Intravascular Ultrasound Comparison of the Retrograde Versus Antegrade Approach to Percutaneous Intervention for Chronic Total Coronary Occlusions

The Clinical Effects of Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Patients with Chronic Total Occlusion: A Meta-Analysis

Background

The clinical effects of intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in patients with chronic total occlusion (CTO) lesions remain unclear.

Methods

We identified all full-text published studies that compared the effects of IVUS-guided CTO-PCI with angiography-guided CTO-PCI by searching electric databases including PubMed, Embase, Cochrane Library, and ISI Web of Science from the establishment to Nov 2021. There was no language limitation. The endpoints included the incidence of major adverse cardiac events (MACE), cardiac death, all-cause death, myocardial infarction (MI), and target vessel revascularization (TVR).

Results

Five studies involving a total of 2320 patients were included in this meta-analysis. Compared to the angiography-guided group, IVUS-guided PCI showed no significant reduction in the incidence of MACE (I² = 27.4%, P = 0.239; RR 0.929, 95% CI 0.765 to 1.128, P = 0.457), cardiac death (I² = 0.0%, P = 0.459; RR 0.574, 95% CI 0.299 to 1.103, P = 0.096), all-cause death (I² = 0.0%, P = 0.964; RR 0.677, 95% CI 0.395 to 1.163, P = 0.158), MI (I² = 46.7%, P = 0.131; RR0.836, 95% CI 0.508 to 1.377, P = 0.482), and TVR (I² = 21.2%, P = 0.279; RR 0.929, 95% CI 0.679 to 1.272, P = 0.648).

Conclusions

IVUS-guided PCI demonstrated no significant benefit on MACE, cardiac death, all-cause death, MI, and TVR in patients with CTO lesions. However, given the study's limitations, additional high-quality RCTs are needed.

Outcomes of contemporary versus conventional reverse controlled and antegrade and retrograde subintimal tracking in chronic total occlusion revascularization

BACKGROUND

Chronic total occlusion (CTO) lesions remain technically challenging for percutaneous coronary intervention (PCI). The introduction of a retrograde approach has allowed marked improvement in the success rate of CTO recanalization. Reverse controlled anterograde and retrograde sub-intimal tracking (reverse CART) is the predominant retrograde wire crossing technique and can be broadly classified into three categories: (1) conventional (2) contemporary and (3) extended. The present study aimed to compare the safety and efficacy of conventional and contemporary reverse CART techniques.

METHODS

From March 2015 to May 2020, 303 patients achieving successful retrograde guidewire crossing with conventional or contemporary reverse CART during CTO PCI were included in the study. The patient characteristics, procedural outcomes and in-hospital and 1-year clinical events were compared between the conventional and contemporary groups.

RESULTS

The distributions of the baseline and angiographic characteristics were similar in both study arms, except the CTO lesions of the conventional group were more complex, as reflected by borderline significantly higher mean J-CTO scores (3.4 ± 0.7 vs. 3.3 ± 0.8; p = 0.059). Recanalization using contemporary reverse CART was associated with a short procedure time (189.8 ± 44.4 vs. 181.7 ± 37.3 min; p = 0.044) and decreased procedural complications, particularly target vessel perforation (3.6% vs. 0.6%; p = 0.063) and major side-branch occlusion (36.7% vs. 28.0%; p = 0.051). Technical and procedural success and the in-hospital and 1-year outcomes were not significantly different between the groups.

CONCLUSIONS

Contemporary reverse CART is associated with favorably high efficiency and low-complication rates and carries a comparable success rate and 1-year clinical outcomes as conventional reverse CART.

Intravascular Ultrasound in Chronic Total Occlusion Percutaneous Coronary Intervention: Solving Ambiguity and Improving Durability

Chronic total occlusions remain among the most technically challenging lesions to treat percutaneously. Limitations of 2-dimensional angiography may further hinder successful treatment of these lesions. Intrasvascular ultrasound has a key role in percutaneous recanalization for a chronic total occlusion by providing key lesion characteristics, facilitating guidewire crossing, elucidating the intraplaque or extralaque path of the guidewire, optimizing lesion preparation, guiding stenting and identifying suboptimal results. Live visualization of the guidewire during crossing may reduce extraplaque wire tracking. This review describes the practical uses of intravascular imaging for commonly encountered scenarios when treating chronic total occlusions.

