Hemodialysis arteriovenous fistula patency revisited: results of a prospective, multicenter initiative

Abstract

Background and objectives: Vascular access standards are predominantly based on older, single-center reports; however, the hemodialysis population has changed dramatically and primary arteriovenous fistula failure is a huge problem. This prospective, multicenter study used standardized definitions to analyze patency rates and potential risk factors that affect functional patency and late arteriovenous fistula functionality.

Design, setting, participants, & measurements: Eleven centers participated in a guidelines implementation program. All new permanent vascular accesses were included. Patency and functional patency, defined as access survival from creation and from first dialysis use, respectively, were calculated using Kaplan-Meier analysis. Risk factors for primary functional patency loss (intervention-free interval) and secondary failure (abandonment) were determined using regression models.

Results: A total of 491 arteriovenous fistulas were placed in 395 patients. Six-, 12-, and 18-mo secondary patency and functional patency were 75 +/- 2.0, 70 +/- 2.3, and 67 +/- 2.7% and 90 +/- 1.9, 88 +/- 2.2, and 86 +/- 2.7%, respectively. Primary failure rate was 40%. Thrombosis rate was 0.14 per patient-year. Diabetes and arteriovenous fistula surveillance were significantly associated with primary functional patency loss. Preoperative duplex was inversely related to secondary failure. The secondary failure rate per hospital varied from 0 to 39%.

Conclusions: This study showed a marked difference between patency and functional patency, likely to be explained by high primary failure rates. Hemodialysis patients with diabetes can be expected to have reduced primary functional patency rates, but if treated adequately, then arteriovenous fistula functionality can be maintained as long as in patients without diabetes.

Figure 1.

Visual explanation of patency rates. Primary patency is the intervention-free access survival. Assisted primary patency is the thrombosis-free access survival. Secondary patency ends when the access is abandoned (14).

Figure 2.

Primary and secondary patency from fistula creation with number of patients at risk. Note the significant number of early complications that led to approximately 20% fistula abandonment within 3 mo.

Figure 3.

Diagram of primary AVF function. Of the 428 fistulas with known outcomes, 170 (40%) had a primary failure; 302 primary successful and salvaged fistulas were successfully used for hemodialysis.