Mechanical Thrombectomy in Difficult Access, Tortuous ICA Anatomy: When an Intermediate Catheter Replaces the Balloon-Guiding Catheter

Thrombectomy has become established as a successful treatment strategy for ischemic stroke, and an increasing number of patients are undergoing this procedure. Due to comorbidities and advanced age, many patients have anatomy that complicates revascularization, particularly difficult aortic arch anatomy, supra-aortic trunks, or both. Any combination of these anatomic parameters is associated with lower rates of treatment success. An 82-year-old man with a history of arterial hypertension, hyperlipidemia, and ischemic heart and peripheral vascular disease was admitted to the hospital with a right hemispheric ischemic stroke and a baseline National Institutes of Health Stroke Scale (NIHSS) score ranging from 10 to 14. He had last been well 7 h prior to admission. The Alberta Stroke Program Early CT Score (ASPECTS) on noncontrast cranial CT was 10, despite a clear hypodense area in the right subinsular region. CT perfusion imaging (CTP) revealed a right hemispheric perfusion deficit, consistent with the patient’s neurological examination findings of right gaze deviation and left hemiparesis. The volume of the area where cerebral blood flow was reduced to <30% of expected levels was 0 ml, and the volume of the area with a time to peak concentration (Tmax) >6 s was 82 ml, for a mismatch ratio defined as infinite. CT angiography showed a cutoff in the M1 segment of the right middle cerebral artery (MCA) and suggested a good collateral pattern. The patient did not receive intravenous thrombolysis and was transferred from the Emergency Department (ED) to the Neuroangiosuite for endovascular intervention. An 8F introducer sheath was placed in the right femoral artery under general anesthesia. Angiogram of the right common carotid artery (CCA) showed a proximal loop in the right internal carotid artery (ICA) that would complicate and prevent safe distal placement of our regularly used balloon-guiding catheter (Cello, Medtronic). A stiff glide wire was unable to correct the carotid loop despite further distal advancement. Instead, the combination of a guiding catheter and intermediate catheters allowed successful endovascular revascularization of the right MCA in a single pass using the pRESET 5/40 mm stent retriever (WallabyPhenox). The patient was diagnosed with atrial fibrillation and started on anticoagulant therapy. He had a good clinical outcome, achieving an NIHSS score of 3 and a modified Rankin Scale (mRS) score of 1 at discharge, with complete neurological recovery at clinical follow-up. Because difficult access anatomy is common in patients undergoing emergency thrombectomy, it is important for the treating physician to be prepared and to adapt access strategies to increase the likelihood of successful revascularization. In this chapter, we focus on the implications of difficult ICA access and the increasing number of technical options to overcome this condition.