The role of intravascular ultrasound in percutaneous coronary intervention of complex coronary lesions

Intravascular ultrasound (IVUS) is a catheter-based coronary imaging technique. It utilises the emission & subsequent detection of reflected high frequency (30-60 MHz) sound waves to create high resolution, cross-sectional images of the coronary artery. IVUS has been the cornerstone of intracoronary imaging for more than two decades. When compared to the invasive coronary angiogram which studies only the silhouette of the contrast-filled artery lumen, IVUS also crucially images the vessel wall. Because of this capability, IVUS has greatly facilitated understanding of the coronary atherosclerosis process. Such insights from IVUS reveal how commonly and extensively plain angiography underestimates the true extent of coronary plaque, the characteristics of plaques prone to rupture and cause acute coronary syndromes (lipid rich, thin cap atheroma), and a realisation of the widespread occurrence of vessel remodelling in response to atherosclerosis. Similarly, IVUS has historically provided salutary mechanistic insights that have guided many of the incremental advances in the techniques of percutaneous coronary intervention (PCI). Examples include mechanisms of in-stent restenosis, and the importance of high-pressure post-dilatation of stents to ensure adequate stent apposition and thereby reduce the occurrence of stent thrombosis. IVUS also greatly facilitates the choice of correct diameter and length of stent to implant. Overall, a compelling body of evidence indicates that use of intravascular ultrasound in PCI helps to achieve optimal technical results and to mitigate the risk of adverse cardiac events. In this review, the role of intravascular ultrasound as an adjunct to PCI in complex coronary lesions is explored. The complex coronary situations discussed are the left main stem, ostial stenoses, bifurcation stenoses, thrombotic lesions, the chronically occluded coronary artery, and calcified coronary artery disease. By thorough review of the available evidence, we establish that the advantages of IVUS guidance are particularly evident in each of these complex CAD subsets. In particular, some consider the use of IVUS to be almost mandatory in left main PCI. A comparison with other intracoronary imaging techniques is also explored.

A Technical Focus on Antegrade Dissection and Re-entry for Coronary Chronic Total Occlusions: a Practice Update for 2019

Coronary chronic total occlusions (CTOs) are a commonly encountered lesion. These present in a diverse patient population with variable anatomy. Technical success rates of ~90% are achievable for CTO lesions in centers with appropriate expertise. Many lesions can be crossed with wire-based techniques. However, the most anatomically complex and technically challenging lesions will often require more advanced approaches such as retrograde access and/or the application of blunt dissection techniques in the vessel to safely navigate long and/or ambiguous CTO segments. Retrograde dissection and re-entry (RDR) and antegrade dissection and re-entry (ADR) strategies are often needed to treat such lesions. In many circumstances, ADR offers a safe and efficient means to successfully cross a CTO lesion. Therefore, operators must remain cognizant of the risks and benefits of differing technical approaches during CTO percutaneous coronary intervention, particularly when both ADR and RDR are feasible. This article provides an overview of the ADR technique in addition to updated approaches in contemporary clinical practice.

Clinical and angiographic outcomes of true vs. false lumen stenting of coronary chronic total occlusions: Insights from intravascular ultrasound

OBJECTIVES

The clinical implications of subintimal stenting (SS) of the recanalized chronic total occlusion (CTO) segment have not been characterized. We evaluated the in-hospital and the long-term clinical and angiographic outcomes of drug-eluting stents (DESs) deployed in true vs. false lumen of successfully recanalized CTO.

METHODS AND RESULTS

Two independent reviewers analyzed the intravascular ultrasound (IVUS) images of 173 successfully recanalized CTO lesions (157 patients), between August 2011 and October 2012. After successful guidewire (GW) crossing, lesions were classified according to IVUS evaluation into two groups: (1) true lumen (TL) stenting group and (2) SS group; and compared with regards to in-hospital and long-term clinical outcomes. In 154 lesions, DESs were deployed in the TL; and in 19 (11%) lesions, DESs were deployed in the subintimal space (95% confidence interval: 6.3-15.6%). False GW tracking in the SS group resulted in increased rates of IVUS-detected dissection flaps (84% vs. 42.6%, P ≤ 0.001), intramural hematoma (32 vs. 11%, P = 0.01), and minor perforations 6/19 (31.6% vs. 8.4%, P = 0.002). At 1-year follow-up, both groups had similar cumulative rates of binary restenosis and target lesion revascularization (P = 0.73 and P = 0.97, respectively). Six patients (4.6%, 6/129 patients) in the TL group and none in the subintimal group died at 1 year.

