Association of preoperative vein mapping with hemodialysis access characteristics and outcomes in the Vascular Quality Initiative

Background: Preoperative vein mapping before arteriovenous fistula (AVF) or arteriovenous graft (AVG) placement has been debated as a possible method of improving hemodialysis access outcomes for patients. However, high-quality national studies that have addressed this relationship are lacking. Thus, we assessed the association of preoperative vein mapping with hemodialysis access configuration and outcomes. Methods: In the present cohort study, we analyzed all patients who had undergone AVF or AVG placement with data captured in the Vascular Quality Initiative hemodialysis access dataset from August 2011 to September 2019. The patients were stratified by whether they had undergone preoperative vein mapping. The primary (configuration) outcomes were access type (AVF vs AVG) and location (upper arm vs forearm). The secondary (longitudinal) outcomes were the successful initiation of hemodialysis, maintenance of secondary patency, and the need for reintervention 1 year after the index operation. Results: Overall, 85.6% of the 46,010 included patients had undergone preoperative vein mapping. Of the 46,010 patients, 76.1% and 23.9% had undergone AVF and AVG creation, respectively. AVF creation (77.6% vs 67.3%) and forearm location (54.6% vs 47.3%) were more frequent for the patients who had undergone preoperative vein mapping than for those who had not (P < .001). After adjusting for baseline differences between the groups, preoperative vein mapping was associated with increased odds of receiving an AVF vs AVG (adjusted odds ratio, 1.64; 95% confidence interval [CI], 1.55-1.75) and forearm vs upper arm access (adjusted odds ratio, 1.22; 95% CI, 1.16-1.30). The incidence of the loss of secondary patency was lower for patients with preoperative vein mapping (P < .001), and persisted after risk adjustment (adjusted hazard ratio, 0.81; 95% CI, 0.75-0.88). Conclusions: Preoperative vein mapping was associated with favorable hemodialysis access configurations and outcomes in real-world practice. These data suggest that the use of preoperative vein mapping could improve the likelihood of favorable outcomes for patients requiring hemodialysis access.