Symptomatic High-Risk Post-Irradiation Internal Carotid Artery Stenosis: Angioplasty and Stenting Under Proximal Flow Control (Arrest/Reversal) and Distal Embolic Protection

Carotid artery stenting (CAS) is an established treatment for carotid stenosis, and despite the lack of randomized controlled trials, distal embolic protection devices (EPDs) have been adopted as the current standard of care to prevent periprocedural stroke and minimize the overall complication rate. In addition to distal EPDs, other techniques include proximal flow control (Mo.Ma EPD, Medtronic; Gore flow reversal system, Gore). The Walrus balloon guide catheter (BGC, Q’Apel Medical) is a new-generation variable stiffness BGC with improved comparative trackability and a large inner diameter designed to accommodate catheters with larger outer diameters compared to those that other BGCs can accommodate in a short 8F sheath. Walrus was approved by the Food and Drug Administration (FDA) in 2019 and has demonstrated high efficacy in mechanical thrombectomy (MT). The recently reported use of the Walrus BGC in CAS offers a new alternative for proximal flow control and flow arrest/reversal in challenging anatomic situations. Here we present a high-risk case of symptomatic carotid stenosis treated with a technical variant of CAS including proximal flow control, flow arrest/reversal, and a distal EPD. A 68-year-old man presented to the emergency department (ED) with a medical history of arterial hypertension, hyperlipidemia, heavy smoking, ischemic heart disease (two percutaneous transluminal coronary angioplasty [PTCA] procedures), chronic obstructive pulmonary disease (COPD), a 19-year history of laryngeal malignancy treated with radiation therapy, and at least eight episodes of transient right eye blindness during the previous 2 months. The patient was brought to the emergency department after two episodes of transient (seconds duration) right eye blindness, followed by his first-ever left arm weakness. The arm weakness began 5 h prior to admission. The patient was taking aspirin and clopidogrel for his heart condition. On admission for this right hemisphere ischemic stroke, the patient was alert and oriented and had chronic dysphonia with persistent cough and bronchial sputum. His admission arterial pressure was 210/110 mmHg, which was controlled with an intravenous nicardipine drip. His neurological examination confirmed a baseline National Institutes of Health Stroke Score (NIHSS) of 3 (arm drift and mild sensory loss). Admission head CT revealed microvascular brain disease. The automated Alberta Stroke Program Early CT Score (ASPECTS) was 10. CT perfusion (CTP) images showed an extensive area of relative hypoperfusion in the right hemisphere watershed distribution (no core, area with Tmax >4.0 s of 92 ml). CT angiography (CTA) showed diffuse aortic and supra-aortic atheromatosisAtheromatosis and near occlusion of the post-bulbar right internal carotid artery (ICA) with incomplete circle of Willis. Rapid evaluation by an otolaryngologist confirmed left vocal cord paralysis, laryngeal edema, and tracheal stenosis. This condition was considered an increased risk for endotracheal intubation. The patient was considered unsuitable for carotid endarterectomy due to previous neck radiation and vocal cord paralysis. The patient’s arm weakness progressed as his admission arterial pressure decreased, and nicardipine was discontinued. The patient did not receive intravenous thrombolysis and was transferred from the emergency department to the neuroangiography suite for endovascular intervention. An 8F introducer sheath was placed in the right femoral artery under local anesthesia. Assessment of platelet reactivity to aspirin and clopidogrel confirmed an adequate inhibitory response. Angiograms of both common carotid arteries (CCA) showed a near-total occlusion of the right ICA caused by an irregularly shaped eccentric atherothrombotic plaque, an incomplete circle of Willis (hypoplasia of the right A1), and aplasia of the left posterior communicating artery (PcomA). Due to the patient’s clinical instability and the severity of the lesion, we performed a technical variant of CAS that included proximal flow control, flow arrest/reversal, and distal EDP. The procedure was well tolerated, and post-procedural head CT ruled out hemorrhagic complications. He had a good clinical course with improvement of his NIHSS score to 0 at 36 h. MRI performed 40 h after surgery showed no diffusion defects. The patient was discharged home 4 days after surgery with a modified Rankin Scale [mRS] score of 0. In this chapter, we present a variant of CAS involving the use of proximal flow arrest/reversal with the recently introduced Walrus BGC in combination with a distal protection device. We found dual-protection CAS to be technically intuitive, safe, and well tolerated. This technique was chosen for the treatment of a stenosis considered to be at high risk for procedural embolic complications but is likely to be used more widely.