RESUMO
Owing to the overall poor medical health of patients with end-stage renal disease, we have sought alternatives to the use of general anesthesia for access procedures. Furthermore, since local anesthesia (1) does not offer the motor block that is sometimes desired and (2) can be difficult to maintain when a large amount of vein needs to be transposed, we examined whether regional blocks can be useful for the creation of new arteriovenous fistulae (AVF). From August 2002 to January 2005, 41 patients scheduled for AVF placement underwent a regional block with the use of a lidocaine and ropivacaine mixture using a nerve stimulator. Either axillary, interscalene, or infraclavicular blocks or a combination was used. Intraoperative duplex ultrasonography was used to assess the degree of venodilatation of the basilic and cephalic veins before and after the block. The site of each measurement was marked on the skin and selected by a clearly identifiable branch point. Each measurement was recorded three times and was made in the (1) native state, (2) after application of a tourniquet with opening and closing of the hand for 15 seconds, and (3) after placement of the block. The average age of the patients was 65 +/- 14 years (SD), with ages ranging from 33 to 91 years, and the prevalence of diabetes mellitus was 50%. Complete brachial plexus block was achieved in 34 patients (83%). Sensory block was accomplished within 10 to 15 minutes and usually lasted 4 to 6 hours. Motor block was accomplished in 10 to 25 minutes. Venodilatation was not noted in patients whose blocks did not work (n = 7) or whose vein was found to be phlebitic on exploration (n = 3). The degree of venodilatation noted as a percentage increase after application of the tourniquet compared with the native state for these 34 patients (in whom the block worked) was 37% for the distal cephalic, 31% for the midcephalic, and 32% for the midbasilic vein. The degree of venodilatation noted as a percentage increase after placement of the block compared with after tourniquet application for these 34 patients was 42% for the distal cephalic, 19% for the midcephalic, and 26% for the midbasilic vein. No instances of systemic toxicity, hematomas, or nerve injury from the block were noted. Accesses placed included 20 radiocephalic AVF, 8 brachiobasilic AVF, 8 brachiocephalic AVF, 2 arteriovenous grafts, 2 radiobasilic AVF, and 1 brachial vein AVF.Regional block is a safe and, in our opinion, preferred technique for providing anesthesia for upper extremity vascular surgery. The venodilatation observed is augmented compared with that using a tourniquet and may allow more options for access placements.