Excimer Laser Atherectomy in Percutaneous Coronary Intervention: A Contemporary Review

Calcium Modification Techniques in Complex Percutaneous Coronary Intervention: State-of-the-Art Review

As patients increase in age and medical complexity, coronary artery calcification is frequently encountered and its presence portends worse outcomes following percutaneous coronary intervention (PCI) - negatively impacting procedural success and long-term outcomes. This review paper explores available imaging techniques and calcium modification technique that can identify, characterize and modify these lesions to facilitate stent implantation. The data supporting these techniques are explored and an algorithm for decision-making during lesion modification is presented. Current barriers and future directions are additionally discussed.

Excimer LASER coronary atherectomy for ST-segment elevation myocardial infarction: Insights from a multicenter registry

BACKGROUND

Excimer laser coronary atherectomy (ELCA) is used for thrombotic culprit lesions in ST-segment elevation myocardial infarction (STEMI), but its effectiveness is still unclear.

METHODS

Consecutive patients undergoing primary percutaneous coronary intervention within 24 h of onset were retrospectively investigated. Patients were divided into ELCA and non-ELCA groups. The primary endpoint was target vessel-related major adverse cardiac events (TV-MACE). Cox regression analysis and propensity score matching were performed to compare clinical outcomes between the two groups.

RESULTS

A total of 2593 patients were included in the analysis, with a median follow-up of 815 (390-1385) days. In the total cohort, there was no significant difference between the two groups in terms of TV-MACE-free survival rate. ELCA use was not a significant determinant of TV-MACE (hazard ratio 1.265, 95 % confidence interval, 0.910-1.757; p = 0.161). Nevertheless, when the ELCA group was stratified by the ELCA catheter size, the large catheter (1.4 mm-1.7 mm) group showed a lower event rate compared to the others in univariate analysis, although this difference was not significant in multivariate analysis. In the propensity score-matched cohort of 736 patients (368 pairs), the TV-MACE-free survival did not differ between the two groups.

CONCLUSIONS

ELCA use was not associated with a reduced rate of adverse cardiac events in patients with STEMI. However, the use of large-sized ELCA catheters showed a potential association with better clinical outcomes, warranting further prospective studies.

Removal of an entrapped guidewire by excimer laser coronary angioplasty in patients with chronic total occlusion intervention

Guidewire entrapment (GE) is a rare complication that warrants complex interventions or surgical procedures. Here, we report the removal of an entrapped guidewire using excimer laser coronary angioplasty (ELCA) in a case of chronic total occlusion (CTO). Plaque tissue trapped with the guidewire was also removed. Histopathological examination revealed that although specific components were entrapped with the guidewire, loosening the adjacent collagen fibres during ELCA contributed to the successful removal of the guidewire. This case showed that ELCA may be a novel modality for the removal of an entrapped guidewire in cases of CTO.

First-in-Man Study of a Novel Peripheral Plaque Atherectomy Device

This first-in-man (FIM) study evaluated the feasibility and safety of a new peripheral plaque atherectomy system in patients with symptomatic lower extremity artery disease (LEAD). Ten patients with symptomatic LEAD (Rutherford class 2-5) were enrolled in a prospective, single-center study from March to April 2024. Patients aged 18-85 years with target lesions showing ≥70% stenosis and reference vessel diameters ≥1.8 mm underwent treatment using a novel atherectomy device with a "shaving" mechanism to excise calcified plaques. Outcomes included post-procedural stenosis improvement, 6-month primary patency rate, and safety endpoints such as thrombosis, vasospasm, acute occlusion, and distal embolization. Statistical analysis used SPSS 23.0. Ten male patients (mean age: 61.4 ± 9.2 years) were treated. Most had diabetes (80%), hypertension (70%), and hyperlipidemia (80%). Pre-procedural ankle-brachial index (ABI) averaged 0.50 ± 0.14. Angiographic analysis showed 60% of lesions in the femoral artery and 40% as chronic total occlusions. No major adverse events occurred, with 100% technical success. Post-procedural ABI improved to 0.92 ± 0.12 (p < 0.05). At 6 months, the primary patency rate was 100%, with no clinically-driven revascularization or adverse cardiovascular events. Mortality was 0%. All patients reported significant improvement in symptoms and walking distance, as well as enhanced quality of life and reduced pain during physical activity. The novel atherectomy device showed promising safety and efficacy for treating calcified LEAD. Larger-scale trials are needed to confirm these outcomes.

