Combined endovascular treatment in posterior circulation tandem occlusion: Vertebral artery thrombus aspiration, basilar artery mechanical thrombectomy and acute vertebral artery stenting

Introduction: We aimed to present the combined endovascular treatment applied in a basilar artery occlusion accompanied by critical vertebral artery stenosis and thrombus.Case: A 49-year-old man with hypertension received intravenous thrombolytic (IV tPA) at another center after vomiting and imbalance that began at 09:00, and was referred for endovascular treatment. He was lethargic. His Glasgow Coma Scale (GCS) score was 6, and strength in the left upper and lower extremities was 2/5. Diffusion imaging showed diffusion restriction in the left lower half of the medulla and the left cerebellar hemisphere. The left hemiparesis, ipsilateral to the left-sided brainstem diffusion restriction, was thought to be related to caudal bulbar ischemia affecting the corticospinal fibers at the level of the pyramidal decussation and those that had already crossed below it. IV tPA was started at 10:30 and arterial puncture was performed at 11:30. On right subclavian injection, the right vertebral artery (VA) was hypoplastic and there was no adequate intracranial filling. On left subclavian injection, there was 90% stenosis in the V2 segment of the left VA with an appearance consistent with a floating thrombus, basilar flow was stagnant, and the appearance was consistent with a thrombus that may have formed on the lateral wall of the basilar artery. A long guide catheter was seated in the left vertebral artery, and aspiration was performed for the thrombus proximal to the stenosis in the left vertebral artery. After aspiration, the mid-segment of the basilar artery showed an appearance consistent with a partial occlusion that slowed flow and caused stasis. Because recanalization could not be achieved with aspiration of the basilar artery, a 6×37 mm stent retriever (SR) was deployed so as to extend from the right posterior cerebral artery (PCA) into the basilar artery. After two thrombectomy passes, Thrombolysis in Cerebral Infarction (TICI) 2c was achieved in the basilar artery and both PCAs. A long thrombus fragment seen on the SR also confirmed a thrombus formed on the lateral wall. A 3.5×23 mm stent was placed across the 90% stenosis in the proximal V2 segment of the left VA that was restricting flow; vertebral artery flow was seen to improve after stenting. Recanalization was achieved at 12:30. Acetylsalicylic acid (ASA) and clopidogrel were loaded and a statin was started. During follow-up the left hemiparesis gradually regressed, and at the outpatient visit at one year his examination had fully normalized and his CTA was normal.Discussion/Conclusion: In a case of acute partial basilar artery occlusion accompanied by critical vertebral artery stenosis and thrombus, the treatment of the patient after IV. tPA is summarized. In this case, a “neck first” approach was preferred because of right vertebral artery hypoplasia, a floating thrombus in the left vertebral artery, and a stenosis causing flow stasis.Keywords: