Retrograde coronary revascularisation in Europe to treat chronic total coronary occlusions

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Alfredo R Galassi (University of Catania Italy and University of Zurich, Switzerland) reports on the use of percutaneous coronary intervention (PCI) with the retrograde approach for the management of chronic total occlusions (CTOs) in Europe and how the Euro CTO Club and Live Summit are spreading the knowledge of new complex PCI techniques for CTOs.

 

When Andreas Gruentzig did his first procedure with his innovative balloon in 1977, he only dared to treat proximal type A lesions. The introduction of guidewires meant that more distal lesions could be treated with coronary angioplasty and the advent of stents—particularly drug-eluting stents—meant that more complex plaques were treatable. However, percutaneous management of CTOs remained a challenge for many years for most interventionalists.


It is interesting, though, that in 1985 (a mere two weeks before his tragic passing in a plane crash), Gruentzig said in an interview: “I like to depart with more total closure, and try to learn how to deal with total closures. We did a study on that, and we found out that 70% of the patients who are rejected for dilatation have been patients with total closures in one or the other artery, while having more diseases in the others. Therefore, the total closure is a real problem, if we cannot solve the total closure problem, we probably will never really address the question of multivessel disease dilatation.”


These days, at least every 10th patient undergoing PCI presents with one or more CTOs.1 After the visionary talk of Andreas Gruentzig, during the last three decades, more much effort has been put forth to develop and standardise CTO recanalisation techniques and provide operators with strategies to optimise their success rate. For example, the success rate has increased from from 60–70% to 80–90% of all CTOs attempted. However, this does not tell the full story because many CTO lesions routinely attempted in the last few years were not even considered previously, except by few highly dedicated operators. The rapid development of dedicated CTO PCI equipment (mainly developed by Japanese expertise and companies) has been crucial for enabling more CTO lesions to be treated with PCI approaches. Long sheaths to optimise back up support, over-the-wire microcatheters for wire support and frequent reshaping and exchange, wires with polymeric coating and escalating stiffness with high steerability and tapering have become indispensable for contemporary CTO recanalisation techniques.


Although an antegrade approach with contemporary equipment is successful in the majority of cases, CTO dedicated operators should also be skilled in retrograde techniques because achieving an up to 90% success rate is not possible without the retrograde approach given that 15–20% of lesions that can be successfully treated with the retrograde approach cannot be treated with the antegrade approach. Since their introduction in the 1990s, retrograde revascularisation techniques have considerably improved procedural success rates but they require substantial operational skills and a profound knowledge of PCI material—even among experienced operators.


In 2005, Katoh established the modern era of retrograde CTO recanalisation, introducing the CART

(Controlled antegrade retrograde subintimal tracking) technique.2 The development of dedicated microcatheters for collateral crossing abolished the necessity for septal dilatation and retrograde dilatation of the occlusion, shifting the field to the reverse CART technique.3 Selective contract injection through microcatheters delineates the course of the collateral channels and soft composite core polymeric wires are employed for collateral channel tracking. Septal surfing technique with soft polymeric wires remains highly efficient in expert hands. More recently,  Brilakis et al introduced the hybrid approach, codifying a strategy of initial selection and rapid switching of antegrade and retrograde approach based on lesion characteristics and response during the procedure.4


The practice of CTO interventions has been propagate to large part by the Euro CTO Club, which was founded in 2006 by the pioneers of the procedure Alfredo R Galassi, Joachim Buttner, Carlo di Mario, Gerald S Werner, Darius Dudek, George Sianos, Nicolaus Reifart, and Hans Bonnier. Since its foundation, the mission of the CTO Club has been to teach the community of interested interventionalists about the procedure and the use of novel materials developed by several companies on a yearly basis.


To that end, yearly live courses have been organised and registries established. Last year’s (2015) European Live Summit on Retrograde CTO Revascularization was held at the University Hospital of Zurich in Switzerland under the direction of Galassi, Thomas F, Lüscher, and George Sianos. The course was endorsed by the EuroCTO Club and the European Association of Percutaneous Cardiovascular Interventions (EAPCI). With Faculty members from Europe, South Africa, United States, Canada, Middle East, Russia and Asia Pacific and 155 participants, the course was based on 12 interactive live cases commented by a panel of international CTO experts allowing interactive discussion of interventional strategies and live in the box case presentations by participants, as well as lectures by highly experienced interventional cardiologist in the Andreas Gruentzig Catheterization Laboratories. Galassi showed the data from the Retrograde Multicenter European Registry recently published in the Journal of the American College of Cardiology (JACC) highlighting how the number of retrograde procedures in Europe has increased, with high rates of success, low rates of major complications, and good long-term outcomes.5

 

References

  1. Galassi et al. Eur Heart J 2015. Epub.
  2. Surmely et al. J Invasive Cardiol 2006; 18: 334–38
  3. Rathore et al. JACC Cardiovasc Interv 2010; 3: 155–64.
  4. Brilakis et al. JACC Cardiovasc Interv 2012; 5: 367–79.
  5. Galassi et al. J Am College Cardiol 2015; 65: 2388–400.