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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Anesthetics, Local, Arteriovenous Shunt, Surgical, Blood Flow Velocity, Brachial Plexus, Bupivacaine, California, Female, Humans, Kidney Failure, Chronic, Male, Middle Aged, Nerve Block, Prospective Studies, Regional Blood Flow, Renal Dialysis, Time Factors, Treatment Outcome, Ultrasonography, Doppler, Duplex, Upper Extremity, Vascular Patency, Vasodilation, Veins.
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Does pre-operative regional block anesthesia enhance operative strategy for arteriovenous fistula creation? Context: We aim to assess the effect of regional block anesthesia on vein diameter, type of AVF placement, and fistula size and flow volume. 30 patients presenting for AV access procedures were followed prospectively. Vein diameters via venous ultrasound and planned location for AV access were documented. Supraclavicular brachial plexus block was followed by repeat ultrasound and alterations in operative plan were noted. Patients returned to clinic for duplex ultrasound assessment. Average increase from baseline vein diameter with regional block was most pronounced in the lower cephalic (34%), upper cephalic (24.2%), and basilic veins (31.3%) and less in the brachial vein (8.7%). Type of AVF was modified following regional block in 14%. The rate of native AVF placement improved from 89% to 93% with regional block. Twenty-three AVF patients were available for follow-up (mean 24 weeks). Average fistula size was 7.9 mm (CI 6.9-8.9) and all patent fistulas developed flow volume >600 mL/min. Primary patency was attained in 83%. One thrombosis occurred after a basilic artery was lacerated during dialysis access. The average fistula increased 0.33 cm from post-block diameter (SD 0.22, P<.05).
assistant
Vein diameter increases significantly in the basilic and cephalic veins following regional block anesthesia and may improve the rate of native fistula placement. Propensity to dilate after regional block anesthesia does not predict size of the fistula. Final Decision: yes