指引导管的选择详解.ppt

* Normal aorta: The aorta has a normal curvature and diameter of 3.5 cm to 4.0 cm. The normal aortic configuration is found in 60 to 70 percent of all patients. Narrow aorta: The aortic arch has a very tight curve and a smaller diameter less than 3.5 cm . Narrow aortic arches can make advancing guiding catheters and interventional devices more difficult. Soft guide catheters can partially compensate for the tight curve in the arch. Smaller left coronary catheters are usually selected in these patients. Dilated aorta: The aortic arch is at a more relaxed angle. The diameter is greater than 4.0 cm. Larger left and right catheters are usually selected in these patients. * The size of the aortic root affects the curve size of the catheter to be used. The average aortic root generally requires a 4.0 cm curve guide catheter, either an FL/JL or EBU for the LCA or an FR/JR for the RCA. A larger aortic root would require a larger curved catheter, such as an FL/FR or EBU 4.5 or 5.0 to provide adequate back-up support from the opposite aortic wall, and enough length to properly cannulate the ostium. A narrowed aortic root would require a smaller FL/FR or EBU curve, such as a 3.0 or 3.5. The curve not only affects back-up support, but also directs tip orientation. A shorter distance between the primary and secondary curves has a tendency to allow the catheter to move farther down into the aortic root, orienting the tip more superiorly, while a larger curve will sit higher in the root and tend to orient the tip more inferiorly. During the diagnostic procedure, one should note how the diagnostic catheter sits in the aorta. The diagnostic catheter only has to sit on the lip of the ostium to inject dye vs. the need for a guiding catheter to provide support. * If the guide catheter is too long, the tip will assume an inferior position. The guidewire will then follow the angle of the curve downward possibly subselecting the LCX. * If the guide catheter is too shor