title: Posterior-to-anterior circulation access using the Penumbra Stroke System for mechanical thrombectomy of a right middle cerebral artery thrombus.
abstract: BACKGROUND
  Mechanical thrombectomy devices rely on the ability of an operator to directly access a thrombus with the device. The authors demonstrate the first reported posterior-to-anterior circulation approach using the Penumbra Stroke System (Penumbra, Inc, Alameda, CA) for thrombectomy in acute stroke.
  
  
  METHODS
  A 53-year-old man presented 5 hours and 15 minutes after onset of left homonymous hemianopia, left facial droop, left upper extremity plegia, and left lower extremity paresis (NIHSS = 15). Computed tomography of the head revealed hyperdense material in the right M1 to M2 segments without loss of gray-white differentiation in the right cerebral hemisphere. Cerebral angiography at 6 hours and 50 minutes revealed occlusion of the right ICA at its origin. Injection of the left vertebral artery demonstrated clot in the right M1 segment with no anterograde flow. An Excelsior 1018 (Boston Scientific, Natick, MA) microcatheter was used to access the right PCOM and subsequently the right ICA and right MCA. A joint decision was made with the stroke neurology service to bury the microcatheter within the right MCA clot and administer 13 mg of tPA. A triaxial system using the Penumbra 041 catheter, Excelsior SL-10 microcatheter, and Synchro2 (Boston Scientific) guidewire was used to traverse the left vertebral and basilar arteries, the right PCOM, and the right ICA to the thrombosed right M1 segment. Aspiration using the Penumbra 41 catheter and 41 Separator was performed, resulting in a TIMI-2 result with minimal residual superior right M2 thrombus.
  
  
  CONCLUSIONS
  In patients with proximal vascular occlusion, mechanical thrombectomy with relatively stiff thrombectomy systems can be achieved through collateral pathways in the circle of Willis. Although the diameter mismatch between the Penumbra 41 catheter and a microguidewire may make sharp turns challenging, the use of an SL-10 microcatheter as a functional obturator may afford access.
authors.affiliation: Department of Radiology, Cerebrovascular Center, Cleveland Clinic Foundation, Cleveland, OH 44195, USA. huif@ccf.org
authors.forename: Ferdinand K
authors.initials: FK
authors.lastname: Hui
authors.forename: Sandra
authors.initials: S
authors.lastname: Narayanan
authors.forename: C Michael
authors.initials: CM
authors.lastname: Cawley
mesh_terms: D017130:Angioplasty / Q000295:instrumentation*; D006801:Humans; D020767:Intracranial Thrombosis / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D017131:Thrombectomy / Q000295:instrumentation*; D015912:Thrombolytic Therapy / Q000295:instrumentation*