ABSTRACT
CO2 is a safe and effective contrast agent for venous injection studies. We use CO2 for
both diagnostic venography and interventional procedures for the treatment of occlusive
lesions of the central veins. Because of its lower viscosity, CO2 can consistently visual-
ize the subclavian vein despite the injection of the gas into a peripheral vein. The
current indications for CO2 venography are to provide a “road map” of the veins of
upper extremities prior to surgical arteriovenous fistula (AVF) placement, transvenous
pacer insertion, and venous interventions (including thrombolysis, angioplasty, and
stent placement).
