Letter to the Editor re: Are intravenous injections of contrast media really less nephrotoxic than intra-arterial injections?

In a recent paper, the authors oppose the opinion that " intra-arterial administration of iodinated-based contrast media (CM) appears to pose a greater risk of contrast-induced nephropathy (CIN) than intravenous administration" . As nephrologists, we are happy to have the opportunity to offer our expertise in the setting of renal disease aimed at optimizing diagnostic algorithm and preventive strategies. Our comment relies on the fact that, from a nephrologist's point of view, there is no doubt that renal damage following CM intra-venous administration in patients not in intensive care or emergency department and treated with conventional preventive strategies not only occurs with low frequency, but also appears of negligible clinical impact; it is confined to an asymptomatic increase of serum creatinine of 25% or 0.5 mg/dL lacking any prognostic negative impact, and in some case not significantly different from controls.True CIN, just related to intravenous CM injection for diagnostic purpose, has to be differentiated from all the other cause of renal involvement in people stricken with sudden and acute illness also receiving intra-arterial CM injection, in order to avoid patients being denied necessary radiological examinations due to an inappropriate fear of risk. KEY-POINTS. Contrast induced nephropathy (CIN) is not any nephropathy following contrast medium(CM). • CIN should only refer to renal damage strictly due to CM infusion. • True CIN following CM intravenous infusion is a clinically insignificant event. • Renal damage following intra-arterial CM infusion in compromised patients is not CIN. • Patients should not forego necessary radiological examinations for inappropriate understanding about risk.