Chronic Total Occlusions Segment Research Articles

Radiomics Analysis of CTO Plaques for Predicting Successful Guidewire Crossing Within 30 Minutes of PCI.

Coronary computed tomography angiography provides valuable information for evaluating the difficulty of chronic total occlusion (CTO) percutaneous coronary intervention. This study aimed to investigate the value of CTO plaque characteristics derived from radiomics analysis for predicting the difficulty of percutaneous coronary intervention. Patients with CTO were retrospectively enrolled from a hospital as training and internal test sets and from the other 2 territory hospitals as external test sets. Radiomics characteristics were extracted from the CTO segment on coronary computed tomography angiography. Radiomics and combined models were developed to predict successful guidewire crossing within 30 minutes (guidewire success) of CTO percutaneous coronary intervention. Subgroup analysis was conducted to investigate the influence of potential risk factors on the radiomics model performance. A total of 551 patients (median, 60; interquartile range, 52.00-66.00 years, 460 men) with 565 CTO lesions were finally enrolled. In the training, internal test, and external test sets, 203 of 357, 85 of 149, and 38 of 59 CTO lesions achieved guidewire success, respectively. Six radiomics features were selected for constructing the radiomics model. In the external test set, the area under the receiver operating characteristic curve of the radiomics model was significantly higher than prior prediction models (P<0.05 for all) with the area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity of 0.86, 74.58%, 81.58%, and 61.90%, respectively. The performance of the radiomics model was dependent on calcification, CTO location, adjacent branch(es), and operator caseload. CTO characteristics revealed by radiomics analysis can be used as effective imaging biomarkers for predicting guidewire success. However, the performance of the radiomics model depends on anatomic and operator factors.

Impact of Bifurcation Involvement and Location in Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From the EuroCTO Registry

Bifurcation involvement close to or within the occluded segment poses increasing difficulties for chronic total occlusion (CTO)-percutaneous coronary intervention (PCI). However, this variable is not considered in the angiography-based CTO scoring systems nor has been extensively investigated in large multicenter series. Accordingly, we analyzed a CTO-PCI registry involving 92 European centers to explore the incidence, angiographic and procedural characteristics, and outcomes specific to CTO-PCIs with bifurcation involvement. A total of 3,948 procedures performed between January and November 2023 were examined (33% with bifurcation involvement). Among bifurcation lesions, 38% and 37% were located within 5 mm of the proximal and distal cap, respectively, 16% within the CTO body, and in 9% of cases proximal and distal bifurcations coexisted. When compared with lesions without bifurcation involvement, CTO bifurcation lesions had higher complexity (J-CTO 2.33 ± 1.21 vs 2.11 ± 1.27, p <0.001) and were associated with higher use of additional devices (dual-lumen microcatheter in 27.6% vs 8.4%, p <0.001, and intravascular ultrasound in 32.2% vs 21.7%, p <0.001). Radiation dose (1,544 [836 to 2,819] vs 1,298.5 [699.1 to 2,386.6] mGy, p <0.001) and contrast volume (230 [160 to 300] vs 190 [130 to 250] ml, p <0.001) were also higher. Technical success was similar (91.5% with bifurcation involvement vs 90.4% without bifurcation involvement, p = 0.271). However, the bifurcation lesions within the CTO segment (intralesion) were associated with lower technical success than the other bifurcation-location subgroups (83.7% vs 93.3% proximal, 93.4% distal, and 89.0% proximal and distal, p <0.001). On multivariable analysis, the presence of an intralesion bifurcation was independently associated with technical failure (odds ratio 2.04, 95% confidence interval 1.24 to 3.35, p = 0.005). In conclusion, bifurcations are present in approximately one-third of CTOs who underwent PCI. PCI of CTOs with bifurcation can be achieved with high success rates except for bifurcations within the occluded segment, which were associated with higher technical failure.

Current evidence for prognostic benefit of intravascular imaging-guided percutaneous coronary intervention in chronic total occlusion intervention.

Although percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has been increasing in recent years, CTO PCI is still one of the most challenging procedures with relatively higher rates of procedural complications and adverse clinical events after PCI. Due to the innate limitations of invasive coronary angiography, intravascular imaging (IVI) has been used as an adjunctive tool to complement PCI, especially in complex coronary artery disease. Considering the complexity of CTO lesions, the role of IVI is particularly important in CTO intervention. IVI has been a useful adjunctive tool in every step of CTO PCI including assisted wire crossing, confirmation of wire location within CTO segment, and stent optimization. The meticulous use of IVI has been one of the greatest contributors to recent progress of CTO PCI. Nevertheless, studies evaluating the role of IVI during CTO PCI are limited. The current review provides a comprehensive overview of the mechanistic advantages of IVI in CTO PCI, summarizes previous studies and trials, and presents future perspective of IVI in CTO PCI.

