The role of regional vs general anesthesia on arteriovenous fistula and graft outcomes: a single institution experience and literature review.

Background: Multiple studies have demonstrated the benefits of creating arteriovenous fistulas (AVFs) under regional anesthesia. This is most likely because of the avoidance of hemodynamic instability and stress response of general anesthesia, as well as the sympathectomy associated with brachial plexus blockade. As vein diameter is the major limiting factor for primary AVF creation and maturation, our aim is to investigate if the vasodilation that accompanies regional anesthesia leads to improved patency and maturation rate of autologous AVF and improved patency of arteriovenous graft (AVG) compared with those placed under general anesthesia. Methods: This retrospective study was approved by the institutional review board. A total of 238 patients who had either an AVF or an AVG placed at the Mayo Clinic, Florida, between 2012 and 2017 were analyzed. Demographics, access type, preoperative vein diameter, anesthesia type, change of plan after regional versus general anesthesia, and outcomes were assessed. All statistical tests were 2 sided, with the alpha level set at 0.05 for statistical significance. Results: Among 238 patients, 120 (50.4%) had regional anesthesia. Differences between the 2 groups in risk factors and 30-day or long-term outcomes (failure, abandonment, or reoperation) were not statistically significant. Of the accesses placed under general anesthesia, 58.5% were abandoned compared with 45.2% of those placed under regional anesthesia. Owing to loss of patency, 25.8% of accesses placed under general anesthesia were abandoned compared with 19.2% of those placed under regional anesthesia. Two-month failure was higher in the general anesthesia group than that in the regional anesthesia group (P = 0.076). After preoperative vein mapping, 22 patients were originally intended to have an AVG placed under regional anesthesia. After brachial plexus blockade, 9 of these patients (41%) were successfully switched to AVF, while the other 13 followed the original surgical plan and received an AVG. Of these, 0 failed and 0 were abandoned because of loss of patency. Conclusions: This study showed possible improvements in failure rates for vascular accesses placed under regional anesthesia compared with those placed under general anesthesia. In addition, we showed an impact of regional anesthesia on the surgical plan by transitioning from a planned AVG to an AVF, intraoperatively. Giving patients with originally inadequate vein diameter the chance to have the preferred hemodialysis access method by simply switching anesthesia type could reduce the number of grafts placed in favor of fistulas.