Multimodality imaging evaluation of arteriovenous fistulas and grafts: a clinical practice review

Abstract

Arteriovenous fistulas (AVFs) and grafts (AVGs) are the preferred forms of vascular access for hemodialysis in patients with severe renal dysfunction. Multimodality imaging plays an important role in the pre-procedural evaluation of these patients. Ultrasound is often used for pre-procedural vascular mapping in preparation for the creation of an AVF or AVG. Pre-procedural mapping includes a comprehensive evaluation of the arterial and venous vasculature including evaluation of vessel diameter, stenosis, course, presence of collateral veins, wall thickness and wall abnormalities. Computed tomography (CT), magnetic resonance imaging (MRI) or catheter angiography are used when sonography is not available or when further characterization of sonographic abnormalities is required. Following the procedure, routine surveillance imaging is not recommended. If there are any clinical concerns or if physical examination is inconclusive, further evaluation with ultrasound is warranted. Ultrasound allows for assessment of vascular access site maturation by evaluating the time-averaged blood flow and helping characterize the outflow vein in the case of an AVF. CT and MRI can play a complementary role to ultrasound. Vascular access site complications include non-maturation, aneurysm, pseudoaneurysm, thrombosis, stenosis, steal phenomena or occlusion typically of the outflow vein, infection, bleeding and rarely angiosarcoma. In this article, we review the role of multimodality imaging in the pre- and post-procedural evaluation of patients with AVF and AVG. Additionally, novel technologies of vascular access site creation using endovascular techniques and upcoming non-invasive imaging techniques for evaluation of AVFs and AVGs are discussed.

Analysis of risk factors for late arteriovenous fistula failure and patency rates after angioplasty in hemodialysis patients: a retrospective cohort study

“…The reason our study data were slightly higher than other studies may be because firstly, we excluded advanced-aged surgical patients, and secondly, in patients with poor vascular conditions, we tried to select larger diameters by preoperative Doppler blood vessel ultrasonography. Actually, clinicians can also use multimodality imaging to evaluate AVFs and grafts for precise assessment ( 43 ).…”

Renal Arteriovenous (AV) Fistula after High-Grade Blunt Renal Trauma Caused by Traffic Accidents

“…This diagnostic method excels at precisely delineating the anatomy of the fistula, assessing its impact on nearby structures, and aiding in the development of an appropriate treatment plan. The non-contrast CT is only capable of revealing a perirenal hematoma [28]. Still the color Doppler ultrasound is well suited to detect a renal AV fistula [29]; phenomena such as a region of high-velocity shift and a low-resistive index can be indicative of AV fistulas [30].…”

Distal Forearm Arteriovenous Fistula Maturation in Diabetic Hemodialysis Patients

“…3 In addition, AVF maturation can also be influenced by vein depth, hemodynamic limitations, blood inflow problems, such as native arterial disease, arteriovenous anastomosis, or outflow problems, such as proximal venous stenosis or collateral veins. 4 Also, cardiovascular comorbidities and a thicker media layer of the radial artery emerged as predictive factors for primary radiocephalic fistila patency, providing valuable insights into the multifaceted determinants of long-term success in radiocephalic fistila procedures. 5 Moreover, diabetes can also cause AVF obstruction due to hypercoagulation, hyperlipemia, hypoalbuminemia, or high insulin levels associated with hyperlipemia.…”

“…According to the KDOQI (Kidney Disease Outcomes Quality Initiative) guidelines, patients requiring hemodialysis should create primary distal forearm AVFs with a snuffbox fistula or distal radiocephalic fistula, as it preserves the vascular integrity of the proximal forearm and arm for subsequent AVF creation. 1 Although AVFs have a high initial failure rate, it is estimated that between 30% and 70% of radiocephalic AVFs fail. 2 It has been suggested that age, female gender, diabetes, and small diameters of the radial artery and vein are the most significant factors influencing early failure of radiocephalic fistulas.…”