Exploring indicators of success in chronic total occlusion percutaneous coronary intervention with Stingray system-based antegrade dissection re-entry: Insights from retrospective analysis.

The predictors of success of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) through antegrade dissection and re-entry (ADR) using the Stingray system (Stingray ADR) remain elusive, mainly owing to the lack of consecutive angiographic and procedural records of patients. This study aimed to identify indicators that can determine the success of CTO PCI performed using the Stingray ADR technique. The clinical data of 115 patients who underwent CTO PCI through Stingray ADR at the same cardiac center were retrospectively and consecutively collected. Multivariate logistic regression analysis was performed to investigate the indicators of the success of ADR attempts. The technical success rate of Stingray ADR in CTO PCI was 72.2%. The overall technical success rate of CTO recanalization was 78.3% in all CTO PCIs having used Stingray Low Profile balloon. Vessel calcification (odds ratio [OR]: 4.03; 95% confidence interval [CI]: 1.49-11.88; p = 0.008), and retrograde puncture indicator (OR: 4.89; 95% CI: 1.51-17.11; p = 0.009) were identified as independent positive predictors. Blunt/no stump proximal to the occlusion segment (OR: 0.22; 95% CI: 0.06-0.64; p = 0.009), decision time before Stingray ADR (per 1 h increase) (OR: 0.54; 95% CI: 0.31-0.92; p = 0.026), operation duration of Stingray ADR (per 10 min increase) (OR: 0.62; 95% CI: 0.40-0.94; p = 0.028), and puncture site at the intraplaque region (OR: 0.24; 95% CI: 0.06-0.84; p = 0.026) were identified as the four negative independent predictors. This study revealed independent predictors of the success of CTO PCI performed using the Stingray ADR technique. As for CTO characteristics, the presence of calcification in the CTO segment and a tapered stump proximal to the lesion site can facilitate successful Stingray ADR. As for the procedures, the success rate of Stingray ADR can be improved by initiating the technique decisively and promptly, operating the system quickly and accurately and creating a puncture in the distal cap region of CTO under retrograde guidance.

A simple mathematical method to identify optimal biplane fluoroscopic angulations for chronic total occlusion percutaneous coronary intervention using CT angiography.

The concept of three-dimensional (3D) wiring for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is now widely accepted among coronary interventionalists. The 3 axes, i.e., the 2 X-ray beams and the CTO segment, should intersect with each other at as close to a right angle as possible. However, how to specify optimal fluoroscopic angulations for a given CTO segment has not been well established. We aimed to develop a simple and practical method to identify optimal fluoroscopic angulations for CTO PCI. A CTO vector can be derived from slab maximum intensity projection (MIP) images of coronary computed tomography (CT) angiography. Using trigonometric functions, the inner product of vectors and the equation of a plane, we calculated 2 fluoroscopic vectors perpendicular to each other and to the CTO vector. We applied this method to a patient with mid-left circumflex CTO and translated the resulting fluoroscopic vectors into optimal fluoroscopic angulations. To facilitate its use, we developed a calculator using spreadsheet software that can output optimal fluoroscopic angulations within a practical range by inputting the x, y, and z components of the CTO vector. This approach also helps to minimise dead angles in biplane fluoroscopy. This method has the potential to make CTO PCI safer and easier, without requiring dedicated equipment or software. Its effectiveness should be validated in clinical practice.

Subintimal shift as mechanism for side-branch occlusion in percutaneous treatment of chronic total occlusions with bifurcation lesions.

