title: Preoperative hemodialysis fistula evaluation: angiography, ultrasonography and other studies, are they useful?
abstract: BACKGROUND
  There is increasing emphasis on optimizing fistula use for end-stage renal disease patients. Although early referral and strategies for vein preservation are clearly important, imaging modalities have assumed an ever-increasing role in preoperative vascular access assessment and management.
  
  
  RESULTS
  Review of available literature demonstrates angiography and ultrasonography provide anatomic information useful in diagnostic decision-making in many clinical settings. Targeted clinical programs can increase fistula use, and various practice patterns have emerged to achieve this goal depending on the available expertise, center-dependent experience, and differing patient populations. In recent years there have been a series of studies evaluating provocative maneuvers assessing vascular mechanics that attempt to increase the predictive power of imaging modalities. Assessing arterial and venous mechanics may help predict outcomes and assist in preoperative planning.
  
  
  CONCLUSIONS
  In the quest to optimize fistula use, study results examining the value of angiography and ultrasonography demonstrate that there is currently no universal application of specific cut-offs on vessel diameter or even measures of distensibility and vessel mechanics. It is clear, however, that implementing programs that include imaging to increase fistula creation do achieve their goal. Conversely, in other settings, fistula failure rates have increased without significantly increasing the numbers of fistulae. The impact of preoperative diagnostic angiography and ultrasonography rests in part on identifying the underlying disease process involving arteries and veins that may change treatment decisions preoperatively. In many clinical settings where the dialysis population is becoming increasingly elderly, diabetic and with more vascular disease, these additional studies may be very useful. Given the variation in clinical study outcome and variations in patient populations, presently these methods will be used most effectively in the setting of strong quality assurance programs, and wherever feasible under study protocols for the purpose of improving practice patterns.
authors.affiliation: University of Michigan, Department of Internal Medicine, Division of Nephrology, 102 Observatory, 312 Simpson Memorial Institute, Ann Arbor, Mich., USA.
authors.forename: William F
authors.initials: WF
authors.lastname: Weitzel
mesh_terms: D000792:Angiography; D001166:Arteriovenous Shunt, Surgical; D006801:Humans; D006435:Renal Dialysis; D014463:Ultrasonography