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| Basic Wire-Handling Strategies for Chronic Total Occlusions | 2/10
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To achieve good handling of the wire once it is inside a CTO, use a balloon catheter or wire delivery catheter (such as Transit®, Interpass® or the Multifunction Probing Catheter®) that allows the wire to move freely. Maneuverability of the wire may be complicated by natural tortuosity in the shape of the artery at the access point (whether one uses the brachial or femoral approach), by tortuosity or the angle of bifurcation at the entry to the coronary artery or the shape of the coronary artery leading up to the lesion. Tortuosity in the iliac or abdominal arteries can also lead to reduced maneuverability. In a tortuous iliac artery, a large caliber 10-12 Fr long sheath can be used to stretch and straighten the vessel and maintain maneuverability. One can even double-up by placing an 8Fr long sheath inside the 10-12 Fr one. Another option is to attempt an approach from the opposite side of the body, left or right. When using an approach from the right brachial or right radial arteries, even minor tortuosity may contribute to reduced maneuverability, and switching to the left side often solves the problem. Always bear in mind that even in vessels that would present no problems for usual PTCA wires, CTO wires face more obstacles on their way to the lesion. When you have difficulty steering the wire through, you may need to check that the guide catheter itself is straight and not bent at some point.
Another cause of poor guide wire maneuverability is when the right coronary artery arises anteriorly and leftward from the right Valsalva sinus and courses towards the atrioventricular sulcus at a very sharp angle. When the LMT branches out from the aortic posterior wall, it may be impossible to insert a guidewire along the vessel. When this happens, the wire is often severely bent at the ostium and maneuverability severely inhibited. To counter this, when the lesion is distal and there is no lesion in the proximal portion, insertion of a 5Fr or 6Fr guide catheter deep into the coronary artery can prevent any dangerous bending at the ostium. When the lesion is proximal, or when for some reason the guide catheter cannot be inserted deep into the coronary artery, a support wire can be used in parallel, inserted to the bifurcation immediately before the occluded portion, and the guide catheter brought properly into line. Alternatively, try the technique of inserting a 5Fr or 6Fr guide catheter through a 7Fr or 8Fr “parent” guide catheter. In all of these cases, care must be taken not to injure the LMT or the proximal portions of LAD or Circumflex arteries.
For good stable wire handling, the guide catheter needs to be stable. Instability is particularly a problem with Judkin’s right (JR) in the RCA, and to a lesser extent, JL in the LCA. When the guide catheter cannot be placed deep into the artery, the result may be that it is not very stable, and keeps falling into the Sinus of Valsalva while during wire maneuvers. I advise changing to other kinds of guide catheters as soon as possible. For the RCA, the best choices are Amplatz left (AL1 or AL1.5) - you must use a guide catheter with side-holes., Hockey Stick, or when the lesion is ostial, a short tip AL2. One word of warning is that there is a higher risk of vessel injury at the ostium with an AL, as compared to a JR. Because of the bent shape of the AL catheter, it is not possible to avoid reduced wire maneuverability, With the improved overall maneuverability that the stiff CTO wires offer, this is no longer a serious drawback. Bear in mind though that when co-axial alignment to the RCA ostium cannot be achieved, the shape of the AL will make it considerably less maneuverable than the JR. In most cases the RCA originates from the anterior upper portion of the right Valsalva Sinus, and torquing the AL catheter in a clockwise direction will improve coaxial alignment. Advancement of the balloon or your Transit catheter into the coronary artery may mitigate problems with poor guiding catheter alignment. When back-up force from the guide catheter acts against the balloon catheter, torquing the JR catheter in a clockwise direction and at the same time changing the shape of the catheter inside the Sinus of Valsalva usually secures it. This does not work for securing the position of the guide cath for CTO wire-handling. It is better to exchange the guide catheter. In the LCA, the most common choices to switch to are the Voda or XB type, AL1, AL1.5 or AL2.0 (especially for the LCX).
Scenarios where the guide catheter causes problems for wire maneuverability are principally CTOs in the ostial LAD, and CTOs in LCX with very sharp bifurcation angles. For CTOs in the ostial LAD, and when the bifurcation of the LAD from the LMT is at a wide angle, short tip JL and AL shapes are best. When the LMT bifurcates posteriorly, an AL will usually be the best option. When it is hard to get the wire into the CTO, even with back-up from the balloon catheter, the best strategy is to bring the tip of a short-tip JL right up to the mouth of the CTO, where back-up and direction from the guide catheter can often be used to good effect, especially with a 7Fr catheter. Even when the LAD deviates sharply from the course of the LMT, a similar technique will usually work. When the LCX bifurcates at a very sharp angle, the best method is to use an AL1.5 or AL 2.0 (with side-holes), pull the catheter back slightly and try to direct the tip into the LCX. Whatever the situation, this is the best way to get the guide catheter coaxial.
Bends or tortuosity of the vessel proximal to the CTO lesion adversely affects maneuverability of guide wires. From my experience, this is especially true in CTOs in the RCA and LCX. One possible solution is to stretch and straighten the bends in the vessel. Usually, just inserting a balloon catheter into the vessel will stretch it sufficiently to improve wire maneuverability. In some cases, where bends are especially tortuous or heavy calcification reduces vessel elasticity, the balloon catheter will bend and the wire lumen will be squashed, and in some instances, wire maneuverability is considerably diminished. When this happens, either 1) change the balloon catheter for a Transit, 2) use a wire with a hydrophilic-coating, 3) use a support wire in parallel to try to force the vessel to stretch and straighten. In all these cases, correctly identifying the conditions beforehand by coronary angiography is extremely important.
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