Novel usage of everolimus-eluting coronary stent for intracranial atherosclerotic disease: a technical report and case series

Introduction

Intracranial atherosclerotic disease (ICAD) is a leading cause of transient ischemic attack (TIA) and acute ischemic stroke.1 In one study, intracranial plaques and stenotic arteries were present in 62% and 43.2% of patients with brain infarct (BI), respectively. Forty-three percent of patients with BI had a luminal occlusion >30%.2 Several clinical trials have been performed to assess the best treatment option for ICAD. These include the Warfarin-Aspirin Symptomatic Intracranial Disease Trial, the Stenting and Aggressive Medical Management for the Prevention of Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial, and the Vitesse Intracranial Stent Study for Ischemic Stroke Therapy (VISSIT) trial.3 SAMMPRIS and VISSIT clinical trials concluded that aggressive medical management was safer than the Wingspan (balloon expandable) stent, with lower rates of stroke, TIA, and deaths.4 5 As a result of those trials, stenting for ICAD is now mainly reserved for severely symptomatic patients with recurrent symptoms despite best medical treatment.

Complications caused by bare metal stents (BMS) fostered the development of other stent systems like the drug-eluting stents (DES). In vertebral artery (VA) stenting, BMS in-stent stenosis rate was reported to range from 10% to 67%.6 Developed as a substitute for BMS, first-generation DES like paclitaxel-eluting stent and sirolimus-eluting stent also showed complications such as late stent thrombosis after stopping dual-antiplatelet therapy in percutaneous coronary interventions (PCI).7–9 Subsequently, second-generation DES like everolimus-eluting stent (EES) was developed and showed promise in lowering revascularization and thrombosis risks in patients.7 10 11

The Xience Skypoint EES is a DES used for PCI. The stent is made from medical-grade cobalt chromium and contains a thin layer of a drug called everolimus on its surface that allows for a controlled release of the drug to the vessel walls.12 Everolimus is an mammalian target of rapamycin inhibitor that reduces tissue growth into the stent.13 Considering EES low thrombotic and revascularization risk, we describe our institutional experience in using this stent for intracranial stenting for treatment of ICAD. This study intends to demonstrate the technical nuances and procedural safety of using a coronary drug-eluting stent, the Xience Skypoint (Abbott Park, Illinois, USA), for treatment of ICAD.

Methods

Results

Procedures

All the procedures were performed by the same endovascular neurosurgeon (HS). No medications were withheld prior to the procedures. In all cases, the Xience stent was deployed using a biaxial system composed of a guide catheter and a coronary guidewire. The 0.014 ASAHI Prowater guidewire (Asahi Intecc, Tokyo, Japan) was exclusively used in each case. In coronary PCI, the ASAHI Prowater was described as highly maneuverable wire with low friction, which facilitates navigation in tortuous vessels and reduces chances of vessel dissections.14 15 Details of each individual cases are described below. Postprocedure all patients were put under 6 months antiplatelet therapy. Data collected are shown in table 1.

Table 1

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Patient, procedural, and radiological data

Case 1

An adult patient presented to the emergency department (ED) with the onset of balance difficulties, trouble walking, and worsening of the patient’s aphasia and facial droop. The patient has a recent history of VA narrowing and posterior circulation ischemic strokes. CT angiography (CTA) revealed total occlusion of the left VA and severe narrowing of the right VA. Diagnostic angiography confirmed left VA occlusion and revealed intracranial VA atherosclerosis with critical right V4 stenosis and likely chronic distal left VA occlusion (figure 1). The patient was kept under dual antiplatelet therapy (DAPT) (aspirin+clopidogrel) throughout the hospital stay. Two days before the procedure, the patient’s platelet function assay test was 8 (180–376 platelet reactivity unit (PRU)), and their platelet count was 104 000 (150 000–450 000). The patient underwent a right VA balloon angioplasty and stenting for adequate recanalization.

