Excimer laser facilitated percutaneous coronary intervention of a nondilatable coronary stent

Excimer laser technology in percutaneous coronary interventions: Cardiovascular laser society's position paper

Excimer Laser Coronary Atherectomy (ELCA) is a well-established therapy that emerged for the treatment of peripheral vascular atherosclerosis in the late 1980s, at a time when catheters and materials were rudimentary and associated with the most serious complications. Refinements in catheter technology and the introduction of improved laser techniques have led to their effective use for the treatment of a wide spectrum of complex coronary lesions, such as thrombotic lesions, severe calcific lesions, non-crossable or non-expandable lesions, chronic occlusions, and stent under-expansion. The gradual introduction of high-energy strategies combined with the contrast infusion technique has enabled us to treat an increasing number of complex cases with a low rate of periprocedural complications. Currently, the use of the ELCA has also been demonstrated to be effective in acute coronary syndrome (ACS), especially in the context of large thrombotic lesions.

Wolverine cutting balloon in the treatment of stent underexpansion in heavy coronary calcification: bench test using a three-dimensional printer and computer simulation with the finite-element method

Heavy coronary calcification hinders successful stent implantation, and cutting balloons can be used for post-dilation after stent deployment. However, evidence regarding its use is limited to case reports. Therefore, this study aimed to investigate in-stent dilation in circumferential coronary calcifications using Wolverine cutting balloons, compared with conventional non-compliance (NC) balloons. Circumferential coronary calcification models were designed based on the patient's intravascular ultrasound images. Three-dimensional printed models were subjected to bench tests and software analysis was performed using the finite-element method (FEM). As a result, the bench test showed that higher balloon pressure was needed to dilate the models with stent implantation, either using Wolverine (17.1 ± 2.7 atm) or NC Emerge (18.9 ± 1.8 atm), while lower pressure was needed in models without stents using Wolverine [11.7 ± 2.9 atm, analysis of variance (ANOVA) p < 0.001]. Furthermore, models without stents were all successfully cracked by Wolverine at the first dilation, while models with stent implantation needed more dilations (ANOVA p = 0.0132). The FEM showed similar results that the first principal stress was the highest in Wolverine-dilated models without stents. In conclusion, implanted stents significantly increase the difficulty of balloon dilation and adequate pretreatment is critical for successful coronary stenting.

Excimer Laser Atherectomy in Percutaneous Coronary Intervention: A Contemporary Review

Excimer laser coronary atherectomy (ELCA) during percutaneous coronary intervention (PCI) has been in use for more than twenty years. While early experiences were not favorable over balloon angioplasty alone, with improvement in operator technique, patient selection and technology, ELCA has established its own niche in contemporary PCI as a safe and effective atherectomy strategy. With growing experience in complex coronary interventions worldwide, ELCA has become one of the essential atherectomy tools offering unique advantages over other atherectomy devices. In the modern era, ELCA is commonly used for patients with in-stent restenosis, stent under expansion, balloon uncrossable lesions and chronic total occlusions. Technical success rates are reported to be >80% in most situations while procedural complication rates such as vessel dissection and perforation among others are reported to average 9% over the past 25 years with improvement over time. In this review, we provide a comprehensive systematic review of the ELCA system, its practical use, indications, and procedural techniques in the contemporary PCI era.

Treatment of In-Stent Restenosis by Excimer Laser Coronary Atherectomy and Drug-Coated Balloon: Serial Assessment with Optical Coherence Tomography

Objectives

We aimed to compare the results of neointimal modification before drug-coated balloon (DCB) treatment with excimer laser coronary atherectomy (ELCA) plus scoring balloon predilation versus scoring balloon alone in patients presenting with in-stent restenosis (ISR).

Background

Treatment of ISR with ELCA typically results in superior acute gain by neointima debulking. However, the efficacy of combination therapy of ELCA and DCB remains unknown.

Methods

A total of 42 patients (44 ISR lesions) undergoing DCB treatment with ELCA plus scoring balloon (ELCA group, n = 18) or scoring balloon alone (non-ELCA group, n = 24) were evaluated via serial assessment by optical coherence tomography (OCT) performed before, after intervention, and at 6 months.

