Reported success rates of percutaneous coronary interventions (PCI) of chronic total occlusions (CTO) range from approximately 60–75%,1–3 and are much lower when compared with PCI of nontotal occlusions.4,5 When combined with specialized equipment, some reports have stated slightly higher success rates.6,7 The most common reasons for procedural failure include the inability of the guidewire to cross the occlusion (80–90%), the inability of the balloon to cross the occlusion (2–15%), and the inability to adequately dilate the lesion (2–5%).7,8,9 In the latter two categories of failure, rotational coronary atherectomy can be helpful in improving procedural success rates.10,11 Use of the Rotablator® rotational atherectomy device (Boston Scientific Corp., Natick, Massachusetts), however, can be limited by recrossing the occlusion with a relatively delicate and less maneuverable 0.009 inch stainless steel RotaWire™ (Boston Scientific). In the circumstance of a resistant CTO, where rotational atherectomy is the only available option, recrossing the occlusion with a less favorable guidewire poses an obstacle. Such a clinical conundrum is encountered in the present case report. The additional use of the Frontrunner™ blunt microdissection catheter (LuMend, Inc., Redwood City, California) allowed for successful recrossing of a resistant CTO with the RotaWire, which led to the ultimate successful PCI result. The challenge of percutaneous revascularization of CTOs requires innovative approaches. This case highlights the effectiveness of combined techniques and devices; other novel approaches are also discussed. Case Report A 68-year-old male who had a history of multiple coronary risk factors including hypertension, diabetes mellitus and dyslipidemia, presented with a non-ST-segment elevation myocardial infarction (NSTEMI). A diagnostic coronary angiogram was performed demonstrating only mild-to-moderate disease in the circumflex and right coronary arteries. The middle left anterior descending artery (LAD) segment, however, had significant proximal disease followed by a 100% chronic occlusion in the middle segment (Figure 1). Distally, the LAD received collateral circulation from the circumflex artery (Figure 2). A 7 Fr CLS 3.5 guide was used for support in the initial attempt to treat the LAD CTO. With added balloon catheter support, wire-probing was performed with multiple coronary guidewires, and the PT Graphix™ (Boston Scientific) was successful in crossing the occlusion (Figure 3). The lesion, however, could not be crossed with multiple 1.5 mm balloon catheters (monorail and over-the-wire systems), including the Maverick2™ (Boston Scientific) and the Voyager™ (Guidant Corp., Indianapolis, Indiana). Plaque modification was deemed necessary at this juncture. However, an attempt to rewire the occlusion with the RotaWire was unsuccessful. The procedure was aborted. The patient declined surgery and was medically managed. Approximately 2 months later, the patient presented with another NSTEMI. A repeat coronary angiogram demonstrated similar findings, with a CTO in the middle segment of the LAD. Guide support was increased with an EBU 4.0 mm catheter, and the occlusion was crossed with an Asahi Miracle Bros 3 gram wire (Abbott Vascular Devices, Redwood City, California). Despite improved guide support, none of the 1.5 mm balloons, including the Maverick2, Voyager™ monorail or over-the-wire systems were able to cross the lesion. A Pilot™ 150 (Guidant) “buddy wire” was placed in a side branch proximal to the occlusion, but did not help with the balloon advancement. An attempt to cross the occlusion with the buddy wire was unsuccessful. Again, rotational atherectomy was deemed as a necessary step toward a successful procedural outcome. Recrossing the CTO with the less maneuverable RotaWire, however, was a major concern. The Asahi Miracle Bros wire was exchanged for a 0.009 inch Extra Support RotaWire to the lesion site; however, the RotaWire was unable to recross the occlusion as in the previous attempt, despite improve guide support. Blunt microdissection was performed using the Frontrunner catheter without complete penetration of the CTO (Figure 4). Microdissection of the plaque at the entrance of the CTO, however, allowed for successful crossing of the occlusion with the RotaWire (Figure 5). Rotational atherectomy was performed with a 1.25 mm burr. The lesion was further pretreated with a1.5 mm and a 2.5 mm Maverick2™ balloon. Stent deployment was performed using multiple Taxus™Express2™ drug-eluting stents (Boston Scientific) from the proximal-to-middle segments of the LAD. Post-dilatation was performed using a NC Monorail™ balloon (Boston Scientific), achieving to a final diameter of 3.42 mm, based on the balloon compliance