Side Branch Compromise Research Articles

The increased main branch to stent diameter ratio is associated with side branch decreased coronary flow in "true" coronary artery bifurcations treated by "provisional" stenting - a two-dimensional quantitative coronary angiography study

Background/Aim. Percutaneous coronary interventions (PCI) in bifurcation lesions having more than 50% stenosis of both the main branch (MB) and the side branch (SB) remain challenging. Measurements of the vessel diameters and angles using quantitative coronary angiography (QCA) software have been used in evaluating PCI outcomes. We investigated potential effects of provisional stenting of the MB on SB coronary blood flow by determining quantitative vessel parameters in ?true? non-left main coronary bifurcation lesions using conventional two-dimensional QCA. Methods. The study was prospective and conducted in a highvolume university PCI center. Study included patients with ?true? native coronary artery bifurcations (Medina 1.0.1; 0.1.1; 1.1.1) treated with ?provisional? stenting of the MB. Patients were excluded from the study if having left ventricular ejection fraction of less than 30%, having renal failure with creatinine clearance below 30 mL/kg/m2 or bifurcation lesions within the culprit artery causing myocardial infarction, grafted surgically or previously treated by PCI. QCA analysis included measurements of reference vessel diameters (RVD), diameter stenosis (DS) and bifurcation angles. Results. The study included 70 patients with 72 ?true? non-left main bifurcations. Most of the bifurcations were located in the left anterior descending (LAD) ? diagonal (Dg) territory. Compromise of the SB ostium defined as thrombolysis in myocardial infarction (TIMI) < 3 coronary flow occurred in 17/72 (23.6%) bifurcations. It was treated by either balloon angioplasty only of the SB ostium (9/17, 52.9%) or stent implantation [8/17 (47.1%)]. In a logistic regression analysis, including previously recognized predictors of SB compromise (bifurcation?s angles, RVD, DS and ratio of MB RVD to stent diameter ratio), only MB RVD to stent diameter ratio after PCI remained independent predictor of SB coronary flow compromise after stent implantation in the MB [OR 2.758 (95% CI 1.298?5.862); p = 0.008]. Conclusions. It appears that SB decreased coronary blood flow after ?provisional? stenting in ?true? non-left main bifurcations is associated with greater MB to stent diameter ratio.

Microcatheter-Protected Orbital Atherectomy for Severely Calcified Bifurcation Coronary Artery Disease With Single-Guiding Catheter Technique

Bifurcation coronary artery intervention may increase the risk of occlusion of an angulated side branch due to the plaque shift while treating (balloon, atherectomy, or stent) the main branch. Although debulking with atherectomy may reduce this risk, side branch compromise is still of concern. The

Predictors of side branch compromise in calcified bifurcation lesions treated with orbital atherectomy.

The aim of the study was to identify the predictors of side branch (SB) compromise in severely calcified bifurcation lesions treated with orbital atherectomy (OA). SB compromise remains a major complication of bifurcation lesion percutaneous coronary intervention (PCI). Higher prevalence of lipid-rich plaques and spotty calcification by optical coherence tomography (OCT) and SB ostial stenosis by angiography have been previously suggested as predictors of SB occlusion after main vessel (MV) stenting. Patients with chronic stable angina and severely calcified bifurcation lesions, in whom provisional stenting strategy was planned, were enrolled in the study. OA was used for lesion preparation in all cases. OCT imaging of the MV was performed before and after stenting. SB compromise was defined as a composite of SB occlusion (TIMI flow grade ≤ 2) and SB intervention after MV stenting. Thirty stable CAD patients with 30 severely calcified bifurcation lesions were included in the study. Twelve patients (40%) had a compromised SB after MV stenting. Compromised SB was characterized by a greater angiographic diameter stenosis (55.4 ± 8.1% vs. 35.0 ± 14.4%, P < 0.01) and a smaller minimal lumen diameters (0.79 ± 0.17 vs. 1.12 ± 0.30 mm, P = 0.002) before PCI compared to noncompromised SB. The prevalence of OCT lipid-rich plaques was low and did not differ between the groups (18 vs. 19%, P = 0.68). There was no difference in other OCT plaque characteristics including the presence of spotty calcification. The severity of SB ostial disease and not MV plaque morphology contributed to SB compromise in severely calcified bifurcation lesions.

