Immediate Access Arteriovenous Grafts Decrease Catheter Days and Complications

Abstract

Introduction - Immediate-access arteriovenous grafts (IAAVG) can be used as peripheral access or in combination with outflow through the Hemodialysis Reliable Outflow (HeRO) graft. This study compares IAAVG to standard arteriovenous grafts (SAVG) as well as describing IAAVG use with HeRO outflow. Methods - All patients who underwent placement of AV graft from 1/2014 - 4/2016 at two large tertiary referral centers were retrospectively identified in the electronic medical record and through the Vascular Quality initiative (VQI). Patients were divided into three groups based on the type of graft implanted (SAVG and IAAVG) and a third group of HeRO/IAAVG. Patient comorbidities, graft configuration, operative characteristics and subsequent follow-up were collected and analyzed with respect to primary patency, primary assisted patency, and secondary patency. Additional outcomes included graft-related complications, time to first canulation, time to tunneled catheter removal, catheter-related complications and overall survival. Patency was defined per Society for Vascular Surgery recommended reporting standards and was determined from the time of the index procedure. Chi-square, Kaplan-Meier and Cox regression analysis were used with the p-value set as significant at <0.05 Results - 254 grafts were identified; 148 SAVG, 62 IAAVG, 44 combined IAAVG-HeRO. Patient characteristics were similar between groups, except for more pre-operative central venous occlusions in the IAAVG vs SAVG (16.3% vs 6.8%, p<0.04) and these vs IAAVG/HeRO (100%, P<.001) . Of the IAAVG group, 50 were Acuseal (Gore) and 12 were Flixene (Atrium). IAAVG/HeR0 patients all used Acuseal. Standard AVG were all ePTFE (Gore Medical). Overall primary, primary assisted, and secondary patency at 6 months were 35.9%, 43.6%, and 51.3% respectively for IAAVG/HeRO. Primary patency at 1 year (SAVG: 39.4%, IAAVG: 56.7%, p=0.4), and secondary patency (SAVG: 50.7%, IAAVG: 52.1%, p=0.73) showed no significant differences. Similarly, there were no significant differences in primary (SAVG: 29.0%, IAAVG: 43.7%, p=0.4) or secondary patency (SAVG: 42.3%, IAAVG: 46.3%, p=0.73) at 18 months. Regression analysis did not show any association to the type of graft; however, IAAVG patients required fewer additional procedures to maintain patency (mean number of procedures 0.99 SAVG vs. 0.61 IAAVG, p=0.025). There was no difference in steal syndrome (SAVG: 6.8%, IAAVG: 8.1%, p=0.74).) or graft infection (19.0% SAVG vs. 12.0% IAAVG, p=0.276). 75% of all grafts were successfully canulated, with shorter median time to first canulation in the IAAVG group (6 days IQR 1-19) compared to the SAVG group (31 days, IQR 26-47) (p<0.01). For IAAVG/HeRO) patients, 95% of grafts were successfully canulated with mean time to canulation of 13.0±51.6 days. 53% of IAAVG/HeRO patients left the OR with this graft as their only access. This group had 100% canulation success at < 24 hours. 65.75% of all pre-existing catheters were removed, with a shorter median time until catheter removal in the IAAVG cohort at 34 days (IQR 22-50) versus 49 days (IQR 39-67) in the SAVG group (p<0.01). Catheter-related complications occurred less frequently in the IAAVG group (16.4% vs. 2.9%, p<0.045). Conclusion - IAAVGs allow earlier canulation and tunneled catheter removal, thereby significantly decreasing catheter-related complications. Patency and infection rates were similar between SAVG and IAAVG, but with fewer secondary procedures performed in IAAVG.