Indexed on: 03 May '08Published on: 03 May '08Published in: Contributions to nephrology
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.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.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.