CONCLUSIONS

Acknowledging some limitations, our observations may suggest that, subintimal stent deployment in a recanalized CTO segments, using second generation DES and IVUS guidance, might have a comparable success rate and long-term angiographic and clinical outcomes as TL stenting.

Coronary chronic total occlusion intervention: A pathophysiological perspective

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is the last frontier in coronary intervention. PCI of CTO carries multiple advantages, such as significant improvement in symptoms, improvement in abnormal wall motion and left ventricular function and, possibly, increased long-term survival. As of today the procedural success is markedly improved because of technical innovations and is limited to highly experienced operators. To enhance the overall success rate from a worldwide perspective, a thorough understanding of its pathophysiology is critical to further development of newer techniques and technologies. In this review, the author outlines in-depth the evidence that underpins our understanding of CTO pathophysiology and its insight into CTO intervention that incorporates various steps and techniques to cross the lesion.

Impact of Chronic Kidney Disease on Outcomes After Percutaneous Coronary Intervention for Chronic Total Occlusions (from the Japanese Multicenter Registry)

The impact of chronic kidney disease (CKD) and potential pharmacologic intervention on clinical outcomes after percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) remains unknown. A total of 1,463 patients underwent successful CTO-PCI between August 2004 and December 2014. Major adverse cardiovascular events (MACE) defined as the composite of all-cause death, myocardial infarction and target lesion revascularization, cardiac death, and stent thrombosis were compared between patients with and without CKD (555 and 908 patients, respectively). The results demonstrated higher risks of MACE (log-rank p = 0.015), all-cause death (log-rank p <0.001), and cardiac death (log-rank p <0.001) in the CKD group compared with the non-CKD group. Multivariable analyses demonstrated that CKD was an independent predictor for MACE (hazard ratio 1.23, 95% confidence interval 1.02 to 1.47, p = 0.03). With regard to pharmacotherapy, statin use was associated with significantly lower rates of MACE in the CKD group (log-rank p = 0.003). In conclusion, the presence of CKD would be an important predictor of long-term clinical outcomes in patients who underwent CTO-PCI, and use of statin may influence in reducing the adverse clinical outcomes.

Intravascular ultrasound enhances the safety of rotational atherectomy

Intravascular ultrasound (IVUS) is mainly used in PCI to treat complex lesions, such as left main bifurcation, chronic total occlusion and calcified lesions. Although IVUS yields useful information such as the presence of napkin-ring calcification, the role of IVUS in rotational atherectomy (RA) is not fully appreciated. Recently, since the deliverability and crossability of IVUS catheters have improved, IVUS should be attempted before RA. Even if the IVUS catheter cannot cross the lesion, IVUS provides information just proximal to the target lesion, which would be useful in the selection of the appropriate guidewire and burr size. IVUS can be repeated following RA, which may influence the decision to continue RA with larger burrs. Circumferential calcification is a good indication for RA, since RA can create a calcium crack that facilitates balloon dilatation. However, if the distribution of calcification is not circumferential, the indication for RA can more safely be determined based on IVUS images than angiographic information alone. Because RA burrs usually follow the route taken by the IVUS catheter, the positional relationship between the IVUS imaging core and calcification would be similar to that between the RA burrs and calcification. The relationship between the RA burrs and distribution of calcification is discussed in this review.

Incidence and impact on midterm outcome of intimal versus subintimal tracking with both antegrade and retrograde approaches in patients with successful recanalisation of chronic total occlusions: J-PROCTOR 2 study

AIMS

The aim of this study was to assess the incidence and impact on midterm outcomes of intimal versus subintimal tracking with both antegrade and retrograde approaches in patients undergoing successful percutaneous coronary intervention for chronic total occlusion (CTO).

