Microcatheter-facilitated reverse wire technique for side branch wiring in bifurcated vessels: an in vitro evaluation

To assess when and how the microcatheter-facilitated reverse wire technique should be applied to cross the guidewire into side branches in coronary bifurcations.

Three interventional cardiologists with different levels of experience performed in vitro bench testing using an originally developed coronary bifurcation simulator which had six coronary bifurcations. The bifurcation angles were 90, 105, 120, 135, 150 and 165 degrees (°). Experiment 1 was conducted to assess in what coronary bifurcation the reverse wire technique is required. Antegrade guidewire advancement was conducted with two different guidewires: the spring coil guidewire SION blue and the polymer-jacket hydrophilic guidewire Fielder FC. Experiment 2 was conducted to determine what the optimal guidewire selection and the optimal guidewire shape for the reverse wire technique would be. Assessment of the guidewire crossability into the highly angulated side branch was performed, and then the balloon crossability was assessed. A total of four guidewire types were compared in experiment 2. In experiment 1, guidewire crossing was impossible by conventional antegrade wiring when the bifurcation angle became 150° or more. In experiment 2, guidewire crossing of more than 150° of bifurcation angle was achievable independent of the guidewire types and shape. Balloon deliverability was best when using a polymer-jacket hydrophilic guidewire with a round shape 3 cm from the guidewire tip.

Although the guidewire crossing into the side branch was impossible by conventional antegrade methods when the bifurcation angle became 150° or more, the guidewire crossing into such a highly angulated side branch was easily possible using the reverse wire technique. The optimal guidewire selection for the reverse wire technique is the polymer-jacket hydrophilic guidewire with a round shape 3 cm from the guidewire tip.