Significance of Perforating Vessels in Vertebrobasilar Territory Acute Ischemic Stroke Treated With Mechanical Thrombectomy: A Review of Cone-Beam Computed Tomography Findings and the Literature

Posterior circulation ischemic stroke generally has a poor prognosis.Compared with ischemic stroke affecting the anterior circulation, few studies have discussed its management.However, the role of the perforating vessels in the vertebrobasilar territory is not well understood.In this letter, we discuss the potential significance of perforating vessels in this cerebrovascular territory in patients with acute ischemic stroke (AIS) who were treated successfully with mechanical thrombectomy (MT), with a particular focus on high-resolution cone-beam computed tomography (CT) (CBCT) imaging findings, brief aspects of clinical management, and eventual outcomes.Relevant literature was also reviewed.As an illustration, we reviewed two patients who presented to our center within 24 hours of symptom onset.Both patients were noted to have basilar artery occlusion (BAO) on pretreatment imaging and underwent MT.Despite successful revascularization in both cases, different clinical outcomes were observed, which we postulate may relate to the pre-and post-MT findings within the brainstem on high-resolution intra-arte-rial CBCT.The first patient was a 58-year-old woman with no known medical history who was brought by her family members to an outside hospital with a complaint of reduced consciousness.Upon arrival at the hospital, the National Institutes of Health Stroke Scale (NIHSS) score was 24/42.However, in the emergency room, her consciousness deteriorated, prompting emergency intubation.A preliminary CT scan at another center revealed a suspicious acute infarct involving the brainstem; she was then referred to us approximately 5 hours after symptom onset.Her prestroke modified Rankin Scale (mRS) score was zero.Upon arrival at our center, an urgent magnetic resonance imaging (MRI) stroke protocol was performed, which demonstrated an acute pontomedullary infarct with associated BAO (Figure 1A-C, white arrows).After discussion with the family members, a decision was made to pursue MT.The onset-to-inguinal puncture time was 6 hours.Prior to MT, high-resolution intra-arterial CBCT showed a paucity of vertebrobasilar perforators (Figure 1D).Nevertheless, aspiration (A Direct Aspiration First Pass Technique [ADAPT]) of the thrombus was performed via a 5-French aspiration catheter