Hemodialysis (HD) access for patients with end-stage renal disease is a steadily increasing necessity, and maintaining patency of native or synthetic fistulas can be challenging. The main physiologic changes of an HD access that cause it to fail are inflow or outflow vessel stenosis or access thrombosis. These are propagated by factors intrinsic to end-stage renal disease, altered hemodynamics from a fistula, and typically further exacerbated by associated comorbidities. Diagnosis of fistula dysfunction can be made with a combination of history, physical examination, HD dynamic measurements, laboratory findings, and invasive or noninvasive imaging. Stenoses can be managed with endovascular interventions, including angioplasty with or without stenting, or open operations. Thrombosis of HD access, which is most often a result of an underlying stenosis, can be managed similarly with either endovascular or surgical thrombectomy with adjunctive treatment. Our goal was to review the pathophysiology of the most common forms of fistula failure, diagnosis, and endovascular and surgical options for flow restoration. (c) 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.