American Board of Pathology (ABPath) Practice Test

Surgical intervention is indeed the most common cause of an arteriovenous fistula (AVF). AVFs are often created intentionally in a surgical setting for access to the vascular system, particularly in patients requiring hemodialysis. This procedure connects an artery directly to a nearby vein, allowing for increased blood flow and easy access for dialysis treatments.

While other causes such as trauma or congenital defects can lead to AVFs, they are not as prevalent as those created surgically. Trauma may lead to accidental AVF formation through injury, and congenital defects may rarely result in AV malformations, but these scenarios are less common compared to the frequency of surgical procedures designed specifically to create AVFs for medical purposes. Infection is also not a common cause of AVFs; rather, it is a complication that can occur following surgical creation of an AVF or in the context of traumatic injuries. Therefore, understanding the clinical setting in which AVFs are most often formed highlights why surgical intervention is deemed the primary cause.