Results

Although there was significantly greater frequency of diffuse restenosis and percent diameter stenosis (%DS) after intervention in the ELCA group, comparable result was shown in %DS, late lumen loss, and binary angiographic restenosis at follow-up. On OCT analysis, a decreased tendency in the minimum lumen area and a significant decrease in the minimum stent area were observed in the ELCA group between 6-month follow-up and after intervention (-0.89 ± 1.36 mm² vs. -0.09 ± 1.25 mm², p = 0.05, -0.49 ± 1.48 mm² vs. 0.28 ± 0.78 mm², p = 0.03, respectively). The changes in the neointimal area were similar between the groups, and target lesion revascularization showed comparable rates at 1 year (11.1% vs. 11.4%, p = 0.85).

Conclusions

Despite greater %DS after intervention, ELCA before DCB had possible benefit for late angiographic and clinical outcome.

Long-term outcomes of rotational atherectomy of underexpanded stents. A single center experience

OBJECTIVES

To analyze the procedural and long-term outcomes of the use of rotational atherectomy (RA) in underexpanded stents in our cohort and to provide an overview of currently available data on this technique.

BACKGROUND

Stent underexpansion (SU) has been related to stent thrombosis and restenosis. RA has been used to treat undilatable SU as a bail-out strategy with encouraging results.

METHODS

This is an observational, single-center study. We included patients who underwent stentablation between 2013 and 2017. Baseline demographics, procedural results, in-hospital major adverse cardiac events (MACE), and long-term follow-up MACE were retrospectively collected.

RESULTS

A total of 11 patients (90.9% males, mean age 65.4 ± 18.6) were included in this study. Median left ventricle ejection fraction was 53.5% [46.2-55]. Median calculated Syntax score was 16 [9-31] and 45.5% of patients were admitted for acute coronary syndrome. Radial approach was used in 63.6% of cases. Most patients only required one burr (45% used a 1.5 mm diameter burr) during the intervention. Procedural success was achieved in 90.9% of the cases. Acute lumen gain was 42.7% [30.7-61.49]. There were no in-hospital deaths or MACE. At a median follow-up of 26 months, only one patient (9.1%) suffered MACE in the context of acute coronary syndrome, and two patients (18.2%) required non-target lesion revascularization. No deaths were reported.

CONCLUSIONS

RA of under expanded stents is a feasible option with a high rate of procedural success. At long-term follow-up, all of them were alive and 90.9% of patients remained free from MACE.

Prevalence, Presentation and Treatment of 'Balloon Undilatable' Chronic Total Occlusions: Insights from a Multicenter US Registry

BACKGROUND

The prevalence, treatment and outcomes of balloon undilatable chronic total occlusions (CTOs) have received limited study.

METHODS

We examined the prevalence, clinical and angiographic characteristics, and procedural outcomes of percutaneous coronary interventions (PCIs) for balloon undilatable CTOs in a contemporary multicenter US registry.

RESULTS

Between 2012 and 2017 data on balloon undilatable lesions were available for 425 consecutive CTO PCIs in 415 patients in whom guidewire crossing was successful: 52 of 425 CTOs were balloon undilatable (12%). Mean patient age was 65 ± 10 years and most patients were men (84%). Patients with balloon undilatable CTOs were more likely to be diabetic (67 vs. 41%, P < 0.001) and have heart failure (44 vs. 28%, P = 0.027). Balloon undilatable CTOs were longer (40 mm [interquartile range, IQR 20-50] vs. 30 [IQR 15-40], P = 0.016), more likely to have moderate/severe calcification (87 vs. 54%, P < 0.001), and had higher J-CTO score (3.2 ± 1.1 vs. 2.5 ± 1.3, P < 0.001) and PROGRESS-CTO complications score (3.9 ± 1.7 vs. 3.1 ± 2.0, P < 0.005). They were associated with lower technical and procedural success (92 vs. 98%, P = 0.024; and 88 vs. 96%, P = 0.034, respectively) and higher risk for in-hospital major adverse events (8 vs. 2%, P = 0.008) due to higher perforation rates. The most frequent treatments for balloon undilatable CTOs were high pressure balloon inflations (64%), rotational atherectomy (31%), laser (21%), and cutting balloons (15%).

CONCLUSIONS

Balloon undilatable CTOs are common and are associated with lower success and higher complication rates.

