Catheterization and Cardiovascular Interventions 00:00–00 (2014)
Interventional Rounds Chronic Total Occlusion Percutaneous Coronary Intervention Case Selection and Techniques for the Antegrade-Only Operator phane Rinfret,1* MD, SM, Dominique Joyal,2 MD, James C. Spratt,3 MD, Ste and Christopher E. Buller,4 MD Coronary chronic total occlusions (CTO) remain a difficult lesion subset to treat. Although CTOs are present at coronary angiography in 15–20% of patients, only a small fraction of eligible patients will be offered percutaneous treatment. Recent publications from centers with dedicated CTO programs using the full range of antegrade and retrograde techniques suggest success rates in the range of 90% even when little anatomic exclusion are used. However, many patients with clinically appropriate CTO targets have simpler anatomy that can predictably be managed without the selected skills and equipment. The purpose of this review is to provide skilled percutaneous coronary intervention operators who have not specialized in complex retrograde CTO techniques, an algorithm for the selection and antegrade management of appropriate CTO cases. Core equipment and techniques are discussed. VC 2014 Wiley Periodicals, Inc. Key words: chronic total occlusion; percutaneous coronary intervention; antegrade; complexity
INTRODUCTION
Coronary chronic total occlusions (CTO) remain a difficult lesion subset to treat. Despite many recent technical advances, the presence of a CTO remains a strong predictor of medical treatment or of referral for coronary bypass surgery [1,2]. Although CTOs are present at coronary angiography in up to 50% of patients, only a small fraction of eligible patients will 1
Institut Universitaire de Cardiologie et de Pneumologie de bec (Quebec Heart and Lung Institute), Universite Laval, Que Quebec, Canada 2 Jewish General Hospital, McGill University, Montreal, Quebec, Canada 3 Spire Edinburgh Hospitals and Spire Shawfair Park Hospital, Edinburg, United Kingdom 4 St-Michael’s Hospital, University of Toronto, Toronto, Canada. Conflict of interest: Dr. Rinfret has received speaker and proctorship honoraria from Boston Scientific (BridgePoint Medical), Abbott Vascular Canada, Medtronic Canada, and Terumo US. He currently holds research support for Medtronic Canada and Abbott Vascular Canada. Dr. Joyal has received speaker and proctorship honoraria from Boston Scientific (BridgePoint Medical). Dr. Spratt has C 2014 Wiley Periodicals, Inc. V
be offered percutaneous treatment, and moreover, this aspect of practice varies widely between centers [1–3]. The reasons for such low and variable rates of percutaneous treatment are several. Technical expertise, although in a new phase of dissemination, remains highly variable between centers and operators [4,5]. CTO percutaneous coronary intervention (PCI) may be considered a higher-risk procedure in many centers, although recent data describe a major cardiac received speaker and proctorship honoraria from Boston Scientific (BridgePoint Medical). Dr. Buller has received speaker and proctorship honoraria from Boston Scientific (BridgePoint Medical). *Correspondence to: Stephane Rinfret, MD, SM, FRCPC; Clinical and Interventional Cardiology, Multidisciplinary Cardiology Department, Quebec Heart and Lung Institute, Associate professor, Laval University, 2725, Chemin Ste-Foy, Quebec City, QC, Canada G1V 4G5. E-mail: [email protected] Received 3 April 2014; Revision accepted 14 July 2014 DOI: 10.1002/ccd.25611 Published online 00 Month 2014 in Wiley Online Library (wileyonlinelibrary.com)
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Fig. 1. An algorithm for the selection of the most likely successful approach in CTO PCI. Adapted from Brilakis ES, Grantham JA, Rinfret S, et al. JACC Cardiovasc Interv 2012;5:367–379.
complication rate of approximately 2–3% in such complex procedures [6]. Finally, time and resource constraints may contribute, particularly if prolonged CTO procedures are perceived to conflict with the laboratories obligation to provide timely primary PCI. Recent self-reported publications from centers with dedicated CTO programs using the full range of antegrade and retrograde techniques suggest success rates in the range of 90% even when little or no anatomic exclusion are used [7–11]. These centers of excellence are presently too few to accommodate the large number of patients who might benefit. Moreover, many patients with clinically appropriate CTO targets have simpler anatomy that can predictably be managed without the selected skills and equipment. The purpose of this review is to provide skilled PCI operators who have not specialized in hybrid CTO techniques, an algorithm for the selection and management of appropriate CTO cases. Core equipment and techniques are discussed. Case Selection
In recent years, the J-CTO registry [7], which included a large number of antegrade CTO procedures, has informed our understanding of the predictors of failure. The J-CTO score has emerged as a useful prediction tool for antegrade success within defined procedure times [12]. The score is composed of five easyto-remember factors; lesion length > 20mm, lesion angulation >45 , blunt proximal cap, calcification within the occluded segment, and a previous failed attempt. All factors count for 1 point. If the sum is 0– 1, the likelihood of antegrade crossing within 30 min was >80% and total success rate >80% in the original study. In patients with J-CTO score 2 or higher, the likelihood of procedural success decreases substantially. The score has recently been validated in an independent Canadian cohort. The prevalence of lesions with J-CTO scores of 0–1 referred to the CTO PCI program in Quebec City was 31%, highlighting that those “easy” CTOs are not rare and therefore constitute
an opportunity for operators to treat. Moreover, all CTOs with a J-CTO score of 0 were crossed within 30 min of wire working time and 71% in J-CTO score of 1 when an antegrade approach was selected. Finally, the final success rate was higher than 90% [13]. Such data therefore confirm the value of using the J-CTO score for guiding case selection for the antegrade-only operator. The North-American algorithm to CTO-PCI was recently published [4]. This algorithm was proposed as a decision tool to not only plan the so-called hybrid procedure to improve success rates but also reduce time, contrast load, and radiation. We propose that this algorithm can also be used for appropriate case selection, as a complement to the J-CTO score, and triage more broadly, i.e., by non-CTO specialists and programs. Although CTO specialists use the algorithm to determine technical strategy and sequence, the same anatomic factors can be used to determine cases suitable for core antegrade techniques. The algorithm focuses on four simple variables (Fig. 1), three of which directly inform antegrade CTO techniques. First, the proximal cap (i.e., the inlet or interface between the patent lumen and occluded segment) occlusion is evaluated. For antegrade-only operators, this variable is pivotally important. A well-defined and clearly visualized proximal cap is desirable, allowing efficient guidewire-based engagement of the occlusion. If the proximal cap is difficult to identify by dedicated angiographic views, it is termed “ambiguous.” An ambiguous cap portends a low chance of primary success using antegrade techniques alone and constitutes the principal reason that specialist operators would select a primary retrograde approach. Referral directly to a specialized CTO operator is likely to avoid unnecessary radiation, procedural hazards, and costs. Second, the target segment distal to the occlusion should be evaluated. Distal target segments that are large, well-visualized, and free of important sidebranches arising in proximity to the distal cap are well-suited to a primary antegrade approach. If the target distal segment is severely diseased or poorly visualized, or if one or more important side branches arise near the distal cap (and are therefore at risk of being excluded from the reconstructed lumen), a primary retrograde approach should again be considered. Third, the occlusion length should be evaluated. Occlusions shorter than 20 mm generally favor a wirebased primary antegrade approach unless the proximal cap or the distal target is unfavorable. Lesions longer than 20 mm are associated with longer procedure times, higher uses of both radiation and contrast, and lower procedural success rates [12]. Most important for non-CTO specialists, long occlusions predict that
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
CTO PCI for antegrade operators
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TABLE I. Case-Selection Criteria for an Antegrade Wire-Based Strategy
Well-visualized proximal cap Presence of a partial or total microchannel in the CTO segment Minimal or no calcification Occlusion length 45 degrees within the CTO segment Suitable distal target No antegrade failed attempt
