Retrograde coronary angioplasty of isolated arterial segments through saphenous vein bypass grafts

Retrograde chronic total occlusion percutaneous coronary intervention via ipsilateral collaterals

BACKGROUND

There is limited data on retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) via ipsilateral epicardial collaterals (IEC).

AIMS

To compare the clinical and angiographic characteristics, and outcomes of retrograde CTO PCI via IEC versus other collaterals in a large multicenter registry.

METHODS

Observational cohort study from the Prospective Global registry for the study of Chronic Total Occlusion Intervention (PROGRESS-CTO).

RESULTS

Of 4466 retrograde cases performed between 2012 and 2023, crossing through IEC was attempted in 191 (4.3%) cases with 50% wiring success. The most common target vessel in the IEC group was the left circumflex (50%), in comparison to other retrograde cases, where the right coronary artery was most common (70%). The Japanese CTO score was similar between the two groups (3.13 ± 1.23 vs. 3.06 ± 1.06, p = 0.456); however, the IEC group had a higher Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) score (1.95 ± 1.02 vs. 1.27 ± 0.92, p < 0.0001). The most used IEC guidewire was the SUOH 03 (39%), and the most frequently used microcatheter was the Caravel (43%). Dual injection was less common in IEC cases (66% vs. 89%, p < 0.0001). Technical (76% vs. 79%, p = 0.317) and procedural success rates (74% vs. 79%, p = 0.281) were not different between the two groups. However, IEC cases had a higher procedural complications rate (25.8% vs. 16.4%, p = 0.0008), including perforations (17.3% vs. 9.0%, p = 0.0001), pericardiocentesis (3.1% vs. 1.2%, p = 0.018), and dissection/thrombus of the donor vessel (3.7% vs. 1.2%, p = 0.002).

CONCLUSION

The use of IEC for retrograde CTO PCI was associated with similar technical and procedural success rates when compared with other retrograde cases, but higher incidence of periprocedural complications.

The Retrograde Approach to Chronic Total Occlusion Percutaneous Coronary Interventions: Technical Analysis and Procedural Outcomes

BACKGROUND

Retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with lower success and higher complication rates when compared with the antegrade approach.

OBJECTIVES

This study sought to assess contemporary techniques and outcomes of retrograde CTO PCI.

METHODS

We examined the baseline characteristics, procedural techniques and outcomes of 4,058 retrograde CTO PCIs performed at 44 centers between 2012 and 2023. Major adverse cardiac events (MACE) included any of the following in-hospital events: death, myocardial infarction, repeat target vessel revascularization, pericardiocentesis, cardiac surgery, and stroke.

RESULTS

The average J-CTO (Multicenter CTO Registry in Japan) score was 3.1 ± 1.1. Retrograde crossing was successful in 60.5% and lesion crossing in 81.6% of cases. The collaterals pathways successfully used were septals in 62.0%, saphenous vein grafts in 17.4%, and epicardials in 19.1%. The technical and procedural success rates were 78.7% and 76.6%, respectively. When retrograde crossing failed, technical success was achieved in 50.3% of cases using the antegrade approach. In-hospital MACE was 3.5%. The clinical coronary perforation rate was 5.8%. The incidence of in-hospital MACE with retrograde true lumen crossing, just marker antegrade crossing, conventional reverse controlled antegrade and retrograde tracking (CART), contemporary reverse CART, extended reverse CART, guide-extension reverse CART, and CART was 2.1%, 0.8%, 5.5%, 3.0%, 2.1%, 3.2%, and 4.1%, respectively; P = 0.01).

CONCLUSIONS

Retrograde CTO PCI is utilized in highly complex cases and yields moderate success rates with 5.8% perforation and 3.5% periprocedural MACE rates. Among retrograde crossing strategies, retrograde true lumen puncture was the safest. There is need for improvement of the efficacy and safety of retrograde CTO PCI.

