Abstract
BACKGROUND: The functional prognosis of patients with carotid T occlusion is poor, but few comprehensive studies have investigated carotid non-T occlusion, in which the terminal internal carotid artery portion is unobstructed. We aimed to elucidate the clinical features of carotid non-T occlusion by comparing patients with acute carotid T occlusion and carotid non-T occlusion. METHODS: Among 362 patients who underwent thrombectomy between January 2015 and June 2018, 20 and 61 were diagnosed with carotid non-T occlusion and carotid T occlusion, respectively. We compared preoperative clinical findings, treatment strategies, treatment complications and functional outcomes between the two groups. RESULTS: Age, sex, preoperative National Institutes of Health stroke scale, cerebral infarction subtypes and medical history did not significantly differ. In contrast, preoperative diffusion-weighted imaging-Alberta Stroke Program early computed tomography scores were 9 (1-11) and 6.5 (0-11) for the carotid non-T occlusion and carotid T occlusion groups, respectively (P = 0.015). The duration of treatment or the median number of passes (2.5 vs. 2.0), the numbers of patients with thrombolysis in cerebral infarction 2b/3, bleeding complications and modified Rankin scale scores of 0-2 on postoperative day 90 did not significantly differ between the two groups. Manual aspiration before, internal carotid artery arrest while crossing a lesion and injection into the contralateral side were significantly more frequent in patients with carotid non-T occlusion. Intracranial internal carotid artery stenosis was significantly more frequent in patients with carotid non-T occlusion (n = 4, 20%) than carotid T occlusion (n = 0), and 10% of patients with carotid non-T occlusion had arterial dissection. CONCLUSION: Patients with carotid non-T occlusion more frequently had a background of intracranial internal carotid artery stenosis or arterial dissection than patients with carotid T occlusion. Specific treatment strategies should be developed to improve the clinical outcomes of patients with carotid non-T occlusion.