OCT-guided Percutaneous Coronary Intervention in Bifurcation Lesions.

Coronary artery bifurcation lesions remain challenging despite significant advancements in stent technology and development of specific bifurcation stenting approaches. Optical coherence tomography (OCT) is the intracoronary imaging technique with the highest resolution and can generate automatically contoured lumen areas across the variable geometry of bifurcation lesions. Knowledge of plaque severity and composition facilitates planning of the best strategy for percutaneous coronary intervention (PCI) and stenting. In particular, the provisional stent strategy preferred in this context can be modified when there is high risk of side-branch compromise at the ostium after main vessel stenting. OCT is unique because it allows the identification of the site of guide wire crossing, an important determinant of the final result. OCT can also be used to assess the procedural success of new dedicated bifurcation stent technologies and for the evaluation at follow-up of potential predictors of stent thrombosis, including stent malapposition, stent under-expansion and stent-edge dissection. Finally, the development of 3D OCT allows a better evaluation of coronary anatomy — particularly of side branch ostium that is difficult to visualise by 2D OCT — further improving the value of this technique in guiding PCI in these patients.

The drug-eluting resorbable magnesium vascular scaffold in complex coronary bifurcations: insights from an in vivo multimodality imaging study.

This acute in vivo study sought to provide insights regarding the feasibility of performing complex bifurcation stenting with Magmaris magnesium alloy bioresorbable scaffolds (Biotronik, Bulach, Switzerland). Twenty-five New Zealand White rabbits underwent stenting of non-diseased aorto-iliac bifurcations with the Magmaris using provisional (PS; n=5), culotte (n=6), modified T (n=6), or T and protrusion (TAP, n=8) stenting techniques. Angiography, optical coherence tomography and micro-computed tomography were performed. Angiographic results were good without evidence of side branch (SB) compromise. In 9/25 procedures, strut fractures were identified with minimal luminal compromise in two cases. PS opened the SB optimally without evidence of scaffold compromise. Culotte resulted in complete bifurcation coverage and good scaffold expansion; single strut fractures were present in three out of six and double fractures in one out of six procedures. Modified T and TAP resulted in complete bifurcation coverage, minimal neocarina double-strut layers and good expansion. In two out of six modified T procedures, strut fractures were present with SB scaffold deformity present in an additional two out of six procedures. In three out of eight TAP procedures, strut fractures were present without compromising overall scaffold integrity. Bifurcation stenting using Magmaris appears feasible. PS with additional TAP whenever needed seems a reasonable approach. Whenever a two-stent technique is planned, TAP appears most favourable whilst modified T and culotte stenting should probably be avoided.

Understanding the Coronary Bifurcation Stenting.

Coronary bifurcation stenting is still complex and associated with a high risk of stent thrombosis and restenosis even with contemporary techniques. Although provisional approach has been proved to be the standard strategy of treatment, There is still lack of evidences for multiple steps of the procedure. For so many years we have been focused on the optimization of side branch (SB), but the clinical outcome is mostly dependent on the main vessel (MV) stenting. The optimal expansion of MV stent without the compromise of SB is the ultimate goal to achieve in the coronary bifurcation stenting. Understanding the anatomy and physiology of coronary bifurcation lesion should be the most important step to this goal. The relationship of vessel diameter between branches and the anatomical and functional significance of plaque shift and carina shift are two most important concepts to understand. They are the science behind the predictors of SB occlusion, and the rationale of proximal optimization technique and final kissing ballooning. This specific review will be devoted to review those concepts as well as clinical evidences to support them.

