Current Topics in Vascular Access: Superficialization of Arteriovenous Fistula.

Background: An arteriovenous fistula (AVF) is considered the gold standard modality of vascular access (VA) for maintenance hemodialysis (HD) because of its superior patency, few complications, provision of high quality of life, and low risk of patient mortality. The rapid growth of the aging population and the high prevalence of comorbidities, particularly diabetes mellitus and peripheral vascular disease, in patients requiring HD inevitably deteriorate the ability to construct and maintain a conventional AVF because of these patients' insufficient vascular adaptability. Furthermore, a substantial proportion of patients undergoing HD encounter non-maturation AVF failure and mis-cannulation-related complications, resulting in the need for a temporary VA procedure. Superficialization of the AVF is an alternative form of VA that facilitates the construction of an autologous fistula by maximizing the availability of a deeply located vein. Superficialization is also utilized in VA revision to improve the cannulability of an arterialized vein.

Summary: Superficialization involves various approaches, including tunnel transposition, elevation, lipectomy, and liposuction. Tunnel transposition and elevation are prerequisites for construction of an alternative autologous AVF, especially a one- or two-stage transposed brachial-basilic AVF, which is widely recognized as preferential to an arteriovenous graft in patients who cannot undergo conventional AVF installation. Elevation, lipectomy, and liposuction are also employed as revisional interventions for approximating the depth of the arterialized vein and ensuring a sufficient cannulable segment in the forearm and upper arm area. More recently, modified minimally invasive techniques for each superficialization procedure have been introduced to avoid postoperative complications. Amid the growing methodological diversity of superficialization, increasingly more studies have been performed in an attempt to clarify its feasibility and outcomes. On the whole, most superficialization procedures have acceptable patency and safety profiles. However, the preferable superficialization approach varies in accordance with both the influence of the anatomic location and the inherent advantages and limitations of each procedure. Key Messages: Both careful assessment of a patient's vascular adaptability and adequate comprehension of the various superficialization modalities that are available will enable optimal establishment of an autologous AVF in individual patients. This could lead to better outcomes and more successful management of HD.