antegrade guide-wire passage beyond the distal end of the occlusion is likely to be accompanied by a subintimal wire position necessitating a lumen re-entry maneuver [4]. Because this cannot be predictably performed with guidewire manipulation alone, procedural success will depend upon skilled familiarity with equipment specifically designed for this purpose (CrossBoss and StingRay system, Boston Scientific, Boston, MA) or with retrograde techniques. Effective use of the CrossBoss and StingRay system requires however considerable training and experience and may be impractical even for highly skilled PCI operators who do not perform a large volume of CTO PCIs [14]. Finally, although the presence of collateral channels, their origins (they are typically multiple), and their suitability to serve as conduits for retrograde PCI is immediately pertinent for CTO specialists, it still remains important for nonspecialists when considering technical options and triage. The ability to visualize the distal target throughout a procedure is vitally important in achieving success because it is the most immediate and reliable way to determine wire tip position in relation to the distal lumen. Many occlusions have brisk antegrade flow from bridge collateral filling tempting operators to use a single catheter approach. Ipsilateral antegrade collaterals are frequently compromised during the course of antegrade vessel instrumentation and manipulation, resulting in progressive loss of antegrade filling and visualization of the distal target. Thus, insertion of a contralateral catheter is best performed before administration of heparin and before poor visualization leads to inadvertent disruption of the distal target by an unrecognized subintimal wire position. Few occlusions receive no contralateral flow such that a contralateral catheter is superfluous; most often, these are left coronary occlusions in a dominant left coronary system. Suitable collaterals can make anatomy that seems marginal or unpredictable for antegrade wire-based approaches well-suited and predictably successful for a primary retrograde approach. Early, reliable identification of such anatomy can improve process of care.
Yes
No
Antegrade Antegrade Antegrade Antegrade Antegrade Antegrade Antegrade
Retrograde Antegrade, retrograde, or antegrade dissection-reentry Antegrade, retrograde, or antegrade dissection-reentry Antegrade dissection-reentry or retrograde Antegrade dissection-reentry or retrograde Retrograde Retrograde or antegrade dissection-reentry
To summarize, integrating the J-CTO score and CTO PCI algorithm (Table I), the following anatomic criteria are proposed for selecting CTO cases suitable for antegrade attempt by nonhybrid antegrade-only operators: 1. A well-visualized proximal cap 2. Presence of a microchannel in the CTO segment, even if partial 3. Minimal calcification 4. Occlusion length 45 within the occluded segment 6. Suitable distal target 7. No concerted failed attempt Experienced antegrade-only PCI operators using these criteria are likely to deliver successful procedures and symptom relief to appropriate patients, and also efficiently identify patients for triage to a CTO specialist. The selection of such cases is likely to result in procedure time shorter than 60 min, which can be of paramount importance in centers that only have one catheterization room for example. This approach also makes more likely that clinical need (ischemic and symptom burden) rather than occlusion anatomy determines which patients are ultimately offered percutaneous treatment of a CTO. Anatomy should instead determine the technique(s) to be used, and by extension, the need for highly specialized expertise during the initial procedure. Equipment Required for Wire-Based Antegrade CTO PCI One of the important advancement of CTO PCI has been the refinement of microcatheters (Table II). For R antegrade CTO PCI, the Terumo FineCrossV (or equivR alent catheter as the Vascular Solution SuperCrossV) is well adapted for this environment. It is a lubricious microcatheter, which is highly flexible at the tip. A marker is present at the tip so the operator can precisely locate where the microcatheter is positioned.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
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TABLE II.
Two Microcatheters You Must Have on Your Shelf For Antegrade-Only CTO PCI
Type of microcatheter
Commercial name and manufacturer
Soft, all-comers microcatheter Stiff, screw-type microcatheter
FineCross (Terumo) Tornus (Asahi Intecc)
R
Alternatively, the Asahi CorsairV can serve the same purpose, but is more expensive. For antegrade procedures, the 135-mm CorsairV version can be used. It is a flexible microcatheter with a screw-like outside pattern, with a polymer inner lining that facilitates wire manipulation. Its outer diameter of 1 mm will help to dilate the CTO segment when advanced using alternative counterclockwise and clockwise rotations. For all operators, regardless of experience of CTO PCI, we strongly encourage use of a microcatheter to help traverse the occlusion and to facilitate rapid changes in wires or wire shaping. Guidewire technology has evolved substantially over the last 10 years. For a CTO with a low J-CTO score, plastic-jacketed guidewires are best suited for the initial attempt to cross the lesion. We would suggest limiting the antegrade CTO guidewire inventory to only four different guidewires, which will serve different purposes (Table III). The Asahi Fielder XTV guidewire is a plastic-jacketed guidewire with a 0.00900 tapered and soft tip (1 g). This wire is currently the ideal wire to start probing less complex CTO plaques. The next important wire is the Abbott Pilot 50V guidewire. This relatively soft 1.5 g plastic jacketed guidewire has a regular 0.01400 nontapered tip and is best suited to cases with a tapered proximal cap and a partial or completely visible microchannel (often called “functional CTOs”). The Abbott Pilot 200V guidewire is another wire of choice for antegrade cases. It is again a plastic-jacketed guidewire with a nontapered tip, but with a tip load of 4.7 g. This wire provides the extra force to penetrate the last few millimeters of a CTO distal segment and would be the next wire to try if the Fielder XT fails to penetrate the CTO proximal cap. The Pilot 200 is the best wire to travel within the occluded segment with the support of the microcatheter. Such a wire in unlikely to perforate the vessel, but can easily penetrate the subintimal planes. Finally, the Asahi Confianza Pro 12V completes the four-wire family. It is a 12-g nonjacketed wire with a 0.00900 tapered tip. The main role of this wire is to penetrate a hard proximal cap, or to precisely advance the guidewire into the distal true lumen. This wire should always be advanced when the course of the vessel is clearly understood, because its powerful penetration power can lead to vessel perforation. As such, no one should advance this wire without a clear visualization R
R
R
R
R
When to use it For almost all CTOs When wire crossed but not the microcatheter
of the distal cap. We think that limiting the number of wires will help the operator to get confidence and improve understanding with the behavior and tactile feedback of each wire. We acknowledge that other wires can have a role in CTO PCI, but expanding the inventory has limited value over understanding how wires should be shaped or used. Techniques for Successful Antegrade Wiring Strategy
It is our belief and experience that the most common reasons for failure in CTO PCI include: 1. The use of only one antegrade guiding catheter, without contralateral injections to visualize the distal target 2. The performance of excessive antegrade injections leading to dissections, vessel hematomas, and perforation 3. Wrong and excessively long curve at the tip of the CTO guidewire 4. Wrong guidewire selection (too soft or too stiff) for the type of lesion attempted 5. Finally, misunderstanding of the probability to succeed in complex cases that would mandate a primary antegrade dissection-reentry technique or a retrograde approach After selecting the appropriate case with the previously mentioned criteria, the operator will have to set the stage for success. Ad hoc CTO PCI is strongly discouraged because it does not allow enough time to understand periprocedural complexity, to adequately consent patients, or to define the strategy most likely to succeed. Such a detailed analysis, including the calculation of a J-CTO score and review of the algorithm is unlikely to be well done under the pressure of an ad hoc setting. As said earlier, we cannot overstate the importance of dual access in nearly all cases, with the possible exception of ipsilateral collaterals; but even in some circumstances, there may be recruitable collaterals from the contralateral side. Use of supportive guides is recommended, from the antegrade approach. As experienced transradial operators have proved that CTO–PCI is feasible through 6F [11], we believe that the choice
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
CTO PCI for antegrade operators TABLE III.