The aim of this study was to describe the mechanism of subintimal shift (SIS), standardise diagnostic criteria and sensitise the interventional community to this phenomenon. The treatment of chronic total occlusions (CTO) by means of percutaneous coronary intervention (PCI) is complicated by bifurcation lesions involved in the CTO segment or adjacent to it. Extraplaque expansion of intracoronary devices during CTO PCI may extend the dissection plane over the bifurcation with the consequential side or main branch compression by an intimo-medial flap. This phenomenon is hereby described for the first time and named subintimal shift. Experienced CTO operators from 3 international high volume centers for CTO PCI retrospectively searched their personal records for paradigmatic cases of SIS, summarising key features and proposing diagnostic criteria. The series comprised 7 demonstrative cases, illustrating SIS by intravascular imaging (2 cases) or indirect angiographic signs during CTO PCI (5 cases). Five cases were triggered by stent expansion, 1 by balloon inflation and 1 case was aborted after angiographic warning signs. In 4 cases, SIS resulted in total occlusion of a branch, refractory to ballooning whenever attempted. Four cases required bailout intervention and in 2 cases the branch was left occluded, resulting in a rise of cardiac markers. Subintimal shift is a noteworthy complication in CTO bifurcations, potentially resulting in occlusion of the relevant side or even the main branch. Intracoronary imaging prior to stenting is recommended to understand the tissue planes. Some counterintuitive peculiarities of this phenomenon, like its refractoriness to ballooning, must be known by CTO operators for its efficient resolution.

The Balloon Paradox - A Case Series

Background: Once regarded as the final frontier of coronary intervention, the success rates of chronic total occlusion (CTO) angioplasties have been steadily increasing. Understandably, the use of specialized hardware makes this an expensive undertaking. We propose a novel, creative, and inexpensive method to address this issue, by simply using a balloon, differently. Case summary: While specialized wires facilitate crossing the CTO segment, lesion preparation remains a challenge. Vigorous manipulation of routine PCI balloons for lesion entry can be detrimental. Tapered micro-catheters are successful as they rely on rotational forces and maintain guide stability. Newer CTO PCI balloons have crossing profiles comparable to most micro-catheters. Hence, applying rotational force on these kink-resistant balloons, facilitates their use as low-cost micro-catheters. We employed this technique, with surprisingly good results. While not all the lesions could be successfully crossed, the financial implications of this study on a small cohort of patients are, in our humble opinion, quite significant. Discussion: The aforementioned method uses inexpensive hardware, which can be used further, for lesion preparation. The balloon functions on the principle of a Tornus catheter, burrowing deep into the occluded segment. While this technique has higher failure rates in heavily calcified lesions, we were able to cross the lesion in a fair number of cases. We believe this technique, which is safe and simple, can reduce the dependence on complicated and expensive CTO hardware in a significant number of cases. Learning Points 1. Balloon can be used like a corsair and tornus in balloon uncrossable lesions 2. It provides a safe and inexpensive way to cross such lesions.

Acomputed tomography algorithm for crossing coronary chronic total occlusions: riding on the wave of the proximal cap and distal vessel segment.

With wider adoption of coronary computed tomography angiography (coronary CTA), chronic total occlusions (CTOs) are being increasingly identified and characterised by non-invasive angiography. In particular, the ability of coronary CTA to clearly delineate atherosclerotic plaque, as well as to display three-dimensional vessel trajectories, has garnered particular attention in the context of preprocedural planning and periprocedural guidance of CTO percutaneous coronary intervention (PCI). Single CTO features and combined scoring systems derived from CTA (mostly exceeding the diagnostic performance of the angiographic J‑CTO score) have been used to predict time-efficient guidewire crossing, and thus grade the CTO difficulty level prior to PCI. In addition, the introduction of three-dimensional CTA/fluoroscopy co-registration for periprocedural navigation during CTO PCI offers the unprecedented opportunity to resolve proximal cap ambiguity and clearly visualise the distal CTO segment, thereby potentially influencing CTO PCI strategies and techniques. In this review, the potential advantages of non-invasive evaluation of CTO by coronary CTA are described, and a CTA-based hybrid algorithm is introduced for further enhancing the efficiency of CTO PCI. Further studies are clearly needed to verify the proposed approach. However, several luminary operators have already implemented coronary CTA for planning and periprocedural guidance of CTO interventions using the hybrid algorithm.

Improvement of the frontal QRS-T angle after successful percutaneous coronary revascularization in patients with chronic total occlusion.