Collateral grading systems in retrograde percutaneous coronary intervention of chronic total occlusions

BACKGROUND

The Japanese Channel (J-Channel) score was introduced to aid in retrograde percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs). The predictive value of the J-Channel score has not been compared with established collateral grading systems such as the Rentrop classification and Werner grade.

AIMS

To investigate the predictive value of the J-Channel score, Rentrop classification and Werner grade for successful collateral channel (CC) guidewire crossing and technical CTO PCI success.

METHODS

A total of 600 prospectively recruited patients underwent CTO PCI. All grading systems were assessed under dual catheter injection. CC guidewire crossing was considered successful if the guidewire reached the distal segment of the CTO vessel through a retrograde approach. Technical CTO PCI success was defined as thrombolysis in myocardial infarction flow grade 3 and residual stenosis <30%.

RESULTS

Of 600 patients, 257 (43%) underwent CTO PCI through a retrograde approach. Successful CC guidewire crossing was achieved in 208 (81%) patients. The predictive value of the J-Channel score for CC guidewire crossing (area under curve 0.743) was comparable with the Rentrop classification (0.699, p = 0.094) and superior to the Werner grade (0.663, p = 0.002). Technical CTO PCI success was reported in 232 (90%) patients. The Rentrop classification exhibited a numerically higher discriminatory ability (0.676) compared to the J-Channel score (0.664) and Werner grade (0.589).

CONCLUSIONS

The J-channel score might aid in strategic collateral channel selection during retrograde CTO PCI. However, the J-Channel score, Rentrop classification, and Werner grade have limited value in predicting technical CTO PCI success.

Recanalisation of coronary chronic total occlusions

Percutaneous treatment of coronary chronic total occlusions (CTO) has advanced greatly since its advent in the late 1970s through the development of dedicated wires and microcatheters, the improved skills of highly experienced operators and the adoption of new sophisticated strategies to guide procedural planning. The contemporary procedural success rate is 80-90% with a reduction in complications. Although there has been no improvement in prognosis in randomised trials to date, they, and other controlled registries of thousands of patients, confirm the pivotal role of CTO recanalisation in the treatment of angina and dyspnoea and an improvement in quality of life. Despite this evidence, CTO recanalisation is grossly underutilised. This review reports a detailed overview of the history, indications and treatment strategies for CTO recanalisation and hopes to increase interest among new, and especially young, operators in this demanding, rapidly evolving field of interventional cardiology.

One 6-F Guiding Catheter and One Microcatheter to Accomplish a Retrograde Chronic Total Occlusion Approach: The “Reverse Tip-In” or “Introspect” Technique

The retrograde approach has significantly increased the overall success rate of chronic total occlusion (CTO) percutaneous coronary intervention (PCI), up to 90% in the hands of experienced CTO operators. The “tip-in” technique involves inserting an antegrade microcatheter over the retrograde guidewire, allowing for antegrade intervention on the CTO segment. Through the presentation of the following case, we want to illustrate how to undertake a retrograde approach to bridge the occluded segment via the “reverse tip-in” or “introspect” technique, using a single guiding catheter with one microcatheter inside.

Retrograde Chronic Total Occlusion Percutaneous Coronary Interventions: Predictors of Procedural Success From the ERCTO Registry

OBJECTIVES

The aim of this study was to identify independent predictors of procedural success after retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

Retrograde CTO PCI is an established technique, but predictors of success remain poorly understood.

METHODS

A multivariable logistic regression model was used to analyze potentially important demographic, clinical, anatomical, and technical aspects of retrograde CTO PCI cases uploaded to the multicenter European CTO (ERCTO) Club Registry.

