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Learning objectives If you want to understand the technical parameters behind the physical characteristics of the guidewires
If you want to get familiar with case-tailored guidewire selection
If you want to learn about tricks and tips of guidewire manipulation.
Curriculum topic: Interventional cardiology
Percutaneous balloon dilatation, first described by Andreas Gruentzig in 1979, was initially performed without the use of guidewires. 1 The prototype balloon catheter was developed as a double lumen catheter (one lumen for pressure monitoring or distal perfusion, the other lumen for balloon inflation/deflation) with a short fixed and atraumatic guidewire at the tip. Indeed, initially the technique involved advancing a rather rigid balloon catheter freely without much torque control into a coronary artery. Bends, tortuosities, angulations, bifurcations, and eccentric lesions could hardly, if at all, be negotiated, resulting in a rather frustrating low procedural success rate whenever the initial limited indications (proximal, short, concentric, non-calcified) were negated. 2 Luck was almost as important as expertise, not only for the operator, but also for the patient. It is to the merit of Simpson who, in 1982, introduced the novelty of advancing the balloon catheter over a removable guidewire, which had first been advanced in the target vessel. 3 This major technical improvement resulted overnight in a notable increase in the procedural success rate. Guidewires have since evolved into very sophisticated devices. Although they all may look alike from the outside, wires are widely different in their materials, internal structure and design, hence, their wide diversity in function. 4 Wiring is of course only one, but not the least, of several steps in coronary intervention, yet the attention given to wire selection is often superficial.
This article is aimed at understanding the way wires are constructed, how this influences their specifications, and how to select them for a given purpose. We propose to cover first the technical aspects of guidewires, followed by a rational approach for wire selection.
Structure of guidewires
Basically, guidewires consist of four major components: the core, the wire tip, the body, and finally the coating of the system ( figure 1 ). There are a few key elements of the structure that need to be understood in detail, before we address the different types of devices. The proper specifications...