Coronary chronic total occlusions (CTOs) are defined as coronary lesions with Thrombolysis in Myocardial Infarction (TIMI) grade 0 flow of at least 3 months in duration. Coronary CTOs are common, being encountered in approximately 1 in 3 patients who are found to have coronary artery disease during coronary angiography (range, 18%-52%; Table 12-1).^1-5 Numerous patients with CTOs have complex coronary artery disease and are referred for coronary artery bypass graft surgery (CABG), but many are referred for percutaneous coronary intervention (PCI).

The main indication for CTO PCI is to improve symptoms^6,7 and decrease the need for antianginal medications. Successful CTO PCI can improve exercise capacity,⁸ decrease the need for CABG, improve left ventricular systolic function,^9-18 and decrease the risk for arrhythmias.¹⁹ Several studies and meta-analyses have demonstrated that patients who underwent successful CTO PCI had lower mortality compared with patients in whom CTO PCI attempts were unsuccessful (Figure 12-1).^7,20-22 This could at least in part be related to achievement of more complete revascularization,^23,24 as CTOs are the most common reason for not achieving complete coronary revascularization. Despite these potential benefits, CTO PCI is infrequently attempted due to concerns about procedural success and complications, as well as limited data from randomized controlled trials.

CTO recanalization can be challenging and requires careful planning. CTO PCI should, in most cases, not be performed at the same time as diagnostic angiography for a number of reasons: (1) to reduce the radiation and contrast dose; (2) to allow discussion with the patient and the family about the risks, goals, benefits, and alternatives of the procedure; and (3) to allow detailed review of the coronary angiogram.

Figure 12-2 outlines some essential components of planning for CTO PCI. Although high success rates can be achieved using radial access,²⁵ CTO PCI is best performed using femoral access with bilateral 8-Fr, 45-cm-long sheaths. Eight-French guide catheters provide excellent support and enable equipment exchanges using the trapping technique. Excellent guide catheter support is important for CTO PCI and can be achieved using large, supportive shape guide catheters, guide catheter extensions, and other techniques, such as the side branch or distal anchoring.^26-28 The AL1 guide is most commonly used for the right coronary artery, and the XB 3.5 or EBU 3.75 is most often used for the left main coronary artery. Unfractionated heparin is preferred for anticoagulation because it can be reversed in case of complication; radiation dose is monitored carefully throughout the procedure, and equipment (covered stents and coils) is available to treat coronary perforations.

CTO PCI requires use of standard and specialized equipment that can be grouped into 10 categories (Table 12-2). An over-the-wire system should be used in all cases, ideally using a microcatheter, such as the Corsair (Asahi Intecc, Nagoya, Japan; Figure 12-3), Turnpike (Vascular Solutions, Minneapolis, MN; Figure 12-4), or Finecross (Terumo, Somerset, NJ; Figure 12-5). Use of an over-the-wire system allows easy guidewire exchanges and enhances their support. Several types of guidewires can be used, but many operators preferentially use the following types (Figure 12-6)²⁹:

1. 
   

   Fielder XT (Asahi Intecc; Figure 12-7): Soft polymer-jacketed, tapered wire for initial antegrade crossing via microchannels

   
   
2. 
   

   Gaia Second (Figure 12-8) and Confianza Pro 12 (Asahi Intecc, Figure 12-9): Stiff, tapered-tip, penetrating wires for subsequent attempts, if the course of the vessel is well understood

   
   
3. 
   

   Pilot 200 (Abbott Vascular, Santa Clara, CA; Figure 12-10): A polymer-jacketed and moderately stiff, nontapered tip wire, when the course of the target lesion and vessel is not well understood

   
   
4. 
   

   Sion (hydrophilic, highly torquable, soft guidewire with excellent shape retention; Asahi Intecc; Figure 12-11) or Fielder FC (polymer-jacketed soft wire; Asahi Intecc; see Figure 12-7) for wiring collaterals during retrograde crossing

   
   
5. 
   

   RG3 (Asahi Intecc; Figure 12-12): A 330-cm-long guidewire designed for externalization when the retrograde approach is used

Specialized dissection/reentry equipment includes the CrossBoss catheter (Figure 12-13) and the Stingray system (Figure 12-14) (Boston Scientific, Natick, MA). Additional equipment includes low-profile balloons, laser, and rotational atherectomy for “balloon uncrossable” and “balloon undilatable” lesions. Use of intravascular ultrasonography can facilitate CTO crossing and stent optimization. Availability of covered stents and coils is important for treating perforations. Collecting all CTO PCI equipment in a single location (CTO cart) can facilitate access to the equipment and improve efficiency of the procedure.