POST-PCI CLINICAL OUTCOME;

Introduction: The incidence of creatine kinase-myocardial band (CK-MB)isoenzyme elevation after percutaneous coronary intervention (PCI) ranges from 11% to 35%,including low-level elevations with no associated signs or symptoms as well as large non–Qwaveand Q-wave myocardial infarction. Whereas the deleterious effect on survival of largeperiprocedural myocardial infarctions have been well documented. Large periproceduralmyocardial infarctions, such as those caused by occlusion of a large side branch, flow-limitingdissection, or distal embolization of a large thrombus, would be undesirable and associatedwith worse subsequent cardiac outcomes. Objectives: To correlate the clinical outcomeafter PCI with cardiac biochemical markers. Study Design: Observational follow-up study.Setting: Faisalabad Institute of Cardiology, Faisalabad. Duration of Study with Dates: Sixmonths (February, 2014 to August, 2014). Patients and Methods: Two hundred patients withsymptoms of myocardial ischemia proceeding for percutaneous coronary intervention wereenrolled in the study. After taking history and clinical examination, the patients divided into twogroups: group I and group II. Group I comprised one hundred and fifty patients having normalcardiac enzymes and group II comprised fifty patients having raised cardiac enzymes. Results:Out of 50 patients with raised cardiac enzymes 42 (84%) were males and 8 (16%) were females,multi vessel coronary disease (58%), multi vessel PCI (54.3%). Periprocedural complicationsdissection (6%), side branch compromise (14%), slow flow (10%), no reflow (2%), sub-acutestent thrombosis (4%) occurred in group II as compared to slow flow (1.4%) and sub-acutestent thrombosis (0.7%) in group I. In hospital mortality (2%) in group II while no mortality ingroup I. On thirty day follow up 32% patients became symptomatic among which 6% developednon ST elevation MI in group II while only 1.4% patients had symptoms of angina in group I.6% patients needed repeat target lesion revascularization in group II and only 0.7% in groupI. Conclusion: Patients with raised cardiac enzymes had worse clinical outcome in terms ofmortality, myocardial infarction and repeat target lesion revascularization than normal cardiacenzymes.

Computed tomography angiography versus angiography for guiding percutaneous coronary interventions in bifurcation lesions – A prospective randomized pilot study

BackgroundThere is no data on the impact of coronary computed tomography angiography (coronary CTA), as an addition to angiography, on the outcomes of percutaneous coronary interventions (PCI) in bifurcation lesions. MethodsPatients with stable coronary artery disease scheduled for elective bifurcation PCI were randomized 1:1 to planning the procedure based on coronary CTA and angiography (CTA group) or angiography alone (CA group). The primary efficacy endpoint was the immediate angiographic result. Secondary efficacy endpoints were: a) procedural characteristics and b) postprocedural fractional flow reserve (FFR) in the side branch (SB) in a subgroup of patients. Safety outcomes were: a) periprocedural myocardial infarction, b) contrast use and c) radiation dose. ResultsPCI of 45 lesions in the CTA group and 47 lesions in the CA group was performed. Postprocedural lumen diameters in the main branch (MB) and SB, frequency of SB compromise or occlusion and mean SB FFR values were not different between study groups. Two or more stents were implanted less frequently in the CTA group than in the CA group (18% vs. 43%, p = 0.01). This difference was driven by less frequent MB 2-stent overlap in the CTA group (7 vs. 21%, p = 0.046) and numerically less SB stenting (11% vs. 21%, p = 0.07). Proximal optimization technique was used more frequently in the CTA group (44% vs. 21%, p = 0.018). ConclusionsCTA-assisted bifurcation PCI leads to similar immediate results compared with angiography alone, however is associated with higher use of single-stent procedures with proximal optimization, less frequent 2-stent overlap and less SB stenting.

The Proximal Optimisation Technique for Intervention of Coronary Bifurcations.

The proximal optimisation technique (POT) has been proposed as a strategy to improve the results of stent scaffolding of bifurcation lesions. It is a straightforward technique whereby a short, appropriately-sized balloon is inflated in the main vessel just proximal to the carina. The technique has several advantages: it reduces the risk of side branch compromise related to shifting of the carina, it improves stent apposition in the proximal main vessel, and it facilitates side branch access after main vessel stent implantation. When treating bifurcations, final kissing balloon dilation (KBD) has traditionally been used routinely to optimise angiographic results. However, recent clinical data have questioned this philosophy and bench models have demonstrated several shortcomings of KBD. Instead, the optimal strategy may centre on performing POT, followed by side branch dilation, and completed with a final (re)-POT. The following review article describes how to perform POT and presents the evidence to support its' routine use.