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Figure 1

Adult patient with severe narrowing of the right vertebral artery (VA). (A) Lateral view of the right VA. (B) Anterior-posterior (AP) view of the right VA with V4 segment stenosis. (C) AP view of the right VA with measurements for stent placement. (D) Lateral view of the right VA after stent deployment. (E) AP view of the right VA after stent deployment.

For this procedure, the patient was placed under general anesthesia. A 6-French slender sheath (Terumo, Somerset, New Jersey, USA) was placed under ultrasound-guided access using a trans-ulnar approach. The Benchmark (Penumbra, Alameda, California, USA) guide catheter was advanced over a Berenstein (Merit OEM, South Jordan, Utah, USA) select catheter and used to select the right VA. The Berenstein select catheter was removed. The Benchmark catheter was advanced into and parked in the V3 segment. A 0.014 ASAHI Prowater guidewire was advanced through the Benchmark catheter and crossed the stenosis into the right PCA. A coronary balloon was advanced, and a submaximal preplasty was performed. The balloon was deflated and removed with wire left in place. The Xience Skypoint stent (4.0×33 mm) was deployed across the lesion without complications. Follow-up runs demonstrated excellent apposition of the stent to the vessel wall without in-stent stenosis. There was no delay in the vertebrobasilar system with excellent opacification of the vessels. Postprocedure angiography demonstrated no evidence of thrombus within the right VA. On post-operative day 1 (POD1), patient developed a mild hematoma on the right upper extremities (RUE). There were no other neurological complications otherwise.

Case 2

An adult patient with a critical right internal carotid stenosis (ICA) in the distal petrous portion of the artery beyond the cervical segment of the petrous segment. Patient was referred by their cardiologist following a history of recurrent strokes despite DAPT (aspirin+clopidogrel). Origin of the stroke was believed to be from atrial arrhythmias. However, the patient continued to have strokes despite anticoagulation therapy and closure of the appendages which prompted further evaluation. CTA performed 2 months prior procedure showed near-total occlusion of the right ICA just inferior to the horizontal segment of the skull base level. Pre-operation diagnostic angiogram confirmed the CTA finding, therefore, the patient was planned for right ICA stent placement for treatment of ICAD (figure 2).

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Figure 2

Adult patient with critical stenosis of the right internal carotid stenosis (ICA) in the distal petrous segment. (A) Anterior-posterior (AP) view of the right ICA with petrous stenosis. (B) Lateral view of the right ICA with petrous stenosis. (C) AP view of the right ICA with measurements for stent placement. (D) AP view of the right ICA after stent deployment. (E) Lateral view of the right ICA after stent deployment.

For this procedure, patient was placed under conscious sedation. A 6-French 23 cm sheath was placed under ultrasound guidance for a trans-radial approach. A RIST (Medtronic, Minneapolis, Minnesota, USA) catheter was advanced into the prepetrous segment of right ICA. A 0.014 ASAHI Prowater guidewire was then used to cross the atherosclerotic lesion and placed in distal middle cerebral artery (MCA). The 0.014 wire was used to advance the Xience Skypoint stent, which was deployed without complications. The patient was then transferred out of the angiographic suite at their preprocedural neurological baseline and discharged at POD2.

Case 3

An adult patient with a prior history of strokes in the left MCA had underwent intracranial submaximal balloon angioplasty of the left ICA and was started on DAPT (aspirin+ticagrelor) 6 months prior. During this period, the patient presented numerous times to the ED with recurrent TIA. The patient’s most common complaints were right-sided weakness (x4) and headache (x2). The patient’s follow-up CTA after angioplasty showed severe narrowing of the left ICA due to diffuse calcified atherosclerosis. Pre-operative diagnostic angiogram showed narrowing of the left supraclinoid ICA; therefore, the patient was selected for left supraclinoid ICA stent placement (figure 3).