chart (Figure 6). The patient did well clinically and was discharged from the hospital. Discussion The present case of PCI of a CTO demonstrated a technical challenge when the balloon failed to cross the lesion after successful passage of the coronary guidewire. The LAD CTO was complicated by prior proximal disease from both clinical and technical standpoints. The proximal disease may have played a role in the patient’s clinical syndrome, since it provided inlet for a moderate-size diagonal branch. It was also unknown whether there was sufficient collateral circulation to the distal LAD. Prior to noninvasive risk stratification, the recurrence of NSTEMI suggested that initial PCI of this segment into the diagonal branch could have been an alternative approach. Significant disease in the proximal LAD also served as a mechanical hindrance to the passage of interventional devices. Friction with the balloon catheter generated in this segment can lessen the transmitted forces to the balloon tip, thereby decreasing its pushability. Nonetheless, PCI of the CTO was successful. Evidence of the clinical benefits to successful PCI of CTOs is apparent,2,12,13 and underscores the importance of achieving successful procedural outcomes. When PCI of CTOs fails due to unsuccessful crossing of the balloon catheter, combination use of the Frontrunner and the Rotablator devices should be considered. The Frontrunner catheter is designed to create blunt microdissections inside the plaque to allow for passage of a guidewire through the lesion.14,15 In this case, the extended application of the Frontrunner is to increase the crossability of any guidewires, including difficult-to-maneuver wires such as the RotaWire. This is a crucial step for the necessary plaque modification that ultimately results in a successful PCI. Other technical options to consider when confronted with failure to balloon-cross may include: increasing guide support, placement of a buddy wire into a proximal branch, placement of a buddy wire through the occlusion into the distal vessel, or the use of an excimer laser.9,16 In the presented case, all of these strategies were explored to no avail; a more supportive guide and a proximal buddy wire did not help the balloon catheter to cross. The buddy wire, in this case, could not be advanced parallel to the first wire to cross the occlusion. The excimer laser and rotational atherectomy are usually the devices of choice when the lesions cannot be crossed with a balloon or cannot be dilated. In general, rotational atherectomy has a higher procedural success rate than laser angioplasty.17 As is the case in many catheterization laboratories, the excimer laser was not available to us. Other equipment and device innovations in PCI of CTOs include the newer, specialized CTO wires with or without taper tips or hydrophilic coating.9 In this case, two of these wires were used with successful crossing of the occlusions: the hydrophilic PT Graphix and the Asahi Miracle Bros 3 gram wire. Along with the Frontrunner, the SafeCross®-RF guidewire (IntraLuminal Therapeutics, Inc., Carlsbad, California) is the other FDA-approved device for the treatment of refractory CTO recanalization. This device utilizes infrared optical coherence reflectometry at the wire tip to guide crossing of the occlusion.18,19 The Asahi Tornus® is the latest FDA-approved device for treatment of CTOs. The manual rotation of the over-the-wire catheter is designed to penetrate severe or total occlusions after successful wire crossing.20 It is a promising technology for the presented scenario, however, its formal approval and availability came after this case. The fixed wire-balloon system, also known as balloon-on-a-wire, was another novel technology designed to facilitate the crossing of guidewire and balloon dilatation using a probing catheter. It was attractive due to its extremely low profile,8,21,22 however, the relative lack of pushability, trackability and steerability diminished its popularity and production.8 Other investigational approaches include drug infusion therapy with fibrinolytic agents23 and collagenase,24 and mechanical vibrational angioplasty.25 Recanalization of CTOs requires innovative approaches. This case study suggests the appropriate combination use of currently available devices that can help to increase the procedural success rate of treating CTOs.
