Hemodialysis vascular access flow surveillance: Current evidence and future directions

A well-functioning vascular access is essential for delivering adequate hemodialysis in patients with end-stage renal disease. However, vascular access dysfunction, particularly stenosis and thrombosis, remains a leading cause of morbidity, repeated interventions, and hospitalization in this patient population. Vascular access monitoring and surveillance are designed to detect hemodynamically significant stenosis early, thereby reducing the risk of thrombosis and maintaining access patency. Evidence from meta-analyses and randomized controlled trials suggests that access blood flow (Qa)-based surveillance may lower thrombosis rates in arteriovenous fistulas (AVFs), while the benefit appears less consistent for arteriovenous grafts (AVGs). Consequently, most guidelines recommended incorporating Qa surveillance into routine clinical monitoring for AVFs, but not as a standard practice for AVGs. However, previous studies have notable limitations, including heterogeneous surveillance protocols and variable definitions of access dysfunction. More rigorously designed randomized controlled trials are needed to clarify the role of Qa surveillance and inform optimal strategies. Looking ahead, emerging technologies such as artificial intelligence and wearable devices for continuous monitoring hold promise for enhancing diagnostic accuracy, enabling earlier detection of dysfunction, and reducing the need for intervention rates. Integrating these innovations with standardized surveillance protocols and individualized patient risk stratification has the potential to improve vascular access longevity, reduce the healthcare burden, and improve outcomes in the hemodialysis population, although further validation is required.