Venous aneurysm after polytetrafluoroethylene arteriovenous dialysis fistula.

True venous aneurysms are uncommon complications in patients undergoing hemodialysis through prosthetic grafts. We report the case of a large cephalic venous aneurysm that occurred proximal to a polytetrafluoroethylene hemodialysis fistula. The incidence, management, and possible cause of this unusual complication of prosthetic arteriovenous fistulas are reviewed.