Regional anesthesia for vascular access surgery
BACKGROUND: Approximately 25% of initial arteriovenous fistula (AVF) placementswill fail as a result of thrombosis or failure to develop adequate vessel size andblood flow. Fistula maturation is impacted by patient characteristics and surgicaltechnique, but both increased vein diameter and high fistula blood flow rates arethe most important predictors of successful AVFs. Anesthetic techniques used invascular access surgery (monitored anesthesia care, regional blocks, and generalanesthesia) may affect these characteristics and fistula failure.METHODS: We performed a literature search using key words in the PubMed/MEDLINE database. Seven articles that related to the effects of anesthesia on AVFconstruction, including sympathetic block, vein dilation, blood flow, adverseoutcomes, or patency rates, comprised the sources for this review.RESULTS: Significant vasodilation after regional block administration is seen in boththe cephalic and basilic veins. These vasodilatory properties may assist with AVFsite selection. In the intraoperative and postoperative periods, use of a regionalblock, compared with other anesthetic techniques, resulted in significantly increasedfistula blood flow. The greater sympathetic block contributed to vesseldilation and reduced vasospasm. Use of regional techniques in AVF constructionyielded shorter maturation times, lower failure rates, and higher patency rates.CONCLUSION: Use of regional blocks may improve the success of vascular accessprocedures by producing significant vasodilatation, greater fistula blood flow,sympathectomy-like effects, and decreased maturation time. However, a largescale,prospective, clinical trial comparing the different anesthetic techniques is stillneeded to verify these findings. Copyright © 2009 International Anesthesia Research Society.