Balloon-assisted subintimal entry (BASE) in chronic total occlusion percutaneous coronary interventions.

BACKGROUND: There is limited data on the use of the balloon-assisted subintimal entry (BASE) technique in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We analyzed the baseline clinical and angiographic characteristics and outcomes of 155 CTO PCIs that utilized the BASE technique at 31 US and non-US centers between 2016 and 2023. RESULTS: The BASE technique was used in 155 (7.9%) of 1968 antegrade dissection and re-entry (ADR) cases performed during the study period. The mean age was 66 ± 10 years, 88.9% of the patients were men, and the prevalence of diabetes (44.6%), hypertension (90.5%), and dyslipidemia (88.7%) was high. Compared with 1813 ADR cases that did not use BASE, the target vessel of the BASE cases was more commonly the RCA and less commonly the LAD. Lesions requiring BASE had longer occlusion length (42 ± 23 vs. 37 ± 23 mm, p = 0.011), higher Japanese CTO (J-CTO) (3.4 ± 1.0 vs. 3.0 ± 1.1, p < 0.001) and PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention chronic total occlusion) (1.8 ± 1.0 vs. 1.5 ± 1.0, p = 0.008) scores, and were more likely to have proximal cap ambiguity, side branch at the proximal cap, blunt/no stump, moderate to severe calcification, and proximal tortuosity. Technical (71.6% vs. 75.5%, p = 0.334) and procedural success (71.6% vs. 72.8%, p = 0.821), as well as major adverse cardiac events (MACE) (1.3% vs. 4.1%, p = 0.124), were similar in ADR cases that used BASE and those that did not. CONCLUSIONS: The BASE technique is used in CTOs with longer occlusion length, higher J-CTO score, and more complex angiographic characteristics, and is associated with moderate success but also low MACE.

"Power knuckle" for facilitating the "move the cap" technique.

Chronic total occlusions with proximal cap ambiguity remains the most challenging to recanalize and are associated with higher failure rate. We describe the "power knuckle" technique, in which the subintimal space proximal to the proximal cap is safely entered with a knuckle wire supported by a microcatheter and an inflated balloon. The "power knuckle" can facilitate entry into the extraplaque space for subsequent antegrade dissection and re-entry.

Collagenase to facilitate guidewire crossing in chronic total occlusion PCI-The Total Occlusion Study in Coronary Arteries-5 (TOSCA-5) trial.

BACKGROUND: Chronic total occlusions (CTO) are common and are associated with lower percutaneous coronary intervention (PCI) success rates, often due to failure of antegrade guidewire crossing. Local, intralesional delivery of collagenase (MZ-004) may facilitate guidewire crossing in CTO. AIMS: To evaluate the effect of MZ-004 in facilitating antegrade wire crossing in CTO angioplasty. METHODS: A total of 76 patients undergoing CTO PCI were enrolled at 13 international sites: 38 in the randomized training stage (collagenase [MZ-004] 900 or 1200 µg) and 38 in the placebo-controlled stage (MZ-004 900 or 1200 µg or placebo). Patients received the MZ-004 or identical volume saline (placebo group) in a double-blind design, injected via microcatheter directly into the proximal cap of the CTO. The following day patients underwent CTO PCI using antegrade wire techniques only. RESULTS: Patients were generally similar except for a trend for higher Japanese chronic total occlusion (J-CTO) score in the MZ-004 group (MZ-004 J-CTO score 1.9 vs. 1.4, p = 0.07). There was a numerical increase in the rates of guidewire crossing in the MZ-004 groups compared to placebo (74% vs. 63%, p = 0.52). Guidewire crossing with a soft-tip guidewire (≤1.5 g tip load) was significantly higher in the MZ-004 groups (0% in placebo, 17% in 900 µg, and 29% in 1200 µg MZ-004 group, p = 0.03). Rates of the major adverse cardiovascular event were similar between groups. CONCLUSION: Local delivery of MZ-004 into coronary CTOs appears safe and may facilitate CTO crossing, particularly with softer tipped guidewires. These data support the development of a pivotal trial to further evaluate this agent.

Modified subintimal transcatheter withdrawal: A novel technique for hematoma decompression to facilitate distal reentry during coronary chronic total occlusion recanalization.

