Management of high-flow arteriovenous access.

An arteriovenous fistula or graft is essential for hemodialysis (HD). It involves connecting a high-resistance artery to a low-resistance vein, which increases cardiac output (CO). In the early days of HD, patients with end-stage kidney disease (ESKD) were typically younger, and their HD access was located in the distal forearm. However, in the modern era, ESKD patients are often the elderly, with many being the very elderly (over 80 years old). These elderly patients often have poor vessel quality, making distal forearm access unsuitable. As a result, upper arm access, which is more prone to high-flow access, is commonly used. The cardiac status of these modern elderly ESKD patients is vulnerable to high-flow access. High-flow HD access can lead to high-output cardiac failure in ESKD patients. Initial evaluation for high-flow access involves measuring the flow volume using Doppler ultrasound. If the HD access flow volume exceeds 2,000 mL/min, further assessments, including CO and cardiopulmonary recirculation ratio caused by the HD access, should be strongly considered. Treatment for high-flow access involves reducing the flow. There are several surgical and endovascular methods for flow reduction, such as aneurysmorrhaphy, short segment small-diameter graft interposition at the inflow area of the HD access, and banding. Patients with high-flow access are generally asymptomatic. Therefore, nephrologists as primary care physicians for HD patients should provide detailed explanations to patients with high-flow access and high-output cardiac failure and ensure that they understand the prognosis of these conditions. Nephrologists need increased attention to high-flow HD access.