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Four Wires You Must Have on Your Shelf for Antegrade-Only CTO PCI
Type of wire
Commercial name and manufacturer 00
Tip load
When to use it First wire for antegrade crossing, with favorable cap Antegrade approach through visible or invisible channels Antegrade crossing, especially when the course of the occluded vessel is less clear Antegrade crossing when vessel course is known
Tapered (0.009 ), polymer-jacketed soft wire Non-tapered (0.01400 ), polymerjacketed soft wire Non-tapered (0.01400 ’), polymerjacketed stiffer wire
Fielder XT (Asahi Intecc)
1.0 g
Fielder FC (Asahi Intecc) OR Pilot 50 (Abbott Vascular) Pilot 200 (Abbott Vascular)
1.5 g
Tapered (0.00900 ), Open coils, No polymer jacket but hydrophilic coating
Confianza Pro 12 (Asahi Intecc)
12 g
4.7 g
Fig. 3. Typical CTO guidewire tip shaping. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.] Fig. 2. Table set-up for careful manifold identification. A red sticker is place on the antegrade manifold, and a yellow on the retrograde one. Corresponding colors are used for the pressure curves. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
of 6, 7, or 8 Fr should be a matter of operator’s preference, acknowledging that the selection process proposed here reduces the likelihood of requiring the larger space and support provided by 8F catheters. However, catheter curves that provide good passive support should be preferred over the ones that require active support, often impossible to perform in CTO– PCI before guidewire crossing. For example and irrespective of the size (6–8F) or the approach (radial or femoral), we think the best curve for the right coronary artery (RCA) is the AL0.75 or AL 1. For a left circumflex (LCX) CTO, AL2 curves are often effective. For left anterior descending (LAD) CTO, XB curves should be favored. On the contralateral side, a 5-Fr diagnostic catheter is sufficient for those cases, as it serves for contralateral visualization only. It is a good opportunity to use the radial approach for this contralateral catheter and benefit from reduced bleeding risk. Pressure curves and manifolds should be carefully identified at the table (Fig. 2). For example, we like to
use the red color for the antegrade guide pressure and put a red sticker on the injector. For the retrograde diagnostic catheter, one can use a different color, with a matched sticker to avoid accidental antegrade injection where retrograde injection was intended. Antegrade injections should be avoided if possible to avoid propagation of hydraulic dissection. In addition, antegrade injection may turn a benign guidewire perforation into an uncontrolled contrast-induced perforation. For these reasons, retrograde injections are best to guide wire manipulation throughout the attempt, keeping in mind that the volume of contrast need to be tracked. Furthermore, for those laboratories using automatic injectors, it should never be put on the antegrade catheter. However, its use on the retrograde side is appropriate. At the beginning, a dual injection should be performed, with the retrograde first followed by the antegrade. This will first confirm if the selected strategy based on single injections is still adequate for the CTO. Often, the CTO length is overestimated with single injections, and it is not rare to find a patent microchannel with dual injection, that will considerably ease the procedure. For LAD CTOs, RAO cranial views are best for the attempt, whereas left anterior oblique
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
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Fig. 4. Trapping technique. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
(LAO) views are best suited for RCA CTOs. For LCX CTOs, LAO and AP caudal are most helpful. Once the dual injection is done, the microcatheter is advanced in the guide catheter, with a workhorse guidewire inside. Once at the tip of the guide, the workhorse wire is manipulated in the proximal CTO vessel up to the proximal cap, and the microcatheter subsequently delivered. Because we are focusing on favorable cases for antegrade wiring strategies, the Fielder XT will usually be the first wire tried. As for all CTO wires, wire should be shaped with a 30–45 degree bend no more proximal than 1 mm of the tip (Fig. 3). This short bend will help the wire to negotiate the path of least resistance with torquing. Regarding the Fielder XT, attention should be paid to keep the tip freely moving with no buckling on the plaque, because this wire is soft. Of note, the Fielder XT provides absolutely no tactile feedback at the fingertip level; the operator has to rely solely on the fluoroscopic appearance of the wire. If this wire encounters resistance or enters the subintimal space, it is most likely to form a loop as a “knuckle”. Although such a knuckle wire can serve dissection and re-entry techniques, this should be avoided if aiming to cross from true lumen to true lumen, especially if the operator is not proficient with antegrade dissection-reentry techniques. If the Fielder XT fails to cross, the FineCross should be advanced within the CTO segment up to the point the Fielder stopped progressing. At this point, there will generally be two options for wires: Pilot 200 or Confianza Pro 12. We prefer the Pilot 200 if there is still more than 10 mm to the distal cap, especially if there is ambiguity about the course of the CTO segment, because this polymer-jacketed guidewire is less
likely to exit the vessel structure. Otherwise, if the FineCross is located within 10 mm of the distal cap, and the trajectory of the vessel is well understood, we favor the Confianza Pro 12. CTO wire manipulation is not a science but rather an art that requires practice. However, most CTO operators will agree that controlled drilling of the wire, either with or without torquing device, is the most likely to succeed. As a good principle in CTO PCI, wires and microcatheters are most efficiently advanced with a combination of rotation and push. Once the resistance to wire manipulation seems to release, it is critical not to advance the wire too far and to perform a retrograde injection, to confirm true lumen positioning of the wire. If the wire is not in the lumen, the microcatheter should be advanced just proximal to the distal cap, in the subintimal space, and a brief attempt to puncture the true lumen using a Confianza Pro 12 or a Pilot 200 should be attempted. Such a technique can be viewed as the simpler version of antegrade dissection and re-entry. We believe such a microcatheter-supported technique involving escalation or de-escalation of wires is the most efficient, and we currently do not use the parallel wire technique if the first wire fails to track the right channel. If true wire positioning is confirmed, the microcatheter should be advanced to the distal bed and the wire exchanged for a soft workhorse guidewire. Although it is tempting to confirm true lumen positioning with contrast injection through the lumen of the microcatheter, we strongly discourage such a risky step; if the microcatheter is sub-intimal instead, an uncontrolled contrast-induced dissection of the distal bed will result. It is simpler to confirm true lumen positioning with a
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
CTO PCI for antegrade operators