A controlled antegrade dissection and reentry technique is the most commonly employed crossing strategy for long coronary chronic total occlusions. The development of compressive hematoma is a recognized complication and results in the impairment of distal vessel visualization and hinders successful reentry attempts. We describe a novel technique utilizing a widely available microcatheter to decompress the subintimal hematoma to restore distal visualization and allow successful reentry.

Challenges With Severe Coronary Artery Calcification in Percutaneous Coronary Intervention: A Narrative Review of Therapeutic Options.

Coronary calcification often complicates atherosclerosis. With an aging population, coinciding with lower thresholds for coronary angiography and percutaneous coronary intervention (PCI), severe calcific coronary stenoses remain a challenge for interventional cardiologists. Although advances in coronary guidewires, percutaneous balloons, and adjunctive procedural devices have improved success of PCI, recalcitrant calcified lesions not amenable to the conventional technique frequently occur. Coronary atherectomy with plaque modification provides a therapeutic alternative. As such, various modalities such as rotational, orbital or laser atherectomy, and more recently shockwave lithoplasty have become therapeutic options for PCI. We provide a summary of the principles, technique, and contemporary evidence for these currently approved devices designed to treat severe coronary calcific lesions.

Novel use of cutting balloon to manage compressive subintimal hematoma during left main stenting in a patient with spontaneous coronary artery dissection.

Spontaneous coronary artery dissection (SCAD) is a common cause of acute coronary syndrome particularly in younger women. Good outcomes with conservative management are generally expected. However, there is uncertainty of how to manage symptomatic or unstable patients. Percutaneous angioplasty may propagate the subintimal hematoma compromising coronary blood flow. Cutting balloon angioplasty can relieve the compressive effects of a propagated subintimal hematoma in SCAD.

Novel use of cutting balloon to treat subintimal hematomas during chronic total occlusion interventions.

Contemporary chronic total occlusion (CTO) percutaneous coronary interventional (PCI) techniques are increasingly dependent upon dissection and reentry techniques (DARTs) especially for long occluded lesions. DARTs can result in compressive hematomas during CTO interventions and traditional treatment with balloon angioplasty and/or coronary stenting are often suboptimal and may extend the hematoma distally. We describe the novel use of a cutting balloon to "express" these compressive hematomas and restore antegrade coronary blood flow.

Balloon-Assisted Microdissection "BAM" Technique for Balloon-Uncrossable Chronic Total Occlusions.

BACKGROUND: After successful guidewire passage, failure to cross the occluded segment with a balloon is the most common cause of procedural failure in coronary chronic total occlusion (CTO) intervention. We evaluated the safety and efficacy of the balloon-assisted microdissection (BAM) technique for treating these complex balloon-uncrossable lesions. METHODS: We identified consecutive cases treated with BAM for balloon-uncrossable CTOs between January 2012 and February 2015 at two experienced CTO percutaneous coronary intervention (PCI) centers and reviewed their clinical and angiographic characteristics and procedural outcomes. RESULTS: During the study period, a total of 17 patients had BAM performed for balloon-uncrossable CTOs. Mean age was 65.5 ± 8.7 years and 94% of patients were males who often had prior myocardial infarction, PCI, and coronary artery bypass graft surgery. The most common CTO target vessel was the right coronary artery. Mean J-CTO score was 2.6 ± 1.1. Despite high lesion complexity, overall procedural success was 94% and BAM facilitated success in approximately one-half of these cases. All BAM failure cases except 1 were successfully recanalized utilizing additional techniques. No patient experienced a major complication. CONCLUSION: BAM is a simple, inexpensive, and safe technique that can facilitate crossing of balloon-uncrossable CTOs and can be considered as first-line treatment for these complex lesions.

Initial Experience With the Gaia Composite Core Guidewires in Coronary Chronic Total Occlusion Crossing.

Inability to cross the occlusion with a guidewire is the most common cause of failure of coronary chronic total occlusion (CTO) interventions. We describe two cases of successful application of the novel Gaia family of coronary guidewires (Asahi Intecc) for crossing coronary CTOs using all available crossing strategies, namely antegrade wire escalation, antegrade dissection/reentry, and retrograde.

"Move the cap" technique for ambiguous or impenetrable proximal cap of coronary total occlusion.

Antegrade crossing remains the most commonly employed crossing strategy for coronary chronic total occlusions (CTOs) but can be challenging to perform in cases of ambiguous or impenetrable proximal cap. To successfully treat such cases, we describe a technique named "move the cap," in which the subintimal space is entered proximal to the proximal cap using a stiff coronary guidewire or facilitated by inflating a slightly oversized balloon. Subintimal guidewire entry is followed by standard antegrade dissection and re-entry. The "move the cap" technique can facilitate crossing of CTOs with ambiguous or impenetrable cap, while minimizing the risk of perforation. This technique is also useful for treating balloon uncrossable lesions.