An In Vitro Study of 355-nm Laser Ablation of Atherosclerotic Lesions Model

A study of 355 nm laser with high pulse energy across various types of atherosclerotic lesion models is presented. The 355 nm laser pulses (10 ns) are delivered via a single fiber (600 μm diameter), and the ablation of calcified tissue, lipid tissue, and thrombus-like tissue are studied under varied laser fluence (40-70 mJ/mm2) and repetition rate (5-30 Hz). The contact and noncontact ablation processes of chicken tibia samples (calcified tissue) are compared at 60 mJ/mm2 and 30 Hz, and the size of ablation particles is in the range of 0.1-1 μm. At the same repetition rate, the advancement rate of tricalcium phosphate samples reaches 150 μm/s at 70 mJ/mm2. Calcified and lipid models demonstrate predictable increases in ablation with higher laser fluence and repetition rate. The fresh porcine blood clot samples exhibit high-quality ablation with good channel effect at 50 mJ/mm2 and 30 Hz.

Atherectomy Techniques: Rotablation, Orbital and Laser

Coronary artery disease remains the leading cause of morbidity and mortality worldwide despite advancements in percutaneous coronary intervention (PCI). With an increasing ageing population, there is a significant challenge in addressing severe calcification in atherosclerotic plaque during angioplasty. This review article focuses on atherectomy strategies such as rotational atherectomy (RA), orbital atherectomy (OA) and excimer laser coronary angioplasty (ELCA) aimed at modifying calcified lesions and improving PCI outcomes. RA modifies plaque through rotational ablation, OA uses eccentrically mounted diamond-coated crown and has a reduced entrapment risk compared to RA. ELCA uses pulsatile laser energy to precisely ablate plaque tissue. This review provides insights into the mechanisms, procedural techniques and clinical outcomes associated with these calcium modification techniques. The selection of appropriate devices and adequate training are crucial for optimising lesion modification and enhancing procedural success. Further research and standardised protocols are required to overcome challenges associated with using these devices and expand their usage in clinical practice.

Intravascular Lithotripsy: Approach to Advanced Calcified Coronary Artery Lesions, Current Understanding, and What Could Possibly Be Studied Next

Calcified and resistant narrowing of arteries poses significant difficulty in performing percutaneous coronary interventions (PCIs), as they increase the risk of subpar outcomes leading to worse clinical outcomes. Despite the existence of dedicated technologies and devices, including various balloons and atherectomy systems, they often do not ensure sufficient plaque modification and ideal vessel preparation for optimal stent deployment. Intravascular lithotripsy (IVL), a technology originally developed for urological procedures, has recently been used to safely and selectively disrupt calcified depositions in both peripheral and coronary arteries by sonic waves that seamlessly transfer to nearby tissue, enhancing vessel compliance with minimal impact on soft tissues. In the coronary arteries, the use of IVL plays a role in the process of "vessel preparation" before the placement of stents, which is crucial for restoring blood flow in patients with severe coronary artery disease (CAD), and is considered a minimally invasive technique, reducing the need for open heart surgeries and associated risks and complications. Studies have shown that IVL can lead to improved procedural success rates and favorable long-term outcomes for patients with severely calcified coronary artery disease. With the advent of IVL, the disruption of severe calcification of coronary artery and stenotic lesions before stent implantations can be performed. Despite promising data for treating calcified lesions, IVL is significantly underutilized in clinical practice, long-term clinical data and extensive research are needed to validate its further safety and efficacy. In this article, we reviewed the literature discussing the use of IVL in the coronary arteries as an approach for addressing intravascular atherosclerotic plaques, particularly focusing on heavily calcified plaques that are resistant to standard initial PCI, while also evaluating its safety in comparison to alternative methods.

Contrast-enhanced excimer laser stepwise approach during PCI for resistant coronary lesions

BACKGROUND

The treatment of resistant coronary lesions (RCL) is a great challenge for interventional cardiologists. The excimer laser coronary atherectomy (ELCA) is a plaque modification tool based on a main mechanism of photomechanical effect leading to mechanical disruption of the plaque. Contrast dye injection during laser delivery has demonstrated to enhance its power.

AIM

To evaluate the effectiveness and safety of the contrast-enhanced ELCA by a stepwise approach in the treatment of RCLs.

METHODS

We retrospectively examined consecutive patients undergoing contrast-enhanced ELCA-assisted PCI between 2018 and 2021 at two Italian sites. RCLs were defined as novo or in-stent undilatable/uncrossable with conventional balloons (SC/NC balloon). The primary endpoint was ELCA technical success defined as the laser catheter crossing the entire length of the target lesion established by angiographic evidence of the catheter tip in the artery distal to the stenosis.

RESULTS

We enrolled 114 patients who underwent contrast-enhanced ELCA-assisted PCI: 58% of the patients had acute coronary syndrome while the left anterior descending artery was the target vessel in 42.1% of cases. The target lesion was most commonly in-stent (56.2%). The 0.9 mm ELCA catheter tip was employed in 89.5% of cases. The most used frequency/fluency profile was 70/70 (39.5%). The use of contrast-enhanced ELCA was associated with high technical, procedural, and clinical success rates (97.4%, 93.7%, and 90.1%, respectively).

CONCLUSIONS

The contrast-enhanced ELCA seems to be a safe and effective treatment option for the management of both de novo and in-stent-resistant coronary lesions.

