Combined use of intravascular lithotripsy and brachytherapy: A new approach for the treatment of recurrent coronary in-stent restenosis

Intravascular lithotripsy for the treatment of inferior mesenteric artery in-stent restenosis

Endovascular revascularization with intraluminal stenting is the recommended first-line therapy for chronic mesenteric ischemia. However, early recurrence and in-stent thrombosis remain significant challenges. We present the case of a patient with recurrent chronic mesenteric ischemia secondary to in-stent restenosis that was successfully treated with intravascular lithotripsy, a novel, safe approach to stent salvage.

The Future of Radioactive Medicine

The discovery of X rays in the late 19th century heralded the beginning of a new age in medicine, and the advent of channeling the power of radiation to diagnose and treat human disease. Radiation has been leveraged in medicine in a multitude of ways and is a critical element of cancer care including screening, diagnosis, surveillance, and interventional treatments. Modern radiotherapy techniques include a multitude of methodologies utilizing both externally and internally delivered radiation from a variety of approaches. This review provides a comprehensive overview of contemporary radiotherapy methodologies, the field of radiopharmaceuticals and theranostics, effects of low dose radiation and highlights the phenomena of fear of exposure to radiation and its impact in modern medicine.

Drug-Eluting Stent Restenosis: Modern Approach to a Classic Challenge

In-stent restenosis (ISR) is a recognized complication following percutaneous coronary intervention in which the luminal diameter is narrowed through neointimal hyperplasia and vessel remodeling. Although rates of ISR have decreased in most recent years owing to newer generation drug-eluting stents, thinner struts, and better intravascular imaging modalities, ISR remains a prevalent dilemma that proves to be challenging to manage. Several factors have been proposed to contribute to ISR formation, including mechanical stent characteristics, technical factors during the coronary intervention, and biological aspects of drug-eluting stents. Presentation of ISR can range from asymptomatic to late myocardial infarction and could be difficult to differentiate from acute thrombus formation. No definite guidelines are present on the management of ISR. In this review, we will discuss the mechanisms underlying ISR and provide insight into patient-related and procedural risk factors contributing to ISR, in addition to highlighting common treatment approaches utilized in the management of ISR.

Novel application of intravascular lithotripsy in stent under-expansion: A single-center experience

INTRODUCTION

Stent under-expansion due to calcification is associated with a less durable result. The development of intravascular lithotripsy (IVL) has provided clinicians with a readily available, simple-to-use treatment option for coronary calcification, but the use of IVL within a previously stented segment is currently off-license. There are, however, developing data suggesting that the use of IVL can be an effective treatment option for patients with calcific stent under-expansion.

METHOD

This was a single-center study of all patients treated with IVL for calcific stent under-expansion between January 2019 and June 2021. The impact of IVL on quantitative coronary angiography (QCA) stenosis and on the minimal stent area (MSA) derived from intracoronary imaging were recorded. The presence of periprocedural complications and adverse cardiovascular events was obtained from the clinical record during the study timeframe.

RESULTS

Thirty-nine patients underwent IVL for calcific stent under-expansion during the study time frame with one patient treated with more than one lesion in the same session. In all lesions, there was an improvement in the QCA stenosis with 37 (92.5%) having a residual stenosis of ≤30%. The mean QCA stenosis pre-IVL was 68 ± 21% and following IVL the mean QCA was 18 ± 9% (p < 0.001). In all lesions, there was an improvement in the MSA, with 26 (92.9%) achieving an MSA of more than 4.5 mm2 . The mean MSA pre-IVL was 3.88 ± 1.51 mm2 and following IVL the mean MSA was 7.41 ± 2.34 mm2 (p < 0.001). There were no major procedural complications. Over a mean follow-up of 506 ± 277 days, one patient died from ventricular arrhythmia but there were no other major adverse cardiovascular events.

CONCLUSION

This single-center study demonstrates that IVL is a safe and effective treatment for calcific stent under-expansion with good medium-term results.

