Algorithmic solutions to common problems encountered during chronic total occlusion angioplasty: The algorithms within the algorithm

Improved technical equipment, dissemination of best practices, and the importance of complete coronary revascularization have led to a renewed interest in coronary chronic total occlusion (CTO) PCI. In particular, the hybrid algorithm has been associated with increasing procedural success rates in the US. However, the hybrid algorithm only covers overarching strategies in the overall approach to these lesions. Several technical challenges can occur during execution of these approaches, each of which has several potential solutions. A systematic or algorithmic approach to dealing with these challenges could contribute to improved procedural efficiency and higher procedural success. While there have been isolated attempts in the past to codify approaches to each of these situations, there has not been a contemporary, comprehensive review of the potential solutions to these problems. We present 10 common problems encountered during CTO PCI and a consensus hierarchical approach to them.

The Hybrid Approach to Chronic Total Occlusion Percutaneous Coronary Intervention: Update From the PROGRESS CTO Registry

OBJECTIVES

The aim of this study was to determine the techniques and outcomes of hybrid chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in a diverse group of patients and operators on 2 continents.

BACKGROUND

CTO PCI has been evolving with constant improvement of equipment and techniques.

METHODS

Contemporary outcomes of CTO PCI were examined by analyzing the clinical, angiographic, and procedural characteristics of 3,122 CTO interventions performed in 3,055 patients at 20 centers in the United States, Europe, and Russia.

RESULTS

The mean age was 65 ± 10 years, and 85% of the patients were men, with high prevalence of diabetes (43%), prior myocardial infarction (46%), prior coronary artery bypass graft surgery (33%), and prior PCI (65%). The CTO target vessels were the right coronary artery (55%), left anterior descending coronary artery (24%), and left circumflex coronary artery (20%). The mean J-CTO (Multicenter Chronic Total Occlusion Registry of Japan) and PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) scores were 2.4 ± 1.3 and 1.3 ± 1.0, respectively. The overall technical and procedural success rate was 87% and 85%, respectively, and the rate of in-hospital major complications was 3.0%. The final successful crossing strategy was antegrade wire escalation in 52.0%, retrograde in 27.1%, and antegrade dissection re-entry in 20.9%; >1 crossing strategy was required in 40.9%. Median contrast volume, air kerma radiation dose, and procedure and fluoroscopy time were 270 ml (interquartile range: 200 to 360 ml), 2.9 Gy (interquartile range: 1.7 to 4.7 Gy), 123 min (interquartile range: 81 to 188 min) and 47 min (interquartile range: 29 to 77 min), respectively.

CONCLUSIONS

CTO PCI is currently being performed with high success and acceptable complication rates among various experienced centers in the United States, Europe, and Russia. (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention [PROGRESS CTO]; NCT02061436).

Percutaneous coronary interventions of chronic total -occlusions; a review of clinical indications, treatment strategy and current practice

Chronic total occlusions (CTOs) are commonly encountered in patients undergoing coronary angiography, but percutaneous coronary intervention (PCI) for CTO is currently infrequently performed owing to the perception of limited clinical benefit, high complexity and cost of intervention, and perceived risk of complications. Numerous observational studies have demonstrated that successful CTO revascularization is associated with better cardiovascular outcomes and enhanced quality of life (QOL). However, in the absence of randomized trials, its prognostic benefit remains debated. Nevertheless, over the past decade the interest in CTO-PCI has exponentially grown due to important developments in dedicated equipment and techniques, resulting in high success and low complication rates. A number of factors must be taken into consideration in selecting patients for CTO-PCI, including presence of symptoms attributable to the CTO, extent of ischaemia distal to the occlusion, and degree of myocardial viability. In this review, we focus on the impact of CTO revascularization on clinical outcomes and QOL and on appropriate patient selection. Data regarding efficacy and safety of recent advances in PCI-CTO techniques will be discussed. Steps involved in setting up a dedicated CTO program will be outlined and the current CTO landscape in Belgium will be briefly highlighted. The overall aim of this review is to promote a more balanced approach to management of patients with a CTO.

