Purpose: To evaluate the usefulness of a new carbon dioxide (CO2) intravascular injection system in digital subtraction angiography.
Material and methods: March 1998 to May 1999, thirty-nine patients were submitted to digital subtraction angiography with CO2 injection by a new delivery system, CO2-Angioset, OptiMed, Ettingen, Germany. The patients were 29 men and 10 women, whose age ranged 32 to 76 (mean: 47), eighteen of them with absolute or relative contraindications to iodinated contrast media and 6 with poor diagnostic findings at previous conventional angiography. CO2 was used for comparison with iodinated contrast agents in 4 patients. We studied the following vascular districts: renal arteries in 9 patients, portal vein in 18, lower limb arteries in 7, upper limb veins in 4. In 1 patient CO2 angiography was carried out for the diagnosis and interventional treatment, by transcatheter embolization, of a postbioptic arteriovenous renal fistula. During the procedure, arterial blood pressure, EKG status and oxygen stauration were monitored, and subjective sensations recorded in all patients.
Results: CO2 angiography provided adequate visualization of vascular districts and of abnormal findings in 32 cases (82%), while its results were considered insufficient for correct and complete assessment in 7 cases (18%). In detail, renal arteries studies were adequate in 9/9 cases, providing good depiction of the arterial trunk and main branches but poor demonstration of interlobar and arcuate arteries. The portal trunk was well depicted in 12/18 cases, but CO2 angiography results were insufficient in 3 cases because of poor catheter wedging in the hepatic vein and in 2 cases because of CO2 drainage by an accessory hepatic vein. Peripheral circulation was clearly depicted in 5/7 cases, while there was incomplete filling of the abdominal aorta and of iliac and femoral arteries in 2 cases. We had only one transient complication (2.57%) due to mesenteric ischemia during an aortic injection, with mild abdominal pain and diarrhea which subsided spontaneously in few minutes.
Conclusions: In our experience the CO2-Angioset delivery system has proved to be a simple and safe tool, particularly suitable for use in patients at risk for allergic reactions to iodinated contrast agents and in those with renal function impairment. Also, the system can help carry out some interventional procedures such as arteriovenous fistula embolization and transjugular portosystemic shunting.