Intravascular lithotripsy for coronary calcium: A case report and review of the literature

BACKGROUND

Coronary calcium poses a challenge for the interventional cardiologist often leading to stent under-expansion and subsequent ischemic events. Aggressive balloon post-dilatation though helpful is usually inadequate. Multiple plaque ablation techniques are in vogue, but they are technically demanding and are not without complications. Shockwave intravascular lithotripsy (S-IVL) has emerged as a user-friendly and effective mechanism for calcium management with a high safety margin. A series of trials (DISRUPT CAD I-IV) have demonstrated both short-term and long-term safety and efficacy of the technique. As experience with the technique grows more and more, therapy areas like stent restenosis are being covered by the S-IVL.

CASE SUMMARY

We report a series of 2 cases successfully managed with S-IVL therapy at our center. The first case is of a 57-year-old smoker who presented with acute coronary syndrome. His left anterior descending coronary artery revealed calcified 90% stenosis on angiogram and a combination of superficial-deep calcium on intracoronary imaging. The calcium was treated with 20 pulses of S-IVL to create discontinuity and a sirolimus eluting drug-eluting stent was successfully implanted. The second case is that of an elderly lady who presented with stable angina and demonstrated diffuse calcified lesions in the left anterior descending artery on angiogram. She also demonstrated a mixture of superficial and deep seated calcium zones on imaging. S-IVL therapy was applied to generate fractures in calcium, and two overlapping drug-eluting stents were implanted successfully without any complications.

CONCLUSION

S-IVL is an emerging, efficient, user-friendly and safe therapy for managing intracoronary calcium in routine interventional practice.

Intravascular imaging in coronary stent restenosis: Prevention, characterization, and management

Despite the introduction of drug-eluting stents to combat the neointimal hyperplasia that occurred after BMS implantation, in-stent restenosis is still encountered in a significant number of patients, particularly as increasingly complex lesions are tackled by percutaneous coronary intervention. Many biological and mechanical factors interplay to produce restenosis, some of which are avoidable. Intravascular imaging provided unique insights into various forms of stent-related mechanical issues that contribute to this phenomenon. From a practical perspective, intravascular imaging can therefore help to optimize the stenting procedure to avert these issues. Moreover, once the problem of restenosis eventuates, imaging can guide the management by tackling the underlying identified mechanism. Finally, it can be used to evaluate the re-intervention results. Nevertheless, with the emergence of different treatment options, more evidence is needed to define patient/lesion-specific characteristics that may help to tailor treatment selection in a way that improves clinical outcomes.

Coronary intravascular brachytherapy for in-stent restenosis: A review of the contemporary literature

Intracoronary stent restenosis (ISR) is a clinically relevant challenge in the modern era. Heterogeneity in patient- and lesion-specific factors can further compound this clinical challenge. Coronary intravascular brachytherapy (IVBT) was the standard therapeutic approach for ISR prior to the advent of drug-eluting stents (DES). Despite prospective data describing the superiority of DES over IVBT for treating de novo ISR, IVBT remains a treatment option for patients with complex disease. The purpose of this review is to evaluate the historical and contemporary literature surrounding IVBT in order to elucidate its role in modern cardiac care and to describe opportunities for future investigations to improve patient selection. Herein, we provide a review of the contemporary literature describing IVBT as a safe and effective treatment option for patients with recurrent, refractory ISR after multilayer DES and no good surgical or mechanical option. Combination therapy with emerging technologies such as DCBs may further increase efficacy.

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.

Intravascular lithotripsy for stent under-expansion: Panacea or Pandora's box?

Balloon undilatable lesions are common and can be challenging to treat, especially within stents, and require a systematic, algorithmic approach. Stent under-expansion is usually treated with high-pressure balloon inflations, followed by plaque modification balloons, laser with contrast, orbital or rotational atherectomy, and subintimal crossing with coronary artery bypass graft being the ultimate solution is all techniques fail to expand the stent. Intravascular Lithotripsy (IVL) appears to be an easy to use and effective tool for treating stent under-expansion, but further study is needed to confirm its efficacy and (acute and long-term) safety.

Intracoronary Lithotripsy: A New Solution for Undilatable In-Stent Chronic Total Occlusions

Percutaneous coronary intervention was performed in a flush in-stent right coronary artery chronic total occlusion. Successful retrograde recanalization was performed but the lesion was balloon undilatable as confirmed by intravascular ultrasound. High-pressure post-dilation with noncompliant and plaque modification balloons failed, but intravascular lithotripsy successfully expanded the lesion. (Level of Difficulty: Advanced.)