Initial Experience and Feasibility of the New Low-Profile Stingray Catheter as Part of the Antegrade Dissection and Re-Entry Revascularization Strategy for Coronary Chronic Total Occlusions

BACKGROUND During antegrade dissection re-entry (ADR) of chronic total occlusions (CTO), the first-generation Stingray catheter requires the use of large-bore guides (sheathless 7.5 Fr or 8 Fr), which increases the risk for access site-related complications and compromises radial approaches. Smaller guiding sizes necessitate long guidewires (e.g., 300 cm) or guidewire extensions for catheter advancement or removal. However, friction between guides and the Stingray catheter can result in unstable guidewire position or unintentional removal. Furthermore, failure to deliver the catheter at the distal re-entry zone is a common problem. To overcome issues of deliverability and reduce the need for pre-dilatations, with its inherent risk of creating subintimal hematomas, the Stingray low-profile (LP) balloon catheter was developed. CASE REPORT We describe 3 cases of successful application of the novel Stingray LP catheter during ADR. In all cases, 7 Fr guiding catheters were successfully used in combination with the device. The lower profile facilitated a good exchange and delivery of the device, without the need for balloon pre-dilatations in 2 cases. This resulted in a limited subintimal plane, enabling a smooth puncture into the true lumen. One case presented with extreme levels of calcification and tortuosity, resulting in a high degree of friction, despite the lower catheter profile. No in-hospital coronary or access site-related complications occurred. CONCLUSIONS This case report illustrates the feasibility of the Stingray LP catheter for the treatment of CTOs via the ADR technique. The lower profile of the catheter potentially increases the deliverability, safety, and exchangeability of the device.

Initial clinical experience of CrossBoss catheter for in-stent chronic total occlusion lesions: A case report

BACKGROUND

The CrossBoss coronary chronic total occlusion (CTO) crossing catheter has been demonstrated to have greatly improved the success rate of crossing CTO lesions, but there are no published data on its application for in-stent CTO lesions.

METHODS

In the current study, we retrospectively reviewed the clinical data of 8 patients with in-stent CTO lesions that were managed with the CrossBoss catheter and herein we report the efficacy and safety of the CrossBoss crossing and re-entry system for this clinically challenging condition.

RESULTS

The CrossBoss catheter was used for 8 patients with in-stent CTO lesions, which resulted in success in 6 cases and failure in 2 cases, with a 75% success rate. Of the 6 patients with successful treatment, 5 cases had the occlusive lesions crossed with the CrossBoss catheter through a proximal lumen-to-distal lumen approach, whereas the remaining case had his occlusive lesions penetrated by the CrossBoss catheter and the guidewire. Two cases failed in treatment as the CrossBoss catheter could not cross the occlusive lesions. The 6 cases with successful treatment included 3 cases with occlusive lesions in the left anterior descending artery, 1 case with occlusive lesions in the obtuse marginal branches, and 2 cases with occlusive lesions in the right coronary artery, and the 2 cases with failure in treatment had their occlusive lesions in the right coronary artery. In addition, patients with a higher Japan chronic total occlusion score were found to have a lower success rate of crossing the occlusive lesions. None of the patients developed complications.

CONCLUSION

Our study demonstrates that the CrossBoss catheter has a high success rate and is safe for in-stent CTOs and can be recommended for this rather clinically challenging condition.

Chronic total coronary occlusion recanalization: Current techniques and new devices

Percutaneous coronary intervention (PCI) of total chronic coronary occlusion (CTO) still remains a major challenge. The prevalence of a CTO has been reported to be up to 30% among patients with a clinical indication for coronary angiography. Progress has been made with further advanced interventional techniques and continuously sophisticated interventional tools. Nevertheless the number of interventions carried out to recanalize a CTO is less than 10% of all procedures. Benefits of a successful CTO recanalization include relief of angina pectoris and ischemia-related dyspnea, substantial improvement in left ventricular function and, avoidance of surgery treatment. A vast variety of new CTO PCI techniques and materials has been introduced into clinical practise and pushed success rates of reopening a CTO up to around 90% in experienced hands. Particulary the introduction of the retrograde technique was a milestone. New developed microcatheters and special polymer coated wires allow to recanalize via small collaterals and vessels. Other tools such as intravascular ultrasound (IVUS) and multislice computertomography (MSCT) help to identify the anatomy and the characteristic of the lesions. Any invasive cardiac center should adopt CTO PCI procedures as standard therapy.