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Figure 3

Adult patient with left supraclinoid internal carotid stenosis (ICA) stenosis. (A) Lateral view of left ICA with catheter in the prepetrous segment. (B) Anterior-posterior (AP) view of the left ICA with M1 stenosis and minimal filling of left anterior cerebral artery (ACA). (C) AP view of the left ICA with measurements for stent placement, X1=distal landing zone, X2=proximal landing zone, X3=stenosis distance. (D) AP view of the left ICA after stent deployment. (E) Lateral view of the left ICA after stent deployment. (F) AP view of the left ICA, with robust ACA filling and improved M1 stenosis after stent deployment. (G) Lateral view of the left ICA after stent deployment. (H) Lateral view of left ICA after stent deployment.

For this procedure, the patient was placed under conscious sedation. An 8-French sheath was placed under ultrasound guidance, for right common femoral artery approach. A Walrus Balloon Guide Catheter (Q’Apel Medical, Fremont, California, USA) was advanced over a 0.35 angled glide wire to the left ICA. A coronary balloon guide was used to mount the Xience Skypoint stent, which was advanced across the lesion over a 0.014 ASAHI Prowater guidewire. The stent was deployed to nominal pressure and follow-up runs indicated increase flow to the MCA candelabra. Patient recovered strength on their right side on post-operative check and was discharged without complaints on POD1.

Discussion

EES have been used with success in PCI for coronary artery disease. In a randomized study by Yamaji et al, researchers looked at different variables to compare polymer sirolimus-eluting stents to durable polymer EES (DP-EES) for PCI.16 The study reported that out of 2260 DP-EES implantation procedure attempts, only 1 failed.16 In addition, the restenosis rate including in-stent restenosis for DP-EES was 4.3% at the 1-year end point.16 Comparing it with the Wingspan stent which is currently approved by the FDA for treatment of symptomatic ICAD,17 EES have shown lower risk of restenosis. In the Wingspan One-year Vascular Events and Neurologic Outcomes, the restenosis rate of patients with Wingspan stents was 17.6%18 after 1 year.

Of the three patients implanted with the Xience Skypoint EES, only one suffered postprocedural complications. In that case, the patient developed a small RUE hematoma that resolved before discharge. There were no neurological complications otherwise.

The Xience Skypoint stent also has procedural advantages compared with other coronary DES used for neurointerventional procedures. The technique used in this study required a biaxial system composed of a guide catheter and a coronary wire. Benefits of this technique include a lower risk of vessel manipulation and damage, less time under anesthesia due to shorter duration of the procedure, and less risk of kidney injuries due to contrast use. While intermediate catheters provide more support to devices and allow them to get around vessels easier, they come with an increased procedural cost. They also increase the length of the procedures, and the time patients must be under anesthesia because they require proper placement and positioning. In our experience, the Xience Skypoint stent was effectively deployed without an intermediate catheter unlike other stents like the Resolute Onyx DES (Medtronic) that have shown success in ICAD treatment.17 The fact that intermediate catheters are not needed for the stent deployment means a reduction in cost and possibly the time of procedure for patients. Moreover, we demonstrate that the Xience Skypoint stent can be deployed using trans-radial, trans-ulnar, and trans-femoral access sites. For neurointerventional procedures, the trans-radial approach resulted in lower odds of complication than the trans-femoral approach.19 While there have not been many studies comparing trans-ulnar with trans-radial approach, a trans-ulnar approach is described as an alternative to trans-radial access.20 In randomized studies for coronary interventions, complication risks using trans-ulnar access were found to be close to trans-radial access.21 22 Therefore, success in deploying the Xience Skypoint using three different approaches demonstrate the stent’s flexibility, which gives providers the ability to perform their cases in a way that will be most beneficial to their patients.

This study has numerous limitations including the patient selection, number of patients, and its retrospective nature. Our goal was not to report on long-term vascular and neurological complications, but mainly to present the technical feasibility of deploying the Xience Skypoint EES for the treatment of intracranial atherosclerotic diseases. We believe that more studies are needed to assess short-term and long-term effects of this stent in ICAD treatment given its promises.