Intravascular Lithotripsy Assisted Carotid Stent Expansion

PURPOSE

Carotid stenting has been demonstrated to effectively reduce the risk of stroke in appropriately selected patients. However, application of carotid artery stenting remains limited in the setting of heavily calcified disease.

CASE REPORT

We present here 3 patients, who were treated with intravascular lithotripsy of the internal and common carotid arteries. All 3 patients recovered uneventfully and have demonstrated excellent stent expansion on surveillance imaging.

CONCLUSION

Intravascular lithotripsy is an effective adjunct for enabling stent expansion in heavily calcified lesions and can be employed for the treatment of high-risk carotid lesions that would otherwise be poor endovascular candidates.

CLINICAL IMPACT

Carotid artery stenting via transfemoral or transcarotid application remains limited by heavily calcified disease. We present here the off-label use of intravascular lithotripsy as an effective adjunct for enabling stent expansion in heavily calcified lesions. There is potential for intravascular lithotripsy to expand the use of carotid stenting.

Usefulness of non-slip element percutaneous transluminal angioplasty scoring balloons in treating severe calcified lesions of the carotid artery for carotid artery stenting: A case report

Background

Treatment of calcified lesions with conventional angioplasty balloons can be difficult due to insufficient lumen expansion, high dissection rates, and repeated revascularization. We report a case in which a scoring balloon was used in lesions resistant to angioplasty with a semi-compliant balloon.

Case Description

A 72-year-old man presented with severe stenosis and a highly calcified lesion in the right cervical internal carotid artery. Right carotid artery stenting (CAS) was planned to prevent future ischemic stroke events. Conventional semi-compliant balloon angioplasty was unsuccessful. Three inflations of a non-slip element (NSE) percutaneous transluminal angioplasty (PTA) scoring balloon (Nipro, Osaka, Japan) successfully achieved CAS without complications.

Conclusion

This is the first report to describe the use of this scoring balloon in de novo carotid artery disease. NSE PTA scoring balloon catheters can be a useful option for refractory, highly calcified stenosis.

Heavily Calcified Symptomatic Carotid Stenosis Treated With Off-Label Use of Lithotripsy Balloon Plus Stenting: 2-Dimensional Operative Video

Severe symptomatic carotid artery stenosis poses a significant risk for recurrent strokes. Best treatment options depend on multiple factors, including patient medical conditions and lesion characteristics.1 Despite treatment options such as carotid endarterectomy, conventional carotid angioplasty/stent, and transcervical carotid revascularization, certain patients are not ideal candidates for any of these modalities. Novel technical advances such as intravascular lithotripsy (Shockwave Medical Inc.) have emerged as a potential treatment modality to treat patients with severely calcified plaques, a well-described limitation for carotid stent expansion and apposition.2-4 The safety and efficacy of intravascular lithotripsy have been demonstrated through select case series and coronary artery disease I-II-III studies, culminating in its Food and Drug Administration approval for the management of novo, calcified, stenotic coronary arteries before stent placement.2,5 This technical video presents an illustrative case of a patient with symptomatic severely calcified carotid plaque with previous neck radiation precluding endarterectomy, treated with off-label use of balloon lithotripsy plus stent.6 The patient consented to the procedure.

Association of stroke or death with severity of carotid lesion calcification in patients undergoing carotid artery stenting

OBJECTIVE

Carotid artery stenting (CAS) for heavily calcified lesions is controversial due to concern for stent failure and increased perioperative stroke risk. However, the degree to which calcification affects outcomes is poorly understood, particularly in transcarotid artery revascularization (TCAR). With the precipitous increase in TCAR use and its expansion to standard surgical-risk patients, we aimed to determine the impact of lesion calcification on CAS outcomes to ensure its safe and appropriate use.

