uidewire crossing is the most important component of a successful percutaneous coronary intervention (PCI) for chronic total occlusions (CTO). Several special guidewires, such as the Magnum wire, [1][2][3] Laser wire 4-6 and hydrophilic wire, 7 have been developed and favorable results have been reported. Other than these guidewires, some Japanese products, such as the Athlete, Miracle, and Conquest wires (Asahi Intecc, Seto, Japan), 8 are used in some countries and constitute a range of stiff products. In particular, the Conquest wire is a tapered spring coil wire with a very stiff tip (9 g) that gives good torque control and penetrating ability even in hard fibrous plaque. This type of guidewire may be the last choice for uncrossable, very old CTOs. 8 Although the Athlete wires will advance into a false lumen at the end of the procedure in unsuccessful cases, we can also use them to penetrate the flap to re-enter the true lumen as a second step.Coronary angiography is limited as a guide for guidewire crossing in PCI for CTOs. On the other hand, by showing the cross-sectional anatomy of the coronary vessels, intravascular ultrasound (IVUS) can provide information on the plaque morphology and distribution, 9 and the exact location of the guidewires within a coronary artery, discriminating a false lumen from the true lumen before guidewire crossing. We report here a novel application of IVUS for very old and hard CTOs (abrupt occlusion with a side branch in case 1 and bending occlusion with severe calcification in case 2) in which the use of very stiff guidewires caused dissections, decreasing the collateral flow.
Case Reports
Case 1: Side Branch MethodA 68-year-old Japanese man had experienced chest oppression on effort since May 2000. He visited hospital in July 2000, and coronary angiography revealed a CTO in the proximal segment of the large left circumflex coronary artery (LCX). There was no significant stenosis in the left anterior descending coronary artery (LAD) or the right coronary artery (RCA). His coronary arteries were left dominant. He had not had any episodes suggestive of acute myocardial infarction. Cardiac catheterization revealed left ventricular dysfunction and moderate mitral regurgitation. PCI for the CTO was unsuccessful at that time. He was treated medically and his condition improved. However, he complained of chest oppression on effort again in October 2001. We attempted to re-open the CTO of the LCX. The age of this CTO was unknown, but was thought to be more than 18 months, based on the angiographic record. We obtained the consent of the patient after fully explaining the efficacy and risks associated with our new technique using IVUS before the PCI.The occlusion was severely calcified and flush with the orifice of the vessel, tapering nicely into a large obtuse marginal artery (Fig 1a). A 10Fr JCL 4.0 with a side hole (Bright Chip, Cordis, Miami, FL, USA) was used in order to prepare for the possible use of a rotablator with a 2.5-mm burr. A 2.9Fr IVUS catheter (Ultracross, Boston Sci...