workhorse guidewire advanced freely in the distal bed, taking branches, and moving smoothly. If advancement of the workhorse wire seems problematic, the operator should recheck the microcatheter position with a retrograde injection as a subintimal position is likely. It is important to emphasize that the workhorse wire should not be polymer coated at the tip; spring-coiled wires such as the Abbott BMWV or the equivalent are much safer in this respect and will give better tactile feedback. In addition, it is imprudent to work on dedicated CTO wire for ballooning and stenting, as the back and forth movement with subsequent equipment manipulation on the wire can cause distal wire perforation. If the microcatheter cannot cross, it should be exchanged for a long (20 mm) 1.25 or 1.5 over-the-wire balloon to dilate the lesion. To remove the microcatheter, the use of a wire extension will be necessary, unless the catheter and device size allow for the performance of a trapping technique (Fig. 4). In 6F catheter, a 2.0 balloon can be used to trap a short 180-cm guidewire at the tip of the guide to remove a FineCross pulled more proximally, without having to extend the guidewire. If the Corsair was used antegradely but could not cross, wire extension may be required in 6F guide because of its larger external diameter (balloon trapping is feasible, but a tight fit), but wire trapping can be achieved using a 2.5-mm balloon in a 7-F guide and a 3.0-mm balloon in an 8-F guide. To penetrate the CTO, the use of long balloons in small sizes is preferable; the central balloon marker, which usually causes a small bump in the balloon profile, is positioned >10 mm back from the tip of the balloon, allowing for the balloon to better engage the lesion. If this step fails, the best results can be achieved with the Asahi TornusV device (Table III). This special eight-wire braided catheter comes in two versions, the 2.1F and 2.6F. The 2.1F size has the advantage of being compatible with a 6-F guide and of being able to be removed with a trapping balloon technique. The Tornus is advanced with up to 20 counterclockwise rotations that distract the wires and convert the rotation power into forward screw-like movement. Once across the lesion with a microcatheter, an overthe-wire balloon, or the Tornus, the wire can be exchanged for a workhorse guidewire or a RotablatorV wire if rotational atherectomy is considered. The Tornus will be removed from the plaque using continuous clockwise rotations. Once a workhorse wire is delivered distally, angioplasty and stenting will complete the procedure. R
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CONCLUSIONS
CTO–PCI remains underperformed in the western world because of a combination of perceived complex-
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ity and confusion of educational message. We think that antegrade-only operator can easily master the skills to perform successful and fast CTO recanalization in less complex CTO lesions such as the ones with a JCTO score of 0 or 1. From a population health standpoint, it would be desirable to see more interventionists treating simpler CTOs, as lower than 15% are currently attempted in North-America. However, it is also advisable that all antegrade-only operators can master the calculation of the J-CTO score, and be knowledgeable of the CTO PCI algorithm, to facilitate appropriate referral of cases which may require retrograde or antegrade dissection re-entry skillsets. REFERENCES 1. Christofferson RD, Lehmann KG, Martin GV, Every N, Caldwell JH, Kapadia SR. Effect of chronic total coronary occlusion on treatment strategy. Am J Cardiol 2005;95:1088– 1091. 2. Fefer P, Knudtson ML, Cheema AN, Galbraith PD, Osherov AB, Yalonetsky S, Gannot S, Samuel M, Weisbrod M, Bierstone D, et al. Current perspectives on coronary chronic total occlusions: The Canadian Multicenter Chronic Total Occlusions Registry. J Am Coll Cardiol 2012;59:991–997. 3. Grantham JA, Marso SP, Spertus J, House J, Holmes DR Jr., Rutherford BD. Chronic total occlusion angioplasty in the United States. JACC Cardiovasc Interv 2009;2:479–486. 4. Brilakis ES, Grantham JA, Rinfret S, Wyman RM, Burke MN, Karmpaliotis D, Lembo N, Pershad A, Kandzari DE, Buller CE, et al. A percutaneous treatment algorithm for crossing coronary chronic total occlusions. JACC Cardiovasc Interv 2012;5:367– 379. 5. Thompson CA. Percutaneous revascularization of coronary chronic total occlusions: The new era begins. JACC Cardiovasc Interv 2010;3:152–154. 6. Patel VG, Brayton KM, Tamayo A, Mogabgab O, Michael TT, Lo N, Alomar M, Shorrock D, Cipher D, Abdullah S, et al. Angiographic success and procedural complications in patients undergoing percutaneous coronary chronic total occlusion interventions: A weighted meta-analysis of 18,061 patients from 65 studies. JACC Cardiovasc Interv 2013;6:128–136. 7. Morino Y, Kimura T, Hayashi Y, Muramatsu T, Ochiai M, Noguchi Y, Kato K, Shibata Y, Hiasa Y, Doi O, et al. In-hospital outcomes of contemporary percutaneous coronary intervention in patients with chronic total occlusion insights from the JCTO Registry (Multicenter CTO Registry in Japan). JACC Cardiovasc Interv 2010;3:143–151. 8. Rathore S, Katoh O, Matsuo H, Terashima M, Tanaka N, Kinoshita Y, Kimura M, Tsuchikane E, Nasu K, Ehara M, et al. Retrograde percutaneous recanalization of chronic total occlusion of the coronary arteries: Procedural outcomes and predictors of success in contemporary practice. Circ Cardiovasc Interv 2009;2:124–132. 9. Thompson CA, Jayne JE, Robb JF, Friedman BJ, Kaplan AV, Hettleman BD, Niles NW, Lombardi WL. Retrograde techniques and the impact of operator volume on percutaneous intervention for coronary chronic total occlusions an early U.S. experience. JACC Cardiovasc Interv 2009;2:834–842. 10. Karmpaliotis D, Michael TT, Brilakis ES, Papayannis AC, Tran DL, Kirkland BL, Lembo N, Kalynych A, Carlson H, Banerjee
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S, et al. Retrograde coronary chronic total occlusion revascularization: Procedural and in-hospital outcomes from a multicenter registry in the United States. JACC Cardiovasc Interv 2012;5: 1273–1279. 11. Rinfret S, Joyal D, Nguyen CM, Bagur R, Hui W, Leung R, Larose E, Love MP, Mansour S. Retrograde recanalization of chronic total occlusions from the transradial approach: Early Canadian experience. Catheter Cardiovasc Interv 2011;78:366–374. 12. Morino Y, Abe M, Morimoto T, Kimura T, Hayashi Y, Muramatsu T, Ochiai M, Noguchi Y, Kato K, Shibata Y, et al. Predicting successful guidewire crossing through chronic total occlusion of native coronary lesions within 30 minutes: The J-
CTO (Multicenter CTO Registry in Japan) score as a difficulty grading and time assessment tool. JACC Cardiovasc Interv 2011;4:213–221. 13. Nombela-Franco L, Urena M, Jerez-Valero M, Nguyen CM, Ribeiro HB, Bataille Y, Rodes-Cabau J, Rinfret S. Validation of the J-chronic total occlusion score for chronic total occlusion percutaneous coronary intervention in an independent contemporary cohort. Circ Cardiovasc Interv 2013;6:635–643. 14. Michael TT, Papayannis AC, Banerjee S, Brilakis ES. Subintimal dissection/reentry strategies in coronary chronic total occlusion interventions. Circ Cardiovasc Interv 2012;5:729–738.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
Interventional Rounds Chronic Total Occlusion Percutaneous Coronary Intervention Case Selection and Techniques for the Antegrade-Only Operator phane Rinfret,1* MD, SM, Dominique Joyal,2 MD, James C. Spratt,3 MD, Ste and Christopher E. Buller,4 MD Coronary chronic total occlusions (CTO) remain a difficult lesion subset to treat. Although CTOs are present at coronary angiography in 15–20% of patients, only a small fraction of eligible patients will be offered percutaneous treatment. Recent publications from centers with dedicated CTO programs using the full range of antegrade and retrograde techniques suggest success rates in the range of 90% even when little anatomic exclusion are used. However, many patients with clinically appropriate CTO targets have simpler anatomy that can predictably be managed without the selected skills and equipment. The purpose of this review is to provide skilled percutaneous coronary intervention operators who have not specialized in complex retrograde CTO techniques, an algorithm for the selection and antegrade management of appropriate CTO cases. Core equipment and techniques are discussed. VC 2014 Wiley Periodicals, Inc. Key words: chronic total occlusion; percutaneous coronary intervention; antegrade; complexity
INTRODUCTION
Coronary chronic total occlusions (CTO) remain a difficult lesion subset to treat. Despite many recent technical advances, the presence of a CTO remains a strong predictor of medical treatment or of referral for coronary bypass surgery [1,2]. Although CTOs are present at coronary angiography in up to 50% of patients, only a small fraction of eligible patients will 1