The QRS-T angle (QRS-Ta) is a novel marker of myocardial repolarization heterogeneity which is related to adverse cardiovascular events. Our aim in this study was to investigate the effect of successful percutaneous coronary intervention (PCI) on frontal QRS-Ta in patients with chronic total occlusion (CTO). A total of 132 patients undergoing PCI for CTO were included in this study. Successful PCI of CTO segment was performed in 84 patients (group 2) while 48 who failed CTO were observed (group 1). Baseline demographic and clinical variables were evaluated and, 12-lead surface ECGs of all subjects were recorded before performing coronary angiography and 1-month and 6-month after the index procedure. QRS-Ta values significantly decreased during follow-up visits compared to baseline values [92.5 (63.25-110.75); 85.0 (59.0-101.0); 80.0 (53.0-99.0), P < 0.001] in group 2 patients. Moreover, there was no significant difference in frontal QRS-Ta measurements in group 1 patients in their clinical 6-month follow-up [87.0 (48.25-103.0); 86.5 (46.0-101.75); 84.0 (49.0-103.75); P = 0.320]. First month frontal QRS-Ta values [92.5 (63.25-110.75); 85.0 (59.0-101.0), P = 0.002] and sixth month frontal QRS-Ta values [92.5 (63.25-110.75); 80.0 (53.0-99.0), P < 0.001] were lower than baseline values while sixth month values [85.0 (59.0-101.0); 80.0 (53.0-99.0), P = 0.002] was lower compared to first month values. Additionally, a decrease in frontal QRS-Ta was observed regardless of target vessel or Rentrop classification. Successful percutaneous revascularization of CTO was effective in ventricular repolarization. Frontal QRS-Ta significantly decreased after successful PCI on CTO patients at a 6-month follow-up.

Incidence, predictors, and outcomes of distal vessel expansion on follow-up intravascular ultrasound after recanalization of chronic total occlusions using new-generation drug-eluting stents: Data from the CTO-IVUS randomized trial.

To evaluate the incidence, predictors, and outcomes of distal vessel expansion on intravascular ultrasound (IVUS) after recanalization of chronic total occlusion (CTO) particularly using new-generation drug-eluting stent (DES). The luminal changes of narrowed vessels distal to CTO segments after recanalization using new-generation DES have rarely been studied. This substudy of the CTO-IVUS (Chronic Total Occlusion InterVention with drUg-eluting Stents) trial included a total of 69 new-generation DES-treated CTOs with serial matched IVUS analyses at index percutaneous coronary intervention (PCI) and at 1-year follow-up. The predictors of distal vessel expansion, any increase of lumen area at the distal reference (LAdistal ) on 1-year follow-up IVUS, were evaluated by multivariable binary logistic analyses. Distal vessel expansion was identified in 46 (67%). Independent determinants of distal vessel expansion were proximal CTO, a smaller LAdistal at the index PCI, a greater minimal stent area-to-LAdistal (MSA-to-LAdistal ) ratio, and a greater lumen area at the distal stent edge-to-LAdistal (LAedge -to-LAdistal ) ratio. The cut-off values of a MSA-to-LAdistal ratio and a LAedge -to-LAdistal ratio predicting the distal vessel expansion by receiver operating characteristic curve analysis were 1.0 and 1.1, respectively. During the median 5.1 years, rates of target vessel revascularization, cardiac death, and stent thrombosis were similar in the distal vessel-expanded and nonexpanded groups. After opening CTO with new-generation DES, two-thirds of patients exhibited distal vessel expansion on 1-year follow-up IVUS. Expansion determinants were a proximal CTO, lower LAdistal , and larger stent areas relative to the LAdistal (modifiable procedural predictors).

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

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. 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. 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.

Overview and proposed terminology for the reverse controlled antegrade and retrograde tracking (reverse CART) techniques.

During recent years, equipment and techniques for percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) have improved significantly. The retrograde approach remains critical to the improved success of CTO PCI. Currently, the reverse controlled antegrade and retrograde tracking (CART) technique has become the dominant retrograde wire crossing technique. In this article, we propose a standardised terminology and classification for this technique divided into three subtypes: a) conventional reverse CART, usually involving the use of large balloons on the antegrade wire to achieve re-entry within the CTO segment; b) "directed" reverse CART, which is characterised by small antegrade balloon size and more active, intentional vessel tracking and penetration with a controllable retrograde wire, still within the CTO segment; and c) "extended" reverse CART, in which the intimal/subintimal dissection is extended proximal or distal to the CTO segment, achieving re-entry outside the CTO segment. The proposed standardised terminology will facilitate the communication, teaching and adoption of the reverse CART techniques.

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

ObjectivesUsing intravascular ultrasound (IVUS), the authors compared outcomes by observed wire position (intraplaque vs. subintimal) achieved during successful chronic total occlusion (CTO) lesion treatment. BackgroundRecent 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. MethodsFrom 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. ResultsOf 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. ConclusionsIVUS-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.