Absorb Bioresorbable Vascular Scaffold in Complex Coronary Bifurcation Interventions: Insights From an In Vivo Multimodality Imaging Study.

Although bioresorbable scaffolds offer potential advantages compared with metallic drug-eluting stents in the treatment of complex coronary bifurcation lesions, there are concerns that the polymeric scaffold integrity may be compromised. This in vivo study sought to provide insights about the feasibility of performing complex bifurcation stenting with Absorb bioresorbable vascular scaffolds (Abbott Vascular, Santa Clara, CA). Twenty New Zealand white rabbits underwent stenting of the nondiseased aortoiliac bifurcation with bioresorbable vascular scaffolds using provisional (PS, n=5), culotte (n=5), modified-T (n=5), or T-and protrusion (n=5) stenting techniques. Angiography, optical coherence tomography, and microcomputed tomography were performed. Angiographic results were excellent without evidence of dissection or side branch (SB) compromise. PS optimally opened the SB ostium without deforming the main vessel (MV) bioresorbable vascular scaffolds, avoiding malapposition, and revealing a single connector fracture in 1 of 5 cases on microcomputed tomography. Culotte stenting resulted in complete bifurcation coverage with extensive segments of double-layered struts and inappropriately apposed struts at the bifurcation level in 3 of 5 cases. On microcomputed tomography, there was MV and SB scaffold distortion at the bifurcation with single strut fractures in 4 of 5 and double fractures in 1 of 5. Modified-T and T-and protrusion resulted in complete bifurcation coverage and in minimal double-strut layers at the neocarina. On microcomputed tomography, no strut fractures were present after modified-T, whereas in 3 of 5 T-and protrusion procedures single strut fractures were noted. Bifurcation stenting using bioresorbable vascular scaffolds is feasible with excellent angiographic results. PS with additional T-and protrusion whenever needed seems a reasonable approach. Whenever a 2-stent technique is planned, modified T-stenting appears the most promising.

Predictors for Side Branch Failure During Provisional Strategy of Coronary Intervention for Bifurcation Lesions (from the Korean Bifurcation Registry)

The most favored strategy for bifurcation lesion is stenting main vessel with provisional side branch (SB) stenting. This study was performed to elucidate predictors for SB failure during this provisional strategy. The study population was patients from 16 centers in Korea who underwent drug-eluting stent implantation for bifurcation lesions with provisional strategy (1,219 patients and 1,236 lesions). On multivariate analysis, the independent predictors for SB jailing after main vessel stenting were SB calcification, large SB reference diameter, severe stenosis of SB, and not taking clopidogrel. Regarding SB compromise, however, the independent predictors were true bifurcation lesion and small SB reference diameter, whereas possible predictors were parent vessel thrombus and parent vessel total occlusion. In addition, SB predilation helps us to get favorable SB outcome. The diameter of SB ostium after main vessel stenting became similar between severe SB lesions treated with predilation and mild SB lesions not treated with predilation. In conclusion, SB calcification, less clopidogrel use, large SB reference diameter, and high SB diameter stenosis are independent predictors for SB jailing, and true bifurcation and small SB reference diameter are independent predictors for SB compromise after main vessel stenting.

Coronary Bifurcation Intervention: What Role Do Bifurcation Angles Play?

Bifurcation angles play an important role in coronary bifurcation intervention. Bifurcation angles affect the coronary bifurcation intervention from many aspects: (1) impact the atherosclerosis proliferation via affecting the hemodynamic parameters at bifurcation regions; (2) impact side branch compromise after main vessel stenting via hemodynamics, atherosclerosis proliferation, geometric characteristics, and plaque/carina shift; (3) affect the long-term clinical outcome after coronary bifurcation stenting. Bifurcation angles are key factors to formulate the intervention strategy of stenting procedure and can also be modified by different bifurcation stenting strategies. In the last few years, significant improvements have occurred in understanding the role of bifurcation angles. However, there are still questions remain to be clarified: (1) How to measure the bifurcation angles accurately and comprehensively? (2) How do bifurcation angles impact the immediate and long term outcome of PCI? (3) Why the results of previous studies remain controversial? The exact influence of bifurcation angles on post-PCI effect like side branch compromise and clinical outcome has not been fully elucidated. In this review, we highlight the current knowledge of bifurcation angles, summarize the questions remained to be clarified, and discuss the implications for clinical practice and future studies.

