What are the common guidewire techniques for CTO lesions?

It is when the guide catheter is difficult to fixate, firstly, one guide wire passes through the branch vessels of the lesion more easily, which serves to fixate the guide catheter, and then another guide wire is introduced into the CTO.2. parallel wire technique: Parallel guide wire technique. It means that when the guidewire enters the false lumen, the guidewire is retained in the false lumen as a signpost, and then a second guidewire is inserted. 3. seesaw technique: seesaw guidewire technique. This refers to the use of parallel guidewires while using two OTW balloons or microcatheters, if the second guidewire can not enter the true lumen, retain the guidewire as a signpost, through the first microcatheter for the appropriate guidewire, and repeatedly alternating until the passage of the CTO. 4. side branch technique: the side branch technique. When the former guidewire cannot pass CTO, another guidewire is inserted into the side branch vessel near the CTO lesion to the distal end, expanding the entrance of the side branch vessel of the CTO lesion in order to squeeze the proximal plaque of the lesion, and then adjusting the first guidewire to pass through the CTO lesion.5. Subtimal tracking and rentry: STAR technique for short. This refers to when the guidewire enters the false lumen, attempts to re-enter the true lumen of the vessel at the distal end of the false lumen, often forming a loop in the false lumen with the tip of the guidewire, forming a blunt detachment in front of one of the branches, and often using an OTW balloon at the same time, and then maneuvering the guidewire into the true lumen of the vessel. 6. retrograde kissing wire technique: The retrograde guidewire-to-kissing technique. It refers to the retrograde delivery of the guidewire to the distal end of the occluded lesion through the collateral circulation vessels, using the retrograde guidewire as a signpost to maneuver the anterior guidewire and the retrograde guidewire to hold each other tightly, and pass through the occluded segment under the guidance of the retrograde guidewire.