Excimer laser coronary angioplasty combined with drug-coated balloon in the treatment of in-stent restenosis

OBJECTIVES

The aim of this study is to investigate the safety and efficacy of excimer laser coronary angioplasty (ELCA) combined with drug-coated balloons (DCBs) in the treatment of in-stent restenosis (ISR), and to explore whether the contrast injection technique would improve the neointimal tissue ablation of ELCA.

METHODS

We studied patients diagnosed with ISR between January 2019 and October 2022 at two medical centers. These patients underwent DCB angioplasty guided by optical coherence tomography (OCT). Based on whether ELCA was performed before DCB treatment, patients were categorized into two groups: the ELCA + DCB group and the DCB group. All patients underwent clinical follow-up 1 year after the procedure. The primary endpoint was the 1-year rate of target lesion revascularization (TLR), which was defined as any repeat percutaneous intervention or bypass surgery on the target vessel conducted to address restenosis or other complications related to the target lesion. The secondary endpoints including immediate luminal gain (ΔMLA, defined as the difference in minimum lumen area before and after the intervention).

RESULTS

A total of 85 lesions in 75 patients were included. The mean age of the study population was 64.2 ± 12.0 years, with 81.3% male. Baseline clinical characteristics were well-balanced, and procedural success was 100% in both groups. The ELCA + DCB group (n = 24) exhibited a greater ΔMLA compared to the DCB group (n = 61) (3.57 ± 0.79 mm² vs. 2.50 ± 1.06 mm², [95% confidence interval, CI: 0.57-1.69], p < 0.001), The reduction in 1-year TLR was more frequently observed in patients from the ELCA + DCB group compared to the DCB group (hazard ratio 0.33 [95% CI: 0.11-0.99]; log-rank p = 0.048). The exploratory analysis showed that ELCA with contrast infusion is associated with greater acute lumen gain compared to ELCA with saline infusion (p < 0.001).

CONCLUSIONS

The combination of ELCA and DCB is a safe and effective treatment strategy for in-stent stenosis. Additionally, compared with saline injection, ELCA with contrast injection is associated with greater acute lumen gain. However, the optimal contrast agent concentration and long-term outcome of the contrast injection technique need confirmation through larger sample sizes and prospective studies.

An analysis of long-term clinical outcome following the use of excimer laser coronary atherectomy in a large UK PCI center

BACKGROUND

Excimer laser atherectomy (ELCA) is an established adjunctive technique to facilitate acute success in percutaneous coronary intervention (PCI). Despite this there are a lack of contemporary outcome data, particulary longer-term, forpatients treated with ELCA PCI.

AIMS

To evaluate the contemporary use ofELCA in PCI, the frequency of periprocedural complications and the longer-term outcomes associated with ELCA PCI.

METHODS

This was a retrospective study that included all patients undergoing PCI (with or without ELCA) between April 2005 and May 2021. Relevant features from all cases were downloaded from the patient record and matched to hospital data on mortality on November 22, 2022. Kaplan Meier curves were used to compare mortality between the ELCA PCI and non-ELCA PCI cohorts with a landmark at 1 year. Multivariable Cox regression was performed to assess whether ELCA PCI was independently associated with long-term mortality.

RESULT

There were 21,256 patients in this analysis, of which 448 (2.1%) were treated with ELCA PCI. ELCA PCI was associated with a higher frequency of any periprocedural complication. Median follow-up was 2812 days (IQR, 1577-4245 days) with higher mortality in ELCA PCI (38.2% vs. 29.0%, p < 0.001). However, on multivariable analysis, ELCA PCI was not independently associated with long-term mortality. The TVR frequency in ELCA PCI was 16.7% but TVR was significantly higher for cases of in-stent restenosis (ISR) (29.5%).

CONCLUSION

Despite ELCA PCI being used in higher risk populations with complex coronary artery disease there was no long-term increased mortality associated with the use of this device. ELCA PCI for ISR is highly effective and safe although TVR in this cohort remains high in long-term follow-up.

A novel approach to saline/contrast delivery in excimer laser coronary atherectomy (ELCA) to enhance efficacy: MAXCon ELCA technique

The advent of excimer laser coronary atherectomy (ELCA) nearly four decades ago heralded a novel way to treat complex lesions, both coronary and peripheral, which were previously untraversable and thus untreatable. These complex lesions include heavily calcified lesions, ostial lesions, bifurcation lesions, chronic total occlusions, in-stent restenosis (including stent underexpansion), and degenerative saphenous vein grafts. We discuss the technology of ELCA, its indications, applications, and complications, and suggest the "MAXCon ELCA" technique for better outcomes without increased risk. Lastly, we present a case of MAXCon ELCA effectively treating a complex lesion.

Excimer laser coronary angioplasty without stenting in a 37-year-old man with acute coronary syndrome involving left main trunk: a case report

Background

Excimer laser coronary angioplasty (ELCA) is utilized to reduce thrombus in acute coronary syndrome (ACS). However, the feasibility and safety of ELCA for patients with ACS involving the left main trunk (LMT) and bifurcation, as well as the safety of a stentless strategy with ELCA, are not well-documented.

