Interventional guidewires are manufactured in three distinct layers: the first layer is called the shaft, which is usually made from stainless steel; the second layer is the coil, which needs to be flexible and resistant (for this reason the coil is usually made of platinum); and the final layer is the coating, which is usually made of silicone or another polymer in order to avoid puncturing the lumen, thus facilitating the insertion of the device. Manufacturers are continually improving the structure, design and construction of guidewires. These improvements are creating more robust and flexible devices, which are becoming popular amongst physicians, particularly during interventions involving a chronic total occlusion (CTO). In addition, there is a shift towards the use of hydrophilic guidewires. While hydrophilic guidewires are more expensive, they have more flexibility and fluidity, making them useful in delicate procedures, particularly in procedures where a CTO needs to be crossed.
Interventional guidewires are often the first type of device to cross an arterial lesion. For this reason, the choice of guidewire is extremely important in order for a procedure to be successful. Interventional guidewires used for coronary applications can be classified into two general types: conventional and specialty guidewires. While conventional guidewires are used for the most common types of procedures, specialty guidewires are used in cases where the lumen is occluded and a conventional guidewire is unlikely to be successful.