The story of side branch predilatation before provisional stenting.

Bifurcation lesions remain a therapeutic challenge and present an increased risk of complications. It also seems clear that the provisional stenting strategy, using only one drug-eluting stent in the main vessel (MV), is the first choice of treatment for most patients. However, provisional stenting is not a unitary approach, and diverse technical possibilities such as the use of final kissing balloon inflation, or the type of drug-eluting stent implanted at the MV may influence the outcome of the procedure. In the context of provisional stenting, predilation of the side branch (SB) before MV stent implantation is another manoeuvre which could facilitate the performance of this technique. However, SB predilation has generated many controversies and it has been discussed at length during several sessions of the European Bifurcation Club meetings. In this paper we analyse the advantages and disadvantages of side branch predilation as well as the most relevant articles dealing with this topic. We conclude that predilation of the SB is in many cases probably not needed, but may be considered in order to simplify the procedure. Predilation of the SB is recommended when SB compromise after MV stenting is highly anticipated, such as in long ostial SB lesions or heavily calcified lesions.

No-kiss sleeve: A technical modification of the sleeve technique to treat true bifurcation lesions in the bioresorbable vascular scaffold era

True bifurcation lesions run a very high risk of side branch (SB) occlusion, particularly if the bifurcation angle is acute [1]. SB compromise occurs in up to one-third of cases, and may lead to substantial myocardial injury and worse clinical outcomes [2]. Committed two-stent strategies are more reliable approaches to treat this lesion subgroup, albeit technically more demanding. Growing evidences from various studies have shown that two-stent strategies are not inferior to provisional strategy using drug-eluting stents (DES) [3–5].

TCTAP A-012 The Protective Effect of Aspiration Thrombectomy on Side Branch Compromise and Twelve Months Clinical Outcomes in AMI with Bifurcation Lesion Undergoing Primary PCI

Bifurcation lesions (BF) remains a challenging lesion subset, often associated with lower success rates. Side branch (SB) compromise in bifurcation lesion is a major determinant of lower procedural success rates and adverse outcomes. Aspiration thrombectomy (AT) prevent distal embolization in acute

Usefulness of Corsair microcatheter to cross stent struts in bifurcation lesions

Side branch compromise after stenting in bifurcation lesions is a matter of concern. It may happen that even low-profile balloon catheters do not cross stent struts after rewiring. The Corsair catheter is a hybrid catheter that has features of a microcatheter and a support catheter. The present study evaluated usefulness of the Corsair catheter to facilitate advancing a low-profile balloon catheter through stent struts in bifurcation lesions. After rewiring, low-profile balloon catheters failed to cross stent struts of 29 bifurcation lesions. The Corsair microcatheter successfully crossed stent struts in all lesions except one (97%) where a stent was implanted to treat in-stent restenosis (stent-in-stent). Low-profile balloon catheters were able to advance into the side branch of all bifurcation lesions where the Corsair microcatheter crossed stent struts. In conclusion, the Corsair microcatheter may be utilized if low-profile balloon catheters are unable to cross stent struts in bifurcation lesions.

