Arteriovenous fistulas are abnormal, direct connections between an artery and a vein. These can occur naturally, often as a result of trauma or through a genetic condition, or they can be surgically created for medical purposes, such as for hemodialysis in patients with kidney failure. Arteriovenous fistulas can result in a number of complications, including thrombosis, aneurysm formation, and heart failure. Research in this area focuses on understanding the underlying mechanisms of arteriovenous fistula formation, improving surgical techniques for creating fistulas, and developing new treatments to prevent or manage complications associated with these abnormal connections.