The use of CO2 to create an optical window during intravascular optical coherence tomography in a patient with an allergic reaction to iodine contrast

A necessary condition for obtaining a high-quality image with optical coherence tomography (OCT) is the displacement of blood from the visualized segment of the vessel to provide a transparent medium between the vascular wall and the photo detector. Traditionally, liquid iodine-containing contrast is used for this, which can be dangerous in patients with iodine allergy or renal insufficiency. We present a clinical case of successful OCT using CO2 in a patient with anaphylactic reaction to iodine-containing contrast. OCT was performed to monitor the safety of radiofrequency renal denervation. CO2 was injected as standard into a guide catheter located in the renal artery. With the help of CO2, it was possible to effectively displace blood from the renal artery and obtain high-quality OCT images of the vascular wall microstructure.