Radial artery access should be obtained per common practices. The wrist should be retroflexed during access with a micro-puncture kit or an angiocath and a 0.035″ straight tip guide wire. The preferred right arm position for CTO PCI from the right radial artery is next to the patient because the operator needs to stay close to the patient to reach the other access in the left radial artery. The left radial artery access poses ergonomic difficulties, because most operators stand on the right side of the patient and have to reach over the patient; otherwise, the patient’s left arm should be pulled to the right side close to the operator. Currently, there are no good available systems to keep the left arm in position close to the operator on the right side of the patient. The left arm tends to fall away from the operator standing on the right side of the patient causing discomfort to the patient, and/or the operator. One solution to the left arm positioning problem is to pull the arm to the right side of the patient using an arm restraint that is tied to the right side of the cath lab table (Fig. 13.1). The patient sometimes tends to bend the left elbow, which will pull the guiding catheter away from the operator and decrease equipment-control; left elbow orthopedic immobilizer will keep the left elbow straight and facilitate the manipulation of the left arm guiding catheter and the interventional gear from the same side. Placing a pillow to prop the left arm up might keep the arm close to the operator standing on the right side of the catheterization table. Until we find better techniques to keep the left arm of the patient pulled close to the right side toward the operator, it is easier to position both arms next to the patient after obtaining access (Fig. 13.2). However, reaching over the patient to the left wrist might be difficult in obese patients with large abdomens. The patient’s hands should be placed in a natural position after obtaining access to avoid discomfort to the patient during lengthy CTO PCI procedures.

Because the CTO PCI frequently requires the use of multiple devices simultaneously in one guiding catheter [6], it is important to use the largest sheath that can fit in the radial artery when obtaining radial artery access for CTO PCI for the antegrade side. While most patients tolerate a 6 Fr sheath, 7 or 8 Fr sheaths can sometimes be used for CTO PCI from the RA access. Studies showed that hydrophilic sheaths are easier to insert in the radial artery with less risk of entrapment [15]. However, the outer diameter of commercially available sheaths is considerably larger than the outer diameter of the corresponding size guiding catheter. If the patient cannot tolerate a large sheath, a thin wall sheath, or ad hoc or dedicated sheathless guiding catheters can be used. Thin wall sheaths are now commercially available, with smaller outer diameter than the same French size conventional sheath; the outer diameter of a 6 Fr thin wall sheath is similar to the outer diameter of a conventional 5 Fr sheath (Fig. 13.3). Patients might have better tolerance if the sheath outer diameter is smaller or the guiding catheter is introduced without an introducer sheath. Moreover, it may prevent subsequent radial artery occlusion, a benign complication, yet precluding future access from the occluded site.

Unlike in femoral artery access, longer sheaths do not provide incremental support from the radial artery access and might increase patients’ discomfort and the risk of sheath entrapment at the end of the procedure. Therefore, the preferred sheath length for radial artery access is 13 cm or shorter. The sheath should not be forced in the radial artery if it encounters significant resistance; in this case, the sheath could be used despite being partly advanced in the radial artery, or the operator could use an ad hoc or predesigned sheathless guide catheter system, described later in this chapter.

The left hand tends to pronate during the procedure, which will hide the sheath from the operator. The left radial artery sheath might slip out of the artery unnoticed during the guiding catheter manipulation; thus the left radial artery sheath can be sutured to the skin or secured in place with adhesive material to prevent the sheath from slipping out of the radial artery.

Large guiding catheters with supportive configuration are needed to facilitate the use of multiple wires, balloons, and specialized devices simultaneously in one guiding catheter. The most important limitation during CTO PCI from a bilateral radial artery access is the need to use smaller guiding catheter size (6 Fr versus 7 or 8 Fr); otherwise, there should be few technical differences related to guiding catheter manipulation and patient positioning between CTO PCI from bilateral CFA accesses and bilateral RA accesses. Several CTO PCI techniques require simultaneous introduction of two or more devices in the same guiding catheter. Most commercially available devices fit simultaneously with other device in an 8 Fr guiding catheter. However, 7 Fr and 6 Fr guiding catheters are most commonly used during RA access CTO PCI. The choice of devices that can fit simultaneously inside 7 or 6 Fr guiding catheter is more complex, as listed in Table 13.2 [3].