Pseudo-Occlusion of the Internal Carotid Artery in Acute Ischemic Stroke: Clinical Outcome after Mechanical Thrombectomy

Abstract

pseudo-occlusion (po) of the cervical internal carotid artery (cicA) can be caused by distal icA occlusion.We explored the clinical impact of po after mechanical thrombectomy (Mt). patients who underwent MT to treat distal ICA occlusions between July 2012 and March 2018 were reviewed. A cICA-PO was defined as when single phase computed tomography angiography (CTA) revealed a gradual decline in contrast above the level of the carotid bulb. We investigated the relationship between a cicA-po and outcome; we also explored the association between successful recanalization and outcome. Among 71 patients, 40 (56.3%) exhibited cICA-PO and more likely to experience poor outcomes (80.0% vs. 25.8%, P < 0.001), hemorrhagic transformation (32.5% vs. 9.6%, P = 0.01), and a lower rate of successful recanalization (65.0% vs. 90.3%, P = 0.014) than the non-PO group. In binary logistic regression, a cICA-PO was independently associated with a poor outcome (odds ratio, 4.278; 95% CI, 1.080-33.006; P = 0.045). In the cICA-PO group, all patients who failed recanalization (n = 15) experienced poor outcomes, as did 69.2% of patients in whom recanalization was successful (P = 0.018). cICA-POs are common and have worse outcomes than non-po patients. patients with cicA-pos are more likely to exhibit poor outcomes after Mt, particularly when recanalization fails.Recent randomized controlled trials have shown that intra-arterial mechanical thrombectomy (MT) effectively and safely reduces morbidity and mortality in patients who present with acute ischemic strokes caused by large-vessel occlusions 1-5 . In the cited studies, computed tomography angiography (CTA) was most commonly used to detect and localize large artery occlusions.A pseudo-occlusion (PO) of the cervical internal carotid artery (cICA) mimics a true occlusion in CTA but the artery is patent when digital subtraction angiography (DSA) is performed during endovascular treatment 6 . The underlying cause of a cICA-PO is sluggish or absent contrast flow caused by distal occlusion of the intracranial vasculature 7 . Several previous studies have reported that cICA-POs develop in 6-15% of patients with anterior circulation strokes and in almost 50% of those with distal ICA occlusions 7-9 . Recently, several studies have used various CTA protocols featuring delayed-phase imaging, or four-dimensional CTA after CT perfusion, to enhance diagnostic accuracy 6,8,[10][11][12][13] . Here, we explored the relationships between cICA-POs in patients with acute distal ICA occlusions and the clinical outcomes after MT. MethodsStudy population and clinical assessment. We retrospectively reviewed consecutive patients with acute ischemic strokes who underwent reperfusion therapy between July 2012 and March 2018. Our data collection protocol was approved by the Institutional Review Board of Ajou University hospital (approval no. AJIRB-MED-MDB-18-301) and implemented in accordance with the ethical standards of the 1964 Declaration of Helsinki and its later amendments. The need for written informed conse...

Outcomes in acute ischemic stroke patients undergoing endovascular thrombectomy: Cervical internal carotid artery pseudo-occlusion vs. true occlusion

“…They suggested that intraoperative exploration using the microcatheter should be the best way to diagnose the occlusion location and further confirm the presence of PO. Previous studies reported the incidence of PO to be 11–56.3% as confirmed by DSA ( 5 , 6 , 10 , 11 ). The prevalence of PO in our series was in line with the findings in the research above.…”

“…It has been accepted that successful revascularization is an important determinant of good outcome in patients with acute ischemic stroke ( 17 ). Two recent studies showed that patients with PO were more likely to have lower recanalization rates (65.0–71.4%) than those without PO (90.3–100.0%) after thrombectomy ( 10 , 11 ). Likewise, Chen et al ( 9 ) reported a lower recanalization rate of 36.8% in PO patients compared with non-PO patients (62.7%) after the treatment of intravenous thrombolysis.…”

“…The mechanism of occlusion and the subsequent thrombectomy planning setting for PO and true occlusion of the cICA are completely different, which may affect reperfusion and prognosis ( 7 , 8 ). Previous publications have demonstrated the clinical impact of PO phenomenon in the populations with distal ICA occlusion or isolated middle cerebral artery (MCA) occlusion ( 9 – 11 ). However, the control groups in the reports above were patients with non-PO, and no analysis was conducted to compare the outcomes after thrombectomy between patients with PO and true occlusion.…”

Acute intracranial internal carotid artery occlusion: Extension and location of the thrombus as an influencing factor in Computed Tomography angiography findings

“…In our study, all patients with pseudo-occlusion had a progressive gradual decrease of contrast in the cervical ICA on CTA, with apparent patency of the bulb. This finding is secondary to the combination of contrast with retained blood; it receives different terms in the scientific literature, being ‘flame-shaped’ occlusion the most used [7] , [9] , [10] , [18] , [19] , [20] .…”

“…Between 45% and 67% of intracranial ICA occlusions, cervical ICA is non-opacified in CTA. This finding is caused by slow arterial flow and can simulate an extracranial occlusion (pseudo-occlusion) [7] , [8] , [9] , [10] . The location and extent of the thrombus concerning anterior choroidea, posterior communicating and ophthalmic arteries could explain the presence of this radiological sign.…”