RESULTS

In calendar years 2018 and 2019, 2,364 retrograde CTO PCI cases constituted the primary analysis cohort. A primary retrograde strategy was used in 1,953 cases (82.6%), and an initial antegrade approach was converted to retrograde in 411 cases (17.4%). Procedural success was achieved in 1,820 cases (77.0%) and was more likely to occur after a primary retrograde attempt versus conversion from an initial antegrade approach (80.9% vs 58.4%; P < 0.0001). After multivariable analysis, an absence of lesion calcification (OR: 1.86; 95% CI: 1.37-2.51; P < 0.0001), a higher degree of distal vessel opacification (OR: 2.47; 95% CI: 1.72-3.55; P < 0.0001), little or no proximal target vessel tortuosity (OR: 1.84; 95% CI: 1.28-2.64; P = 0.001), Werner collateral connection CC1 (OR: 4.87; 95% CI: 2.90-8.19; P < 0.0001) or CC2 (OR: 5.33; 95% CI: 3.02-9.42; P < 0.0001), and the top tertile of operator volume (>120 cases over 2 years) (OR: 1.88; 95% CI: 1.26-2.79; P = 0.002) were associated with the greatest chance of achieving angiographic success.

CONCLUSIONS

Less calcification with good distal vessel opacification, little or absent proximal vessel tortuosity, and visible collateral connections, along with high-volume operator status, were all independently predictive of angiographically successful retrograde CTO PCI.

Antegrade versus retrograde techniques for Chronic Total Occlusions (CTO): a review and comparison of techniques and outcomes

Introduction: As the field of chronic total occlusion percutaneous coronary intervention has evolved, technical approaches have evolved and been refined.Areas covered: In this review, we discuss the major techniques utilized in modern CTO PCI including antegrade wiring, antegrade dissection reentry, retrograde wiring, and retrograde dissection reentry. Retrograde techniques have been extensively studied in comparison to antegrade techniques. Retrograde techniques have contributed to increases in CTO PCI success rates and are generally used in higher complexity lesions. Observational data ssuggestincreased sshort-termcomplications in procedures requiring the use of retrograde techniques; however, llong-termCTO PCI durability and patient outcomes have been shown to be similar among procedures using antegrade only versus retrograde techniques.Expert opinion: Retrograde techniques play a vital role in the technical success of CTO PCI, particularly among more complex lesions and in patients with high burdens of comorbidities. Increases in procedural safety with equipment iteration and in the use of adjunctive imaging will play an important role in the selection of appropriate retrograde conduits and the overall success rates of CTO PCI.

Outcomes of retrograde chronic total occlusion percutaneous coronary intervention: A report from the OPEN-CTO registry

OBJECTIVES

We sought to assess in-hospital and long-term outcomes of retrograde compared with antegrade-only percutaneous coronary intervention for chronic total occlusion (CTO PCI).

BACKGROUND

Procedural and clinical outcomes following retrograde compared with antegrade-only CTO PCI remain unknown.

METHODS

Using the core-lab adjudicated OPEN-CTO registry, we compared the outcomes of retrograde to antegrade-only CTO PCI. Primary endpoints included were in-hospital major adverse cardiac and cerebrovascular events (MACCE) (all-cause death, stroke, myocardial infarction [MI], emergency cardiac surgery, or clinically significant perforation) and MACCE at 1-year (all-cause death, MI, stroke, target lesion revascularization, or target vessel reocclusion).

RESULTS

Among 885 single CTO procedures from the OPEN-CTO registry, 454 were retrograde and 431 were antegrade-only. Lesion complexity was higher (J-CTO score: 2.7 vs. 1.9; p < .001) and technical success lower (82.4 vs. 94.2%; p < .001) in retrograde compared with antegrade-only procedures. All-cause death was higher in the retrograde group in-hospital (2 vs. 0%; p = .003), but not at 1-year (4.9 vs. 3.3%; p = .29). Compared with antegrade-only procedures, in-hospital MACCE rates (composite of all-cause death, stroke, MI, emergency cardiac surgery, and clinically significant perforation) were higher in the retrograde group (10.8 vs. 3.3%; p < .001) and at 1-year (19.5 vs. 13.9%; p = .03). In sensitivity analyses landmarked at discharge, there was no difference in MACCE rates at 1 year following retrograde versus antegrade-only CTO PCI. Improvements in Seattle Angina Questionnaire Quality of Life scores at 1-year were similar between the retrograde and antegrade-only groups (29.9 vs 30.4; p = .58).

