Acute Dominant Vertebral and Basilar Artery Tandem Occlusions: Intracranial Stent Retriever-Assisted Thrombectomy of the Basilar Artery and Extracranial Vertebral Artery Stenting: “Closed Road Path” Approach, Retrograde Technique, Followed by Posterior Fossa Decompressive Craniectomy

Acute occlusion of the extracranial vertebral artery (VA) with thromboembolism to the basilar artery (BA) and its major branches is seen in a poorly characterized subgroup of patients presenting for emergency endovascular treatment due to major acute vertebrobasilar stroke. The natural history of this condition is usually defined by the BA occlusion. Thus, the prognosis is generally grim. However, in some cases, the prognosis also depends on the fate of a concomitant sole or dominant VA occlusion. A 48-year-old homeless man was found unconscious by the police and intubated in the field by paramedics of the emergency ambulance system. He had a history of repeated hospital admissions after multiple traumatic alcoholism-related injuries and had been diagnosed on these occasions with hypertension, dyslipidemia, hepatitis, and advanced chronic renal failure. He was admitted to the emergency room in a coma with miotic reactive pupils, absent left corneal reflex, present gag reflex, and weak decerebrate posturing. The last time he had been seen well was not known. General blood exams and toxic screening tests found he was hypoglycemic, presented leukocytosis with elevated hepatic enzymes, and was under the effects of alcohol. The patient was ventilated and hemodynamically stabilized. Admission cranial CT showed a large suboccipital cerebellar infarct with mass effect causing herniation. Whole-body CT revealed a hepatic tumoral mass. The patient was immediately transferred to the angiography suite for evaluation and urgent endovascular revascularization treatment. Angiograms of the right VA showed hypoplasia with the distal segment ending at the posterior inferior cerebellar artery (PICA). The left VA was found proximally occluded with no collateral supply through cervical arteries. Blind catheterization of the left VA allowed navigation of an intermediate catheter through the V2 segment. We confirmed a tandem occlusion of the left proximal VA and the upper half of the BA trunk. Stent retriever-assisted embolectomy allowed revascularization of the BA and its major branches except for the left PICA. Revascularization of the left PICA was not attempted since its supply territory was already infarcted. A single IV bolus of eptifibatide was administered (90 mcg/kg body weight, Integrilin, Schering-Plough/Essex) was administered. Stent-assisted angioplasty then allowed complete revascularization of the left proximal VA. Immediately after the endovascular procedure, the patient was brought to the operating theater for posterior fossa decompressive craniectomy, partial suboccipital infarctectomy, and placement of an external ventricular drain. After a long postoperative course complicated with pneumonia and urinary tract infection, the patient was finally extubated on postoperative day 8 and transferred for rehabilitation on day 18. A 30-day evaluation of the patient showed residual gait ataxia and mild left hemiparesis. At 90 days, his modified Rankin Scale (mRS) score was 2. Early literature suggested that VA ostium lesions do not cause artery-to-artery embolism and that their relation to stroke is primarily hemodynamic. Nevertheless, there is a subgroup of patients presenting with VA atherosclerotic stenosis complicated by acute atherothrombotic occlusion that is also the source of a second major acute occlusion in the BA. This clear pathophysiology is analogous to acute carotid tandem occlusions, and offers irrefutable proof of the role of VA ostium atherosclerotic stenosis as a source of embolic vertebrobasilar stroke. Revascularization of the basilar trunk is thus of paramount importance, and every effort should be made to accomplish this objective. When a single VA constitutes the sole supply to the basilar trunk, revascularization of this sole/dominant VA might also be essential. In our practice, for cases of complete VA occlusion (“closed road path approach”), the retrograde technique is preferred. This chapter describes this revascularization strategy, its rationale, and its eventual limitations.