Coronary Intervention with the Excimer Laser: Review of the Technology and Outcome Data

Excimer laser coronary atherectomy (ELCA) is a long-established adjunctive therapy that can be applied during percutaneous coronary intervention (PCI). Technical aspects have evolved and there is an established safety and efficacy record across a number of clinical indications in contemporary interventional practice where complex lesions are routinely encountered. The role of ELCA during PCI for thrombus, non-crossable or non-expandable lesions, chronic occlusions and stent under-expansion are discussed in this review. The key advantage of ELCA over alternative atherectomy interventions is delivery on a standard 0.014-inch guidewire. Additionally, the technique can be mastered by any operator after a short period of training. The major limitation is presence of heavy calcification although when rotational atherectomy (RA) is required but cannot be applied due to inability to deliver the dedicated RotaWire^TM (Boston Scientific), ELCA can create an upstream channel to permit RotaWire passage and complete the case with RA - the RASER technique.

Successful rotational atherectomy for a repetitive restenosis lesion with underexpansion of double layer drug-eluting stents due to heavily calcified plaque

A 72-year-old male was treated. First percutaneous coronary intervention (PCI) for chronic total occlusion of proximal left anterior descending artery was performed after rotational atherectomy with 1.5-mm burr. Focal underexpansion of Promus stent occurred due to the heavily calcified plaque. After first restenosis, OCT-guided PCI was performed with 26 atm balloon dilatation. After second restenosis, Resolute Integrity was implanted. After third restenosis, rotational atherectomy with 1.5-, 1.75- and 2.15-mm burrs was performed. All stent struts disappeared at the lesion and Promus Element was implanted. No restenosis occurred after 6 months. Cautious rotational atherectomy could ablate double layer drug-eluting stents effectively.

Successful retrieval of an entrapped guide wire between a deployed coronary stent and severely calcified vessel wall using excimer laser coronary atherectomy

We report the successful retrieval of an entrapped interventional guide wire between a newly deployed coronary stent and severely calcified vessel wall. Using a buddy wire technique, the stent was deployed at high pressure in a culprit lesion of the left anterior descending (LAD) artery. The buddy wire in the LAD artery was entrapped between the deployed stent and severely calcified vessel wall, as it was not removed before stent deployment, and could not be retrieved. Neither balloon catheters nor a microcatheter were able to be advanced behind the stent over the entrapped guide wire. Excimer laser coronary atherectomy (ELCA) was performed within the stent to modify and soften the calcification behind the deployed stent. Consequently, the entrapped guide wire was retrieved successfully and safely. This case illustrates that ELCA can be utilized to retrieve an entrapped guide wire between a deployed stent and calcified vessel wall.

Successful expansion of an underexpanded stent by rotational atherectomy

The current routine use of intracoronary stents in percutaneous coronary intervention (PCI) has significantly reduced rates of restenosis, compared with balloon angioplasty alone. On the contrary, small post-stenting luminal dimensions due to undilatable, heavily calcified plaques have repeatedly been shown to significantly increase the rates of in-stent restenosis. Rotational atherectomy of lesions is an alternative method to facilitate PCI and prevent underexpansion of stents, when balloon angioplasty fails to successfully dilate a lesion. Stentablation, using rotational atherectomy to expand underexpanded stents deployed in heavily calcified plaques, has also been reported. We report a case via the transradial approach of rotational-atherectomy-facilitated PCI of in-stent restenosis of a severely underexpanded stent due to a heavily calcified plaque. We review the literature and suggest rotational atherectomy may have a role in treating a refractory, severely underexpanded stent caused by a heavily calcified plaque through various proposed mechanisms.

The use of excimer laser for complex coronary artery lesions

Excimer laser coronary atherectomy (ELCA) has been used for coronary intervention for more than 20 years. Advances in delivery systems for laser energy using the xenon-chlorine pulsed laser catheter deliver higher energy density with lower heat production. The Spectranetics CVX-300 (Spectranetics, Colorado Springs, CO, USA) excimer laser catheter system has been used for the treatment of complex coronary lesions. We report our experience with the use of this advanced system for stenoses for which were unsuitable for standard percutaneous coronary intervention; for example, balloon-resistant lesions, chronic total occlusions, and for underexpanded stents in calcified lesions. ELCA may also be valuable for thrombus-containing lesion. We find ELCA to be indispensable in the catheterization laboratory for specific complex or calcified lesions. Its role should be explored in a large randomized trial of thrombus containing lesions and saphenous vein grafts.