METHODS AND RESULTS

In 2012, a total of 1,573 CTO cases from 30 hospitals were enrolled in the Japanese CTO registry. Successful guidewire crossing was performed in 1,411 cases (89.7%). Among them, the guidewire penetration position was clearly identified using intravascular ultrasound (IVUS) imaging in 352 cases, and clinical follow-up at 12 months was performed in 323 cases. These 323 cases were enrolled in this retrospective study: 242 cases were treated with the antegrade approach (antegrade group) and 81 cases were treated with the retrograde approach (retrograde group). The endpoint of this study was target vessel revascularisation (TVR) and major adverse cardiac events (MACE) at 12-month follow-up. Subintimal tracking occurred more frequently in the retrograde group (11.6% vs. 30.9%, p<0.01). TVR was more frequent in the subintimal tracking group in the retrograde group (7.1% vs. 16.0%, p=0.03) but not in the antegrade group (2.8% vs. 3.6%, p=0.99). Although the occlusion length was similar, the subintimal tracking group required a longer stent length compared to the intimal tracking group in the retrograde approach (59.7±24.4 mm vs. 74.0±24.4 mm, p<0.01).

CONCLUSIONS

Subintimal tracking was more frequent in the retrograde approach. Intimal tracking should be recommended in the retrograde approach to reduce stent length and to improve follow-up outcomes.

Antegrade Dissection and Reentry as Part of the Hybrid Chronic Total Occlusion Revascularization Strategy

Background—

Development of the CrossBoss and Stingray devices for antegrade dissection and reentry (ADR) of chronic total occlusions has improved historically suboptimal outcomes. However, the outcomes, safety, and failure modes of the technique have to be studied in a larger patient cohort. This preplanned substudy of the RECHARGE registry (Registry of CrossBoss and Hybrid Procedures in France, the Netherlands, Belgium and United Kingdom) aims to evaluate the value and use of ADR and determine its future position in contemporary chronic total occlusion intervention.

Methods and Results—

Patients were selected if an ADR strategy was applied. Outcomes, safety, and failure modes of the technique were assessed. The ADR technique was used in 23% (n=292/1253) of the RECHARGE registry and was mainly applied for complex lesions (Japanese chronic total occlusion score=2.7±1.1). ADR was the primary strategy in 30% (n=88/292), of which 67% were successful. Bail-out ADR strategies were successful in 63% (n=133/210). The Controlled ADR (ie, combined CrossBoss-Stingray) subtype was applied most frequently (32%; n=93/292) and successfully (81%; n=75/93). Overall per-lesion success rate was 78% (n=229/292), after use of additional bail-out strategies. The inability to reach the distal target zone (n=48/100) or to reenter (n=43/100) most commonly led to failure. ADR-associated major events occurred in 3.4% (n=10/292).

Conclusions—

Although mostly applied as a bail-out strategy for complex lesions, the frequency, outcomes, and low complication rate of the ADR technique and its subtypes confirm the benefit and value of the technique in hybrid chronic total occlusion percutaneous coronary intervention, especially when antegrade wiring or retrograde approaches are not feasible.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT02075372.

Intravascular Ultrasound Analysis of Intraplaque Versus Subintimal Tracking in Percutaneous Intervention for Coronary Chronic Total Occlusions and Association With Procedural Outcomes

OBJECTIVES

Using intravascular ultrasound (IVUS), the authors compared outcomes by observed wire position (intraplaque vs. subintimal) achieved during successful chronic total occlusion (CTO) lesion treatment.

BACKGROUND

Recent successes in CTO percutaneous coronary intervention (PCI) have used both intraluminal and subintimal wire tracking to improve procedural success. IVUS may be used to determine the course of wire tracking after crossing a CTO.

METHODS

From March 2014 to March 2016, data were collected into a single-center database from 219 patients undergoing CTO PCI with concomitant IVUS imaging. IVUS-visualized wire tracking patterns were then retrospectively examined. Clinical outcomes with a composite in-hospital cardiovascular endpoint of all-cause death, periprocedural myocardial infarction, and in-hospital target lesion revascularization were analyzed along with IVUS-detected vascular injury.

RESULTS

Of the 524 lesions assessed, 219 patients with successfully recanalized CTO lesions had adequate IVUS imaging and were included. Subintimal tracking was detected in 52.1% of overall cases (86.7% dissection re-entry, 27.9% wire escalation). Minimal stent area of the CTO segment and prevalence of significant edge dissection were similar in the 2 groups. In the subintimal tracking group, there was a higher rate of the composite endpoint, mostly driven by periprocedural myocardial infarction. Subintimal tracking was associated with significantly greater IVUS-detected vascular injury, angiographic dye staining/extravasation, and branch occlusion.

CONCLUSIONS

IVUS-detected subintimal tracking is observed in approximately one-half of all successful CTO PCI cases and is associated with an expected higher, yet acceptable, event rate with no difference in minimal stent area or edge dissection among patients undergoing contemporary hybrid CTO PCI.