Institut Universitaire de Cardiologie et de Pneumologie de bec (Quebec Heart and Lung Institute), Universite Laval, Que Quebec, Canada 2 Jewish General Hospital, McGill University, Montreal, Quebec, Canada 3 Spire Edinburgh Hospitals and Spire Shawfair Park Hospital, Edinburg, United Kingdom 4 St-Michael’s Hospital, University of Toronto, Toronto, Canada. Conflict of interest: Dr. Rinfret has received speaker and proctorship honoraria from Boston Scientific (BridgePoint Medical), Abbott Vascular Canada, Medtronic Canada, and Terumo US. He currently holds research support for Medtronic Canada and Abbott Vascular Canada. Dr. Joyal has received speaker and proctorship honoraria from Boston Scientific (BridgePoint Medical). Dr. Spratt has C 2014 Wiley Periodicals, Inc. V
be offered percutaneous treatment, and moreover, this aspect of practice varies widely between centers [1–3]. The reasons for such low and variable rates of percutaneous treatment are several. Technical expertise, although in a new phase of dissemination, remains highly variable between centers and operators [4,5]. CTO percutaneous coronary intervention (PCI) may be considered a higher-risk procedure in many centers, although recent data describe a major cardiac received speaker and proctorship honoraria from Boston Scientific (BridgePoint Medical). Dr. Buller has received speaker and proctorship honoraria from Boston Scientific (BridgePoint Medical). *Correspondence to: Stephane Rinfret, MD, SM, FRCPC; Clinical and Interventional Cardiology, Multidisciplinary Cardiology Department, Quebec Heart and Lung Institute, Associate professor, Laval University, 2725, Chemin Ste-Foy, Quebec City, QC, Canada G1V 4G5. E-mail: [email protected] Received 3 April 2014; Revision accepted 14 July 2014 DOI: 10.1002/ccd.25611 Published online 00 Month 2014 in Wiley Online Library (wileyonlinelibrary.com)
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Fig. 1. An algorithm for the selection of the most likely successful approach in CTO PCI. Adapted from Brilakis ES, Grantham JA, Rinfret S, et al. JACC Cardiovasc Interv 2012;5:367–379.
complication rate of approximately 2–3% in such complex procedures [6]. Finally, time and resource constraints may contribute, particularly if prolonged CTO procedures are perceived to conflict with the laboratories obligation to provide timely primary PCI. Recent self-reported publications from centers with dedicated CTO programs using the full range of antegrade and retrograde techniques suggest success rates in the range of 90% even when little or no anatomic exclusion are used [7–11]. These centers of excellence are presently too few to accommodate the large number of patients who might benefit. Moreover, many patients with clinically appropriate CTO targets have simpler anatomy that can predictably be managed without the selected skills and equipment. The purpose of this review is to provide skilled PCI operators who have not specialized in hybrid CTO techniques, an algorithm for the selection and management of appropriate CTO cases. Core equipment and techniques are discussed. Case Selection
In recent years, the J-CTO registry [7], which included a large number of antegrade CTO procedures, has informed our understanding of the predictors of failure. The J-CTO score has emerged as a useful prediction tool for antegrade success within defined procedure times [12]. The score is composed of five easyto-remember factors; lesion length > 20mm, lesion angulation >45 , blunt proximal cap, calcification within the occluded segment, and a previous failed attempt. All factors count for 1 point. If the sum is 0– 1, the likelihood of antegrade crossing within 30 min was >80% and total success rate >80% in the original study. In patients with J-CTO score 2 or higher, the likelihood of procedural success decreases substantially. The score has recently been validated in an independent Canadian cohort. The prevalence of lesions with J-CTO scores of 0–1 referred to the CTO PCI program in Quebec City was 31%, highlighting that those “easy” CTOs are not rare and therefore constitute
an opportunity for operators to treat. Moreover, all CTOs with a J-CTO score of 0 were crossed within 30 min of wire working time and 71% in J-CTO score of 1 when an antegrade approach was selected. Finally, the final success rate was higher than 90% [13]. Such data therefore confirm the value of using the J-CTO score for guiding case selection for the antegrade-only operator. The North-American algorithm to CTO-PCI was recently published [4]. This algorithm was proposed as a decision tool to not only plan the so-called hybrid procedure to improve success rates but also reduce time, contrast load, and radiation. We propose that this algorithm can also be used for appropriate case selection, as a complement to the J-CTO score, and triage more broadly, i.e., by non-CTO specialists and programs. Although CTO specialists use the algorithm to determine technical strategy and sequence, the same anatomic factors can be used to determine cases suitable for core antegrade techniques. The algorithm focuses on four simple variables (Fig. 1), three of which directly inform antegrade CTO techniques. First, the proximal cap (i.e., the inlet or interface between the patent lumen and occluded segment) occlusion is evaluated. For antegrade-only operators, this variable is pivotally important. A well-defined and clearly visualized proximal cap is desirable, allowing efficient guidewire-based engagement of the occlusion. If the proximal cap is difficult to identify by dedicated angiographic views, it is termed “ambiguous.” An ambiguous cap portends a low chance of primary success using antegrade techniques alone and constitutes the principal reason that specialist operators would select a primary retrograde approach. Referral directly to a specialized CTO operator is likely to avoid unnecessary radiation, procedural hazards, and costs. Second, the target segment distal to the occlusion should be evaluated. Distal target segments that are large, well-visualized, and free of important sidebranches arising in proximity to the distal cap are well-suited to a primary antegrade approach. If the target distal segment is severely diseased or poorly visualized, or if one or more important side branches arise near the distal cap (and are therefore at risk of being excluded from the reconstructed lumen), a primary retrograde approach should again be considered. Third, the occlusion length should be evaluated. Occlusions shorter than 20 mm generally favor a wirebased primary antegrade approach unless the proximal cap or the distal target is unfavorable. Lesions longer than 20 mm are associated with longer procedure times, higher uses of both radiation and contrast, and lower procedural success rates [12]. Most important for non-CTO specialists, long occlusions predict that
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
CTO PCI for antegrade operators
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TABLE I. Case-Selection Criteria for an Antegrade Wire-Based Strategy
Well-visualized proximal cap Presence of a partial or total microchannel in the CTO segment Minimal or no calcification Occlusion length 45 degrees within the CTO segment Suitable distal target No antegrade failed attempt
