[Morphology of aortic isthmus stenosis--invasive study using intravascular ultrasound]

In patients with coarctation of the aorta, intravascular ultrasound can yield important additional diagnostic information concerning stenosis morphology and aortic wall structure that, thus far cannot be obtained with conventional angiography. For the first time, we were able to visualize, in vivo, the eccentric thickening of the posterior aortic wall, which is the typical morphological finding in patients with coarctation of the aorta, known from post mortem or intraoperative specimens. The additional information about stenosis morphology and aortic wall structure, obtained with intravascular ultrasound, is especially valuable for the newer interventional therapy of balloon angioplasty. With intravascular ultrasound, not only the direct quantitative assessment of the aortic cross-sectional luminal area, but also the immediate visualization of local dissections and aneurysms is possible. Using special angioplasty catheters with integrated ultrasonic crystals (which are currently under manufacturing development), a step-wise dilation with immediate evaluation of the therapeutical success may improve the short- and long-term results of balloon angioplasty. At present, intravascular ultrasound is still only an additional diagnostic tool. If it is combined with interventional balloon angioplasty, however, it could gain increasing clinical importance for the treatment of aortic coarctation in the near future.