors.forename: J
authors.initials: J
authors.lastname: Barker
authors.forename: M H
authors.initials: MH
authors.lastname: Deierhoi
authors.forename: M L
authors.initials: ML
authors.lastname: Robbin
mesh_terms: D000328:Adult; D000368:Aged; D001166:Arteriovenous Shunt, Surgical; D044383:Black People; D001808:Blood Vessels / Q000000981:diagnostic imaging; D002408:Catheters, Indwelling; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012737:Sex Factors; D014463:Ultrasonography; D044465:White People