With the proper angiographic catheter and techniques, contrast reduction is possible.
Thomas A. Sos, MD, FSIR, FACR, FAHA
Director, Peripheral Arterial Disease, Weill Cornell Interventional
Professor and Vice Chair of Radiology, New York Presbyterian Hospital Weill Cornell
Aortogram performed on a 75 y.o. woman with chronic renal failure and a Serum Creatinine of 4.1 mg/dL. A total of 10 mL of 1:2 (1/3) dilution of 300mg Iodine per mL contrast in saline injected at 10 mL/sec (i.e. the equivalent of only 3.3 mLs of full strength contrast) was used. The aortogram clearly delineated the severe right renal artery stenosis and aortic atheroma as well as the left renal artery occlusion prior to intervention.
Note: Using the OmniFlush (AngioDynamics, Queensbury, N.Y.) catheter, with its end hole pointed caudad and side holes laterally, there is virtually no reflux of contrast cephalad to the renal arteries, the region of interest. This allows for a greater concentration of contrast in the region of interest as well as lack of reflux stealing contrast from the region of interest and opacifying the undesired branches of the SMA and celiac arteries, which could overlap and obscure the renal arteries. In this patient, the Sos Flick technique with a SOS Omni (AngioDynamics, Queensbury, N.Y.) selective catheter was used to enter and cross the right renal artery stenosis without using any contrast. Right renal artery stenting was subsequently successfully performed and the patient's Serum Creatinine fell to 1.7 mg/dL within few days. The amount of contrast used during the intervention was 5 mL of 1/3 dilute contrast at 5 mL/sec, and the completion aortogram through the long vascular sheath used 5 mL of 1/3 dilute contrast injected at 7 mL/sec. The total procedure required only 20 mL of 1/3 dilute contrast, which is equivalent to less than 7 mL of full-strength contrast. This patient was thin; in heavier patients a 1:1 dilution of contrast (i.e. half-strength) may be necessary to obtain similarly high quality studies.
The contrast delivery characteristics of OmniFlush (AngioDynamics, Queensbury, N.Y.) catheter allow the optimal use of dilute contrast for minimizing the use of nephrotoxic iodinated contrast in all patients, but especially in those with pre existent renal compromise.
Thomas A. Sos, MD, FSIR, FACR, FAHA receives royalties for the Sos Omni from AngioDynamics, Inc.