Case summary

A 37-year-old man without any past medical history presented with chest pain. Electrocardiogram showed ST-segment elevation in leads I, aVL, and V2-V6. Emergent coronary angiography (CAG) showed a 99% stenosis from LMT to proximal left anterior descending artery (LAD). Intra-aortic balloon pumping (IABP) was initiated. Intravascular ultrasound revealed massive thrombus at the culprit lesion. Thrombus aspiration was not enough to reduce the thrombus, thus, we conducted thrombus vaporization with a 0.9 mm ELCA catheter. Coronary angiography after the procedure showed reduced thrombus with thrombolysis in myocardial infarction grade 3 flow. Considering his age and the complexity of stenting the LMT, we completed the procedure without stenting. After the intervention, we initiated triple antithrombotic therapy. On Day 3, we removed the IABP. On Day 11, CAG showed no significant stenosis. Optical coherence tomography revealed ulceration, indicating the presence of plaque disruption at the proximal LAD as the likely cause of thrombosis. With improvement in CAG findings, we stopped heparin and continued dual antiplatelet therapy. He was discharged on Day 20.

Discussion

Excimer laser coronary angioplasty without stenting can be an option for the patients with ACS involving LMT, especially for younger patients who are suitable to avoid stenting on bifurcation lesions for lifelong management.

In-Stent Restenosis Overview: From Intravascular Imaging to Optimal Percutaneous Coronary Intervention Management

Despite ongoing progress in stent technology and deployment techniques, in-stent restenosis (ISR) still remains a major issue following percutaneous coronary intervention (PCI) and accounts for 10.6% of all interventions in the United States. With the continuous rise in ISR risk factors such as obesity and diabetes, along with an increase in the treatment of complex lesions with high-risk percutaneous coronary intervention (CHIP), a substantial growth in ISR burden is expected. This review aims to provide insight into the mechanisms, classification, and management of ISR, with a focus on exploring innovative approaches to tackle this complication comprehensively, along with a special section addressing the approach to complex calcified lesions.

Intravascular lithotripsy: A novel option for severe calcification of coronary artery

BACKGROUND

Severe coronary artery calcification is associated with low success rate of interventional operation, perioperative adverse cardiac events, and poor prognosis, which is a major problem faced by operators. The existing therapy methods all have inherent limitations, such as unsatisfactory balloon crossability, inadequate balloon dilation, and so on. The emergence of intravascular lithotripsy (IVL) has brought the dawn of the treatment of calcified lesions by using unfocused acoustic pressure waves to fracture calcification in situ. And IVL is the only technology capable of targeting deep calcification.

HYPOTHESIS

IVL may have great clinical application values and potential prospects.

METHOD

Based on the existing clinical evidence of IVL and traditional treatment ways, this review discusses the safety and efficacy of IVL. Combined with clinical practice, the precautions and coping strategies of IVL are analyzed. And the review improves the management algorithm of coronary calcification.

RESULTS

IVL has extremely high safety and effectiveness for severe coronary calcification compared with other ways, and structural improvements of IVL will further expand its value.

CONCLUSIONS

The emergence of IVL could set off a revolution in the treatment of coronary artery calcification.

Excimer laser coronary atherectomy with distal protection for neoatherosclerosis rupture: a case report

Background

Neoatherosclerosis, a prominent contributor to in-stent restenosis (ISR), persists as a formidable challenge during percutaneous coronary intervention. Excimer laser coronary atherectomy (ELCA) and embolic protection devices may help reduce coronary flow disturbance from procedure-related distal embolization.

Case summary

A 71-year-old man experienced in-stent neoatherosclerosis rupture-related non-ST segment elevation myocardial infarction. Multidisciplinary intracoronary imaging, including intravascular ultrasound and optical coherence tomography (OCT), suggested that the ISR was caused by a neoatherosclerosis rupture that can potentially lead to distal embolization. Excimer laser coronary atherectomy (fluence, 45 mJ/mm2 and frequency, 25 pulse/s) using a 1.7 mm concentric catheter was performed with distal protection using Filtrap (Nipro Corporation, Tokyo, Japan), which significantly reduced the volume of the neoatherosclerosis. However, subsequent ELCA on the highest setting (fluence, 60 mJ/mm2 and frequency, 40 pulse/s) led to a filter no-reflow phenomenon, although OCT revealed a further effective vaporization of the neoatherosclerosis and an apparent reduction of soft tissue compatible with the thrombus. After removing the embolic protection device, drug-coated balloon angioplasty provided optimal results without coronary flow disturbance.