1. Hoye A, van Domburg RT, Sonnenschein K, Serruys PW. Percutaneous coronary intervention for chronic total occlusions: The Thoraxcenter experience 1992‚Äì2002. Eur Heart J 2005;26:2630‚Äì2636. 2. Olivari Z, Rubartelli P, Piscione F, et al for the TOAST-GISE Investigators. Immediate results and one-year clinical outcome after percutaneous coronary interventions in chronic total occlusions: Data from a multicenter, prospective, observational study (TOAST-GISE). J Am Coll Cardiol 2003;41:1672‚Äì1678. 3. Noguchi T, Miyazaki MD S, Morii I, et al. Percutaneous transluminal coronary angioplasty of chronic total occlusions. Determinants of primary success and long-term clinical outcome. Catheter Cardiovasc Interv 2000;49:265‚Äì266. 4. Kinoshita I, Katoh O, Nariyama J, et al. Coronary angioplasty of chronic total occlusions with bridging collateral vessels: Immediate and follow-up outcome from a large single-center experience. J Am Coll Cardiol 1995;26:409‚Äì415. 5. Tan K, Sulke N, Taub N, Sowton E. Clinical and lesion morphologic determinants of coronary angioplasty success and complications: Current experience. J Am Coll Cardiol 1995;25:855‚Äì865. 6. Wong P, Tse KK, Chan W. Recanalization of chronic total occlusion after conventional guidewire failure: Guided by optical coherent reflectometry and facilitated by radiofrequency energy ablation. J Invasive Cardiol 2004;16):58‚Äì59. 7. Sievert H, Rohde S, Ensslen R, et al. Recanalization of chronic coronary occlusions using a laser wire. Cathet Cardiovasc Diagn 1996;37:220‚Äì222. 8. Freed MS, Safian RD. Chronic total occlusion. In: Safian RD and Freed MS, eds. The Manual of Interventional Cardiology, 3rd Ed. Royal Oak, Michigan: Physicians‚Äô Press. 2002, p. 288. 9. Stone GW, Reifart NJ, Moussa I, et al. Percutaneous recanalization of chronically occluded coronary arteries: A consensus document: Part II. Circulation 2005;112:2530‚Äì2537. 10. Omoigui N, Reisman M, Franco I, Whitlow P. Rotational atherectomy in chronic total occlusions. J Am Coll Cardiol 1995;25:97A. 11. Braden GA, Kutcher MA, Rankin KM, et al. Debulking using rotational atherectomy of chronic total occlusion leads to high initial success and very low restenosis rates. J Am Coll Cardiol 2001;37:46A. 12. Suero JA, Marso SP, Jones PG, et al. Procedural outcomes and long-term survival among patients undergoing percutaneous coronary intervention of a chronic total occlusion in native coronary arteries ‚Äì A 20 year experience. J Am Coll Cardiol 2001;38:409‚Äì414. 13. Ramanathan K, Gao M, Nogareda GJ, et al. Successful percutaneous recanalization of a non-acute occluded coronary artery predicts clinical outcomes and survival. Circulation 2001;104:II‚Äì415A. 14. Orlic D, Stankovic G, Sangiorgi G, et al. Preliminary experience with the Frontrunner coronary catheter: Novel device dedicated to mechanical revascularization of chronic total occlusions. Catheter Cardiovasc Interv 2005;64:146‚Äì152. 15. Whitbourn RJ, Cincotta M, Mossop P, Selmon M. Intraluminal blunt microdissection for angioplasty of coronary chronic total occlusions. Catheter Cardiovasc Interv 2003;58:194‚Äì198. 16. Berger PB, Bresnahan J. Use of excimer laser in the treatment of chronic total occlusion of a coronary artery that cannot be crossed with a balloon catheter. Cathet Cardiovasc Diagn 1993:28:44‚Äì46. 17. Reifart N, Vandormael M, Krajcar M, et al. Randomized comparison of angioplasty of complex coronary lesions at a single center. Excimer laser, rotational atherectomy, and balloon angioplasty comparison (ERBAC) study. Circulation 1997;96:91‚Äì98. 18. Cordero H, Warburton KD, Underwood PL, Heuser RR. Initial experience and safety in the treatment of chronic total occlusions with fiberoptic guidance technology. Catheter Cardiovasc Interv 2001;54:180‚Äì187. 19. Baim DS, Braden G, Heuser R, et al. Utility of the safe-cross-guided radiofrequency total occlusion crossing system in chronic coronary total occlusions (results from the Guided Radio Frequency Energy Ablation of Total Occlusions Registry Study). Am J Cardiol 2004;94:853‚Äì858. 20. Tsuchikane E, Katoh O, Shimogami M, et al. First experience of a novel penetration catheter for patients with severe coronary artery stenosis. Catheter Cardiovasc Interv 2005;6:368‚Äì373. 21. Little T, Pichard AD, Lindsay J Jr. Probe angioplasty of total coronary occlusion using an intracoronary probing catheter. Cathet Cardiovasc Diagn 1989;17:218‚Äì223. 22. Shawl FA. Probe III catheter, an improved balloon-on-a-wire system: Initial experience. Probe III Investigators Group. J Invasive Cardiol 1990;2:139‚Äì145. 23. Zidar FJ, Kaplan BM, O‚ÄôNeill WW, et al. Prospective, randomized trial of prolonged intracoronary urokinase infusion for chronic total occlusions in native coronary arteries. J Am Coll Cardiol 1996;27:1406‚Äì1412. 24. Strauss BH, Goldman L, Qiang B, et al. Collagenase plaque digestion for facilitating guide wire crossing in chronic total occlusions. Circulation 2003;108:1259‚Äì1262. 25. Michalis LK, Rees MR, Davis JA, et al. Use of vibrational angioplasty for the treatment of chronic total coronary occlusions: Preliminary results. Catheter Cardiovasc Interv 1999;46:98‚Äì104.