Risk factors in patients having surgery to create an arteriovenous fistula

Patients requiring creation of an arteriovenous (AV) fistula for long-term dialysis access have a high incidence of cardiovascular risk factors, as well as immunosuppression, neuropathy, and platelet dysfunction related to renal failure. However, the morbidity and mortality of AV fistula creation, and the effect of anesthetic technique on outcome, have not been reported. We therefore retrospectively studied all patients (n = 469) having an AV fistula placed at the Mayo Clinic between 1986 and 1991. Preoperative variables studied were age (mean 63 +/- 14 yr), sex (60% male), diabetes mellitus (26% incidence), hypertension (92%), the presence of a previous AV fistula (31%), coronary artery disease (86%), and previous myocardial infarction (MI) (42%). Outcome variables studied were fistula failure prior to first attempted dialysis (8.7% incidence), infection (3.4%), neuropathy (1.9%), seizure (0.2%), nonfatal cardiac event (MI or arrest) (1.5%), and fatal cardiac event (2.1%). Associations of preoperative factors, outcomes, and anesthetic technique were analyzed by analysis of variance and Wilcoxon rank sum analysis for age, and by exact conditional frequency table analysis for all other factors. A previous AV fistula was associated with infection (P < 0.002) and nonfatal cardiac events (P < 0.003). Increased age (P < 0.025) and previous MI (P < 0.01) were associated with adverse cardiac outcomes. Neither local anesthesia, brachial plexus block, nor general anesthesia were significantly associated with an increased frequency of any adverse outcome. The comparison of general with local and brachial plexus anesthetics was limited by low statistical power.(ABSTRACT TRUNCATED AT 250 WORDS)