[Visualization of stenosis in vascular access by bubble method under carbon dioxide (CO2) angiographic procedures].

A percutaneous transvascular angioplasty (PTA) is performed to relieve failed vascular access for hemodialysis. Angiography using non-ionic iodinated contrast media is the imaging modality of choice for performing PTA. However, the use of iodinated contrast media is contraindicated for patients with a history of iodine allergy. Since 1920, carbon dioxide (CO(2)) has been used as a safe contrast medium in various studies. In CO(2) shunt angiography for hemodialysis, visualization of the vascular structures was often suboptimal due to shunt-specific conditions, such as rapid flow and narrow diameter of the vessels. In the present report, we attempted an improvement of the visualization by injection of CO(2) bubbles in view of the properties of CO(2) (floating and low viscosity). The results indicated that the CO(2) bubbles angiography clearly demonstrated the narrow vessels and stenotic portions that were not visualized by conventional CO(2) angiography. In addition, the required volume of CO(2) could be reduced in comparison with previous studies in the literature. Therefore, the method seemed to be effective in reducing exposure and preventing complication by CO(2). Thus, CO(2) bubbles angiography may be useful for shunt angiography and sequential angioplasty when experiencing shunt problems.