What does a thrill upon fistula palpation indicate?

A thrill upon palpation of a fistula indicates patency, which means the fistula is open and blood is flowing through it adequately. This tactile sensation occurs when blood is moving rapidly through an arteriovenous fistula, typically created for hemodialysis access. The presence of a thrill signals that the connection between the artery and the vein is functioning correctly and that there is sufficient blood flow to sustain the dialysis process. An absent thrill would raise concerns about the fistula being clotted or occluded, indicating potential complications. Therefore, feeling a thrill is a reassuring sign of the fistula's viability.