Discussion

Excimer laser coronary atherectomy reduces soft plaque and thrombus burden, which can reduce the occurrence of distal embolization in select cases. In the case of this patient, procedure-related distal embolization may have been induced by the heightened photomechanical effects resulting from the use of the highest setting in ELCA under increased intracoronary arterial pressure caused by continuous saline injection during ELCA. Concomitant distal protection during ELCA may be more feasible for preventing coronary flow disturbance in patients with a large amount of neoatherosclerosis.

Intravascular laser lithotripsy for calcium fracture in human coronary arteries

BACKGROUND

Electrical intravascular lithotripsy (E-IVL) uses shock waves to fracture calcified plaque.

AIMS

We aimed to demonstrate the ability of laser IVL (L-IVL) to fracture calcified plaques in ex vivo human coronary arteries and to identify and evaluate the mechanisms for increased vessel compliance.

METHODS

Shock waves were generated by a Ho:YAG (Holmium: yttrium-aluminium-garnet) laser (2 J, 5 Hz) and recorded by a high-speed camera and pressure sensor. Tests were conducted on phantoms and 19 fresh human coronary arteries. Before and after L-IVL, arterial compliance and optical coherence tomography (OCT) pullbacks were recorded, followed by histology. Additionally, microcomputed tomography (micro-CT) and scanning electron microscopy (SEM) were performed. Finite element models (FEM) were utilised to examine the mechanism of L-IVL.

RESULTS

Phantom cracks were obtained using 230 μm and 400 μm fibres with shock-wave pressures of 84±5.0 atm and 62±0.4 atm, respectively. Post-lithotripsy, calcium plaque modifications, including fractures and debonding, were identified by OCT in 78% of the ex vivo calcified arteries (n=19). Histological analysis revealed calcium microfractures (38.7±10.4 μm width) in 57% of the arteries which were not visible by OCT. Calcium microfractures were verified by micro-CT and SEM. The lumen area increased from 2.9±0.4 to 4.3±0.8 mm2 (p<0.01). Arterial compliance increased by 2.3±0.6 atm/ml (p<0.05). FEM simulations suggest that debonding and intimal tears are additional mechanisms for increased arterial compliance.

CONCLUSIONS

L-IVL has the capability to increase calcified coronary artery compliance by multiple mechanisms.

Comparison of Orbital Atherectomy and Rotational Atherectomy in Calcified Left Main Disease: Short-Term Outcomes

BACKGROUND

Coronary calcifications, particularly in left main disease (LMD), are independently associated with adverse outcomes of percutaneous coronary intervention (PCI). Adequate lesion preparation is pivotal to achieve favorable short- and long-term outcomes. Rotational atherectomy devices have been used in contemporary practice to obtain adequate preparation of the calcified lesions. Recently, novel orbital atherectomy (OA) devices have been introduced to clinical practice to facilitate the preparation of the lesion. The objective of this study is to compare the short-term safety and efficacy of orbital and rotational atherectomy for LMD.

METHODS

we retrospectively evaluated a total of 55 consecutive patients who underwent the LM PCI supported by either OA or RA.

RESULTS

The OA group consisted of 25 patients with a median SYNTAX Score of 28 (26-36). The Rota group consisted of 30 patients with a median SYNTAX Score of 28 (26-33.1) There were no statistical differences in MACCE between the RA and OA subpopulations when recorded in-hospital (6.7% vs. 10.3% p = 0.619) as well as in a 1-month follow-up after the procedure (12% vs. 16.6% p = 0.261).

CONCLUSION

OA and RA seem to be similarly safe and effective strategies for preparating the lesion in the high-risk population with calcified LMD.

Ablation of porcine subcutaneous fat and porcine aorta tissues by a burst-mode nanosecond-pulsed laser at 355 nm

High-energy laser pulses used in laser angioplasty are challenging the laser cost, delivery system damage, efficiency, and laser catheter operating time. 355 nm nanosecond-pulsed laser in burst mode has shown potentials in reducing the system complexity and selective ablation of tissues. In this paper, burst mode laser ablation of porcine subcutaneous fat and porcine aorta is investigated. A histopathological analysis demonstrates that porcine subcutaneous fat can be ablated at a rate of greater than 0.2 mm/s when the number of pulses per burst is 1500 (corresponding to a fluence of 0.12 mJ/mm² per pulse and 180 mJ/mm² per burst), and the temperature of tissue during lasing is lower than 45°C. The porcine aorta remains nearly unaffected at the same laser parameter, and the tissue temperature during lasing is lower than 35°C. It shows the feasibility of using a burst-mode laser for selective ablation of tissue.

Histological evaluation of vascular changes after excimer laser angioplasty for neointimal formation after bare-metal stent implantation in rabbit iliac arteries

BACKGROUND

Excimer laser is used to treat coronary artery disease, especially in case of lesions with thrombus and in-stent restenosis (ISR). However, there are no in vivo preclinical studies that have evaluated the pathological reactions of the vessel wall after excimer laser ablation.

