Predictive Value of Susceptibility Vessel Sign for Arterial Recanalization and Clinical Improvement in Ischemic Stroke

Abstract

Background and Purpose— Our goal was to evaluate whether the presence of a low signal intensity known as susceptibility vessel sign (SVS) on T2*-gradient echo imaging sequence was predictive of arterial recanalization and the early clinical improvement after mechanical thrombectomy. Methods— This observational study was based on a prospective database of acute ischemic strokes treated by mechanical thrombectomy. Inclusion criteria were patients with acute anterior ischemic stroke, diagnosed by magnetic resonance imaging, including a T2*-gradient echo imaging sequence, and treated by mechanical thrombectomy. Two independent readers assessed the presence of an SVS. Successful recanalization was defined as a Thrombolysis in Cerebral Infarction score of 2b-3 after mechanical thrombectomy. Early clinical improvement was estimated by the difference between the baseline National Institutes of Health Stroke Scale and the National Institutes of Health Stroke Scale on day 1 after treatment Results— The SVS was detected in 137 (76%) out of 180 patients. The kappa interrater agreement was 0.71 with a 95% CI of 0.59 to 0.82. Successful recanalization was associated with an SVS+ with odds ratio, 2.48; 95% CI, 1.05–5.74; P =0.03. The early clinical improvement was better in patients with an SVS+ (median, −6; interquartile range, −11 to 0) compared with SVS− patients (median, −1; interquartile range, −10 to 3) with P =0.01. Conclusions— The visualization of SVS is a reliable and easily accessible predictive factor of recanalization success and early clinical improvement.

Factors Associated with Unsuccessful Recanalization in Mechanical Thrombectomy for Acute Ischemic Stroke

“…In previous reports, more proximal occlusions, such as those in the internal carotid artery (ICA) and M1 segment of the middle cerebral artery (MCA), was associated with successful recanalization [5, 6]. Other studies have revealed that an erythrocyte-rich thrombus, appearing as a hyperdense signal on computed tomography or a low-intensity signal (known as a susceptibility vessel sign) on T2*gradient echo magnetic resonance imaging, predicts successful recanalization [7, 8, 9]. Conversely, difficult anatomical access [10, 11] and intracranial atherosclerotic stenosis [9, 12] have been reported to be associated with unsuccessful recanalization.…”

Impact of Clot Shape on Successful M1 Endovascular Reperfusion

“…There were no differences between S-SVS and A-SVS with respect to patient age [72 (IQR, 63-79) vs. 67 (IQR, 55-76), p = 0.960], female sex (52 vs. 54%, p = 1.000), baseline NIHSS [14 (IQR, 10-20) vs. 17 (IQR, [13][14][15][16][17][18][19][20][21][22], p = 0.12], or frequency of left sided occlusions (71 vs. 54%, p = 0.19), respectively (Table 1). A-SVS clots were significantly longer compared to S-SVS clots [19 mm (IQR,[15][16][17][18][19][20][21][22][23][24] vs. 8 mm (IQR, 10-15), p = 0.0002] (Table 2). There were no other significant differences between the two groups with regard to neuroimaging variables, which included core infarction volume, penumbra volume, and HIR collateral robustness (Table 2).…”

“…Prior studies have used SVS identified on gradient-echo imaging (T2 * ) ( 21 ) to detect ( 5 ), localize ( 22 ), and measure clot length ( 5 , 22 ) without contrast administration. Whether SVS is a predictor of reperfusion after MT remains controversial ( 9 , 23 ). Our findings support the hypothesis that SVS is a biomarker of reperfusion when thrombus morphology is considered.…”

Susceptibility vessel sign as a predictor for recanalization and clinical outcome in acute ischaemic stroke: A Systematic Review and Meta-analysis

“…A total of 22 studies presented a relationship between SVS/PHVS, recanalization status and / or clinical outcomes in patients with acute ischaemic stroke (AIS). Of the 22 studies, 7 studies were further excluded from qualitative analysis due to either inadequate data 19 27 28, using different definition of SVS 29, non-standardized definition of recanalization 4 30 or mRS was evaluated at 6 months 31 (see Supplementary Table 1 ). No studies were considered to be seriously flawed as per the QUADAS-2.…”