Collateral filling efficiency of comorbid chronic total occlusion segment on short-term mortality in ST-elevation myocardial infarction

BackgroundCollateral filling of chronic total occlusion (CTO) segments is considered to affect hemodynamic stability in primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) with CTO, however its value as a prognostic indicator for mortality is uncertain. The present study examined the relationship between collateral filling of CTO segments and short-term mortality in patients with STEMI with a comorbid CTO lesion. MethodsAmong 829 STEMI patients who underwent primary PCI, 74 patients with CTO were identified. Collateral filling of their CTO segment was assessed by Rentrop grade (0; n=10, 1; n=13, 2; n=31, 3; n=20) in their initial angiogram and whether the origin of the feeding collateral donor artery was infarct-related artery (IRA) was evaluated using their final angiogram in primary PCI; IRA (n=26) and non-IRA group (n=48). The relationship between these classifications and 30-day all-cause mortality was examined retrospectively. ResultsThe 30-day mortalities were 4.5% in single-vessel disease, 18.3% in multi-vessel disease (MVD) without CTO and 25.7% in MVD with CTO. Mortality of MVD with CTO reduced with increasing Rentrop grade from 0 to 3 (80.0%, 30.8%, 19.4%, and 5.0%, respectively). IRA was associated with a significant higher mortality than those of non-IRA (50.0% vs. 12.5%, P=0.0004). Low Rentrop grade 0 or 1 was extracted as an independent predictor of 30-day death (HR 3.28, 95% CI 1.20–9.96, P=0.0203). ConclusionsPoor collateral filling of the CTO segment assessed by Rentrop grade was an independent angiographic predictor for 30-day death in patients with STEMI combined with CTO.

Utility of Intravascular Ultrasound inPercutaneous Revascularization ofChronicTotal Occlusions: An Overview.

Intravascular ultrasound has been used for >20 years to guide percutaneous coronary intervention in different subsets of coronary lesions. During the last decade, the interest in percutaneous coronary intervention for chronic total occlusion (CTO) has increased dramatically, leading to high success rates. Failure of guidewire crossing is the most common reason for failed CTO attempts. Certain angiographic features, such as blunt proximal CTO cap, tortuosity, heavy calcification, and lack of visibility of path in the distal vessel, increase procedural difficulty. A better understanding of the behavior of the guidewire within the CTO segment may represent a key issue to achieve successful outcome. In this respect, intravascular ultrasound imaging might have potential roles in the recanalization of CTOs. In this paper, we focused on the usefulness andthe applications of intravascular ultrasound imaging in percutaneous CTO recanalization, underlying its impact on clinical outcome.

Clinical Prediction Score for Successful Retrograde Procedure in Chronic Total Occlusion Percutaneous Coronary Intervention

Objective: To develop and validate a prediction score for a successful retrograde procedure in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Methods: A total of 228 CTO lesions in 223 patients who underwent PCI by retrograde approach were analyzed. All subjects were randomly grouped to a derivation set and a validation set at a ratio of 2:1. A successful retrograde procedure was set as the end point. Each of the identified predictors for the end point by logistic regression was assigned 1 point and summed. Results: Independent predictors of a successful retrograde procedure were Werner's score [odds ratio (OR) 4.841, 95% confidence interval (CI) 1.952-12.005, p = 0.001], diameter of distal CTO segment (OR 5.263, 95% CI 2.067-13.398, p < 0.001) and tortuous collateral (type b; OR 0.119, 95% CI 0.032-0.444, p = 0.002). The predictive model developed in the derivation set stratified the difficulty of achieving a successful retrograde procedure into 4 grades - very difficult (10.5%), difficult (23.7%), intermediate (50.7%) and easy (15.1%) - and was demonstrated significantly in the validation set: very difficult (15.8%), difficult (18.4%), intermediate (47.4%) and easy (18.4%). The area under the receiver-operating characteristic curve was 0.832 ± 0.042 for the derivation set and 0.912 ± 0.041 for the validation set with an almost equal performance. Conclusions: According to the experience of our center, this model performed excellently in predicting the difficulty in achieving a successful retrograde procedure.