CONCLUSIONS

In the OPEN-CTO registry, retrograde CTO procedures were associated with higher rates of in-hospital MACCE compared with antegrade-only; however, post-discharge outcomes, including quality of life improvements, were similar between technical modalities.

Advances in the Post-coronary Artery Bypass Graft Management of Occlusive Coronary Artery Disease

Revascularisation of chronic total occlusion (CTO) represents one of the most challenging aspects of percutaneous coronary intervention, but advances in equipment and an understanding of CTO revascularisation techniques have resulted in considerable improvements in success rates. In patients with prior coronary artery bypass grafting (CABG) surgery, additional challenges are encountered. This article specifically explores these challenges, as well as antegrade methods of CTO crossing. Techniques, equipment that can be used and reference texts are highlighted with the aim of providing potential CTO operators adequate information to tackle additional complexities likely to be encountered in this cohort of patients. This review forms part of a wider series where additional aspects of patients with prior CABG should be factored into decisions and methods of revascularisation.

Retrograde Approach to Chronic Total Occlusion Percutaneous Coronary Intervention

The retrograde approach has increased the success rate of chronic total occlusion percutaneous coronary intervention but has also been associated with a higher risk of complications. The retrograde approach is usually performed in complex lesions, in which the antegrade approach is not feasible or has failed previously. Using a systematic 10-step approach can maximize the likelihood of success and minimize the risks of retrograde chronic total occlusion interventions.

Therapeutic angiogenesis as a treatment for Coronary Artery Occlusions

Cardiovascular diseases are one of the leading causes of death in the world. The inflammation or accumulation of a substance in arteries generates the formation of atherosclerosis, stenosis, coronary artery disease, coronary thrombosis, and occlusion. The present study offers some solutions under investigation for the mentioned pathologies. Traditionally this condition is treated mainly by a percutaneous coronary intervention, bypass, or by specific medications. In the present review, based on original articles, the more suitable treatments were chosen. These angiogenic treatments show the best assessments on coronary artery occlusions. All these treatments focus on the generation of new blood vessels from the already existing vasculature.

Retrograde recanalization of a nonchronic total occlusion lesion

The use of the retrograde approach to treat chronic total occlusion (CTO) has improved overall success rate in this lesion subgroup. Its use to treat complex non-CTO lesions unable to be revascularized by an antegrade approach has not been described. We report a case of the use of the retrograde approach to recanalize a non-CTO lesion under Impella support in a patient with critical stenosis and poor left ventricular function. The retrograde approach may be an alternate pathway in selected non-CTO lesions where the antegrade has been unsuccessful.

A step-by-step guide to mastering retrograde coronary chronic total occlusion intervention in 2018: The author's perspective

Chronic total occlusion remains one of the most challenging subsets and represents the "last frontier" of percutaneous coronary intervention. Retrograde recanalization is one of the most significant amendments of the technique and has become an important complement to the classical antegrade approach. It yields a high success rate even in most complex patients. With emergence of important iterations, this approach has become safer, faster, and more successful. The author proposes a step-by-step guide to the retrograde approach with alternatives to various steps for operators wishing to embark on this strategy.

Ideal Guiding Catheter Position During Bilaterally Engaged Percutaneous Coronary Intervention

Using a novel combined angiography computed tomography (CT) system, we evaluated the impact of the intra-aortic root position of a right coronary artery (RCA) catheter on its coaxiality. We retrospectively enrolled 19 patients who underwent CT scans during bilaterally engaged percutaneous coronary intervention. Coaxiality was defined as the angle between the RCA and the RCA catheter. The coaxiality was better when the RCA catheter was placed anterior to the left main coronary artery catheter (median 27.0° vs 53.7°, p = 0.02). The position of the RCA catheter had a significant impact on the coaxiality of it, with a coaxiality improvement ratio of 0.506 (95% confidence interval 0.294 to 0.871, p = 0.017). Three-dimensional reconstructed CT images of the right anterior oblique projection could determine the position of catheters in all cases. In conclusion, the RCA catheter should be placed anterior, rather than posterior, to the left main coronary artery catheter for better coaxiality during bilaterally engaged percutaneous coronary intervention. The right anterior oblique projection is useful for determining the catheter position.