antegrade guide-wire passage beyond the distal end of the occlusion is likely to be accompanied by a subintimal wire position necessitating a lumen re-entry maneuver [4]. Because this cannot be predictably performed with guidewire manipulation alone, procedural success will depend upon skilled familiarity with equipment specifically designed for this purpose (CrossBoss and StingRay system, Boston Scientific, Boston, MA) or with retrograde techniques. Effective use of the CrossBoss and StingRay system requires however considerable training and experience and may be impractical even for highly skilled PCI operators who do not perform a large volume of CTO PCIs [14]. Finally, although the presence of collateral channels, their origins (they are typically multiple), and their suitability to serve as conduits for retrograde PCI is immediately pertinent for CTO specialists, it still remains important for nonspecialists when considering technical options and triage. The ability to visualize the distal target throughout a procedure is vitally important in achieving success because it is the most immediate and reliable way to determine wire tip position in relation to the distal lumen. Many occlusions have brisk antegrade flow from bridge collateral filling tempting operators to use a single catheter approach. Ipsilateral antegrade collaterals are frequently compromised during the course of antegrade vessel instrumentation and manipulation, resulting in progressive loss of antegrade filling and visualization of the distal target. Thus, insertion of a contralateral catheter is best performed before administration of heparin and before poor visualization leads to inadvertent disruption of the distal target by an unrecognized subintimal wire position. Few occlusions receive no contralateral flow such that a contralateral catheter is superfluous; most often, these are left coronary occlusions in a dominant left coronary system. Suitable collaterals can make anatomy that seems marginal or unpredictable for antegrade wire-based approaches well-suited and predictably successful for a primary retrograde approach. Early, reliable identification of such anatomy can improve process of care.
Yes
No
Antegrade Antegrade Antegrade Antegrade Antegrade Antegrade Antegrade
Retrograde Antegrade, retrograde, or antegrade dissection-reentry Antegrade, retrograde, or antegrade dissection-reentry Antegrade dissection-reentry or retrograde Antegrade dissection-reentry or retrograde Retrograde Retrograde or antegrade dissection-reentry
To summarize, integrating the J-CTO score and CTO PCI algorithm (Table I), the following anatomic criteria are proposed for selecting CTO cases suitable for antegrade attempt by nonhybrid antegrade-only operators: 1. A well-visualized proximal cap 2. Presence of a microchannel in the CTO segment, even if partial 3. Minimal calcification 4. Occlusion length 45 within the occluded segment 6. Suitable distal target 7. No concerted failed attempt Experienced antegrade-only PCI operators using these criteria are likely to deliver successful procedures and symptom relief to appropriate patients, and also efficiently identify patients for triage to a CTO specialist. The selection of such cases is likely to result in procedure time shorter than 60 min, which can be of paramount importance in centers that only have one catheterization room for example. This approach also makes more likely that clinical need (ischemic and symptom burden) rather than occlusion anatomy determines which patients are ultimately offered percutaneous treatment of a CTO. Anatomy should instead determine the technique(s) to be used, and by extension, the need for highly specialized expertise during the initial procedure. Equipment Required for Wire-Based Antegrade CTO PCI One of the important advancement of CTO PCI has been the refinement of microcatheters (Table II). For R antegrade CTO PCI, the Terumo FineCrossV (or equivR alent catheter as the Vascular Solution SuperCrossV) is well adapted for this environment. It is a lubricious microcatheter, which is highly flexible at the tip. A marker is present at the tip so the operator can precisely locate where the microcatheter is positioned.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
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TABLE II.
Two Microcatheters You Must Have on Your Shelf For Antegrade-Only CTO PCI
Type of microcatheter
Commercial name and manufacturer
Soft, all-comers microcatheter Stiff, screw-type microcatheter
FineCross (Terumo) Tornus (Asahi Intecc)
R
Alternatively, the Asahi CorsairV can serve the same purpose, but is more expensive. For antegrade procedures, the 135-mm CorsairV version can be used. It is a flexible microcatheter with a screw-like outside pattern, with a polymer inner lining that facilitates wire manipulation. Its outer diameter of 1 mm will help to dilate the CTO segment when advanced using alternative counterclockwise and clockwise rotations. For all operators, regardless of experience of CTO PCI, we strongly encourage use of a microcatheter to help traverse the occlusion and to facilitate rapid changes in wires or wire shaping. Guidewire technology has evolved substantially over the last 10 years. For a CTO with a low J-CTO score, plastic-jacketed guidewires are best suited for the initial attempt to cross the lesion. We would suggest limiting the antegrade CTO guidewire inventory to only four different guidewires, which will serve different purposes (Table III). The Asahi Fielder XTV guidewire is a plastic-jacketed guidewire with a 0.00900 tapered and soft tip (1 g). This wire is currently the ideal wire to start probing less complex CTO plaques. The next important wire is the Abbott Pilot 50V guidewire. This relatively soft 1.5 g plastic jacketed guidewire has a regular 0.01400 nontapered tip and is best suited to cases with a tapered proximal cap and a partial or completely visible microchannel (often called “functional CTOs”). The Abbott Pilot 200V guidewire is another wire of choice for antegrade cases. It is again a plastic-jacketed guidewire with a nontapered tip, but with a tip load of 4.7 g. This wire provides the extra force to penetrate the last few millimeters of a CTO distal segment and would be the next wire to try if the Fielder XT fails to penetrate the CTO proximal cap. The Pilot 200 is the best wire to travel within the occluded segment with the support of the microcatheter. Such a wire in unlikely to perforate the vessel, but can easily penetrate the subintimal planes. Finally, the Asahi Confianza Pro 12V completes the four-wire family. It is a 12-g nonjacketed wire with a 0.00900 tapered tip. The main role of this wire is to penetrate a hard proximal cap, or to precisely advance the guidewire into the distal true lumen. This wire should always be advanced when the course of the vessel is clearly understood, because its powerful penetration power can lead to vessel perforation. As such, no one should advance this wire without a clear visualization R
R
R
R
R
When to use it For almost all CTOs When wire crossed but not the microcatheter
of the distal cap. We think that limiting the number of wires will help the operator to get confidence and improve understanding with the behavior and tactile feedback of each wire. We acknowledge that other wires can have a role in CTO PCI, but expanding the inventory has limited value over understanding how wires should be shaped or used. Techniques for Successful Antegrade Wiring Strategy
It is our belief and experience that the most common reasons for failure in CTO PCI include: 1. The use of only one antegrade guiding catheter, without contralateral injections to visualize the distal target 2. The performance of excessive antegrade injections leading to dissections, vessel hematomas, and perforation 3. Wrong and excessively long curve at the tip of the CTO guidewire 4. Wrong guidewire selection (too soft or too stiff) for the type of lesion attempted 5. Finally, misunderstanding of the probability to succeed in complex cases that would mandate a primary antegrade dissection-reentry technique or a retrograde approach After selecting the appropriate case with the previously mentioned criteria, the operator will have to set the stage for success. Ad hoc CTO PCI is strongly discouraged because it does not allow enough time to understand periprocedural complexity, to adequately consent patients, or to define the strategy most likely to succeed. Such a detailed analysis, including the calculation of a J-CTO score and review of the algorithm is unlikely to be well done under the pressure of an ad hoc setting. As said earlier, we cannot overstate the importance of dual access in nearly all cases, with the possible exception of ipsilateral collaterals; but even in some circumstances, there may be recruitable collaterals from the contralateral side. Use of supportive guides is recommended, from the antegrade approach. As experienced transradial operators have proved that CTO–PCI is feasible through 6F [11], we believe that the choice
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
CTO PCI for antegrade operators TABLE III.
