Acute Cervical Internal Carotid Artery and Middle Cerebral Artery Tandem Occlusion Due to Spontaneous Carotid Tonsillar Loop Dissection: Retrograde Approach, Intracranial Stent-Retriever-Assisted Middle Cerebral Artery Thrombectomy, and Reconstruction of the Dissected Segment by Flow-Diverter Stent Implant, with a Favorable Outcome

Carotid artery dissection (CAD) is an important cause of ischemic stroke, particularly in young and healthy individuals, and can lead to severe sequelae. Arterial tortuosity is frequently recognized in patients with CAD and has also been shown to be indicative of underlying subclinical connective tissue weakness. Severe tortuosity of the internal carotid artery (ICA) may preclude navigation of large-profile stiff carotid stents, thus making dissections in loop segments particularly challenging to treat. We report the case of a 42-year-old man who presented with 1 h of acute left-sided weakness and facial asymmetry. He had a National Institutes of Health Stroke Scale (NIHSS) score of 3 at admission. Noncontrast CT indicated no acute findings. CT angiography showed tapered occlusion of the right cervical ICA with reconstitution at the cavernous segment, and a patent right middle cerebral artery (MCA). CT perfusion imaging demonstrated a region of a total cerebral blood flow reduction to less than 30% the expected levels with a low perfusion volume of 52 ml, located predominantly in a watershed zone. The region with a time-to-maximum prolongation >6 s had a volume of 178 ml. After completion of CT, the patient’s NIHSS score had declined to 16. He was urgently transferred to the angiography suite, where tonsillar loop dissection of the right cervical ICA and embolic occlusion of the right MCA (tandem occlusion) were revealed. The patient underwent successful endovascular revascularization of the right MCA followed by reconstruction of the cervical ICA dissection through flow-diverter stent implantation in an uneventful procedure. He received loading doses of aspirin and ticagrelor at the end of the procedure. Follow-up head CT revealed an ischemic stroke in the right parietal lobe. The patient experienced marked neurological improvement during admission. He was discharged after 10 days with an NIHSS score of 3 and modified Rankin Score of 2. Urgent endovascular management of the tandem occlusions secondary to spontaneous ICA dissections affecting tortuous arterial segments is the main topic of this chapter.