METHODS

Bare-metal stents were placed in the external iliac arteries of six healthy rabbits. Twenty-eight days later, excimer laser ablation was performed with low-power (45 (fluency)/25 (rate)) in one side, and high-power (60/40) in the opposite side, followed by optical coherence tomography (OCT) evaluation. Rabbits were sacrificed 15 min after the procedure, and histological assessment was performed.

RESULTS

Morphometry analysis of OCT showed similar stent and lumen size between low-power and high-power group. Histological evaluation suggested endothelial cell loss, fibrin deposition, and tissue loss. The low-power group showed significantly less pathological changes compared with the high-power group: angle of endothelial cell loss, 32.4° vs. 191.7° (interquartile range, 8.8°-131.7° vs. 125.7°-279.5°; p < 0.01); fibrin deposition, 1.1° vs. 59.6° (0.0°-70.4° vs. 31.4°-178.4°; p = 0.03); and tissue loss 0.0° vs. 18.2° (0.0°-8.7° vs. 0.0°-42.7°; p = 0.03).

CONCLUSIONS

The pathological changes in neointima were more prominent after high-power excimer laser ablation than after low-power excimer laser. To improve safety in clinical practice, understanding the pathological changes of tissues after excimer laser in lesions with ISR is essential.

A feasibility study on removing lipid deposition in atherosclerotic plaques with ultrasound-assisted laser ablation

Objective. Atherosclerosis is the buildup of fats, cholesterol, and other substances on the inner walls of arteries. It can affect arteries of heart, brain, arms, legs, pelvis and kidney, resulting in ischemic heart disease, carotid artery disease, peripheral artery disease and chronic kidney disease. Laser-based treatment techniques like laser atherectomy can be used to treat many common atherosclerostic diseases. However, the use of laser-based treatment remains limited due to the high risk of complications and low efficiency in removing atherosclerostic plaques as compared with other treatment methods. In this study, we developed a technology that used high intensity focused ultrasound to assist laser treatment in the removal of the lipid core of atherosclerotic plaques.Approach. The fundamental mechanism to disrupt atherosclerostic plaque was to enhance the mechanical effect of cavitation during laser/ultrasound therapy. To promote cavitation, spatiotemporally synchronized ultrasound bursts of 2% duty cycle at 0.5 MHz and nanosecond laser pulses at 532 nm wavelength were used. Experiments were first performed on pig belly fat samples to titrate ultrasound and laser parameters. Then, experiments were conducted on human plaque samples, where the lipid depositions of the plaques were targeted.Main results. Our results showed that fat tissue could be removed with an ultrasound peak negative pressure (PNP) of 2.45 MPa and a laser radiant exposure as low as 3.2 mJ mm-2. The lipid depositions on the atherosclerostic plaques were removed with laser radiant exposure of 16 mJ mm-2in synchronizing with an ultrasound PNP of 5.4 MPa. During all the experiments, laser-only and ultrasound-only control treatments at the same energy levels were not effective in removing the lipid.Significance. The results demonstrated that the addition of ultrasound could effectively reduce the needed laser power for atherosclerotic plaque removal, which will potentially improve treatment safety and efficiency of current laser therapies.

The many roles of urgent catheter interventions: from myocardial infarction to acute stroke and pulmonary embolism

INTRODUCTION

Cardiovascular diseases (CVDs) are the leading cause of cardiovascular mortality and a major contributor to disability worldwide. The prevalence of CVDs is continuously increasing, and from 1990 to 2019, it has doubled. Global cardiovascular mortality has increased from 12.1 million in 1990 to 18.6 million cases in 2019. The development of therapeutic options for these diseases is at the forefront of interest concerning the extensive socio-economic consequences. Modern endovascular transcatheter therapeutic options contribute to the reduction of cardiovascular morbidity and mortality.

AREAS COVERED

The article concentrates on the triad of the most common causes of acute cardiovascular mortality and morbidity - myocardial infarction, ischemic stroke, and pulmonary embolism. Current evidence-based indications, specific interventional techniques, and remaining unsolved issues are reviewed and compared. A personal perspective on the possible implications for the future is provided.

EXPERT OPINION

Primary angioplasty for ST-segment elevation myocardial infarction is a well-established therapeutic option with proven mortality benefits. We suppose that catheter-based interventions for acute stroke will spread quickly from centers of excellence to routine clinical practice. We believe that ongoing research will provide a basis for the expansion of interventional treatment of pulmonary embolism soon.