Objective

This review wants to assess and describe the latest development in CTO recanalization strategies.

Application and outcomes of a hybrid approach to chronic total occlusion percutaneous coronary intervention in a contemporary multicenter US registry

BACKGROUND

A hybrid approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) prioritizing and combining all available crossing techniques was developed to optimize procedural efficacy, efficiency, and safety, but there is limited published data on its outcomes.

METHODS

We examined the procedural techniques and outcomes of 1036 consecutive CTO PCIs performed using a hybrid approach between 2012 and 2015 at 11 US centers.

RESULTS

Mean age was 65 ± 10 years and 86% of the patients were men, with a high prevalence of diabetes mellitus (43%) and prior coronary artery bypass graft surgery (34%). Most target CTOs were located in the right coronary artery (59%), followed by the left anterior descending artery (23%) and the circumflex (19%). Dual injection was used in 71%. Technical success was achieved in 91% and a major procedural complication occurred in 1.7% of cases. The final successful crossing technique was antegrade wire escalation in 46%, antegrade dissection/re-entry in 26%, and retrograde in 28%. The initial crossing strategy was successful in 58% of the lesions, whereas 39% required an additional approach. Overall, antegrade wire escalation was used in 71%, antegrade dissection/re-entry in 36%, and the retrograde approach in 42% of procedures. Median contrast volume, fluoroscopy time, and air kerma radiation dose were 260 (200-360) ml, 44 (27-72) min, and 3.4 (2.0-5.4) Gray, respectively.

CONCLUSION

Application of a hybrid approach to CTO crossing resulted in high success and low complication rates across a varied group of operators and hospital practice structures, supporting its expanding use in CTO PCI.

Chronic total occlusions - Current techniques and future directions

Chronic total occlusions (CTOs) of coronary arteries represent a common and significant challenge to interventional cardiology. Medical therapy is often regarded as an adequate long term strategy in the management of these lesions with surgical intervention for refractory symptoms. Extensive collateralisation is used as a marker of distal coronary perfusion, further reinforcing non-invasive strategies. This together with relatively low percutaneous success rates outside of specialised centres has meant that rates of percutaneous intervention have remained low. Increasing evidence suggests that CTOs are not a benign entity. Further, symptom control and quality of life improve significantly with successful percutaneous revascularisation. Both factors have reignited interest in percutaneous modalities. The Japanese have been pioneers in the field of CTO intervention although their success rates have been difficult to replicate. New techniques and equipment developed in North America offer an alternative to the Japanese approach. These techniques focus on time, radiation and contrast minimisation. This review will assess the histopathology of CTO and shifting paradigms in CTO treatment strategies.

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Chronic total occlusions are common and prognostically important.

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Strategies for chronic occlusions are pioneered by Japanese, adapted by North American operators.

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Japanese and North American strategies appear divergent, both add considerable expertise.

Advances in the management of coronary chronic total occlusions

Chronic total occlusions (CTOs) have been called "the last frontier" of percutaneous coronary intervention (PCI) due to traditionally low success rates and high risk for restenosis and re-occlusion. Recent advances in equipment and crossing techniques have significantly increased CTO PCI success rates while maintaining low risk of complications. Specifically, the retrograde approach and controlled antegrade dissection and re-entry in conjunction with advanced guidewires and microcatheters have significantly improved procedural success rates. Moreover, the introduction of the "hybrid" approach has created a unified framework for operators to approach CTOs in a systematic and efficient fashion. Finally, drug-eluting stents, especially second generation, have improved long-term patency after CTO PCI.