METHODS

We identified patients in the Vascular Quality Initiative who underwent first-time transfemoral CAS (tfCAS) and TCAR between 2016 and 2021. Patients were stratified into groups based on degree of lesion calcification: no calcification, 1% to 50% calcification, 51% to 99% calcification, and 100% circumferential calcification or intraluminal protrusion. Outcomes included in-hospital and 1-year composite stroke/death, as well as individual stroke, death, and myocardial infarction outcomes. Logistic regression was used to evaluate associations between degree of calcification and these outcomes.

RESULTS

Among 21,860 patients undergoing CAS, 28% patients had no calcification, 34% had 1% to 50% calcification, 35% had 51% to 99% calcification, and 3% had 100% circumferential calcification/protrusion. Patients with 51% to 99% and circumferential calcification/protrusion had higher odds of in-hospital stroke/death (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.02-1.6; P = .034; OR, 1.9; 95% CI, 1.1-2.9; P = .004, respectively) compared with those with no calcification. Circumferential calcification was also associated with increased risk for in-hospital myocardial infarction (OR, 3.5; 95% CI, 1.5-8.0; P = .003). In tfCAS patients, only circumferential calcification/protrusion was associated with higher in-hospital stroke/death odds (OR, 2.0; 95% CI, 1.2-3.4; P = .013), whereas for TCAR patients, 51% to 99% calcification was associated with increased odds of in-hospital stroke/death (OR, 1.5; 95% CI, 1.1-2.2; P = .025). At 1 year, circumferential calcification/protrusion was associated with higher odds of ipsilateral stroke/death (12.4% vs 6.6%; hazard ratio, 1.64; P = .002).

CONCLUSIONS

Among patients undergoing CAS, there is an increased risk of in-hospital stroke/death for lesions with >50% calcification or circumferential/protruding plaques. Increasing severity of carotid lesion calcification is a significant risk factor for stroke/death in patients undergoing CAS, regardless of approach.

Debris generated by laser and/or balloon cause cerebral infarction with different severity

The purpose of this study is to determine the effects that debris generated by laser and/or balloon on the brain. Debris generated by laser, balloon, and laser combined with balloon were collected and then injected into rats' left common carotid artery. Rats were divided into five groups: sham, saline, laser (L), balloon (B), and laser combined with balloon (LB). The cognition ability of rats was evaluated by Morris water maze. Cerebral blood flow (CBF) was examined by laser speckle. TTC staining and MRI scan were conducted to detect cerebral ischemic infarction. Intracranial arteries in rats were visualized by MRI angiography via contrast medium injected via tail vein. Immunohistologic staining for NeuN and Iba1 and hematoxylin-eosin staining were performed to assess brain infarction. White matter demyelination was assessed by Luxol fast blue staining. Long-term memory and CBF of rats in different groups exhibited no significant difference. No obstruction sign in intracranial artery tree was noticed in each group. Debris generated by different treatments all caused brain infarction. Infarction lesion caused by debris produced by balloon was much more severe than the one caused by debris generated by laser. While the LB group lay in between. The thickness of white matter decreased in the B group, but not in the L and LB groups. Rat brain has a tolerance for debris as cognition ability and cerebral blood flow are not significantly declined. The severity of cerebral infarction varies by debris generated by different treatments.

Intravascular lithotripsy for severely calcified carotid artery stenosis - A new frontier in carotid artery stenting?

Carotid stenosis due to severely calcified plaque can pose a significant therapeutic challenge. Extremely calcified scars/stenosis plaques can be challenging from an endovascular treatment perspective as severely calcified lesions are prone to technical failure, stent re-coil and restenosis. Intravascular lithotripsy, approved for treatment of severely calcified coronary lesions, can be used for breaking up the calcium build up in the intimal and medial layers of the vessel wall prior to stenting. This was designated as a breakthrough device innovation by the Food and Drug Administration. This new technique addresses the challenge of the disease without compromising patient safety during the procedure. We here report procedural set-up, execution and early patient follow up from our first use of this emerging technology in a neurointerventional practice setting.