Influence about the flow of distal branch after intervention of the right coronary artery chronic total occlusion

OBJECTIVE

Limited data are available for the clinical outcomes after the recanalization of right coronary artery (RCA) chronic total occlusion (CTO). The study aims to assess the clinical outcomes in the antegrade flow of the distal branch after successful RCA CTO percutaneous coronary intervention (PCI).

METHODS

Between January 2002 and December 2012, 538 patients who underwent RCA CTO PCI were enrolled. The clinical outcomes as myocardial infarction (MI), target vessel revascularization, cardiac death, major adverse cardiac events, and all-cause mortality, were compared to the antegrade flow of distal branch after successful RCA CTO PCI.

RESULTS

The CTOs were located in proximal segments (57.6%), mid segments (27.5%) and distal segments (14.9%). The average Syntax score was 18.4±9.6 and 47.8% patients had a Syntax score greater than 27.5. A total of 62.8% patients had final thrombolysis of myocardial infarction (TIMI)-3 flow of distal branch, 16.9% patients had final TIMI-3 flow of only one major branch, 11.3% patients had TIMI-1-2 flow, and 8.9% patients had no antegrade flow. The incidence of periprocedural MI was lower in both side branches were preserved (13.9% vs. 23.0% and 18.8%, p=0.01). The clinical outcomes were similar between the groups with and without good antegrade flow of distal side branch. End stage renal disease (ESRD) and left ventricular ejection fraction (LVEF) <40% predicted three-year cardiac death.

CONCLUSIONS

There is no significant difference of clinical outcomes when distal side branches of RCA are recanalized successfully. ESRD and LVEF <40% were the predictors for three-year cardiac death.

Application of a snare technique in retrograde chronic total occlusion percutaneous coronary intervention - a step by step practical approach and an observational study

Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has recently become popular among interventional cardiologists. CTO originating from the ostium has been one of the most difficult CTO lesions to treat with PCI for a number of reasons. Our aim was to illustrate a specific technique during retrograde CTO PCI referred to as the "snare technique."We retrospectively examined the use of "snare technique" among 371 consecutive retrograde CTO PCIs performed at our institution between 2006 and 2015."Snare technique" was used in 10 patients among the 371 retrograde CTO PCIs. The baseline clinical and angiographic characteristics of patients with or without "snare technique" were similar. The "snare technique" group had significantly fewer side branches at occlusion (30.0% vs 71.2%, P = 0.01) and a higher incidence of externalization (90% vs 25.5%, P < 0.001). The contrast volume was significantly lower in the "snare technique" group (285.0 ± 68.5 vs 379.2 ± 144.0, P = 0.04). The incidence of major complications, retrograde success, or final success did not differ between the groups.The "snare technique" is safe and feasible in retrograde CTO PCI, especially in cases of difficult coronary engagement in cases such as ostial occlusion, challenging coronary anatomy, or retrograde guidewire cannot get in antegrade guiding catheter.

Use of Intravascular Imaging During Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Contemporary Multicenter Registry

BACKGROUND

Intravascular imaging can facilitate chronic total occlusion (CTO) percutaneous coronary intervention.

METHODS AND RESULTS

We examined the frequency of use and outcomes of intravascular imaging among 619 CTO percutaneous coronary interventions performed between 2012 and 2015 at 7 US centers. Mean age was 65.4±10 years and 85% of the patients were men. Intravascular imaging was used in 38%: intravascular ultrasound in 36%, optical coherence tomography in 3%, and both in 1.45%. Intravascular imaging was used for stent sizing (26.3%), stent optimization (38.0%), and CTO crossing (35.7%, antegrade in 27.9%, and retrograde in 7.8%). Intravascular imaging to facilitate crossing was used more frequently in lesions with proximal cap ambiguity (49% versus 26%, P<0.0001) and with retrograde as compared with antegrade-only cases (67% versus 31%, P<0.0001). Despite higher complexity (Japanese CTO score: 2.86±1.19 versus 2.43±1.19, P=0.001), cases in which imaging was used for crossing had similar technical and procedural success (92.8% versus 89.6%, P=0.302 and 90.1% versus 88.3%, P=0.588, respectively) and similar incidence of major cardiac adverse events (2.7% versus 3.2%, P=0.772). Use of intravascular imaging was associated with longer procedure (192 minutes [interquartile range 130, 255] versus 131 minutes [90, 192], P<0.0001) and fluoroscopy (71 minutes [44, 93] versus 39 minutes [25, 69], P<0.0001) time.

