CO2 as a contrast medium in endoluminal treatment of high flow vascular malformations

Purpose: To evaluate the diagnostic usefulness of CO2 as a radiologic contr ast medium in pre and post-embolization of hemodynamically active vascular malformations. Material and methods: Eight pre and post-embolization angiog raphies were performed on five patients with hemodynamically active vascula r malformations. In all cases sequentially iodinated contrast medium and CO 2 were used. Procedures were performed using Philips Integris V equipped wi th specific software to process images obtained with CO2 as contrast medium and with a purpose-built gas injector pump. The images were assessed by th ree interventional radiologists who evaluated the findings by consensus. Th ey were asked whether uptake of the malformations were better, worse or the same with iodinated contrast and CO2. The images were judged according to the following characteristics; quality, the filling in of the contrast in a fferent artery of the HAVM, caliber and number of vessels and existence of pathologic communications in HAVM. These characteristics were assessed in a ll the patients of the study, both before and after embolization. Results: The CO2 angiographic results were compared to those obtained using iodinate d contrast material, Iodinated contrast provided superior image quality in all performed studies. The filling of arterial afference of HAVM was well d efined with both contrast media. In all performed cases with CO2, the malfo rmations showed more vessels. No inmediate nor subsequent complications dev eloped with CO2, injections, except in one female patient, who presented an intense sensation of cramps in the lower limbs. Conclusion: CO2 is a usefu l diagnostic and assessment tool before and especially during the embolizat ion of hemodynamically active vascular malformations. It improves quantific ation and uptake of the malformation's vascular architecture, detecting col lateral circulation and arteriovenous shunts. It also detects residual post -embolization disease when iodinated contrast agent is unsuccessful. (C) 19 99 Elsevier Science Ireland Ltd. All rights reserved.