Bailout antegrade coronary reentry with the stingray™ balloon and guidewire in the setting of an acute myocardial infarction and cardiogenic shock

Emergent coronary artery bypass surgery for failed percutaneous coronary intervention (PCI) during acute myocardial infarction (MI) is a bailout strategy that is associated with a high in-hospital morbidity and mortality (7-10%). Innovative strategies to improve the probability of PCI success in this setting are needed. Antegrade coronary re-entry with the Stingray™ balloon and guidewire has been shown to facilitate recanalization of chronic total occlusions in stable patients. We report a case where the Stingray™ device was successfully used as a bailout strategy in the setting of an acute MI complicated by cardiogenic shock.

Subintimal dissection/reentry strategies in coronary chronic total occlusion interventions

Subintimal dissection/reentry techniques are increasingly being used for crossing coronary chronic total occlusions both antegradely (using a knucle wire or the Bridgepoint system) or retrogradely (using the controlled antegrade and retrograde tracking and dissection, and reverse controlled antegrade and retrograde tracking and dissection technique). Subintimal dissection/reentry techniques can increase procedural success rates, but their subsequent clinical outcomes are poorly studied, and they appear to be associated with high rates of in-stent restenosis and repeat target lesion revascularization. In the present review, we describe in detail the chronic total occlusions subintimal dissection/reentry techniques, clarify the related terminology and summarize the published studies in this area and the current gaps of knowledge.

Coronary Chronic Total Occlusion Recanalisation - Current Techniques and Approaches

Coronary chronic total occlusions (CTOs) are among the most challenging coronary artery lesions to treat percutaneously. In the last decade, great strides have been made to develop techniques to improve success rates. While success rates among high-volume operators are >90 %, non-CTO operators still continue to struggle with this lesion subset. Thus, efforts have been made to develop algorithms to help operators achieve successful recanalisation consistently and improve patient outcomes. The North American Total Occlusion (NATO) algorithm emphasises dual coronary injection using two guide catheters, which allows for switching from an antegrade to retrograde approach or vice versa should the initial strategy fail - the so-called 'hybrid' approach. Special attention is paid to four angiographic characteristics: 1) location of the proximal cap, 2) lesion length, 3) presence and suitability of collateral vessels for retrograde crossing and 4) location and quality of target vessel distal cap. The ultimate goal of this algorithm is to provide a strategy to achieve successful CTO revascularisation while using the least amount of fluoroscopy, contrast and equipment possible.

[Treatment strategies for chronic total occlusion: current status and outlook]

The present article discusses the current status of treatment strategies for chronic total occlusion (CTO) and the prospects offered by new therapies. The indication for revascularisation recognized in the current European guidelines includes the presence of typical symptoms and evidence of ischemia of over 10% of the total myocardium, while in patients with multiple vascular diseases the aim is complete revascularisation. Although the vast majority of patients with CTO fulfil these criteria, they are currently not receiving interventional treatment as frequently as expected. The reasons often given for this include the low success rates and high recurrence rates. However, both problems have been improved by drug-eluting stents (DES) on the one hand and by wire techniques and strategies on the other, such that results almost comparable with non-occluded coronary lesions can be achieved. While more advanced approaches like retrograde recanalization should be restricted to specialized centres, marked improvements can be achieved even without these special techniques by means of consistent further training and the application of modern techniques. Despite the aggressiveness of these approaches to pass through an occluded artery, the complication rate is not higher than with non-occluded lesions when the specific complications of recanalization are avoided in a careful approach. Further technical improvements are expected with the use of modern imaging techniques such as intravascular ultrasound and high-resolution CT imaging of coronary arteries.

Use of the Stingray Re-Entry System in Two Complex Cases of Occluded Superficial Femoral Arteries

Totally occluded infrainguinal arterial disease presents formidable challenges to endovascular revascularization. A variety of devices have been made available to make the crossing of these lesions more amenable to endovascular techniques. We discuss the novel use of a device that has been developed for crossing occluded coronary arteries, the Stingray Re-Entry System.