CONCLUSIONS

Intravascular imaging is frequently performed during CTO percutaneous coronary intervention both for crossing and for stent selection/optimization. Despite its use in more complex lesion subsets, intravascular imaging was associated with similar rates of technical and procedural success for CTO percutaneous coronary intervention.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02061436.

Guidewire crossing techniques in coronary chronic total occlusion intervention: A to Z

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) poses a management dilemma for the interventional cardiologist. Effective wiring technique is the key to success of PCI in CTO, which requires more patience and skill of the operator. The author herein intends to explore in detail the different wiring strategies such as antegrade approach, dissection and reentry, retrograde and hybrid approach. Hopefully, this review would enhance the understanding of this complex procedure and, consequently, promote safe and effective PCI.

Angiographic and clinical comparisons of intravascular ultrasound- versus angiography-guided drug-eluting stent implantation for patients with chronic total occlusion lesions: two-year results from a randomised AIR-CTO study

AIMS

This study sought to compare angiographic endpoints at one-year follow-up after a drug-eluting stent implantation guided by either intravascular ultrasound (IVUS) or angiography in patients with chronic total occlusion (CTO) lesions.

METHODS AND RESULTS

Patients with at least one CTO lesion recanalised successfully were randomly assigned to the IVUS-guided or the angiography-guided group. The use of IVUS for penetration of the true lumen and optimisation of stent expansion was only done in the IVUS-guided group. The primary endpoint was in-stent late lumen loss (LLL) at one-year follow-up. A total of 230 patients with CTO lesions after successful recanalisation were enrolled and followed with office visits or telephone contact up to 24 months. In-stent LLL in the IVUS-guided group was significantly lower compared to the angiography-guided group at one-year follow-up (0.28±0.48 mm vs. 0.46±0.68 mm, p=0.025), with a significant difference in restenosis of the "in-true-lumen" stent between the two groups (3.9% vs.13.7%, p=0.021). The minimal lumen diameter and minimal stent cross-section area significantly and negatively correlated with LLL (all p<0.001). The rates of adverse clinical events were comparable between the IVUS- and angiography-guided groups at two-year follow-up (21.7% vs. 25.2%, p=0.641).

CONCLUSIONS

The IVUS-guided stenting of the CTO lesion was associated with less LLL and a lower incidence of "in-true-lumen" stent restenosis. Additional study is required to identify the clinical benefit of the IVUS-guided procedure for CTO lesions. [ChiCTR-TRC-10000996].

Knowledge of chronic total occlusion among Polish interventional cardiologists

Introduction

Chronic total occlusion (CTO) recanalization is indicated in patients with symptoms and evidence of ischemia, but in most cases those types of lesions are still treated medically. In the last few years CTO angioplasty technique has changed dramatically due to considerable advances in techniques and dedicated equipment.

Aim

An attempt to assess the state of knowledge of technical aspects of CTO angioplasty of coronary arteries among Polish interventional cardiologists.

Material and methods

Questionnaire survey performed during two major Polish invasive cardiology workshops.

Results

In the study there participated 113 physicians with an average length of work experience of 13 years, most of them cardiologists certified as independent primary operators. The majority of respondents recognized the need of prevention of thrombotic complications through control of activated coagulation time during the CTO procedures. Prevention of renal complications and X-ray protection are also recognized as a significant part of the procedures. The benefits from the use of over-the-wire microcatheters and balloons, the proper choice of dedicated guidewires, contralateral injections and retrograde technique are underestimated.

Conclusions

Despite satisfactory knowledge about indications and qualification for the CTO procedure, the awareness of procedural aspects (particularly the retrograde technique) as well as the dedicated CTO equipment among Polish interventional cardiologists is still insufficient.

