Abstract
Background: Intravascular ultrasound (IVUS) shows vascular structures and positions of interventional devices in cross sectional-short axis to support interventions, especially for complex lesions. On the other hand, extravascular ultrasound (EVUS) visualizes the devices and vessel structures in long and short axis and reduces the radiation exposure by avoiding the use of fluoroscopy during guidewire manipulation. The images obtained from EVUS handling to guide the guidewire manipulation in both long and short axis is more difficult, time consuming, and stressful than IVUS, which is in short axis only. To solve this issue, we propose a novel guidewire crossing method in conjunctive with the use of both modalities, named “extra and intravascular ultrasound (E&IVUS)” guided intervention.Main text: This is the first report of a combined use of EVUS and IVUS for femoropopliteal occlusions. EVUS-guided intervention is mandatory to check the position of the device in long and short axis. However, the images of long axis are sometimes different from the original ones when EVUS is required to image from the short axis to the long axis. E&IVUS allows to dedicate EVUS to acquisition of the long axis and IVUS to the short axis view when confirming the device position. As a result, E&IVUS shortens the operation time and reduces the stress due to the manipulation of the probe to switch from the long to short axis image and vice versa. Moreover, we can accurately manipulate the guidewire to perform intimal tracking according to the information of EVUS long axis and the IVUS short axis images. Case involved a 76-year-old female with right superficial femoral artery occlusion was angiographically contrasted from a contralateral 6-Fr sheath. A hard wire supported with an over-the-wire typed IVUS was advanced into the CTO with EVUS and IVUS to confirm their positions until the guidewire crossing. We repeatedly performed this process, and all intimal tracking succeeded. The drug-coating balloons appropriately sized by IVUS measurement were deployed. Finally, a sufficient blood flow was achieved without complications.Conclusions: E&IVUS is a preferred strategy than using EVUS or IVUS alone. We should evaluate the clinical outcomes of this technique.
Determination of the Center of Left Ventricule and Border Detection on Short Axis Image of Echocardiogram