Primary percutaneous coronary intervention of native chronic total occlusions to treat ST elevation myocardial infarction secondary to acute vein graft occlusion

Primary percutaneous coronary intervention (PCI) is the treatment modality of choice in patients presenting with ST elevation myocardial infarction (STEMI). Clinical outcomes have dramatically improved with the wide adoption of primary PCI in patients with STEMI because of acute thrombotic native coronary artery occlusion. However, patients with prior coronary artery bypass graft (CABG) surgery who present with STEMI because of acute saphenous vein graft (SVG) occlusion continue to have worse outcomes because of poor acute and long-term results of SVG stenting. Therefore, it may be preferable to treat the native coronary artery supplied by the occluded graft although this can be challenging if the native vessel is a chronic total occlusion (CTO). Recent advances in technology and techniques in CTO PCI have significantly improved the success rate and efficiency of CTO procedures. At our institution we have developed a high volume CTO programme with high success rates. We present three cases of acute inferior STEMI because of SVG occlusion which were treated with successful retrograde PCI of the native vessel CTO, utilising the occluded graft as a retrograde channel in two cases and native septal collaterals in the other. Thrombolysis In Myocardial Infarction (TIMI) 3 flow in the native coronary artery was achieved in all three cases with good acute outcomes. Our case series highlights the benefits of a high volume CTO programme. With recent advances in CTO techniques, acute PCI to native vessel CTO is feasible and may be the treatment of choice in selected cases of acute SVG failure. © 2017 Wiley Periodicals, Inc.

Recanalization of Chronic Total Occlusion Lesions: A Critical Appraisal of Current Devices and Techniques

Chronic Total Occlusion (CTO) has been considered as one of the "final frontier" in interventional cardiology. Until recently, the patients with CTO are often managed surgically or medically due to lack of published evidence of clinical benefits and lower success rate of percutaneous recanalization of CTO. However, the introduction of enhanced guidewires, microcatheters combined with novel specialized devices and techniques reduce the number of unapproachable CTO. In this review article, current techniques and devices of percutaneous recanalization of CTO have been systematically summarized, which may help budding interventional cardiologists to theoretically understand these complex procedures and to deliver safe and effective percutaneous management of CTO to the patients.

Extravascular Revascularization of a Chronic Total Occlusion Using the Dual Bull’s-Eye Technique

Purpose: To describe the dual bull’s-eye technique to achieve successful extravascular revascularization of an occlusion after vessel perforation when the antegrade and retrograde catheters are too far apart for salvage with a reentry catheter. Technique: The dual bull’s-eye technique, which is an adaptation of the “gun-sight” method for transjugular portosystemic shunt procedures, is demonstrated in a popliteal artery occlusion in which multiple recanalization attempts have produced vessel perforation. Via antegrade femoral and retrograde anterior tibial artery accesses, 10-mm Amplatz GooseNeck snares were advanced in plane from each access to rendezvous in the popliteal fossa to obtain through-and-through wire access. A 15-cm Chiba needle was advanced percutaneously in plane through both snares, and a hydrophilic guidewire was maneuvered across an extravascular tract parallel to the popliteal artery. The tract was carefully predilated, and a 5×100-mm Viabahn stent-graft was deployed across the extravascular tract. Conclusion: Owing to potential complications (limited patency, injury to adjacent structures) and only single-case use, this new technique should be considered a bailout strategy exclusively employed for limb salvage when traditional methods have failed and there are no viable surgical options.

Comparison of the ipsi-lateral versus contra-lateral retrograde approach of percutaneous coronary interventions in chronic total occlusions

BACKGROUND

Retrograde recanalization of coronary chronic total occlusions (CTO) via contralateral (CL) collateral connections (CCs) is successful in 60-70% of patients in whom conventional antegrade approach fails or is unpromising. This study describes our experience with retrograde CTO-PCI via ipsi-lateral (IL) CCs in patients with unfavorable CL CCs.