Successful interventional recanalization against heavily calcified chronic total occlusion of proximal right coronary artery utilizing retrograde guidewire trapping technique at the terminal aorta

We described a case of chronic total occlusion (CTO) of the ostial right coronary artery (RCA) in a 79-year-old woman that had been undergoing hemodialysis. Coronary intervention of the ostial RCA-CTO was performed via the retrograde approach. The retrograde hard wire was able to pass through the CTO segment via a transseptal collateral and advanced at the ascending aorta. However, the microcatheter tip could not advance into the heavily calcified plaque of the CTO segment. Moreover, it was very difficult to catch the retrograde hard wire tip in the ascending aorta using a 10mm Gooseneck snare at the ostium of the antegrade guiding catheter due to three-dimensional size mismatch. Thereby, we attempted to cross the occluded segment directly using a long-shaft soft guidewire designed for retrograde CTO intervention (0.009 inch 330 cm). The unassisted long-shaft wire tip was passed successfully through the CTO segment retrogradely. After the retrograde wire tip was pushed ahead of the terminal aorta, it was caught using the former snaring system, and another guiding catheter for the antegrade approach was pulled in. After wire externalization was completed, balloon dilatation and stent deployment through the CTO segment were performed successfully via the antegrade approach. Here, we report a case of successful interventional revascularization of a heavily calcified and device-uncrossable CTO lesion by the retrograde wire trapping technique using a gooseneck snare device at the terminal aorta. The method in which the capture of a retrograde wire using Gooseneck snare system may be not novel in itself. But, in case of difficulty in uncrossability devices and catching it at the ascending aorta as well, this combinative technique is beneficial to the ease of wire externalization.

Which parameters are important before attempting chronic total occlusions recanalization?

Which parameters are important before attempting chronic total occlusions recanalization?

Role of CT Coronary Angiography in Recanalization of Chronic Total Occlusion

Chronic total occlusion (CTO) is considered as the most challenging frontier in interventional cardiology and the last one to be conquered. With availability of state of the art hardware, wires and catheters in particular and increased skills of the operators, the success rate for recanalization of CTO by percutaneous catheter intervention (PCI) has improved. Yet the complications rate and longterm adverse events are high, mostly due to failure in tracking or navigation of hardware through the occluded CTO segment, prolonged exposure to radiation and high doses of contrast used. Therefore, proper selection of patient is of utmost importance. One of the major challenges for successful CTO recanalization is satisfactory visualization of the occluded CTO segment. Conventional invasive catheterization fails to fill the gap and the shortcomings and handicaps of such invasive imaging can be resolved with the use of non-invasive CT coronary angiography (CTCA). CTCA helps to better define the morphological features of the occluded CTO segment, which are established predictors of success, like the actual length of the occluded segment and any calcification or tortuosity in its course. Integration of reconstructed three-dimensional CT coronary images with twodimensional fluoroscopic images, offers directional guide to select the best angiographic plane for visualization of angiographically “missing segment”. With advances in CT technology, CTCA has now become an established technology for pre-procedure evaluation of CTO segment, thereby help in planning and execution of successful PCI.

Coronary Artery Total Occlusion: MR Angiographic Imaging Findings and Success Rates of Percutaneous Coronary Intervention according to Intraluminal Signal Intensity Patterns.

To compare the success rates of percutaneous coronary interventions (PCIs) for chronic total occlusion (CTO) lesions according to the different signal intensity (SI) patterns seen at coronary magnetic resonance (MR) angiography. Institutional review board approval was obtained, and all patients gave written informed consent. This study included 95 CTO lesions in 93 consecutive patients who underwent steady-state free-precession coronary MR angiography with a 1.5-T imager before PCI. The SI and length of CTO lesions were evaluated at coronary MR angiography, and the lesions were classified into two groups according to the continuity of the areas of high SI in the CTO lesions. Invasive angiographic findings including lesion length and collateral grades were analyzed. A multivariable logistic regression analysis was performed to identify variables associated with successful PCI. Seventy-eight (82%) of 95 CTO lesions were treated successfully with PCI. On coronary MR angiograms, areas of continuous high SI were found in 42 lesions (44%), and 40 (95%) of them were treated successfully with PCI. Thirty-eight (72%) of 53 lesions with low SI or interrupted high SI throughout the CTO segments were successfully treated with PCI. The presence of areas of continuous high SI in the CTO segments was the only independent predictor of PCI success (odds ratio, 8.20; 95% confidence interval: 1.08, 62.15; P = .042). Continuous areas of high SI in CTO lesions on coronary MR angiograms are predictive of better success rates with PCI than are discontinuous or absent areas of high SI.