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Four Wires You Must Have on Your Shelf for Antegrade-Only CTO PCI
Type of wire
Commercial name and manufacturer 00
Tip load
When to use it First wire for antegrade crossing, with favorable cap Antegrade approach through visible or invisible channels Antegrade crossing, especially when the course of the occluded vessel is less clear Antegrade crossing when vessel course is known
Tapered (0.009 ), polymer-jacketed soft wire Non-tapered (0.01400 ), polymerjacketed soft wire Non-tapered (0.01400 ’), polymerjacketed stiffer wire
Fielder XT (Asahi Intecc)
1.0 g
Fielder FC (Asahi Intecc) OR Pilot 50 (Abbott Vascular) Pilot 200 (Abbott Vascular)
1.5 g
Tapered (0.00900 ), Open coils, No polymer jacket but hydrophilic coating
Confianza Pro 12 (Asahi Intecc)
12 g
4.7 g
Fig. 3. Typical CTO guidewire tip shaping. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.] Fig. 2. Table set-up for careful manifold identification. A red sticker is place on the antegrade manifold, and a yellow on the retrograde one. Corresponding colors are used for the pressure curves. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
of 6, 7, or 8 Fr should be a matter of operator’s preference, acknowledging that the selection process proposed here reduces the likelihood of requiring the larger space and support provided by 8F catheters. However, catheter curves that provide good passive support should be preferred over the ones that require active support, often impossible to perform in CTO– PCI before guidewire crossing. For example and irrespective of the size (6–8F) or the approach (radial or femoral), we think the best curve for the right coronary artery (RCA) is the AL0.75 or AL 1. For a left circumflex (LCX) CTO, AL2 curves are often effective. For left anterior descending (LAD) CTO, XB curves should be favored. On the contralateral side, a 5-Fr diagnostic catheter is sufficient for those cases, as it serves for contralateral visualization only. It is a good opportunity to use the radial approach for this contralateral catheter and benefit from reduced bleeding risk. Pressure curves and manifolds should be carefully identified at the table (Fig. 2). For example, we like to
use the red color for the antegrade guide pressure and put a red sticker on the injector. For the retrograde diagnostic catheter, one can use a different color, with a matched sticker to avoid accidental antegrade injection where retrograde injection was intended. Antegrade injections should be avoided if possible to avoid propagation of hydraulic dissection. In addition, antegrade injection may turn a benign guidewire perforation into an uncontrolled contrast-induced perforation. For these reasons, retrograde injections are best to guide wire manipulation throughout the attempt, keeping in mind that the volume of contrast need to be tracked. Furthermore, for those laboratories using automatic injectors, it should never be put on the antegrade catheter. However, its use on the retrograde side is appropriate. At the beginning, a dual injection should be performed, with the retrograde first followed by the antegrade. This will first confirm if the selected strategy based on single injections is still adequate for the CTO. Often, the CTO length is overestimated with single injections, and it is not rare to find a patent microchannel with dual injection, that will considerably ease the procedure. For LAD CTOs, RAO cranial views are best for the attempt, whereas left anterior oblique
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
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Fig. 4. Trapping technique. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
(LAO) views are best suited for RCA CTOs. For LCX CTOs, LAO and AP caudal are most helpful. Once the dual injection is done, the microcatheter is advanced in the guide catheter, with a workhorse guidewire inside. Once at the tip of the guide, the workhorse wire is manipulated in the proximal CTO vessel up to the proximal cap, and the microcatheter subsequently delivered. Because we are focusing on favorable cases for antegrade wiring strategies, the Fielder XT will usually be the first wire tried. As for all CTO wires, wire should be shaped with a 30–45 degree bend no more proximal than 1 mm of the tip (Fig. 3). This short bend will help the wire to negotiate the path of least resistance with torquing. Regarding the Fielder XT, attention should be paid to keep the tip freely moving with no buckling on the plaque, because this wire is soft. Of note, the Fielder XT provides absolutely no tactile feedback at the fingertip level; the operator has to rely solely on the fluoroscopic appearance of the wire. If this wire encounters resistance or enters the subintimal space, it is most likely to form a loop as a “knuckle”. Although such a knuckle wire can serve dissection and re-entry techniques, this should be avoided if aiming to cross from true lumen to true lumen, especially if the operator is not proficient with antegrade dissection-reentry techniques. If the Fielder XT fails to cross, the FineCross should be advanced within the CTO segment up to the point the Fielder stopped progressing. At this point, there will generally be two options for wires: Pilot 200 or Confianza Pro 12. We prefer the Pilot 200 if there is still more than 10 mm to the distal cap, especially if there is ambiguity about the course of the CTO segment, because this polymer-jacketed guidewire is less
likely to exit the vessel structure. Otherwise, if the FineCross is located within 10 mm of the distal cap, and the trajectory of the vessel is well understood, we favor the Confianza Pro 12. CTO wire manipulation is not a science but rather an art that requires practice. However, most CTO operators will agree that controlled drilling of the wire, either with or without torquing device, is the most likely to succeed. As a good principle in CTO PCI, wires and microcatheters are most efficiently advanced with a combination of rotation and push. Once the resistance to wire manipulation seems to release, it is critical not to advance the wire too far and to perform a retrograde injection, to confirm true lumen positioning of the wire. If the wire is not in the lumen, the microcatheter should be advanced just proximal to the distal cap, in the subintimal space, and a brief attempt to puncture the true lumen using a Confianza Pro 12 or a Pilot 200 should be attempted. Such a technique can be viewed as the simpler version of antegrade dissection and re-entry. We believe such a microcatheter-supported technique involving escalation or de-escalation of wires is the most efficient, and we currently do not use the parallel wire technique if the first wire fails to track the right channel. If true wire positioning is confirmed, the microcatheter should be advanced to the distal bed and the wire exchanged for a soft workhorse guidewire. Although it is tempting to confirm true lumen positioning with contrast injection through the lumen of the microcatheter, we strongly discourage such a risky step; if the microcatheter is sub-intimal instead, an uncontrolled contrast-induced dissection of the distal bed will result. It is simpler to confirm true lumen positioning with a
