Increased minimum vein diameter on preoperative mapping with duplex ultrasound is associated with arteriovenous fistula maturation and secondary patency.

ABSTRACT

OBJECTIVE: Autogenous arteriovenous hemodialysis accesses (arteriovenous fistulas [AVFs]) are preferred for chronic hemodialysis access. Preoperative vein mapping by duplex ultrasound is recommended before AVF creation, but there are few data correlating vein diameter with postoperative outcomes. Also, vein diameter has not been included in prior predictive models of fistula maturation. This study aims to test whether preoperative vein diameter is associated with failure of AVF maturation and long-term (secondary) patency. METHODS: We performed a retrospective analysis of clinical variables of patients undergoing brachiobasilic or brachiocephalic AVF creation. Kaplan-Meier and multivariate Cox regression models tested whether preoperative minimum vein diameter (MVD) and clinical covariates were associated with failure of AVF maturation and secondary patency. RESULTS: The sample included 158 adults (54 ± 14 years; 45% male; 61% white; 56% diabetes; body mass index, 32 ± 8; MVD, 3.4 ± 1.1 mm; follow-up, 12 ± 9 months [range, <1-40 months]). Increased MVD was associated with decreased risk of AVF failure. More than one third of AVFs with MVD <2.7 mm failed to mature within 6 months. Multivariate models that adjusted for age, diabetes, race, gender, body mass index, and preoperative dialysis status demonstrated that increased MVD was associated with decreased risk of failure of maturation and better long-term patency overall (P = .005 and P = .001, respectively). CONCLUSIONS: Patients with a larger MVD on preoperative vein mapping are at lower risk for failure of fistula maturation and have increased long-term AVF patency. MVD is the only clinical or demographic factor associated with both AVF maturation and long-term patency. MVD is an important preoperative indicator of fistula success in assessment of potential AVF sites. Future predictive models of fistula maturation and patency should include MVD.