TCT-405 Regular Drug Eluting Stent versus Dedicated Bifurcation Sirolimus Eluting Stent BiOSS LIM in Coronary Bifurcation Treatment - POLBOS II Randomized Study

The provisional T-stenting (PTS) is the recommended strategy for the coronary bifurcation treatment. However, results obtained with use of regular drug eluting stents (DES) are not optimal and relatively often associated with a side branch compromise and restenosis. Dedicated bifurcation stents are

Comparative analysis of lumen enlargement mechanisms achieved with the bifurcation dedicated BiOSS® stent versus classical coronary stent implantations by means of provisional side branch stenting strategy: an intravascular ultrasound study

The aim of this study was to analyze the mechanisms of lumen enlargement in bifurcation lesions, as assessed by intravascular ultrasound (IVUS), after percutaneous treatment with classic provisional “T” stenting with conventional drug-eluting stents (DES) versus bifurcation dedicated BiOSS® (Balton, Warsaw, Poland) stent. In this prospective study between Jan and Dec/11, 32 patients with single de novo coronary bifurcation lesions suitable for treatment with BiOSS stents were randomized (1:1). IVUS method included pre- and post-procedure analysis in the parent vessel. Vessel, lumen and plaque cross-sectional areas were determined at the target lesion [minimum lumen area (MLA) site], proximal limb, distal limb, and “window”—defined as the segment between the carina (flow divider) and the vessel wall at the level of the side branch inflow. All lesions were treated with provisional approach and only 1 case in BiOSS group had a stent implanted in the side branch. Angiographic and IVUS results including MLA at the target site and proximal/distal references were similar. However, mean window length—largest diameter within the window, was similar at baseline, but BiOSS measured significantly longer at postprocedure (2.21 ± 0.37 vs. 1.76 ± 0.52 mm, p = 0.01). In addition, the magnitude of changes in vessel (27 ± 24 % vs. 9 ± 10 %, p = 0.01) and plaque (2 ± 26 % vs. −2 ± 26 %, p = 0.02) areas at the window were significantly different for DES versus BiOSS groups, respectively. The contribution of vessel extension for lumen enlargement represented 54 versus 43 %, 130 versus 46 %, 98 versus 80 % and 51 versus 19 % of the result achieved at the proximal limb, window, distal limb and MLA sites for DES versus BiOSS, respectively; as for plaque re-distribution, results were 36 versus 57 %, −30 versus 54 %, 2 versus 20 %, and 49 versus 81 %, at the proximal limb, window, distal limb and MLA sites, respectively. These results suggest different mechanisms of lumen enlargement comparing conventional DES versus BiOSS dedicated bifurcation stent, which can impact side branch compromise during procedure.

Elliptical stretch as a cause of side branch ostial compromise after main vessel stenting in coronary bifurcations: New insights from numerical analysis.

The side branch (SB) compromise after main vessel (MV) stenting remains a significant problem in coronary bifurcation treatment. Currently the two major hypotheses for the mechanism of SB compromise are carina shift from MV into the SB and plaque shift into the ostium of side vessel. It is proposed herein, SB ostial deformation leading to reshaping of the ostium from circle to ellipse is a third possible mechanism. In the current study, the theoretical effects and correlation of ostial deformation with fractional flow reserve (FFR) is explored. Based on angiographic measurements and theoretical analysis formulas, three different SB ostial areas using circular ostial shape assumption and elliptical ostial shape assumption were calculated. Three different types of ostial areas with FFR values after MV stenting in 49 patients from the FIESTA registry were compared and analyzed. It was found that there is significant overestimation of stenosis severity when estimated by the circle formula, than with the ellipse formula - ASc vs. ASds with 25% ± 13%, p < 0.001, ASc vs. ASmld with 9% ± 10%, p < 0.001. The elliptical shape assumptions provide more accurate ostial area stenosis, which correlates better with FFR. This finding is more significant in less severe stenosis (< 70% area stenosis) than in a more severe one. A third possible mechanism of SB compromise after MV stenting of coronary bifurcation stenosis is elliptical ostial deformation at the ostium of SBs. The ostial area, calculated based on elliptical assumption correlates better with FFR, than area stenosis calculated with the traditional circular formula.

SAFETY AND FEASIBILITY OF SZABO TECHNIQUE IN PERCUTANEOUS CORONARY INTERVENTION OF OSTIAL LESIONS

ObjectivesPercutaneous coronary intervention (PCI) on ostial lesions in coronary arteries can pose unique challenges and associated with higher procedural and medium-term complication rates. It has been technically difficult because it...