METHODS

Between January 2013 and September 2015, 392 consecutive CTO procedures were performed by two high volume CTO-operators and the relevant data were fed into an online registry (ERCTO® EuroCTO-club). Most patients (222/392; 57%) were approached antegradely, whereas 43% were attempted retrogradely (170/392). After exclusion of all procedures performed via bypass-grafts (n = 12), PCI via CL CCs, the CL-group (n = 114/158; 72%), was compared with the IL-group that was attempted via IL CCs (n = 44/158; 28%).

RESULTS

Both groups were similar with respect to risk factors and morphologic criteria of CTO-severity. The initial primary strategy was successful in 78% in the CL-group and in 68% in the IL-group. In both patient groups, the initial strategy had to be switched in five patients from CL toward IL (4.4%, n = 5/114) and from IL to CL (11.3% n = 5/44). The rate of major complications was 7% (CL) and 5% (IL), respectively (n.s.). After retrograde failure and cross-over to an antegrade controlled re-entry strategy the overall success rates increased to 92% (CL) and 93% (IL).

CONCLUSIONS

In experienced hands retrograde CTO-PCI via IL CCs appears as safe and successful as the CL approach. © 2016 Wiley Periodicals, Inc.

Recanalization of Chronic Total Occlusions in Patients With Previous Coronary Bypass Surgery and Consideration of Retrograde Access via Saphenous Vein Grafts

Background—

The prevalence of native coronary chronic total occlusions (CTOs) after coronary artery bypass grafts (CABGs) is higher than in non-CABG population. We examined outcomes of CTO percutaneous coronary intervention (PCI) post-CABG versus without CABG. Then, we looked at feasibility and outcomes of retrograde CTO PCI via patent or occluded saphenous vein graft.

Methods and Results—

We compared patient and procedural characteristics of 470 CTO cases treated from January 2010 to December 2015 depending on history of CABG. We assessed major adverse cardiac events, including cardiac death, myocardial infarction, ischemia-driven target-vessel revascularization, or reocclusion 1 year after successful CTO PCI in patients treated before February 2015. Post-CABG patients (175 cases) had a higher J-CTO score (2.5 versus 2.1; P =0.002). In-hospital complications were similar, although the incidence of contrast-induced nephropathy was higher in post-CABG patients (4.6% versus 1%; P =0.01). With multivariable analysis, post-CABG status was associated with higher incidence of 1-year major adverse cardiac event (hazards ratio=2.2; P =0.02). As a second level analysis, we looked at the feasibility and safety of CTO PCI via saphenous vein grafts (19% of post-CABG cases) versus collateral channels (36%) versus with an antegrade-only approach (45%), and assessed short-term outcomes and complications. High success was achieved in the saphenous vein graft group. In-hospital events were similar in the 3 groups.

Conclusions—

Post-CABG CTO PCI is associated with similar high success and low complications compared with CTO PCI in patients who never had CABG. However, it is associated with higher recurrent events at 1 year. To achieve high success rate, use of saphenous vein grafts as retrograde conduits seems to be safe and effective.

Retrograde approach to an ostial left anterior descending chronic total occlusion through a left internal mammary artery graft

Retrograde approach to chronic total occlusions (CTO) has been described via saphenous vein grafts, septal and epicardial collaterals. We report for the first time a successful retrograde approach to an ostial left anterior descending (LAD) artery CTO through a failed left internal mammary artery (LIMA) to LAD anastamosis. This case demonstrates the technical aspects of using a LIMA conduit as a retrograde approach to CTO. © 2015 Wiley Periodicals, Inc.