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
CTO PCI for antegrade operators
workhorse guidewire advanced freely in the distal bed, taking branches, and moving smoothly. If advancement of the workhorse wire seems problematic, the operator should recheck the microcatheter position with a retrograde injection as a subintimal position is likely. It is important to emphasize that the workhorse wire should not be polymer coated at the tip; spring-coiled wires such as the Abbott BMWV or the equivalent are much safer in this respect and will give better tactile feedback. In addition, it is imprudent to work on dedicated CTO wire for ballooning and stenting, as the back and forth movement with subsequent equipment manipulation on the wire can cause distal wire perforation. If the microcatheter cannot cross, it should be exchanged for a long (20 mm) 1.25 or 1.5 over-the-wire balloon to dilate the lesion. To remove the microcatheter, the use of a wire extension will be necessary, unless the catheter and device size allow for the performance of a trapping technique (Fig. 4). In 6F catheter, a 2.0 balloon can be used to trap a short 180-cm guidewire at the tip of the guide to remove a FineCross pulled more proximally, without having to extend the guidewire. If the Corsair was used antegradely but could not cross, wire extension may be required in 6F guide because of its larger external diameter (balloon trapping is feasible, but a tight fit), but wire trapping can be achieved using a 2.5-mm balloon in a 7-F guide and a 3.0-mm balloon in an 8-F guide. To penetrate the CTO, the use of long balloons in small sizes is preferable; the central balloon marker, which usually causes a small bump in the balloon profile, is positioned >10 mm back from the tip of the balloon, allowing for the balloon to better engage the lesion. If this step fails, the best results can be achieved with the Asahi TornusV device (Table III). This special eight-wire braided catheter comes in two versions, the 2.1F and 2.6F. The 2.1F size has the advantage of being compatible with a 6-F guide and of being able to be removed with a trapping balloon technique. The Tornus is advanced with up to 20 counterclockwise rotations that distract the wires and convert the rotation power into forward screw-like movement. Once across the lesion with a microcatheter, an overthe-wire balloon, or the Tornus, the wire can be exchanged for a workhorse guidewire or a RotablatorV wire if rotational atherectomy is considered. The Tornus will be removed from the plaque using continuous clockwise rotations. Once a workhorse wire is delivered distally, angioplasty and stenting will complete the procedure. R
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CONCLUSIONS
CTO–PCI remains underperformed in the western world because of a combination of perceived complex-
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ity and confusion of educational message. We think that antegrade-only operator can easily master the skills to perform successful and fast CTO recanalization in less complex CTO lesions such as the ones with a JCTO score of 0 or 1. From a population health standpoint, it would be desirable to see more interventionists treating simpler CTOs, as lower than 15% are currently attempted in North-America. However, it is also advisable that all antegrade-only operators can master the calculation of the J-CTO score, and be knowledgeable of the CTO PCI algorithm, to facilitate appropriate referral of cases which may require retrograde or antegrade dissection re-entry skillsets. REFERENCES 1. Christofferson RD, Lehmann KG, Martin GV, Every N, Caldwell JH, Kapadia SR. Effect of chronic total coronary occlusion on treatment strategy. Am J Cardiol 2005;95:1088– 1091. 2. Fefer P, Knudtson ML, Cheema AN, Galbraith PD, Osherov AB, Yalonetsky S, Gannot S, Samuel M, Weisbrod M, Bierstone D, et al. Current perspectives on coronary chronic total occlusions: The Canadian Multicenter Chronic Total Occlusions Registry. J Am Coll Cardiol 2012;59:991–997. 3. Grantham JA, Marso SP, Spertus J, House J, Holmes DR Jr., Rutherford BD. Chronic total occlusion angioplasty in the United States. JACC Cardiovasc Interv 2009;2:479–486. 4. Brilakis ES, Grantham JA, Rinfret S, Wyman RM, Burke MN, Karmpaliotis D, Lembo N, Pershad A, Kandzari DE, Buller CE, et al. A percutaneous treatment algorithm for crossing coronary chronic total occlusions. JACC Cardiovasc Interv 2012;5:367– 379. 5. Thompson CA. Percutaneous revascularization of coronary chronic total occlusions: The new era begins. JACC Cardiovasc Interv 2010;3:152–154. 6. Patel VG, Brayton KM, Tamayo A, Mogabgab O, Michael TT, Lo N, Alomar M, Shorrock D, Cipher D, Abdullah S, et al. Angiographic success and procedural complications in patients undergoing percutaneous coronary chronic total occlusion interventions: A weighted meta-analysis of 18,061 patients from 65 studies. JACC Cardiovasc Interv 2013;6:128–136. 7. Morino Y, Kimura T, Hayashi Y, Muramatsu T, Ochiai M, Noguchi Y, Kato K, Shibata Y, Hiasa Y, Doi O, et al. In-hospital outcomes of contemporary percutaneous coronary intervention in patients with chronic total occlusion insights from the JCTO Registry (Multicenter CTO Registry in Japan). JACC Cardiovasc Interv 2010;3:143–151. 8. Rathore S, Katoh O, Matsuo H, Terashima M, Tanaka N, Kinoshita Y, Kimura M, Tsuchikane E, Nasu K, Ehara M, et al. Retrograde percutaneous recanalization of chronic total occlusion of the coronary arteries: Procedural outcomes and predictors of success in contemporary practice. Circ Cardiovasc Interv 2009;2:124–132. 9. Thompson CA, Jayne JE, Robb JF, Friedman BJ, Kaplan AV, Hettleman BD, Niles NW, Lombardi WL. Retrograde techniques and the impact of operator volume on percutaneous intervention for coronary chronic total occlusions an early U.S. experience. JACC Cardiovasc Interv 2009;2:834–842. 10. Karmpaliotis D, Michael TT, Brilakis ES, Papayannis AC, Tran DL, Kirkland BL, Lembo N, Kalynych A, Carlson H, Banerjee
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CTO (Multicenter CTO Registry in Japan) score as a difficulty grading and time assessment tool. JACC Cardiovasc Interv 2011;4:213–221. 13. Nombela-Franco L, Urena M, Jerez-Valero M, Nguyen CM, Ribeiro HB, Bataille Y, Rodes-Cabau J, Rinfret S. Validation of the J-chronic total occlusion score for chronic total occlusion percutaneous coronary intervention in an independent contemporary cohort. Circ Cardiovasc Interv 2013;6:635–643. 14. Michael TT, Papayannis AC, Banerjee S, Brilakis ES. Subintimal dissection/reentry strategies in coronary chronic total occlusion interventions. Circ Cardiovasc Interv 2012;5:729–738.
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