The role for adjunctive image in pre-procedural assessment and peri-procedural management in chronic total occlusion recanalisation

Non invasive coronary angiography with multislice computed tomography has exquisite sensitivity to detect calcium and even the faintest late contrast filling of the distal vessel. Calcium burden and occlusion length are still valuable markers of duration, complexity and success of the recanalisation procedure. The ability to visualise the vessel also in the occluded segment, especially if calcified, can also help the operator to understand where to pierce the proximal cap in stumpless occlusions and to predict unusual courses, especially in very tortuous arteries. Imaging side by side CT images and angiography during the recanalisation procedure is an established practice in many active CTO laboratories and algorithms for co-registration are designed to overcome the challenges of systo-diastolic and respiratory motion. Intravascular ultrasound is used in almost all cases by the experienced Japanese CTO operators but most of the times its main use is a better identification of the diseased segment after predilatation to ensure complete stent cover and appropriate stent expansion, an application similar to other complex non occlusive lesions. The specificity of IVUS during CTO recanalisation is the identification of the vessel path in stumpless occlusions and the guidance of wire reentry especially during reverse Controlled Retrograde Anterograde Tracking. Optical coherence tomography has limitations in the setting of CTO recanalisation because of the need of forceful contrast flushing to clear blood, contraindicated in the presence of anterograde dissections, and the limited penetration. The variability in the use of both non-invasive and invasive imaging during CTO recanalisation is immense, going from more than 90% in Japan to less than 20% in Europe and intermediate penetration in the USA. Probably the explanation is almost only in availability and cost because all countries see a progressive increase of use suggesting that these methods are becoming an established tool for guidance of CTO recanalisation.

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.

Occlusion of left main coronary artery during percutaneous coronary intervention for chronic total occlusion of left circumflex artery with retrograde approach

The retrograde approach, a new technique of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO), allows coronary interventionalists to improve the success rate. However, this technique occasionally has serious complications. We report a case with the occlusion of left main coronary artery (LMCA) during PCI for CTO in the proximal LCX with retrograde approach because of backward spiral dissection formed by retrograde wire. We could perform bail-out stenting for LMCA. In PCI for CTO in the proximal site of left coronary artery with retrograde approach, we should keep in mind a backward dissection to LMCA formed by retrograde wire.

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.

Fundamental wire technique and current standard strategy of percutaneous intervention for chronic total occlusion with histopathological insights

Currently, successful treatment of chronic total occlusion (CTO) seems markedly improved, due to several new techniques and dedicated device developments. However, this improved success rate is often limited to procedures performed by skilled, highly experienced operators. To improve the overall success rate of percutaneous coronary intervention of CTO from a worldwide perspective, a deeper understanding of CTO histopathology might offer insights into the development of new techniques and procedural strategies. In this review, CTO histopathology and wire techniques are discussed on the basis of the fundamental concepts of antegrade and retrograde approaches. Although details pertaining to wire manipulation are very difficult to explain objectively, we tried to describe this as best as possible in this article. Finally, a systematic review of the current standard CTO strategy is provided. Hopefully, this article will enhance the understanding of this complex procedure and, consequently, promote safe and effective CTO-percutaneous coronary intervention for patients who present with this challenging lesion subset.

Effect of preoperative evaluation by multidetector computed tomography in percutaneous coronary interventions of chronic total occlusions

BACKGROUND

The prevalence of success of percutaneous coronary interventions (PCIs) of chronic total occlusions (CTOs) remains relatively low. We determined the effect of preoperative multidetector computed tomography coronary angiography (CTCA) in PCIs of CTOs.

METHODS

The study population was 100 consecutive patients who underwent PCIs of CTOs from January 2005 to December 2007 at Keio University School of Medicine. They were divided into two groups according to the absence (non-CT group, n=60) or presence (CT group, n=40) of preoperative CTCA. The effect of preoperative CTCA was assessed in the prevalence of success of the procedure, prevalence of complications, irradiation time, and the dose of contrast agents.

RESULTS

The prevalence of procedural success was similar in both groups (non-CT group vs CT group 80.0% vs 77.5%, p=0.76). Irradiation time and the dose of contrast agents were also similar between these groups. The prevalence of complications was significantly reduced in the CT group (23.3% vs 7.5%, p=0.039), especially coronary perforations, which required treatment only in the non-CT group (10.0% vs 0.0%, p=0.039). Multiple logistic regression analysis revealed that use of a rotablator (odds ratio [OR]: 4.40, 95% confidence interval [CI]: 1.19-16.27, p=0.027) and absence of preoperative CTCA (OR: 4.26, 95% CI: 1.04-17.49, p=0.044) were independent determinants of complications.

CONCLUSION

Preoperative CTCA does not affect the prevalence of procedural success, irradiation time and the dose of contrast agents, but may be useful to reduce the prevalence of complications during PCIs of CTOs.