Update on Coronary Chronic Total Occlusion Percutaneous Coronary Intervention.

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has significantly evolved during recent years. High success rates are being achieved by experienced centers and operators, but not at less-experienced centers. Use of CTO crossing algorithms can help improve the success and efficiency of these potentially lengthy procedures. There is a paucity of clinical trial data examining clinical outcomes of CTO PCI, which is critical for further adoption and refinement of the procedure. We provide a detailed overview of the clinical evidence and current available crossing strategies, with emphasis on recent developments and techniques.

Physiologic significance of coronary collaterals in chronic total occlusions.

Chronic total occlusions (CTOs) are commonly found in patients with coronary artery disease, and a system of collateral connections are found in almost all of these patients. These collateral vessels serve to prevent myocardial necrosis but are not sufficient to prevent myocardial ischemia during exercise. Unfortunately, the presence of well-developed collaterals has been used as argument against CTO revascularization. Many continue to falsely believe that these patients are "protected" by collaterals and, therefore, CTO recanalization is not indicated. Our knowledge of the physiologic significance of coronary collaterals has increased significantly over the past several years. Studies utilizing coronary pressure and flow velocity have answered a number of basic physiologic questions. We therefore sought to review the evidence for coronary collateral flow and their clinical significance in patients with CTOs.

"Tip-in" technique for retrograde chronic total occlusion revascularization.

Use of the retrograde approach significantly improves the success rate of chronic total occlusion (CTO) percutaneous coronary intervention. The most commonly applied retrograde technique is placing a guidewire just distal to the distal cap using collateral vessels, with subsequent retrograde crossing of the occlusive segment. This is followed by advancement of a microcatheter and externalization of a long guidewire to allow antegrade delivery of balloons and stents. However, there are occasions when a microcatheter or balloon cannot be delivered retrogradely through the occlusive segment, resulting in procedure failure. We describe the "tip-in" technique, which involves intubation of the retrograde guidewire with an antegrade microcatheter to allow successful revascularization of a CTO after failure to externalize.

Adoption of the hybrid CTO approach by a single non-CTO operator: procedural and clinical outcomes.

BACKGROUND: The feasibility of adopting the "hybrid" approach by a single operator without prior experience in percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) has not been described. METHODS: Consecutive patients who underwent CTO-PCI by a single operator using the "hybrid" approach between 2012 and 2013 formed the analytic cohort. No patient was declined on the basis of angiographic findings. Clinical and angiographic characteristics together with procedural and hospital outcomes are described. RESULTS: During the study period, a total of 48 consecutive patients underwent PCI of 50 CTOs. Mean age was 63.4 ± 9.4 years and most patients (83%) were men. The right coronary artery (RCA) was the most commonly treated CTO vessel (54%) and mean J-CTO score was 2.3 ± 1.1. A primary retrograde approach was chosen for 33% of lesions and 40% required use of an epicardial collateral vessel. The primary strategy was effective in 65% of successful cases, 35% required one change in strategy, and 15% requiring two strategy changes. Procedural success rate was 92%. The median number of stents used was 3 (interquartile range [IQR], 2-4] and the total stent length was 73 mm [IQR, 38-96 mm). Mean contrast volume was 356.4 ± 148.3 mL and the mean air kerma radiation exposure was 3.5 ± 2.0 Gy. No patient experienced a major periprocedural complication. CONCLUSION: The "hybrid" approach to CTO-PCI can be successfully adopted by a single operator with excellent early procedural success and low complication rates, despite a lack of prior CTO-PCI experience.

Subintimal space plaque modification for "balloon-uncrossable" chronic total occlusions.

Novel techniques for percutaneous revascularization of chronic total occlusions or other complex coronary lesions utilize the subintimal space to safely and efficiently traverse the occluded coronary segment. Antegrade and retrograde dissection reentry is gaining popularity, and is an elegant method to successfully cross coronary chronic total occlusions. We describe a "subintimal space plaque modification" that involves use of antegrade and retrograde dissection reentry techniques to treat "balloon-uncrossable" coronary lesions.

Advances in the management of coronary chronic total occlusions.

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