Mechanical Thrombectomy for Medium Vessel Occlusion with Extracranial Vessel Tortuosity Using Quadruple Coaxial System: A Case Series

Abstract

Objective: Medium vessel occlusions (MeVOs) during acute ischemic stroke present challenges due to their distal occlusion sites. Furthermore, MeVO cases with tortuous extracranial vessels are complex, and effective management techniques are lacking. This study reports the utility of combining a 6-French distal access catheter with a low-profile aspiration catheter, guiding catheter, and microcatheter to establish a quadruple coaxial system for treating MeVOs with tortuous extracranial vessels.

Methods: We retrospectively reviewed data from mechanical thrombectomy cases with MeVO at our institution between March 2022 and February 2024. A total of 81 patients were enrolled, and 5 patients were treated using the quadruple coaxial system. The primary efficacy outcome was the first pass effect (FPE), and the rate of successful recanalization, determined by the expanded thrombolysis in cerebral infarction (eTICI 2b/3) at the end of treatment. The safety assessment included hemorrhagic and procedure-related complications.

Results: Of the 81 enrolled patients, 5 patients were treated using the quadruple coaxial system. Three men and 2 women, with a mean age of 77 years, were included in this study. The median baseline National Institutes of Health Stroke Scale score was 10 points, and a tissue plasminogen activator was administered to 2 patients. Four patients had M2 occlusions, and 1 patient had a P2 occlusion. In 4 cases, the guiding system could not be advanced distally because of extracranial vessel tortuosity. The quadruple coaxial system achieved a significantly higher rate of FPE (80% vs. 30%; P = 0.0401) than the standard coaxial system, with no postoperative intracerebral hemorrhage or procedure-related complications.

Conclusion: The quadruple coaxial system is a valuable approach for treating MeVOs with severe extracranial vessel tortuosity. This system offers a reliable and safe treatment modality when a guiding system cannot be advanced distally.

Keywords: distal access catheter; extracranial vessel tortuosity; mechanical thrombectomy; medium vessel occlusion; quadruple coaxial system.

Fig. 1. Quadruple coaxial system. Configuration of the quadruple coaxial system (A). Proximal side of the system (B). GC, 6-F DAC, low-profile AC, and MC are shown on the left. Distal side of the system (C). GC, 6-F DAC, low-profile AC, and MC are shown on the left. AC, aspiration catheter; DAC, distal access catheter; GC, guiding catheter; MC, microcatheter

Fig. 2. Images of extracranial vessel tortuosity. Anterior–posterior angiography of Case #1 shows notable extracranial vessel tortuosity (A). Owing to the tortuosity, the BGC is positioned at the left ICA orifice (arrowhead, A). A kinky right VA orifice is observed on the initial angiography of Case #2 (B). Owing to this kink, it was difficult for the guiding sheath to advance distally (arrowhead, B). Lateral angiography of Case #3 shows a narrow-angle cervical ICA, in which the surgeon was unable to navigate the BGC distally (arrowhead, C). A curved ICA is observed in the cervical portion on the initial angiography of Case #4 (D). BGC, balloon guiding catheter; ICA, internal carotid artery; VA, vertebral artery

Fig. 3. Treatment images of Case #4. MRA reveals tortuous extracranial vessels (A). Anterior–posterior (B) and lateral (C) views of the left M2 superior trunk occlusion. A curved ICA is observed in the cervical portion. Because of the tortuosity, the BGC was positioned at the CCA just proximal to the ICA–ECA bifurcation (arrowhead, E). The 6-F DAC was advanced and positioned in the ICA C2–3 portion (arrow, D, E). From the 6-F DAC, a coaxial microcatheter with a low-profile aspiration catheter was advanced to the occlusion site. Contact aspiration was performed with a low-profile aspiration catheter, and it was retrieved into the 6-F DAC. The red thrombus was retrieved (F). Final anterior–posterior (G) and lateral (H) angiography show eTICI 3 recanalization without any findings of vessel dissection or vasospasm. BGC, balloon guiding catheter; CCA, common carotid artery; DAC, distal access catheter; ECA, external carotid artery; eTICI, expanded thrombolysis in cerebral infarction; ICA, internal carotid artery