The Hybrid Approach to Intervention of Chronic Total Occlusions

The “hybrid” approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) was developed to provide guidance on optimal crossing strategy selection. Dual angiography remains the cornerstone of clinical decision making in CTO PCI. Four angiographic parameters are assessed: (a) morphology of the proximal cap (clear-cut or ambiguous); (b) oc-clusion length; (c) distal vessel size and presence of bifurcations beyond the distal cap; and (d) location and suitability of a retrograde con-duit (collateral channels or bypass grafts) for retrograde access. Antegrade wire escalation is favored for short (<20 mm) occlusions, usually escalating rapidly from a soft tapered-tip polymer-jacketed guidewire to a stiff polymer-jacketed or tapered-tip guidewire. Antegrade dissection/re-entry is favored in long (≥20 mm long) occlusions, try-ing to minimize the dissection length by re-entering into the distal true lumen immediately after the occlusion. Primary retro-grade approach is preferred for lesions with an ambiguous proximal cap, poor distal target, good interventional collaterals, and heavy calcification, as well as chronic kidney disease. The “hybrid” approach advocates early change between strategies to enable CTO crossing in the most efficacious, efficient, and safe way. Several early studies are demonstrating high success and low complication rates with use of the “hybrid” approach, supporting its expanding use in CTO PCI. .

Retrograde Coronary Chronic Total Occlusion Intervention

Coronary chronic total occlusion (CTO) is a frequent finding in patients with coronary artery disease. It remains one of the most challenging subsets, accounting for 10-20% of all percutaneous coronary interventions (PCI). Although remarkable progress in PCI has been made, it is reasonable to state that successful recanalization of CTO represents the “last frontier" of PCI. PCI of CTOs has been limited historically by technical success rates of 50-70%. The introduction of enhanced guidewires, microcatheter, channel dilatator with increasing operator experience, and innovative techniques such as the retrograde approach have raised hopes for better outcomes. This article goes into depth into various strategies of retrograde approach in CTO.

New Advances in Chronic Total Occlusions

Coronary chronic total occlusions (CTOs) still represent the greatest technical challenge that interventional cardiologists face. CTOs remain seriously undertreated with percutaneous techniques, far below their prevalence. One reason for the low uptake was the suboptimal CTO percutaneous coronary intervention (PCI) success rates over a long period of time. During the last years, dedicated groups of experts in Japan, Europe and United States fostered the development and standardisation of modern CTO recanalisation techniques, along with providing focused training and proctorship worldwide. As a result, dedicated operators achieved success rates far beyond 90 %, while coping with lesions of increasing complexity. A series of studies, mainly retrospective and observational in nature, explored the prognostic impact of CTO PCI, revealing that successful lesion recanalisation is related to improved patient outcome and anginal status; further evidence from randomised trials is on the way. The following review reports on the most recent advances in the field of CTO recanalisation, in an attempt to promote a more balanced approach in patients with chronically occluded coronary arteries and encourage more operators to cope with these inherently complex lesions.

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.

Changing strategies of the retrograde approach for chronic total occlusion during the past 7 years

OBJECTIVE

We reviewed the technical changes and results achieved with the retrograde approach since we introduced it 7 years ago.

SUBJECTS AND METHODS

The subjects were 1,268 patients who were treated for CTO between January 2004 and December 2010. They were investigated with respect to the success rate, the frequency of employing the retrograde approach and its outcome, and other factors.

RESULTS

The retrograde approach was employed in ∼30% of chronic total occlusion (CTO) patients (n = 281) and the retrograde guidewire success rate was 81.1%. The kissing wire technique was substituted for the retrograde approach in 126 of the 281 patients, with antegrade crossing of a guidewire being successful in 88 of them (70%). The retrograde approach was combined with the CART and reverse controlled antegrade retrograde tracking (CART) techniques in 22 and 21 patients, respectively. Among 83 patients treated with Corsair catheters, crossing of the CTO was achieved in 63. The overall procedural success rate was 79.7% (224 patients). Complications of the retrograde approach included collateral channel dissection (2.1%), channel perforation (1.7%), CTO perforation (1.7%), and donor artery occlusion (1.1%).

CONCLUSION

The success rate and safety of the retrograde approach are both satisfactory if the appropriate devices and techniques are selected.