Benefits of excimer laser coronary angioplasty over thrombus aspiration therapy for patients with acute coronary syndrome and thrombolysis in myocardial infarction flow grade 0

In primary percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS), the presence of a thrombus or unstable plaque can cause microvascular obstructions, which may increase infarct size and reduce survival. Excimer laser coronary angioplasty (ELCA) is a unique revascularization technique that can vaporize plaques and thrombi. However, to date, only few reports indicate the efficacy of ELCA for ACS. We retrospectively analyzed 113 consecutive ACS patients who underwent PCI with either ELCA or manual thrombus aspiration therapy (TA) before balloon angioplasty or stenting and who had a Thrombolysis in Myocardial Infarction flow (TIMI) grade 0 on the first contrast injection within 24 h of onset at our hospital from March 2011 to March 2020. Patients were divided into two groups by the procedure used: ELCA (N = 48) and TA (N = 50). Door-to-reperfusion time was significantly shorter in the ELCA group than TA group (89.2 ± 6.7 vs. 137.9 ± 12.3 min, respectively; P < 0.01). There was also a significant difference in peak creatine kinase-myocardial band between the ELCA and TA groups (242 ± 25 vs. 384 ± 63 IU/L, respectively; P = 0.04). Although there was no difference in myocardial blush grade (MBG) before treatment, the MBG after treatment was higher in the ELCA group (P < 0.01). In-hospital major adverse cardiac events (MACE) were also significantly fewer in the ELCA group than in the TA group (8% vs. 20%, P = 0.045). ELCA for TIMI grade 0 ACS may shorten reperfusion time, improve the MBG score, and reduce MACE when compared to TA.

Management of in-stent restenosis

In-stent restenosis (ISR) remains the most common cause of stent failure after percutaneous coronary intervention (PCI). Recent data suggest that ISR-PCI accounts for 5-10% of all PCI procedures performed in current clinical practice. This State-of-the-Art review will primarily focus on the management of ISR but will begin by briefly discussing diagnosis and classification. We then move on to detail the evidence base underpinning the various therapeutic strategies for ISR before finishing with a proposed ISR management algorithm based on current scientific data.

Review on Laser Technology in Intravascular Imaging and Treatment

Blood vessels are one of the most essential organs, which nourish all tissues in our body. Once there are intravascular plaques or vascular occlusion, other organs and circulatory systems will not work properly. Therefore, it is necessary to detect abnormal blood vessels by intravascular imaging technologies for subsequent vascular treatment. The emergence of lasers and fiber optics promotes the development of intravascular imaging and treatment. Laser imaging techniques can obtain deep vascular images owing to light scattering and absorption properties. Moreover, photothermal and photomechanical effects of laser make it possible to treat vascular diseases accurately. In this review, we present the research progress and applications of laser techniques in intravascular imaging and treatment. Firstly, we introduce intravascular optical coherent tomography and intravascular photoacoustic imaging, which can obtain various information of plaques. Multimodal intravascular imaging techniques provide more information about intravascular plaques, which have an essential influence on intravascular imaging. Secondly, two laser techniques including laser angioplasty and endovenous laser ablation are discussed for the treatment of arterial and venous diseases, respectively. Finally, the outlook of laser techniques in blood vessels, as well as the integration of laser imaging and treatment are prospected in the section of discussions.

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.

Peripheral Artery Disease: A comprehensive updated review

Peripheral arterial disease is estimated to affect more than 200 million people worldwide. Although more than 50% of those affected are asymptomatic, it accounts for 3-4% of amputations and a crude five-year death rate of 82.4 deaths per 1000 patient-years when adjusted for duration of follow-up. Additionally, peripheral artery disease is often an indicator of obstructive atherosclerotic disease involvement of cerebral and coronary vessels, consequently increasing the risk of stroke, cardiovascular death, and myocardial infarction in these patient populations. The management of peripheral arterial disease includes conservative therapies, pharmacological treatments, interventional and surgical revascularization of blood vessels. Percutaneous transluminal angioplasty with balloons and stents has improved clinical outcomes compared to medical treatment alone. Despite these advances, the prevalence of peripheral arterial disease remains high. This review article aims to provide focused, up-to-date information on the clinical course, diagnosis, medical and interventional approach of the management of peripheral artery disease.

Excimer laser coronary atherectomy for a severe calcified coronary ostium lesion: A case report

BACKGROUND

Percutaneous coronary intervention can be challenging for ostial coronary artery lesions due to calcium burden and elastic fiber content. Excimer laser coronary atherectomy (ELCA) is a less common treatment for severe calcified coronary ostium lesions.

CASE SUMMARY

An 81-year-old male presented to the Cardiology Department of Qingdao Municipal Hospital with a 1-year history of chest pain. Coronary angiography showed severe calcific stenosis (approximately 90%) in the right coronary artery ostium. The right coronary artery ostium was unable to be advanced using a 2.5 mm × 12.0 mm balloon (NC Sprinter, Medtronic, United States) or dilated using a 2.0 mm × 12.0 mm balloon (Sprinter, Medtronic, United States). The patient underwent successful ELCA and balloon dilation of the calcified coronary ostium lesion.

CONCLUSION

ELCA appears to be a safe and effective treatment for the management of severe calcified coronary ostium lesions.

The therapeutic effects of excimer laser coronary atherectomy therapy for in-stent restenosis chronic total occlusions

OBJECTIVES

To evaluate the safety and efficacy of excimer laser coronary atherectomy (ELCA) in patients with in-stent restenosis chronic total occlusions (ISR CTOs).

