Most vascular labs only reach for CO2 angiography when the creatinine is already ugly.
Mariano Palena has been using it as his default for over 15 years. Not as a backup. Not as a last resort for the patient with a GFR of 18. As standard of care, even in patients with normal kidneys.
That reframing changed how I think about contrast use in diabetic CLTI.
Here’s what we typically do: we reach for iodinated contrast because it’s familiar, the images are beautiful, and CO2 feels like a compromise. Meanwhile we’re burning through expensive contrast (Visipaque for diabetics isn’t cheap) and stacking nephrotoxic risk on patients who already have kidneys hanging by a thread.
Mariano’s approach cuts iodine use by at least 50%. And with proper technique, bending the foot to eliminate movement artifact, using nerve blocks so the patient isn’t flinching, the CO2 images are genuinely diagnostic. In the case we reviewed together, the CO2 angiogram is what revealed a plantar circulation fed by a peroneal posterior branch that three surgeons had missed on open surgical exploration. That anatomical finding is what saved the leg.
The economics are hard to ignore too. CO2 is significantly cheaper per case than premium iodinated contrast. Multiply that across every diabetic CLTI patient in a busy cath lab and the numbers add up fast.
Miguel said something honest during our conversation: he only reaches for CO2 when a patient has bad CKD. And I think that’s where most of us are. We treat it like a workaround instead of a first-line tool.
The question I keep sitting with is simple. If CO2 reduces nephrotoxicity, costs less, and in the right hands produces images good enough to catch what open exploration missed, why is it still the backup plan?