Percutaneous coronary intervention by retrograde approach for chronic total occlusion of the proximal left anterior descending artery via a gastroepiploic artery graft

Coronary arteries connecting to septal branch are often occluded in post-coronary artery bypass graft cases. A 70-year-old male had undergone CABG; radial artery graft to the LCX, and gastroepiploic artery (GEA) graft to the RCA. Coronary angiography revealed total occlusion in proximal LAD, while both graft vessels had good flow. Retrograde percutaneous coronary intervention (PCI) procedure from the septal channel via GEA graft to the RCA was performed for total occlusion of LAD. Despite the tortuous GEA, deep engagement with a 4-french guiding catheter ensured powerful back-up force. After retrograde wire crossing, two drug-eluting stents were implanted, successfully.

Retrograde Procedural Planning, Skills Development, and How to Set Up a Base of Operations

This article addresses the practical steps required when adopting retrograde access as part of the treatment of chronic total occlusions (CTOs). The article focuses on procedure rationale, equipment required, the practical steps, and considerations involved in collateral-channel crossing and setting up a "base of operations" at the proximal cap of the CTO. It also describes simple methods of wire escalation.

Corsair microcatheter for retrograde coronary chronic total occlusion recanalization: early experience outside the realm of dedicated recanalization specialists

OBJECTIVE

To determine the extent to which use of the Corsair microcatheter (CM, Asahi Intecc Co., Japan) improves procedural outcomes when an experienced operator who is not a dedicated recanalization specialist attempts retrograde chronic total occlusion (CTO) recanalization through collateral channels during percutaneous coronary intervention.

BACKGROUND

The recently introduced CM has improved success rates of retrograde CTO recanalization to nearly 100% in the hands of dedicated coronary recanalization specialists; however, the impact the CM has on the results of non-specialist operators attempting retrograde CTO recanalization is not known.

METHODS

A non-specialist operator attempted CM-assisted recanalization in seven consecutive CTO cases requiring retrograde recanalization. The results obtained were compared with those achieved by the same operator in eleven consecutive retrograde CTO recanalization procedures during the last 2 years before the CM became available.

RESULTS

CM-assisted retrograde CTO recanalization was successful in 6 of 7 cases (86%), but failed in one case attempted through a tortuous epicardial collateral; there were no complications. In contrast, during the 2 years before the CM became available, retrograde CTO recanalization was successful in only 3 of 11 attempted cases (27%), and was associated with significant morbidity. Lesions in the two groups were comparable in terms of technical difficulty and procedural risk.

CONCLUSIONS

The non-specialist operator's retrograde CTO recanalization results improve significantly when using the CM. Given the effectiveness and safety of CM-assisted retrograde CTO recanalization, operators should be less aggressive with anterograde recanalization attempts, and should switch to the retrograde approach earlier and more often.

Total aorto-ostial chronic occlusion of the right coronary artery successfully recanalized via retrograde approach

Chronic total occlusions remain a technical challenge for interventional cardiologists. This group of lesions carries a decreased rate of success and continues to be an important reason for surgical revascularization. Recently, retrograde percutaneous coronary intervention of total occlusions via epicardial and septal perforators was introduced as an alternative approach when a previous antegrade attempt has failed. We describe a unique case where retrograde approach was used as the initial recanalization technique in the absence of a right coronary ostium.

Coronary chronic total occlusion

Chronic total coronary occlusions (CTOs) are a frequent finding in patients with coronary disease and remain one of the most challenging target lesion subsets for intervention. CTOs have been reported in approximately one-third of patients undergoing diagnostic coronary angiography. By nature of their complexity, CTO percutaneous interventions (PCIs) are associated with lower rates of procedural success, higher complication rates, greater radiation exposure, and longer procedure times compared with interventions in non-CTO stenoses. Despite these obstacles, reported benefits of successful CTO PCI include a reduction in symptoms and improvement in both ventricular function and survival. This article examines the technical challenges, procedural complications, and possible outcomes associated with CTO PCI.