BACKGROUND

ISR CTOs are a challenge in percutaneous coronary intervention (PCI). Although they can be treated by ELCA, limited data are available on the effects of ELCA treatment in these patients.

METHODS

Fifty-nine consecutive patients underwent PCI for ISR CTOs at Beijing Hospital between December 2017 and September 2020. According to whether or not ELCA was performed, they were divided into two groups. Quantitative coronary angiography (QCA) analyses were performed routinely, including measurement of the minimal lumen diameter and calculation of the percentage diameter stenosis. The procedural success rate, the frequency of peri-procedural complications, and the incidence rates of major adverse cardiac events (MACEs) over nine months were assessed. The primary endpoint in the study was the percentage diameter stenosis.

RESULTS

Procedure success was achieved in most patients in both groups (75.9%). Patients in the ELCA group exhibited a lower percentage diameter stenosis (24.5 ± 9.09 vs. 35.1 ± 18.6, p = 0.048) and a larger minimal lumen diameter (2.36 ± 0.29 mm vs. 1.78 ± 0.64 mm, p < 0.001) than those in the control group and the 9-month incidence rates of MACEs did not differ (9.5% vs 15.8%, p = 0.699).

CONCLUSIONS

This study demonstrated that ELCA may be a safe and effective technique in the treatment of ISR CTOs, and the use of ELCA can achieve good immediate angiographic results, as measured by QCA, without increasing peri-procedural complications or the incidence rates of 9-month MACEs.

Impact of in-stent tissue characteristics on excimer laser coronary angioplasty prior to drug-coated balloon treatment

BACKGROUND

Percutaneous coronary intervention with drug-coated balloon (DCB) angioplasty is one of the standard treatments for lesions with in-stent restenosis (ISR). However, the efficacy of additional excimer laser coronary angioplasty (ELCA) for ISR lesions prior to DCB angioplasty has not been elucidated. The aims of this study were to elucidate the efficacy of ELCA prior to DCB treatment for ISR and the difference in effectiveness by lesion morphology.

METHODS

This was a multicenter, retrospective observational study. We enrolled 208 ISR lesions from 204 patients which were treated with DCB angioplasty under optical coherence tomography (OCT) guidance. We compared the acute gain evaluated by quantitative coronary angiography and clinically driven target lesion revascularization (CD-TLR) between the ELCA (+) (47 lesions) and ELCA (-) (161 lesions) groups.

RESULTS

The acute gain was significantly larger in the ELCA (+) group (1.51 ± 0.47 mm versus 1.29 ± 0.52 mm, P = 0.012). Even after adjustment for comorbidities, the ELCA had a significant impact on the acute gain (coefficient 0.24 [95% confidence interval 0.067-0.41]). In addition, the ELCA usage was significantly associated with larger acute gain in lesions with a homogeneous pattern, although there was no association between ELCA and either the heterogeneous pattern or neoatherosclerosis. The freedom from CD-TLR was not different between the ELCA (-) and ELCA (+) groups (hazard ratio 0.53 [0.24-1.18]).

CONCLUSIONS

ELCA had a significant impact on the larger acute gain in ISR lesions, especially may did in those with a homogenous pattern, while it did not impact CD-TLR significantly.

Contemporary technologies to modify calcified plaque in coronary artery disease

With aging society, one of the more challenging obstacles in percutaneous coronary interventions are calcified coronary lesions. Calcified lesions may impede stent delivery, limit balloon and stent expansion, cause uneven drug distribution, and hinder wire advancement. Even in the setting of acceptable procedural success, vessel calcification is independently associated with increased target lesion revascularization rates at follow-up and lower survival rates. In order to effectively manage such lesions, dedicated technologies have been developed. Atherectomy aims at excising tissue and debulking plaques, as well as compressing and reshaping the atheroma, generally referred to as lesion preparation that enables further balloon and/or stent expansion in contemporary clinical practice. In the current review, we will discuss the available methods for atherectomy, including rotational, orbital, and excimer laser coronary atherectomy, as well as intravascular lithotripsy. In addition, we will review the role of imaging in calcified lesions.

Shockwave coronary intravascular lithotripsy system for heavily calcified de novo lesions and the need for a cost-effectiveness analysis

The optimal management for severely calcified coronary artery disease is multi-adjunctive. Different strategies with dedicated devices should be available in the cardiac catheterization laboratory with their selection depending on the nature of the calcific disease and its anatomical distribution. Shockwave Intravascular Lithotripsy (S-IVL) system offers a novel option for lesion preparation of heavily calcified plaques in coronary and peripheral vessels. S-IVL is based on the fundamental principles of lithotripsy, a technology that has been used to modify renal stones for over 30 years. Pulsatile mechanical energy is used to fragment selectively amorphous calcium, sparing soft tissue. S-IVL has the potential of more widespread adoption because of its proven safety, efficacy and operational simplicity, but cost-effectiveness of such advanced technology will need to be analyzed.